Dubai Building Code (2021)

Dubai Building Code

Part K: Villas

K 69

Regulations (2010), Approved Document Part K, 2013 Edition. Contains public sector information licensed

under the Open Government Licence v3.0)

In accordance with Section 5, Ch. 1 of UAE FLSC

[Ref. K.1]

, safety glazing for use in

critical locations shall conform to the minimum classifications in either Table K.16 or

Table K.17.

Critical location

Height

Classification in test standard

BS EN 12600

Low-level areas

All height

Class 1

Doors
Doors side panel

Below 900 mm from FFL

Class 2

Above 900 mm from FFL

Class 3

Table K.16 Minimum classification for safety glazing requirements

Table K.17 Minimum classification for safety glazing requirements

Area of glazing in critical

location (m

)

Classification in test standard

ANSI Z97.1

CPSC 16 CR 1201

[Ref. K.13]

≤0.9

>0.9

K.7.6.2

Containment

Glazing at areas lower than 800 mm from FFL and protecting a change in level

greater than 760mm shall provide containment, as shown in Figure K.54.

Figure K.54

Examples of glazed areas that need to provide containment

Key

01: Internal FFL

02: External FFL

800

>760

800

Key

01:Floor level

Dubai Building Code

Part K: Villas

K 70

If a glazing panel covers areas above and below 800mm from FFL, the entire glazing

panel shall provide containment.

K.7.6.3

Overhead glazing

Overhead glazing shall be laminated. It shall include a post-breakage containment

system, such that if the glass breaks, the glass is held in place until it can be replaced.
The safety and fragility of overhead glazing shall be determined in accordance with

CWCT TN 66

[Ref. K.14]

Overhead glazing shall be tested in accordance with CWCT TN 67

[Ref. K.15]

K.7.7

Fire safety

K.7.7.1

General

The fire safety of building envelopes (façade and roofs) shall conform to Ch. 1 of UAE

FLSC

[Ref. K.1]

and the specific requirements of this section.

The requirements for guardrails and balustrades as described in Section 2.17,

Ch. 1 of UAE FLSC

[Ref. K.1]

are superseded by K.5.2.5.2.

The requirements for safety glazing in Sections 5.4.2 to 5.4.4, Ch. 1 of UAE FLSC

[Ref. K.1] are superseded by K.7.6.

K.7.7.2

Fire testing of non-fire-rated, non-load-bearing façades and aesthetic

features/mashrabiya

The requirements of Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. K.1]

shall be met, with

the following amendments.
a)

The exceptions listed in Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. K.1]

are expanded

to include concrete, terracotta, glass, ceramics and mineral wool.

In addition to the materials listed in Section 4.2.1, Ch. 1 of UAE FLSC

[Ref. K.1]

solid metal panels conforming to K.7.7.3 may be used.

The requirements in Section 4.5, Ch. 1 of UAE FLSC

[Ref. K.1]

shall be met, with the

following amendments.
1)

Steel flashing is not required around window openings.

Flashing shall match the flashing included in the NFPA 285 fire test(s) forming

the basis of the fire safety design(s) of the façade.

K.7.7.3

Solid metal panels

Solid metal panels, including any coatings, shall conform to Sections 4 to 7, Ch. 1 of

UAE FLSC

[Ref. K.1]

and shall achieve the fire safety classifications and fire safety

performance criteria of Table K.18 where applicable.

Occupancy and type of building Fire testing required for solid

metal panel

Fire testing required for façade

assembly

Low-rise building (e.g. villa,

townhouse)

Panel shall be tested in the

thickness intended to be used,

including any coatings to

BS EN 13501-1 with pass

criteria B-s1-d0

BS 8414-1 or BS 8414-2 with

pass criteria in accordance with

BR 135

[Ref. K.16]

NFPA 285

with pass criteria “pass”
or

FM 4881

with pass criteria “pass”
or
ISO 13785-2
with pass criteria “pass”

Table K.18 Fire test requirements for solid metal panels on non-fire resistance rated and non-load-bearing

exterior building envelope and aesthetic features/mashrabiya.

Dubai Building Code

Part K: Villas

K 71

K.7.7.4

Roof assemblies

Roofing systems shall conform to the performance requirements of Section 6, Ch. 1

of UAE FLSC

[Ref. K.1]

K.7.8

Solar panels

Photovoltaic (PV) cells or panels installed on roofs or façades shall conform to

Section 2.2, Ch. 14 of UAE FLSC

[Ref. K.1]

. If PV panels are attached to or integrated

with the façade then they shall also be tested in accordance with Section 4,

Ch.1 of UAE FLSC

[Ref. K.1]

K.7.9

Maintenance

A method of safely maintaining the building envelope shall be provided.
Permanent maintenance equipment attached to either roof or façades shall be

treated as permanent fixture loading (see K.7.1.1.4).
Hard or sharp components of the maintenance equipment shall be covered with soft

protection prevent the building envelope from being impacted.
The energy impact that the maintenance equipment or operator might exert on

the building envelope shall be calculated. The building envelope shall be capable of

withstanding applied or transferred impacts that might occur during maintenance

without sustaining damage that is not repairable and without deterioration of its

performance.

Dubai Building Code

Part K: Villas

K 72

K.8

Structure

K.8.1

Structural system requirements

K.8.1.1

General conditions

The structural design of buildings shall be undertaken

by the Engineer. The Engineer shall only use

appropriate structural analysis and design software,

approved by the Authority.
Villas/townhouses and all their components, as well as

materials, shall satisfy the minimum safety standards

defined herein and the referenced documents.

The design shall facilitate safe fabrication, transport,

handling and erection with due regard to site-specific

conditions. As far as is reasonably practicable, it shall

also take account of the needs of maintenance, final

demolition, recycling and reuse of materials.

Typical design issues are presented in Figure K.55 for

inclusion in the design stages.

K.8.1.2

Design life

The recommended minimum design life for villas/

townhouses is 50 years. The Engineer shall discuss and

agree the design life of the structure with the Owner

and the Authority before the design commences. The

Engineer shall clearly specify the adopted design life in

the design documentation.

OPTIMIZED STRUCTURAL

DESIGN

MATERIAL

SPECIFICATION

BUILDABILITY

AESTHETICS

SUSTAINABILITY

MAINTENANCE

MOVEMENT

STRUCTURAL

PERFORMANCE

SUBSOIL PERFORMANCE

COST

SAFETY/RISK

Substructure

Superstructure

Site

Access

Ground conditions

Weather

Recycling

Re-using

Pollution

Energy

Construction

Use

Re-use

Decommissioning

Appearance

Sense of place

Bearing

Settlement

Soil retention

Liquefaction

Groundwater

Design

Construction

Maintenance

Decommissioning

Strength

Sti

ﬀne

Durability

Stability

Robustness

Dead load

Live load

Wind

Seismic

Soil pressure

Blast

Wave

Thermal

Alternative sources

Embedded energy

Energy consumption

during building life

hole

life

costi

Fire

Figure K.55

Typical issues in relation to structural design requirements

Dubai Building Code

Part K: Villas

K 73

K.8.1.3

Design acceptance criteria

The design shall honour all design acceptance criteria

defined by the design basis codes and standards

(see K.3.5).
Ordinarily, these acceptance criteria are defined as limit

states. As applicable, designs shall include:
a) strength limit states including general yielding,

rupture, buckling and transformation into a

mechanism;

b) serviceability limit states including member and

global deflections, vibration and occupancy comfort;

c)  stability against overturning and sway;
d)  fracture due to fatigue and brittle fracture;
e)  corrosion and durability;
f)

fire; and

g) accidental loads (blast, impact, etc.).

K.8.1.4

Structural system and robustness

Measures shall be taken to ensure that the building is

stable under the design basis load conditions. Where

necessary, these measures shall also allow for the

maximum credible loads for which the collapse limit

state might be chosen as being applicable.
Any features of the structure that have a critical

influence on its overall stability shall be identified and

included in the design, including all members that

provide restraint to critical members in compression.

A structure shall be designed to behave as one three-

dimensional entity. The layout of its constituent parts,

such as foundations, primary frame, steelwork, joints

and other structural components should constitute

a robust and stable system under normal loading to

ensure that, in the event of misuse or accident, damage

will not be disproportionate to the cause.
Measures shall be taken to ensure that the building

is robust and resistant to disproportionate collapse

under the specified load conditions. The Engineer

shall include implicit considerations of resistance to

progressive collapse during the design process through

the provisions stipulated under Appendix C of ASCE/

SEI 7-16 (indirect design approach).

K.8.1.5

Durability

All elements shall be designed with appropriate

detailing and material specifications to achieve the

specified design life, considering the environment of

the project and the whole lifecycle of the building.

The following specific requirements shall be met.

For concrete structures, the Engineer shall

implement the recommendations of BS EN 206

and BS 8500-1 in the design and specifications of

concrete structures. The criteria listed under

F.11

shall also be followed.

For steelwork structures, the Engineer shall provide

the steelwork material specifications, stating the

steel grades and protective paint systems which are

durable and compatible with the climate of Dubai.

The paint protective coatings for steelwork shall

be specified in accordance with BS EN 12944 as a

minimum, with additional requirements to address

the susceptibility of the protective coatings to ultra

violet degradation.

K.8.2

Fire resistance

Villas shall be classified group A or group B in

accordance with Table 1.1, Ch. 1 of

UAE FLSC

[Ref. K.1]

Construction type and fire resistance of the structure

shall be defined based on the classification of the villa,

the height and general arrangement of the largest

storey of the villa and whether it is sprinkler protected

or not in accordance with Table 1.7, Ch. 1 of

UAE FLSC

[Ref. K.1]

Villas/townhouses do not require fire-rated or listed

roof assemblies (see Section 6.3.7, Ch. 1 of

UAE FLSC

[Ref. K.1]

The structure supporting 2 h fire-rated walls between

townhouses (see K.5.11) shall also achieve 2 h fire

resistance.

Dubai Building Code

Part K: Villas

K 74

Material

Code of reference

Remarks

Reinforced concrete

ACI 318-19

—

Post-tensioned concrete ACI 318-19

TR43

[Ref. K.20]

can be adopted as

further reference

Pre-cast concrete

ACI 318-19 and Precast/

prestressed Concrete Institute (PCI)

design handbook

[Ref. K.21]

—

Steel

AISC 360 and AISC 341-16

—

Masonry

TMS 402/602:2016 or

BS EN 1996-1, 2 and 3

Load-bearing masonry shall conform

to TMS 402/602:2016.

Aluminium

IBC Ch. 20

[Ref. K.2]

IBC refers to AA ASM 35, Aluminium

Sheet Metal Work in Building

Construction, and AA ADM 1,

Aluminium Design Manual.

Wood

IBC Ch. 23

[Ref. K.2]

—

Gypsum board

IBC Ch. 25

[Ref. K.2]

—

Plastic

IBC Ch. 26

[Ref. K.2]

—

Table K.19

Codes of reference for the material requirements

K.8.3

Materials

The structural design shall meet the material requirements specified in the codes and

standards listed in Table K.19.

Other materials, such as aluminium, timber, gypsum board, glass and plastic, shall be

used only where also permitted by Ch. 1 of UAE FLSC

[Ref. K.1]

The specification of all constituent materials of the structural system shall be

compatible with the specified codes and clearly detailed in the design documentation.

Structural designs can be prepared by referring to building codes and standards

other than those mentioned in Table K.19, subject to obtaining the approval of the

Authority.

K.8.4

Loads

K.8.4.1

General

Loads shall be defined in accordance with ASCE/SEI 7-16 and this section.

K.8.4.2

Load combinations

Loads shall be factored and combined in accordance with Ch. 2 of ASCE/SEI 7-16.

The results from compatible linear analyses of load cases acting individually may be

combined and summed algebraically.

K.8.4.3

Dead loads

Dead loads shall be calculated using the densities and volumes of the materials

making up the construction.

Default densities of common materials are scheduled in Table K.20.

NOTE: More refined densities and the densities of other materials can be sourced

from the referenced codes and standards, material data sheets, or obtained via

testing. The Engineer is responsible for ensuring the densities assumed in design

align with those of the specified construction materials.

Description

Load (kN/m

)

Concrete (normal weight, including allowance for reinforcement)

Concrete (lightweight, including allowance for reinforcement)

Concrete blockwork (normal weight)

Concrete blockwork (autoclave aerated block)

Steel

Screed and blinding

Float glass

Table K.20

Default material densities

Where appropriate, dead loads shall make provision for additional weight

concentrated at structural connections.

Dubai Building Code

Part K: Villas

K 75

K.8.4.4

Superimposed dead loads

The Engineer is responsible for determining the superimposed dead loads for

components not included as either live or dead loads (including the anticipated

internal partitions, floor and ceiling finishes, facades and external cladding). Loads

shall be defined as concentrated point loads, uniform loads on plan, and/or uniform

loads on elevation, as appropriate.

The following minimum load allowances (defined as average uniform loads on plan)

shall be adopted for the purpose of evaluating the maximum load effect:
a) internal drywall partitions:

0.75 kN/m

;

suspended services with ceiling finishes:

0.50 kN/m

;

suspended services without ceiling finishes:

0.30 kN/m

The Engineer shall provide detailed calculations supporting the superimposed dead

load assumptions. If supporting calculations are not provided, the vertical load listed

in Table K.21 shall be included for the partition assumptions.

Type of wall

Superimposed dead load applied vertically, including finishes (kN/m

)

Lightweight block wall

4.5

Normal weight block wall

5.5

Drywall

4.0

Table K.21

Minimum superimposed dead load

Loading plan drawings showing the load provision should be submitted for approval.

The design assumptions shall be validated against the systems installed. Any late

amendments and/or retrospective changes shall not be made without new approval.

K.8.4.5

Live loads

Minimum uniform live loads shall be not less than those listed in Ch. 4

of ASCE/SEI 7-16. The following requirements shall also be followed.
a)

Concentrated live loads shall be evaluated for objects creating significant point

loads, including machinery, vehicles and storage racks.

The minimum live load for garage and car parking is 3.5 KN/m

which should be

validated based on the type of vehicles accessing the facility.

The live load for drained areas of floor surrounding a swimming pool is 2 kN/m

Pool tanks and other areas susceptible to flooding shall be designed for a load not

less than the maximum retained head of water.

d) The Engineer shall design the supporting structure to withstand the loading

imposed by the mechanical, electrical and public health (MEP) equipment in the

designated areas and along the proposed equipment access route.

K.8.4.6

Soil loads and hydrostatic pressure

Minimum soil and hydrostatic pressures shall be not less than those listed in

Table K.22. Lower values shall not be used without project specific justification.

Description

Minimum load (kN/m

)

Soil for planters (saturated)

Compacted soil for trafficable areas

Water

Brackish water

10.3

Table K.22

Material densities

Dubai Building Code

Part K: Villas

K 76

In addition to the geotechnical requirements specified under K.8.6, the Engineer shall

include the following aspects in the design of permanent structures:
a) All foundation elements and retaining walls shall be designed by the

recommendations given in the geotechnical interpretive report (GIR).

The design water table shall be established in the GIR considering the fluctuation

of the water table level during the design life of the structure. In particular, the

effect of dewatering in the neighbouring areas, the seasonal variation of the water

table, future developments (such as canal, water bodies, landscaping and similar)

and potential impact of climate change shall be included in the definition of the

design groundwater level. The design groundwater level and its fluctuations shall

be stated by the Engineer in the design drawings and agreed with the Authorities.

c) In any case, the minimum water table level shall be assumed as follows:

in proximity to bodies of water: ±0.00 m Dubai Municipality Datum (DMD)

plus 1.0 m for seasonal and tidal variations and

2) away from bodies of water: actual water table level with dewatering taken into

account, as defined in the GIR, plus 1.0 m for seasonal and tidal variations.

For structures below the water table, hydrostatic uplift and lateral pressures shall

be checked in accordance with Section 10 of BS EN 1997-1:2004+A1:2013 and

the associated UK NA. Any dewatering system, whether used for construction or

throughout the design life, is temporary unless the system can be demonstrated

to be reliable throughout the design life.

e) Where construction of the project is staged, or in case of construction on an

adjacent plot, any possibility of unbalanced lateral soil load shall be included.

f) Any retaining wall assumed to be subjected to lateral pressure during

construction shall be designed according to possible surcharge and hydrostatic

loading. The lateral soil pressure arising from compacted soil placement shall be

included where this exceeds the at rest or passive pressure (as relevant).

g) Bracing conditions of the retaining structure and construction sequence shall be

carefully captured in the analysis and design.

h) Uplift due to heave shall also be included for both permanent and temporary

conditions whenever applicable.

K.8.4.7

Construction load

Minimum design load requirements during construction of buildings shall be defined

in accordance with ASCE 37.
Construction-stage loads, including locked-in stresses arising from the construction

sequence and affecting the overall behaviour of the structure, shall be included by the

Engineer.
The Engineer shall clearly state the construction load assumptions on the detailed

design drawings and verify that the structural system can withstand these loads

during all stages of construction.
Any departure from the Engineer’s assumptions that are invoked by the Contractor’s

construction sequence shall be assessed.

K.8.4.8

Accidental impact load

Structural elements shall be designed to resist accidental impact loading conditions

specified under Section 4.6 of ASCE/SEI 7-16. A secondary protection system should

be provided to all primary structural members to avoid accidental impact load.

K.8.4.9

Self-straining forces

Structures shall be designed to resist any self-straining forces arising from the

contraction or expansion of structural elements.
Such volume changes can result from shrinkage, creep and/or moisture change in

component materials, including the soil. It might occur at any stage in the structure’s

lifecycle.
The use of details to alleviate self-straining forces may be used when practical and

not in violation of any assumed load paths. Such details, where permanent, shall be

durable and/or have provision for maintenance.

Dubai Building Code

Part K: Villas

K 77

K.8.4.10 Thermally induced forces

Thermally induced forces shall be derived considering the structural restraints, and

the changes in temperature of structural members arising across the construction/

operational phases, seasonal and daily variations.

For effects on covered concrete structural members, mean monthly temperatures

should be used to establish an appropriate range. A default thermal range of ±20 °C

may be used for exposed concrete elements and ±15 °C for non-exposed concrete

elements.

For steel structural members and structural members exposed to solar radiation,

a range equivalent to the maximum temperature swing is appropriate. A default

thermal range of ±25 °C may be used for protected steel elements. For exposed

steelwork, this can arise from hourly maxima and minima. The Engineer shall assess

the thermal range and assess the thermally induced forces on a case by case basis

considering the construction stages, exposure and when the steel structure is locked

in the final configuration.

NOTE: Relative humidity values and mean monthly temperature for specific sites are

available from the National Centre for Meteorology and Seismology website

[Ref. K.17]

K.8.4.11 Design for wind loading effects

K.8.4.11.1 General

The Engineer shall calculate the effects of wind loading, taking into account strength

for life safety, and serviceability for building movements affecting cladding or building

occupant comfort.
Calculations for wind design shall be based on ASCE/SEI 7-16 and additional rules

for application in Dubai from this section.

K.8.4.11.2 Wind pressures

This subclause provides the basis for calculation of wind pressures to be used with

ASCE/SEI 7-16.

The wind speeds of Table K.23 replace the use of the wind maps of Section 26.5

or ASCE/SEI 7-16. Wind reference speed for 50 MRI shall be used only for strength

design in accordance with Clause 5.3.5 of ACI 318 19.

Application – risk category

Reference wind speed, V = Vref

(m/s)

ASCE/SEI 7-16 MRI (years)

Strength

Strength – category II*

700

Serviceability – deflections

* Risk category is described in Section 1.5 of ASCE/SEI 7-16. For villas/townhouses in Dubai, use

category II.

Table K.23

Reference wind pressures and speeds per risk category and mean recurrence interval (MRI)

(extracted from

[Ref. K.18]

)

In all cases, the design wind pressure shall be not less than 1 kN/m

K.8.4.12 Design for earthquake effects

Every villa/townhouse, and portion thereof, including non-structural components

that are permanently attached to structures and their supports, shall be designed

and constructed to resist the effects of earthquake motions in accordance with

ASCE/SEI 7-16 (Section 11.1.2) and

F7.13

Dubai Building Code

Part K: Villas

K 78

K.8.5

Structural performance and serviceability requirements

K.8.5.1

Design basis

The basis of design for villas/townhouses shall include these aspects as a minimum:
a) strength;
b)

deflection control in concrete and steel structures;

c)  crack control in concrete structures;
d)  building movement and motions due to wind;
e)  building movement due to seismic;
f)  movement joint and building separation;
g)  vibration;
h)  lateral acceleration;
i)  fatigue; and
j)  additional requirements for transfer elements.

K.8.5.2

Strength

Villas/townhouses and parts thereof, shall be designed and constructed to support

safely the factored loads in load combinations defined in this section without

exceeding the appropriate strength limits states for the material of construction.

K.8.5.3

Deflection control

Deflection limits shall be adopted that enable functional requirements to be

maintained. Limits may be governed by the requirements of internal and/or external

furniture, finishes, fixtures and fittings.
Vertical and horizontal deflections shall be within the limits specified in the

referenced design standards, as applicable, and the project specific requirements.
When checking for deflections the most adverse realistic combination and

arrangement of serviceability loads shall be included.

The Engineer shall verify that the adopted deflection limits will enable the functional

performance of the building to be maintained. In particular, the following apply.
a)

Deflection limits for steel structures shall conform to the requirements stipulated

in AISC 360 and AISC design guide 3

[Ref. K.24]

Deflection limits for concrete slabs and beams shall be in accordance with

24.2.2 of ACI 318-19. The value of the incremental deflection shall not exceed

20 mm after the installation of partition and finishes and shall be calculated in

accordance with ACI 435R-95 and ACI 318-19. When evaluating the deflection

of concrete structures, the detrimental effects of cracking shall be included by

modifying the stiffness (EI) for areas which have exceeded the allowable tensile

stresses. The modified EI shall be chosen based on the extent of cracking under

the design load. Default stiffness modifiers given in ACI 318-19 may be followed

for regular structures subject to approximately uniform loads.

c) Design for strength and serviceability requirements of post-tensioned concrete

members shall conform to ACI 318-19. Structural calculations shall verify that

both short and long-term deflections, camber, vibration frequency and amplitude

are within permissible limits.

K.8.5.4

Crack control in concrete structure

The Engineer shall perform crack width calculation checks for reinforced concrete

structures in accordance with ACI 224R.

In the absence of more specific requirements, the following maximum crack width

limits shall be adopted:
a)

For section of the structure in contact with groundwater, the crack width limits

) are defined as a function of the ratio of the hydrostatic pressure, h

to the

wall thickness of the containing structure, h

For h

<5, w

= 0.2 mm.

For h

>35, w

= 0.05 mm.

Dubai Building Code

Part K: Villas

K 79

For intermediate values of h

, linear interpolation between 0.2 mm and 0.05

mm may be used.

c) Section of the structure not in contact with water: w

= 0.3 mm.

d) Structural elements (such as piles) under permanent tension loads: w

= 0.1 mm.

The above listed limits may be adopted providing that they do not contradict the

requirements of ACI 224R and a proprietary waterproofing system is provided for

structural elements in contact with water in accordance with BS 8102.

It is also recommended that basements and liquid retaining structures are classified

in relation to the degree of protection against leakage. An appropriate limit to

cracking depending on the classification should be selected by the Engineer and

Owner’s representative, paying due regard to the required function of the structure,

the intrinsic durability requirements, soil and water properties. Where structural

walls, columns and piles provide significant restraint to shrinkage and temperature

movements, it is recommended that the reinforcement provisions are verified against

the requirements stated under either ACI 89-S15 (as in R24.4.2 of ACI 318-19) or

CIRIA C766

[Ref. K.22]

K.8.5.5

Drift and deformation

K.8.5.5.1 General

The Engineer shall assess the drift and deformation of the building considering the

whole life of the structure, including the construction stages.

K.8.5.5.2 Drift and deformation due to wind

Building overall displacements shall be calculated using 10-year return (MRI) wind

pressures and total building height (H). The overall displacement of the building due

to wind action shall be limited to H/500 using the serviceability parameters listed in

Table K.23.

The displacement limits may be varied provided that provision for any larger than

normal movements is clearly specified on drawings and implemented.

The purpose of this calculation is to control displacements of the building which

can cause overstress or fatigue damage or loss of effectiveness to cladding, internal

partitions or other non-structural components of buildings.

K.8.5.5.3 Drift and deformation due to seismic

Movements of buildings due to earthquake effects shall conform to the requirements

stipulated under Section 12.12 of ASCE/SEI 7-16.

K.8.5.6

Movement joints and building separation

Movement joints shall be provided, where necessary, to address the requirements

of expansion and/or deflection under load for above-ground structures.

The minimum separation between a structure and any surrounding obstructions shall

be not less than the total maximum displacement, as specified in Section 12.12 of

ASCE/SEI 7-16.

Movement joints are a common source of water infiltration. Structures below ground

level should be designed without movement joints to mitigate the risk of water

ingress. Design for construction without permanent joints below ground level can

be achieved by following the recommendations provided in CIRIA C766

[Ref. K.22]

K.8.5.7

Vibration

Vibration and oscillation of building structures should be limited to avoid discomfort

to the users, damage to contents or damage to the structure, as detailed below.
a)

Steelwork. The natural frequency of steelwork floor systems for normal

occupancy shall be evaluated in accordance with AISC Design guide 11

[Ref. K.25]

or SCI P354

[Ref. K.26]

Dubai Building Code

Part K: Villas

K 80

Reinforced concrete. Cast-in-place floor systems designed in accordance with the

minimum thickness and deflection requirements of ACI 318-19 have generally

been found to provide vibration performance suitable for human comfort under

typical service conditions. However, there might be situations where serviceability

conditions are not satisfied, for example:

long spans and open floor plans;

2) facilities subject to rhythmic loadings or vibrating mechanical equipment.

NOTE: Further guidance is given in the ATC Design Guide 1

[Ref. K.23]

Post-tensioned slab. The performance of post-tensioned concrete floors may

follow the recommendation of TR43

[Ref. K.20]

Table 1 and Appendix G.

d) Precast concrete. Structures shall be checked for vibration as detailed in

Section 9.7 of PCI design handbook

[Ref. K.21]

K.8.5.8

Fatigue

Structural members that support significant vibrating machinery, vehicles or plant

should be checked for fatigue resistance. Where fatigue is critical, all design details

shall be fully defined, including clear specification of the workmanship and quality

assurance tests. The design shall be checked in accordance with the following codes:
a) Appendix 3 of AISC 360-16 for steel; and
b) ACI 318-19, ACI 215R and ACI 408.2R for concrete.

K.8.5.9

Transfer elements

Any beam, slab or truss structure used to redirect the vertical gravity or lateral load

path of upper storeys to the vertical structure of the lower storeys shall be treated as

a transfer element.

Such elements are typically used where a change of use on a floor dictates a different

column or wall arrangement, or to accommodate architectural features.

Transfer structures have significant design, cost, material and construction schedule

implications, requiring careful consideration of construction logistics, as well as

consideration of the impact of long-term deflections of the transfer members and

supporting elements. As such, transfer structures should be avoided where possible.
The following requirements shall be met in the design of transfer elements.
a) Transfer beams shall be supported on at least two direct supports.
b) Eccentricity between the column axis and the longitudinal axis of the beam is not

permitted. The load transferred to the planted column, transfer beam or slab shall

be not less than the loads calculated by manual method (tributary area).

Any structural elements supporting planted/floating columns that might cause

a progressive collapse shall to be included as a key element. Reinforcement shall

be detailed to facilitate robustness by means of provision of adequate peripheral,

vertical and horizontal ties.

d) The entire length of the supporting columns shall be included as critical length

and the stirrups shall be spaced to provide effective confinement for the columns.

e) Structural system elements of the planted portions of the structure shall have

redundancy to facilitate alternative load paths in the case of failure of any

structural member, as specified under K.8.1.4.

f) Any structural members or elements that do not fall under the purview of the

adopted design codes should be analysed and designed for various possible

critical combinations.

g) Transfer structure should be capable of withstanding the reactions from any

attached building components. The reactions should be the maximum values

that might reasonably be transmitted considering the strength of the connecting

component and its connection.

The Engineer shall check that the deflections of the structural members

supported by the transfer elements are within the deflection limits specified in

K.8.5.3.

Dubai Building Code

Part K: Villas

K 81

BS EN 1997-1

General rules

Other Eurocodes

BS EN ISO 14689

Identiﬁcation of rock

BS EN 1993-5

Steel piling

BS EN 1536

Bored piles

BS EN 14199

Micro piles

BS EN 12699

Displacement piles

BS EN 1997-2

Ground investigation

BS EN ISO 22476

Field testing

BS EN ISO 14688

Identiﬁcation of soil

BS EN ISO 22475

Groundwater

BS EN ISO 17892

Laboratory testing

BS EN ISO 22282

Geohydraulic testing

UK NATIONAL

ANNEX

UK NATIONAL

ANNEX

UK NATIONAL

ANNEX

EXECUTION OF SPECIAL

GEOTECHNICAL WORKS

GEOTECHNICAL

INVESTIGATION & TESTING

GEOTECHNICAL DESIGN

K.8.6

Geotechnics

K.8.6.1

General

This subsection provides minimum geotechnical

requirements that are appropriate for the geology,

stratigraphy, geotechnical and groundwater conditions

of Dubai. A major characteristic of the ground in Dubai

is its calcareous origin for both soils (e.g. calcareous

sand) and soft calcareous rocks, with clay minerals of

various expansion potential. Groundwater is saline with

chlorites and sulphates that make a very aggressive

environment for concrete and reinforcement in the

ground.

Figure K.56

Suite of standards for geotechnical investigation and testing, design and execution of piling works.

The geotechnical requirements and design aspects are

discussed in K.8.6.3 to K.8.6.5.

The geotechnical design of buildings in Dubai shall

be based on the requirements stated herein and the

referenced standards (see Figure K.56 for piling works).

This subsection should also be read in conjunction with

all the other relevant subsections of K.8.

Additional studies should be conducted for unusual

constructions and might result in a variation from

these requirements which would require approval from

the Authority.
The geotechnical site investigations and testing shall

be undertaken by the geotechnical laboratory. All

geotechnical reports submitted by the geotechnical

laboratory shall be reviewed and approved by the

Engineer who witnessed the execution of soil testing.

Dubai Building Code

Part K: Villas

K 82

Any geotechnical design packages submitted and executed by the Geotechnical

Specialist Contractor shall be reviewed and approved by the Engineer.
All the geotechnical design works and site investigation reports shall be submitted to

the Authority for the necessary approval.

All the geotechnical design and execution packages shall be undertaken by a qualified

Geotechnical Civil Engineer.

K.8.6.2

Standards

Geotechnical site investigations and geotechnical works shall be designed to meet or

exceed the minimum requirements of the codes and standards listed in K.3.5.5.

K.8.6.3

Geotechnical site investigation

K.8.6.3.1 General

Geotechnical site investigations shall be planned and carried out in accordance with

BS 5930, BS EN 1997-2 and the associated UK NA, BS 1377 and BS 10175.

As indicated in BS 5930, the primary objectives of a geotechnical investigation are as

follows:
a) to assess the general suitability of the site for the proposed works;
b) to enable an adequate and economic design to be prepared;
c)

to foresee and provide against difficulties that may arise during construction due

to ground and local conditions; and

d) to predict any adverse effect of the proposed construction on neighbouring

structures.

A schematic representation of the geotechnical site investigation is illustrated in

Figure K.57.

Figure K.57

Schematic organization of a site investigation

DECISION TO DEVELOP SITE AND

CARRY OUT SITE INVESTIGATION

DESK STUDY

FIELD WORKS

AND TESTS

SAMPLES

LABORATORY

TESTING

WALK-OVER SURVEY

GEOTECHNICAL INVESTIGATION

FACTUAL REPORT (GIFR)

GEOTECHNICAL INTERPRETATIVE

REPORT (GIR)

DESIGN

GROUND INVESTIGATION

•

Preliminary investigation

•

Main investigation

Dubai Building Code

Part K: Villas

K 83

K.8.6.3.2 Geotechnical desk study

The geotechnical desk study shall provide a conceptual model of the site based on all

the available morphological, geological, hydrological, geotechnical information, and

land use history from public sources and technical literature. The extent of the study

shall be determined according to the nature of the project and the anticipated ground

conditions.

K.8.6.3.3 Planning geotechnical investigation

The extent of the geotechnical investigation is dependent on the complexity, size and

criticality of the development. Guidance on the spacing and depth of the investigation

points is given in Annex B of BS EN 1997-2:2007 and the associated UK NA. Soil

investigation for any building shall be defined by:

a) the location of the building;
b) the magnitude of the imposed loads;
c)

the number of floors;

d)  the shape of the building;
e)  previous uses of the land;
f)  terrain surface features;
g)  geological features; and
h)  surface water drainage.

K.8.6.3.4 Geotechnical on-site investigations

The requirements for geotechnical soil investigations are provided in BS EN 1997-

2 and the associated UK NA and BS 5930. As a minimum, the investigations shall

include the following:
a)  non-intrusive investigations (mapping, geophysics);
b)  intrusive investigations (boreholes, trial pits, observation wells);
c)  sampling of soils, rocks and groundwater;
d)  in-situ testing including:

1)  standard penetration test (SPT);
2)  cone penetration test (CPT);
3)  pressure meter;
4)  permeability;
5)  in-situ strength; and
6)  deformability.

The depth of investigation shall extend at least three times the shortest plan

dimension of the proposed foundation as specified in Annex B of BS EN 1997-

2:2007.
The minimum number of boreholes shall be in accordance with BS EN 1997-2

and the following:
a) for a community of villas/townhouses: one borehole for each plot; and
b) for single villas: minimum two boreholes per villa.

An example of organization and phasing of on-site investigation is given in Figure

K.58.

Dubai Building Code

Part K: Villas

K 84

Figure K.58

Typical organization and phasing of on-site investigation

K.8.6.3.5 Geotechnical laboratory testing

The requirements for geotechnical soil investigations shall conform to BS 1377, BS

EN 1997-2 and the associated UK NA, and BS 5930. The following list indicates a

minimum level of laboratory testing:
a)

soil classification/index tests;

b) soil engineering properties tests (strength, stiffness, deformability);
c)

rock classification/index tests;

d) rock engineering properties tests; and
e) soil, rock and groundwater chemical tests.

Soil tests shall be conducted in laboratories licensed and approved by EIAC. All soil

tests shall conform to EIAC approved standards.

K.8.6.3.6 Geotechnical reporting

Throughout, and particularly at the end of, the investigation, the geotechnical

laboratory shall issue the geotechnical investigation factual report (GIFR) and

geotechnical interpretative Report (GIR) which are reviewed and approved by the

Engineer.

For major developments and special projects, the GIR should be issued by the

Engineer based on the GIFRs issued by the geotechnical laboratory.
The following items shall be as a minimum included in the GIFR:

clear definition of the site, general topography;

b)  site plan/drawing with all as-completed investigation location coordinates;
c)  time and duration of on-site investigations;
d)  meteorological/weather conditions at the time of investigations;
e)  the use and state of the site at the commencement of the on-site investigation;
f)

accurate account of the equipment with key specifications mobilized and used for

the on-site investigation and in-situ testing and the methodologies and standards

adopted;

g) all levels of topography including any lidar scans or other means of obtaining

point cloud data, all site investigation points (e.g. trial pits, boreholes, CPTs, SPTs),

all stratigraphic levels, groundwater levels recorded and similar, to be specified in

the DMD;

h)  groundwater monitoring level, period and frequency;
i)  groundwater temperature;
j)  borehole and trial pit logs with coordinates and description of encountered strata

and levels, levels and types of all specimens taken (soil, rock and groundwater);

RB-1

RB-2

RB-3

RB-4

DMP-1

DMP-2

CP-1

CP-3

CP-2

Key

01: Soil test boring with SPT
02: CPT
03: Dilatometer test

Dubai Building Code

Part K: Villas

K 85

k) qualitative and quantitative description of boring (e.g. rock quality designation,

total core recovery, etc.);

l) levels and results of all in-situ tests (e.g. SPT);
m) borehole logs shall be supplemented with all relevant laboratory tests that

facilitate classification of strata (e.g. uniaxial compressive strength);

n) colour photos of borehole cores, including depth labels and colour chart;
o) full documentation of all performed laboratory tests, with suitable illustrative

plots/diagrams;

ground profile plot with key information of stratigraphy and groundwater level

(see Figure K.59).

The GIR shall include the following details as a minimum when submitted to the

Authority:

Figure K.59

Typical geological section

Key

01–07: Boreholes
08: Ground fill

09: Sand

10: Sandstone
11: Conglomerate
12: Calcisiltite

1) details of the recommended foundation system, with allowable bearing capacity,

modulus of sub-grade reaction and allowable settlement;

2) provision to mitigate the effects of expansive and collapsible soils in accordance

with the recommendations provided in Ch. 32 and 33 of the ICE Manual of

geotechnical engineering (vol. I)

[Ref. K.27]

;

3) provision to mitigate the effect of soil liquefaction, which shall be assessed as

stipulated in K.8.9.4;

4) provision to mitigate the effect of soil settlement and loads from adjacent plots;
5) various seismic parameters for the uppermost 30 m, in accordance with the

specified codes;

6) piles working load capacity under compression and tension for different sizes, at

varying depths and effective length (all levels should be in DMD);

if applicable, recommendations for pile groups with modification factors for load

and settlement;

8) values of modulus of elasticity of soil (Es);
9)

horizontal modulus of sub-grade reactions (Kh);

10) constant of horizontal sub-grade reaction (nh);
11)

vertical spring constants (Kv);

12) Poisson’s ratio;
13)

piles stiffness (Ks);

14) optimal spacing between piles within a pile group;
15) soil parameters required for shoring and basement wall design, such as:

i) average bulk density;

08 09 10 11

Dubai Building Code

Part K: Villas

K 86

ii) angle of shearing resistance;
iii) cohesion;
iv)

coefficients of soil pressure at rest (K0) pressure; and

coefficient of active and passive soil pressure for all soil layers.

16)

soil classification and index test results (particle size distribution, plasticity

chart);

17)

rock classification and index test results;

18)  permeability of soil and rock layers;
19)  plan showing boreholes, in-situ test location and coordinates;
20)  water table level (in DMD) and temperature;
21)  laboratory test results on soil and groundwater samples for the presence

and concentration of pH, sulphate and chloride, or any other chemicals or

components that might affect the structure;

22)  type of cement based on the chemical test results of soil types;
23)  summary of soil parameters;
24)  subsoil conditions and description;
25)

recommendation on the earth work, excavation, filling and compaction; and

26)

recommendations for suitability of site material to be used as fill material.

K.8.6.4

Geotechnical design

K.8.6.4.1

Earthworks (excavation and fill)

Excavation works shall be designed in accordance with BS EN 1997-1 and the

associated UK NA, and BS 6031. The design recommendations of Ch. 23 of the ICE

manual of geotechnical engineering (vol. I)

[Ref. K.27]

should also be followed for the

slope stability analysis.
The Geotechnical Specialist Contractor shall provide slope stability analysis for any

open cut excavation (see Figure K.60).

Figure K.60

Open cut excavation

Dubai Building Code

Part K: Villas

K 87

The Geotechnical Specialist Contractor shall design remedial actions when slopes

display signs of instability or the geotechnical analysis confirms the risk of failing.

The list below presents some of the common slope stabilization techniques which

may be used in Dubai.
a)

Regrading of the slope

. If the available land plot permits, the slope can be

regraded to reduce the slope angle.

Drainage

. Deep drains are perforated plastic tubes that can be embedded into the

slope to reduce the pore water pressure.

Retaining wall

. Retaining walls shall be designed in accordance with K.8.6.4.3.1.

Soil nailing

. An in-situ reinforcement technique consisting of drilling or driving

steel bars into the soil mass (see Figure K.61 and Figure K.62). The soil nails are

secured to steel plates at the surface and optional erosion and vegetation control

geosynthetic mesh can be placed over the slope face. If the soil is loose on the

surface, concrete can be sprayed to cover the slope face (see Figure K.61). Further

guidance can be sought in Ch. 74 of the ICE manual of geotechnical engineering

(vol. II)

[Ref. K.27]

Filling material

. The material used for backfilling purposes shall be of selected fill

composed of sand/granular mixture. The plasticity index of the backfill material

should not exceed 10%. The maximum particle size of backfill material shall not

exceed 75 mm. The percentage passing through a 75 mm sieve shall not exceed

20%. The organic materials content shall not exceed 2% and the water-soluble

salt content shall not exceed 5%

Compaction

. The backfill materials shall be placed in layers of thickness 150 mm

to 250 mm and compacted to not less than 95% of the maximum dry density.

The Engineer shall state whether the material available on site could be used for

general backfilling or not after performing the necessary analysis.

Figure K.61 Soil nailing detail (modified figure based on Figure 2.1 from CIR 7 FHWAO-IF-03-017 Geotechnical

engineering circular no.7 Soil nail walls, 2003, United States Department of Transportation Federal Highways

Administration)

Key

01: Permanent facing (e.g.

cast-in-place reinforced

concrete)
02: Temporary facing

(shotcrete)
03: Geocomposite strip

drain
04: Grout
05: Steel bar
06: Welded wire mesh
07: Reinforcement
08: Bearing plate
09: Washers
10: Nail head
11: Studded head

Dubai Building Code

Part K: Villas

K 88

Figure K.62

Installation of soil nailing system

K.8.6.4.2 Foundations design

K.8.6.4.2.1

General

The geotechnical design of foundations shall be undertaken in accordance with BS

EN 1997-1 and the associated UK NA.
The typical foundation systems in Dubai are illustrated in Figure K.63.

Figure K.63 Types of foundation (© ACI. Modified figure based on Figure R13.1.1, ACI 318-19, pg.192)

Key

01: Strip footing

02: Isolated footing

03: Stepped footing

04: Combined footing

05: Mat foundation

06: Deep foundation

system with piles and

pile cap

07: Retaining and

buttressed wall

foundation

08: Column

09: Piles

10: Pile cap

11: Stem

12: Toe

13: Key (optional)

14: Heel

15: Counterfort

Dubai Building Code

Part K: Villas

K 89

K.8.6.4.2.2

Shallow and raft foundations

The geotechnical design of shallow foundations (i.e. isolated, strip, stepped, combined

footing and raft) shall be in accordance with Section 6 of BS EN 1997-1:2004 and

the associated UK NA.

The most common limit states for spread foundations are:
a) loss of overall stability;
b) bearing resistance failure (the equations for bearing capacity are given in Annex

D, BS EN 1997-1 and the associated UK NA);

c)  failure by sliding;
d)  combined failure in the ground and in the structure;
e)  structural failure due to foundation movement;
f)

excessive settlements (refer to Annex H of BS EN 1997-1:2004 and the

associated UK NA);

g) excessive heave due to swelling, frost and other causes; and
h) unacceptable vibrations.
Design of the permanent concrete structural elements shall follow

F.6

F.8

and

ACI 318-19.

Raft foundations shall be designed as “rigid” unless a specific geotechnical model and

calculation are adopted to validate the design approach.

K.8.6.4.2.3

Deep and piled foundations

The geotechnical design of deep and piled foundations shall be in accordance with

Section 7 of BS EN 1997-1:2004 and the associated UK NA.

The following limit states shall be included in the design of deep foundations:
a) loss of overall stability;
b) bearing resistance failure of the pile foundation;
c)

uplift or insufficient tensile resistance of the pile foundation;

d)  failure in the ground due to transverse loading of the pile foundation;
e)  structural failure of the pile in compression, tension, bending, buckling or shear;
f)  combined failure in the ground and in the pile foundation;
g)  combined failure in the ground and in the structure;
h)  excessive settlement;
i)  excessive heave;
j)  excessive lateral movement;
k)  unacceptable vibrations; and
l)  liquefaction effects on piles.
The load-bearing mechanism (i.e. end bearing, friction, friction with end bearing piles)

shall be recommended in the GIFR. In particular, the end bearing capacity shall be

agreed with the Authority before the design is commenced.
Design of the permanent concrete structural elements shall be in accordance with

F.6

F.8

and ACI 318-19.

The design criteria listed in Table K.24 are applicable to reinforced concrete

foundations on piles.

Dubai Building Code

Part K: Villas

K 90

Table K.24

Piles foundation minimum design criteria

Design criterion

Minimum requirement

Pile design: general

Ensure pile design allows for both gravity and lateral loads.
Piles to be designed for out of verticality tolerance of 1/75.
Piles to be designed for eccentricity of vertical load of 75 mm.

Factor of safety shall be at least 2.5, unless geotechnical model

and geotechnical calculations based on the geotechnical site

investigation are provided.
Minimum rock socket length of three times pile diameter.
The use of bentonite is not recommended. If it is used, the shaft

capacity shall be reduced.
Pile caps shall be designed in accordance with the requirements

specified under ACI 318-19.

Crack width limit for tension

piles (w

)

0.2 mm considering the tension load.
0.1 mm considering the uplift load due to permanent tension load

(i.e. groundwater uplift, out of balance gravity loads).

Geotechnical design parameters The recommendations provided in the GIR shall be followed unless

a specific geotechnical model and geotechnical calculation are

developed.

Materials test reports

(aggregate, steel, concrete, etc.)

To be implemented by laboratories approved by DM or EIAC.

Minimum bar diameter

12mm

Minimum number of bars

Six bars evenly spaced.

Minimum percentage of

reinforcement

To be provided for the full length of the piles in order to provide

ductility and in accordance with Table 18.13.5.7.1 of ACI 318-19.

Minimum stirrup reinforcement Bars of 10 mm diameter for all the piles.

The top region of the pile below the caps or raft, shall be confined

effectively with closely spaced stirrups, for a length of three times

the pile diameter.
Stirrup reinforcement shall be in accordance with Table 18.13.5.7.1

of ACI 318-19.

Design criterion

Minimum requirement

Minimum design of horizontal/

lateral force

For the lateral pile design, the following requirements shall be

included:
a)

minimum 5% of pile capacity and not less than the horizontal

loads resulting from the superstructure and foundation

analysis;

b) moments due to out of position (75 mm) piles; and
c) horizontal force due to verticality (1/75).
The above design (a) may be excluded if geotechnical calculations

and geotechnical models are provided and the following items are

included in the design:
1) isolated temperature changes within raft, and temperature

distribution from column to raft;

2) detailed pile group assessment considering soil-structure

interaction, building stiffness and foundation stiffness;

3)  moments due to slab dishing;
4)  kinematic effects of earthquake loading;
5)  sensitivity checks should piles be constructed out of position;
6)  embedment of raft; and
7)  lateral load path analysis and load transfer into the raft slab.

Rational study of pile spacing

not available

Minimum pile spacing shall be 2.5 times the diameter.

Pile stress under compression

load

Maximum 25% of concrete strength.

Lateral stiffness of piles

50% to 100% of vertical stiffness.
Any other percentage (such as 10% to 15% of vertical stiffness)

shall be justified by geotechnical models and calculations including

the piles lateral group effect.

Vertical stiffness of piles

The impact of subsidence of the piles group on vertical stiffness,

as well as its effect on the raft and piles, shall be validated by

geotechnical models and calculations.

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Part K: Villas

K 91

K.8.6.4.3 Shoring and retaining systems

K.8.6.4.3.1

General

The geotechnical design of earth retaining systems shall be performed in accordance

with Section 9 of BS EN 1997-1:2004+A1:2013 and the associated UK NA. Design

of the concrete structural elements shall be in accordance with

F.6

F.8

and

ACI 318-19.
Shoring systems and retaining structures are deemed to be temporary if the design

life of the system is less than two years. They shall not be treated as part of the

permanent structures. A physical segregation shall be provided between temporary

and permanent structural systems.
The shoring and retaining systems shall be designed to retain the soil and actual

groundwater pressure (including tidal effect).

NOTE: Shoring and earth retaining systems typically used and accepted in Dubai are

as follows:
a) non-watertight shoring systems:

1)  soldier piles with lagging system/king post walls;
2)  contiguous pile walls;
3)  slurry walls;

b) watertight shoring systems:

1)  secant pile walls;
2)  diaphragm walls;
3)  sheet piles;

c) bracing for temporary earth retaining systems:

1)  anchors;
2)  rakers; and
3)  struts.

Alternative techniques specified in accordance with international codes and

standards may also be accepted.
The shoring and bracing systems are further described in Ch. 62, 63 and 64 of the

ICE manual of geotechnical engineering (vol. II)

[Ref. K.27]

K.8.6.4.3.2

Required shoring systems

Table K.25 should be followed for different depths of excavation and site conditions.

Table K.25

Type of shoring system

Permitted under following criteria

All types

up to 5 m deep excavation;
one basement.

All types, except soldier pile with lagging

up to 9 m depth and no buildings in the adjacent plots.

Shoring system preventing water leakage

presence of buildings in the adjacent plots;
high groundwater level;
proximity to water bodies.

It is possible to adopt shoring systems other than those in Table K.25, based on

the soil examination report, groundwater level, presence of water sources, adjacent

buildings and surrounding constructions.

The minimum requirements listed in Table K.26 shall be included in the design of

temporary shoring systems.

Dubai Building Code

Part K: Villas

K 92

Design criteria

Minimum requirement

Minimum additional loads

Additional uniform distributed load of 20 kN/m

shall be taken into

consideration in proximity to roads and land plots. The additional

surcharge load needs to be assessed based on the actual conditions

on-site and adjacent structures.

Minimum distance between

anchors

1.2 m

Maximum length of anchors

10 m

Minimum length of anchors

3 m

Maximum lateral displacement 40 mm
Unplanned excavations

Retaining walls shall be designed assuming presence of unplanned

excavations in front of the wall, with depth of not less than 10% of

the total height of vertical walls, or 10% of vertical distance between

the lowest anchor and the bottom of the excavation, but not less

than 0.5 m.

Heave

The geotechnical design shall assess heave if swelling and

collapsible soils have been identified in the GIFR. Further guidance

can be sought in Ch. 32 and 33 of the ICE Manual of geotechnical

engineering (vol. I)

[Ref. K.27]

K.8.6.4.3.3

Permanent earth retaining system

Any retaining structure is deemed to be permanent if the design life of the system is

more than two years. The permanent retaining system shall be designed to retain the

soil and future groundwater pressure (including tidal effect) without allowing for the

temporary retaining system.

The temporary retaining structures listed under the NOTE to K.8.6.4.3.1 may be

designed as permanent structures, provided they are included in the analysis of the

overall structure. The same design life, performance and durability requirements shall

be applied to both the main structural system and the permanent retaining system.

Table K.26

Minimum requirements for earth retaining system

In addition to the requirements for temporary retaining systems stipulated under

K.8.6.4.3.2, the Engineer shall design the retaining systems considering the intended

design life. In particular, the Engineer shall consider the applicable performance,

serviceability and durability requirements of

F.6

and

F.8

The geotechnical design of permanent earth retaining systems (including

counterfort/buttressed wall systems) shall be performed in accordance with

Section 9 of BS EN 1997-1:2004 and the associated UK NA. Design of the concrete

structural elements shall be in accordance with

F.6

F.8

and ACI 318-19.

K.8.6.4.3.4

Basement walls

A permanent basement concrete wall should be provided in front of the temporary

retaining systems detailed in K.8.6.4.3.1. The permanent basement wall shall be

designed to retain the soil and future groundwater pressure (including tidal effect)

without considering the temporary retaining system.
The permanent basement wall shall be fully integrated with the main structural

system of the building. The same design life, performance and durability

requirements shall be applied to the main structural system and the basement walls.
The geotechnical design of permanent basement walls shall be performed in

accordance with Section 9 of BS EN 1997-1:2004 and the associated UK NA. Design

of the concrete structural elements shall follow

F.6

F.8

and ACI 318-19.

K.8.6.4.4 Groundwater control and dewatering

Dewatering systems shall be designed in accordance with BS EN 1997-1 and the

associated UK NA and CIRIA C750

[Ref. K.28]

, taking into account the following:

a) All existing facilities shall always be protected.
b) The dewatering system shall reduce the loss of soft materials in the soil and any

effect on the surrounding structures. The hydrogeological model shall identify and

assess any piping effect. (see Figure K.64).

Dubai Building Code

Part K: Villas

K 93

BS EN 1997-1:2004. Permission to reproduce extracts from British Standards is granted by BSI Standards

Limited (BSI). No other use of this material is permitted).

Key

01: Free water level

02: Piezometric level in the permeable subsoil

03: Low permeability soil

c) The depth of shoring systems and internal excavations shall prevent soil heave.

This is to avoid the possibility of seepage, and to ensure compatibility between

the designs of the shoring systems and the dewatering system (see Figure K.65).

d) A seepage analysis and groundwater/hydrogeological model shall be prepared for

at least 20 m below the bottom of the excavation. The model shall determine the

following:
1)  type of soil and rocks;
2)  horizontal permeability of each layer;
3)  incoherent or gypsum soils; and
4)  other areas exposed to water leakage under the surface.

Figure K.66 shows the permeability of different soil types and recommended

dewatering systems.

04: Permeable soil

05: Possible well; starting point for pipe

06: Possible pipe

from BS EN 1997-1:2004. Permission to reproduce extracts from British Standards is granted by BSI Standards

Limited (BSI). No other use of this material is permitted).

Key

01: Excavation level (left);

free-water level (right)

02: Water

03: Sand

Figure K.66

Permeability of soil and dewatering systems

Permeability (m/s)

wn (m)

-8

-7

-6

-5

-4

-3

-2

-1

Key

01: Dewatering not feasible

and may not be necessary

02: Vacuum necessary

03: Vacuum beneficial

04: Sump pump

05: Single stage well point

system

06: Two stage well point

system/Deepwell system

07: Deepwell systems

08: Excessive seepage

flows: cut-off or wet

excavation may be

necessary

09: Ejectors

Dubai Building Code

Part K: Villas

K 94

K.8.6.4.5 Liquefaction

This section shall be read in conjunction with

F.7.13

and Section 11.8

of ASCE/SEI 7-16.

The 2% probability of exceedance within a 50-year period hazard parameters are

given in Table K.27. Specifically, the values of peak ground acceleration (PGA) and

the life safety, 5% damped spectral responses acceleration parameter at short period

S LS

) and at a period of 1s (S

1 LS

) are given. The long-period transition period (T

) is

also provided.

Location

PGA

S LS

1 LS

(s)

Dubai

0.13

0.33

0.11

Table K.27 Life safety seismic ground motion parameters for Dubai (site class B)

The following amendments to ASCE/SEI 7-16 Section 11.8 shall be used.
Section 11.8.1 of ASCE/SEI 7-16 does not apply to Dubai.

Liquefaction shall be assessed using a PGA determined based on either (1) a site-

specific study considering soil amplification effects as specified in

F.7.13.9

or (2) the

PGA

, from Eq. K.1.

Site class

Short period F

PGA

0.80

0.90

1.27

1.54

2.25

*A site response analysis shall be performed in accordance with 21.1 of ASCE/SEI 7-16 for structures

on site class F sites. A site response study or a ground motion hazard analysis is not required in any

other circumstances unless specifically requested by the Authority.

Table K.28 PGA site coefficient F

PGA

for liquefaction assessment in Dubai

The factor of safety (FS) against the occurrence of earthquake-induced liquefaction

shall be defined as the available soil resistance to liquefaction, the cyclic resistance

ratio (CRR) divided by the cyclic stress generated by the design event, the cyclic

stress ratio (CSR) as shown in Eq. K.2. The FS shall be not less than 1.5.

PGA

= F

PGA

. PGA

Eq. K.1

Where PGA is the MCE

peak ground acceleration taken from Table K.27 and F

PGA

the site coefficient from Table K.28.

FS ≥ 1.5 (CRR/CSR)

Eq. K.2

The groundwater level shall be selected based on the peak over the design period,

which allows natural changes (such as the "spring" tide peak), land use changes and

considerations for global warming.
In calculating the CSR, a magnitude of 6.2 shall be used for Dubai.
When assessing the potential for liquefaction any published and internationally

accepted methodology

[Ref. K.19]

can be used provided it is internally consistent.

The impact of carbonate sands on the liquefaction potential should also be included.

Dubai Building Code

Part K: Villas

K 95

100

0.1

0.01

0.001

0.0001

4.75

0.075

Particle size (mm)

tage ﬁner

eig

0.002

0.0001

The requirements for foundations design in liquefiable sites shall follow the

requirements in Section 12.13.9 of ASCE/SEI 7-16 and associated subclauses. This

shall include consideration of the following issues regarding liquefaction, namely:
a)  lateral spreading;
b)  global and differential settlements;
c)  provision of ties between individual foundations; and
d)  negative skin friction (i.e. downdrag) on vertical capacity of piles.
Where the impact of liquefaction exceeds the requirements of ASCE/SEI 7-16

(Table 12.13-2 for lateral spreading and Table 12.13-3 for differential settlement

thresholds), suitable ground improvement shall be required.

K.8.6.4.6 Ground improvement

Ground improvement shall be designed according to BS EN 1997-1 and ICE Manual

of geotechnical engineering (vol. I) Ch.25

[Ref. K.27]

Note: The following ground improvement techniques are accepted in Dubai

(see Figure K.67):

a)  dynamic compaction;
b)  vibro-compaction;
c)  soil replacement;
d)  soil mixing;
e)  grouting; and
f)  vertical drains.

Alternative techniques specified in accordance with international codes and

standards may also be accepted.

Figure K.67

Type of ground improvement systems and type of soil

Key

01: Explosive compaction

02: Deep dynamic compaction

03: Vibratory probes

04: Particulate

(cement) grout

05: Compaction grouting

06: Jet grouting

07: Vibro replacement

08: Drains for liquefaction

09: Drains for compaction

10: Compaction piles

11: Admixtures

12: Deep soil mixing

13: Remove and replace

14: Gravel

15: Sand

16: Silt

17: Clay

Dubai Building Code

Part K: Villas

K 96

Figure K.68 illustrates the indicative range of soil type (particle size sieve analysis)

suitable for compaction techniques.

Figure K.68

Range of soil types suitable to compaction

Key

01: Stone columns are a solution for a foundation in these soils. There is a resulting increase in bearing

capacity and reduction on total and differential.

02: Compaction is only possible by adding suitable backfill (material from zones 03 or 04) from the

surface (stone columns or sand columns).

03: The soils in this zone are suited for vibro compaction. They have a fines content of less than 10%.

04: The soils of this zone are very well compactable.
The right borderline indicates an empirically found limit where the amount of cobbles and boulders

prevents compaction because the vibroprobe cannot reach the compaction depth.

K.8.6.5

Execution of geotechnical works

K.8.6.5.1 General

Geotechnical works shall be carried out in accordance with the BS EN standards

listed in K.3.5.5. The Engineer and Geotechnical Specialist Contractor shall also

conform to the following subclauses.

K.8.6.5.2

Earthworks (excavation and filling)

In addition to the requirements specified BS EN 6031, the following requirements

shall be included in the execution of excavation and backfill activities.

The materials used for backfilling purposes shall consist of selected materials

such as sand/granular mixture free from organic materials or other biodegradable

materials. The Engineer shall determine whether excavated materials can be used

in general backfilling works after conducting necessary testing.

b) All excavations exceeding 1.2 m in depth require an excavation permit issued by

the Authority.

c) All health and safety requirements shall be strictly followed while executing any

excavation works.

d) All excavation activities shall be carried out inside the plot limits only. A no

encroachment, no parking, and no stopping zone with a minimum width of 1 m

shall be provided in proximity to the excavated area.

For any works required outside of the plot limits, NOC approval from the relevant

Authorities, departments or plot Owners shall be submitted.

Execution of excavation and filling activities should meet the requirements

stipulated in Ch. 75 of the ICE Manual of geotechnical engineering

(vol. II)

[Ref. K.27]

g) Installation of soil nails shall conform to the requirements of BS EN 14490.

Further guidance can be sought in Ch. 88 of the ICE Manual of geotechnical

engineering (vol. II)

[Ref. K.27]

0.001

0.01

0.1

100

1000

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Particle size (mm)

Dubai Building Code

Part K: Villas

K 97

K.8.6.5.3 Shoring retaining systems

In addition to the requirements of BS 8081, BS EN 1536, BS EN 1537, BS EN 1538

and BS EN 12063, the following requirements shall be included in the construction of

earth retaining structures:
a) All existing structures and utilities shall always be protected.
b) All works of shoring systems shall be carried out within the land plot.

The Geotechnical Specialist Contractor shall obtain all required approvals from

all concerned Authorities and owners of the adjacent plots regarding any shoring

system or anchors protruding outside the land plot limits.

c) The top 2 m of the shoring systems on the roads or services side shall be removed

upon completion of the basement wall works.

d) All works of shoring systems shall be continuously monitored by the Geotechnical

Specialist Contractor.

e) Anchors can be removed on site only after obtaining the written consent

of the Engineer.

K.8.6.5.4 Foundations

It is envisaged that the following foundation systems will be typically provided

for buildings in Dubai:
a)  shallow foundations;
b)  deep foundations; and
c)  raft foundations.
In addition to the requirements of BS EN 1536, BS EN 12699 and BS EN 14199,

the minimum testing criteria listed in Table K.29 shall be followed during and after

the execution of reinforced concrete foundations on piles.

Test

Minimum requirement

Static test on working piles

Minimum 1% of all piles and each different diameter

Dynamic test on working piles

5% of all piles

Cross-hole sonic logging (for more than

1 m diameter and 20 m length)

10% of all piles 900 mm or greater with minimum four

tubes/holes and minimum three tubes for 750 mm.

Minimum length of testing 20 m or full length if shorter.

End bearing piles full length testing

Integrity test working piles

100%

Cubes test (concrete)

as per technical specification

Reinforcement test

as per technical specification

Table K.29

Minimum testing requirements for pile foundation

It is the responsibility of both the Engineer and the Geotechnical Specialist

Contractor to select a test location which does not interfere with the location of

the permanent structural piles of the main structure. The Geotechnical Specialist

Contractor may propose test locations to be reviewed by the Engineer who may

accept them or propose alternative locations. Non-working preliminary test pile

(PTP) location and arrangement shall be submitted officially to the Authority during

the design stage and shall at least include the following.
1) Detailed drawings that clearly show the location of the test pile and

instrumentation.

2) Information detailing the planned duration of the PTP.
3)

An official covering letter from the Engineer and/or the Geotechnical Specialist

Contractor.

4) Minimum 1No. PTP for each project. The maximum diameter and length of pile

should be considered, assuming that they are the most representative for the

site.

PTP results shall be used to optimize the pile design in accordance with

BS EN 1997-1 and the associated UK NA.

Dubai Building Code

Part K: Villas

K 98

K.8.6.5.5 Groundwater control and dewatering

In addition to the requirements given in CIRIA C750

[Ref. K.28]

, the following

requirements shall also be included during the execution of dewatering on site.
a) All existing facilities and utilities shall always be monitored and protected by the

Geotechnical Specialist Contractor.

b) A network shall be developed to monitor the groundwater pressure/piezometric

pressure separated from the dewatering system, the vertical groundwater

gradients as well as the horizontal gradients, and the water rises inside and

outside the excavations/shoring systems.

c) Dewatering works shall not be stopped without the written approval of the

Engineer, after achieving balance between water pressure and the weight of

construction. The factor of safety shall be at least 1.1, irrespective of the friction

between walls and soil.

Care shall be taken during the dewatering process to ensure that fine particles soil

is not removed during pumping as this might lead to unexpected subsidence in

the surrounding lands and the associated structures.

K.8.6.5.6 Ground improvement

Ground improvement shall be executed in accordance with BS EN 12715, BS EN

12716, BS EN 14199, BS EN 14475, BS EN 14679, BS EN 14731, BS EN 15237.

In addition to the requirements specified in the referenced codes and standards,

the following requirements shall also be included during the execution of ground

improvement on site.
a) The technical design should be prepared by the Geotechnical Specialist Contractor

and approved by the Engineer prior to submission to the Authority.

b) Tests shall be conducted before and after the ground improvement activities.

Tests shall be proposed by the Geotechnical Specialist Contractor, reviewed by the

Engineer and approved by the Authority. The Geotechnical Specialist Contractor

should perform the following tests as a minimum.

Bearing capacity:

i) One plate load test per each 750 m

area (minimum one test for each

building) shall be carried out in accordance with ASTM D1195M.

The recommended acceptance criterion is to achieve the targeted bearing

pressure with total settlements less than 25 mm.

ii) One zone load test in accordance with ASTM D1195M shall be performed

for major development comprising more than one building and special

structures.

Improvement to mitigate liquefaction risk:

The efficiency of the improvement

shall be verified with CPT readings (in accordance with ASTM D5778 or

BS EN ISO 22476). The pre-improvement CPT tests should be carried out

every 900 m

maximum (or as stipulated in project specifications) to compare

the results with the post-improvement CPT tests. The locations of post-

improvement CPT tests should be selected at the central points between the

improved points. Weighted average of CPT tip resistance for near and far

tested points, should be not less than 6.0 MPa for shallow foundations.

Deep piled foundation:

It is recommended that, after completion of the

ground improvement, the weighted average of the CPT tip resistance profile

is at least 8.0 MPa.

c) A ground improvement report, based on tests conducted after performing

the ground improvement, shall be approved by the Engineer and submitted

to the Authority.

d) All existing facilities and utilities shall always be monitored and protected

by the Geotechnical Specialist Contractor.

All activities shall be carried out inside the plot limits only. For any activity outside

of the plot limits, a NOC from all of the relevant Authority departments

(e.g. DEWA, RTA. etc.) or plot Owners shall be submitted to the Authority.

Dubai Building Code

Part K: Villas

K 99

K.9

Incoming utilities

K.9.1

Design, erection and installation of electrical systems

K.9.1.1

General

This section outlines the requirements for the design of electrical installations.

It is based on the latest edition of BS 7671 and Institution of Engineering and

Technology (IET) documents

[Ref. K.29 and Ref. K.30]

Subsections K.9.1 to K.9.3 are not intended to:

take the place of a detailed specification;

b) instruct untrained persons; or
c) provide for every circumstance.
Where a situation arises which is not covered or allowed for within these subsections,

DEWA shall be consulted to obtain further clarity and guidance.

K.9.1.2

Electrical supply

The nominal electric supply voltage from DEWA (IEC 60038) is 230/400 V ± 10%,

50 Hz, three-phase, 4-wire with separate neutral and protective conductor (generally

metallic armour of the DEWA service cable). The neutral is solidly earthed at

DEWA’s substations and shall not be earthed elsewhere in the consumer’s electrical

installations. The design fault level within the substation is 40 kA (fault duration 1 s),

except for fuse protected equipment/circuits.

All equipment, apparatus, materials and accessories used in electrical installations

shall be designed and rated for operation on this electric supply. Overload, short

circuit and earth leakage protective devices shall be provided. Depending on the

design of consumer installations, protective devices shall also be provided to protect

against the following as required:
a) over voltages;
b)

fluctuations;

c)  transients and harmonics;
d)  loss of one or more phases; and
e)  unforeseen interruptions.

K.9.1.3

Incoming and metering

Before commencing building design, the consumer shall obtain confirmation of the

availability of a power supply from DEWA. Power supply from DEWA’s network is

subject to all applicable terms and conditions as issued by DEWA.
The consumer shall protect all elements of DEWA installations provided for and

within the premises. Any violation, defect or damage to DEWA lines, equipment or

metering shall be reported immediately.

Where the total connected load (TCL) exceeds 400 kW, provision shall be made

within the building or plot for a DEWA substation. In some circumstances a DEWA

substation might be required for connected loads less than 400 kW.
Meters shall be installed to measure and record the electricity demand and

consumption of the facility. All tariff meters shall conform to DEWA specifications.

Tariff meters are supplied and installed by DEWA.

Tariff metering shall be in accordance with K.9.1.5.

Dubai Building Code

Part K: Villas

K 100

K.9.1.4

Point of supply

K.9.1.4.1 General

Point of supply shall be made available at one location within a plot/project, unless

otherwise approved by DEWA. The point of supply defines the boundary of DEWA

equipment, and shall be decided by DEWA.
The circuit breaker(s) and/or main distribution board (MDB) provided at the point

of supply shall be designed and rated to suit the required application, and to conform

to all applicable requirements of K.9.

All incoming cable terminations/live connections in metering cabinets, MDBs

and SMDBs shall be adequately shrouded and insulated.

All exposed live terminal connections and busbars in any low voltage (LV) distribution

board (DB) shall be shrouded and/or insulated.
Refer to

G.4.4

in the event of a main electrical switchroom and LV distribution panel

being required.

K.9.1.4.2 Switchgear locations

Where a main or submain electrical switchroom is required, refer to

G.4.4

for further

details and requirements.

K.9.1.5

Tariff metering

K.9.1.5.1 Individual consumers premises

Individual consumer premises include villas, townhouses, farms, gardens and

accommodation blocks. The metering cabinet (including main incomer circuit

breaker) in such premises shall be installed in the compound wall as illustrated

in Figure K.69.

A minimum clearance of 2 m shall be maintained between electricity and water

service cabinets/points.

Dubai Building Code (2021) - page 26