AI-S Tower Kuwait

1.0          Introduction

This paper describes the structural concepts proposed for the Al-S Tower Development in Kuwait. The project comprises a very slender high-rise tower with a maximum height of approximately 430 m above the ground located in the Megwaa area of Kuwait City. The podium of the building comprises two retail floors, four floors for hotel facilities, three parking floors and four basement levels.

Several structural systems have been investigated with priority given to the following factors:

  • Economy of construction
  • Buildability
  • Speed of construction
  • Accommodation of architectural requirements
  • Adaptability for the provision of building services
  • Availability of local resources and experience
  • Maximising prefabrication and repetition
  • Minimising long lead-in items
  • Site access and storage restrictions
  • Fire resistance

 

2.0       Structural Materials

Consideration has been given to structural solutions using reinforced concrete and structural steel as the primary materials. The advantages and disadvantages of each of them are summarised as follows.

For a reinforced concrete structure, the positive points are:

  • Traditional well-proven method of construction in Kuwait resulting in competitive price and availability.
  • Use of local materials
  • No lead-time as in steelwork for ordering, delivery and fabrication
  • Suitability for cladding fixtures
  • Inherent fire resistance
  • Better acoustic performance
  • More flexible for building services requirements
  • Higher inherent damping compared to  steel structures

The negative points of a reinforced concrete system are:

  • Heavier self-weight of the structure
  • Larger member sizes compared to steel system
  • Longer construction time

 

Benefits of a steel structure are:

  • Lighter structural self-weight
  • Smaller member sizes compared to reinforced concrete
  • Speed of construction because most of the framework is fabricated in the workshop.
  • More efficient for larger spans or for open spaces than concrete structures.
  • Recyclable or re-usable material.

The negative aspects of steelwork are as follows:

  • Higher material cost
  • Longer lead time
  • Additional fire and corrosion protection
  • Additional structural depth required for steel beams, which may potentially conflict with the building services requirements
  • Lack of local experience in fabrication of heavy sections

Based on the above considerations, the structural steel option is discounted.

3.0       Proposed Structural Systems

3.1       Floor Systems for the Tower

In the typical floor plans, there are two zones that will have different floor systems. These are the zones within the cores, which include corridors, service areas and lift shafts, and the zones beyond the cores, which includes regular hotel/residential, office and retail areas. The zones within the cores will generally be conventional reinforced concrete slabs (150 to 200mm thick) with beams where required. For the remaining zones four floor system options have been considered (with one sub-option), as described below.

Option 1 – Hollow Core Pre-tensioned pre-cast slabs (HCS) on RC beams

This product is available in Kuwait and is extensively used in buildings. A cast in-situ structural concrete screed will be provided for levelling and to ensure diaphragm action

The advantages of this system are:

  • Lighter floor than a PT slab or 2-way RC slab
  • Reduced sizes of columns and foundations
  • Faster construction
  • Elimination of floor formwork
  • Good sound insulation

The disadvantages of this system are:

  • Reduced flexibility in penetrations in slab
  • Visible joints and nibs under soffit- aesthetics
  • More crane works and coordination required
  • Requires coordination with specialist sub-contractor on site

Option 2– Solid Reinforced Concrete 2-way spanning Slab

This is traditional construction, with the slab thickness controlled by deflection criteria.

The advantages of this system are:

  • Simple method of construction not needing specialist capabilities
  • Simple traditional formwork
  • Minimal site coordination
  • Flexibility for the passage of horizontal services and cutting small openings

The disadvantages are:

  • Heavier than most if the other options, leading to larger  columns and foundations.
  • Aesthetics- down stand beams in both directions, visible  in non-ceiling areas.
  • In-situ placement of large amount of rebar which takes longer than for pre-cast or post-tensioned slabs

 

Option 2A– Solid Reinforced Concrete Slab with Secondary RC Beams

This is traditional construction, with the slab thickness minimised by use of secondary beams.

The advantages of this system are:

  • Simple method of construction not needing specialist capabilities
  • As light as ribbed slab floor system if 2 secondary  beams are used per bay
  • Minimal site coordination
  • Flexibility for the passage of horizontal services and cutting small openings

 

The disadvantages are:

  • Larger amounts of shuttering which may result in  higher cost and longer construction time
  • Aesthetics- down stand beams will be visible in non-ceiling areas.
  • In-situ placement of large amount of rebar which takes longer than for pre-cast or post-tensioned slabs

 

Option 3 – One Way Spanning Ribbed Slab

This is a very efficient and light construction, with the slab thickness minimised by use of ribs at 900mm centres.

The advantages of this system are:

  • Simple method of construction not needing specialist capabilities
  • Lightest overall floor system (similar to option 2A)
  • Minimal site coordination
  • Easy to incorporate fairly large vertical riser  penetrations
  • Flexibility for the passage of horizontal services and cutting small openings
  • Possibility of pre-casting double-tee units, hence sharing advantages of off-site fabrication

The disadvantages are:

  • Larger amounts of special shuttering (moulds) which may result in higher cost and longer construction time
  • Aesthetics- ribs will be visible in non-ceiling areas.
  • Lower acoustical insulation than the other options

 

Option 4 – Post – Tensioned (PT) Concrete Slab

A solid post-tensioned one-way spanning slab supported on main RC beams. (Note: 2-way PT slabs are not possible for the tower due to the restraints imposed by the external “pierced tube” framework.

The advantages of this system are:

  • Shallower structural depth compared to solid RC slab, option 2
  • Fastest in-situ concrete option

 

The disadvantages of this system are:

  • Limitation on fixing services and cutting openings after the  slab has been cast
  • More coordination with a specialist sub-contractor on site
  • Heavier than the many of the other options
  • Not commonly used in Kuwait
  • Restraint of external tube structure of tower will require special gap-strips

 

Cost Comparison

At this stage cost comparisons can only be made on the basis of materials usage and overall weight as that has considerable impact on the sizes of columns and foundations. The system can be further refined and priced during the preliminary design stage, taking account of rebar consumption as well as shuttering/formwork costs. The conceptual sizes of floor framing members and volumes of concrete utilized for the different floor options have been worked out in order to make an appropriate recommendation.

Recommendations

For high-rise towers, as the floor system has a big impact on the sizes of beams, columns and foundations, the best system to adopt should be the lightest system. Based on that consideration and taking all other pros/cons into account, the recommended option at this stage is the one-way ribbed slab system (option 3), although the options will be further studied for the final selection during the preliminary design stage. The ribbed slab depth can be further reduced to 400mm for the shorter spans.

The conceptual framing system used for the ETABS model for the tower is shown in the screen shots in the next page, for the reducing floor plates up the tower. The 3-D image shows Level 34 from underneath.

It is important to highlight that the choice of this floor system does not preclude the contractor from proposing traditional RC slab system with secondary beams (option 2A) as this is equivalent in weight to the ribbed slab system. Some local areas within the lift lobby shall be conventional reinforced concrete due to short spans, presence of a large number of openings and heavy loading.

The mechanical floors and the roof slab will likely be conventional reinforced concrete slab, which will be thicker than normal floors to account for vibration and noise controls.

3.2     Floor System for the Car Parking Levels

At this stage the proposed car parking is planned to be by automated delivery system, which will rely on steelwork framing fitted within the concrete walls/columns. Where necessary, in order to reduce the slenderness of columns, RC beams may need to be provided at some of the floor levels. In addition, certain parts of the parking floors may require traditional RC floor slabs, for which provision has been made during the conceptual design.

The column grid spacing for the car parking outside the footprints of the towers is fairly regular which permits the possibility of considering two-way spanning flat slabs in addition to the other options considered for the tower. Due to headroom restrictions, the option of using HCS is only possible by use of shallow depth band beams. 

 

3.3     Floor System for the Retail, Restaurant and Gymnasium Areas

The column grid spacing for the retail area follows either the regular grid outside the footprints of the towers or it follows the same grid as the towers under their footprints without the need for any transfer structures. The recommended floor option for this zone, under the footprint of the tower, is also Option 3, using 400mm and 500mm deep ribbed slabs depending on the spans and the loading.

In the podium floors the column grid spacing is fairly regular and has fewer number floors compared to the tower, so self-weight is not so critical. Hence the recommended slab system at this stage is a flat slab of 300mm thickness with drop panels of 450 thick where ever required. Perimeter beams of size 400X800 are provided where ever possible to avoid drop panels.

3.4     Floor System for the Mechanical Areas in Podium

The recommended floor system for the mechanical floors is 350mm thick flat slab with 500mm thick drop panels wherever required. The thicker than normal floor is to account for vibration, noise controls and higher live load due to mechanical equipment. The floor system for the third floor is 300 thick solid slab supported on 600X800mm beams.

3.5    Floor System for the Ballroom

The recommended slab system at this stage is a flat slab 300mm thick with drop panels of 450 thickness wherever required.

3.6     Floor System for the Fourth floor

Some of the columns along grids R and S have to be stopped at second floor to permit an open floor area for the ballroom. This necessitates the use of trusses for the span of 27m to support the floors above. The depth of the trusses is 3.8m using structural steel sections. The remaining area with smaller spans is to be conventional one way solid slab of 300 thickness supported on beams of sizes 600 x 900mm.

3.7     Podium Roof

A steelwork retractable roof supported on steel beams/trusses will be provided for the podium roof.

 

4.0     Lateral Stability and Gravity Support Systems

Lateral forces due to wind and notional loads need to be safely transferred from individual floors down to the foundation without excessive deflections in the structure.

Al -S Tower is very slender indeed, with an aspect ratio of about 12:1 in one direction and about 9:1 in the other and therefore is a very challenging building to design. Compared to this other tall buildings in the world have a maximum aspect ratio of around 8:1 (such as Burj Dubai, Taipei 101, Petronas Towers, etc). This tower is about the same height as the latter two towers quoted above.

Having considered other options, such as shear /core wall systems, dual system with moment-resisting frames, braced systems, etc, the best one that suited the architectural/functional requirements and the exacting performance required for lateral sway and acceleration, is the system described below as being the most appropriate.

The lateral stability is provided primarily by the external “pierced-tube” system (also referred to as a punched-tube system), in conjunction with the lift and stairway cores, coupled with shear walls and moment-resisting frames in certain locations. Outrigger and Belt Truss systems have been incorporated at service floors at this stage but these may not be necessary after wind tunnel loading has been assessed, unless additional stiffness is required for the acceleration control. Preliminary wind loads for the tower portion, as per the ASCE wind code, have been assessed and the tower is sufficiently stiff to resist these. It is expected that the final wind loads from the wind tunnel tests will be less than these code values.

 

The main advantages of this structural system are:

  • Very stiff and efficient for lateral stability as the members are at the perimeter of the tower.
  • Torsionally stiff.
  • Little reliance for lateral stability on the internal lift shaft cores, so that they remain relatively thin- 300mm even at the base.
  • Freedom to plan the internal layout and column/core positions without compromising the overall lateral stability.
  • Ability to remove alternative tube columns to suit architectural/functional requirements
  • Repetitive use of standard size formwork for the punched rectangles in the tube.
  • Suited for fast slip-forming.
  • Efficient usage of materials; current design consumes only about 0.6 m3 of concrete per m2 of gross floor area, which is very good for a building of this height and slenderness.
  • Minimises requirement for external blockwalls, as all the openings will be glazed.
  • Provides very good thermal mass to the exterior, hence minimising solar gain into the building.

The lateral stability for the podium is provided primarily by lift and stairway cores, coupled with shear walls and moment-resisting frames in certain directions.

As far as possible, all gravity load paths have been kept simple and vertical, but in three locations in the tower this was not possible and the transfer structures are described below.

4.1   Sloping Set-backs

In order to find the most optimal solution, the sloping beams have been used as raking columns to pick up gravity loading from the edges of the set-back floor slabs. This forms a very efficient triangulated system which will reduce the beam sizes (as they will not need to be cantilevers) and also results in the raking columns acting as bracing against lateral sway of the tower.

The screen shot below shows the axial forces in the raking columns as well as in the mullions which will be spaced at 4.2m centres to coincide with the intersection of the raking column with each floor plate.

4.2   Gravity Transfer at Gridline D

The 5m setback at Levels 9-10 does not coincide with any columns below, so between Levels 8 and 9 there are floor-height transfer walls which efficiently transfer the gravity loading on to the external tube and the columns on gridline E.

4.3   Gravity Transfer at Gridline E

Column 9E stops at Level 21 and then continues at Level 32. Therefore this column is supported on a transfer wall within the double height MEP floor at Level 31. Due to the geometry of this structure it is economical in terms of materials usage, as it also assists in the tower’s lateral stability as a belt truss/wall.

4.4   Viewing Deck/Spire Structure

At this stage the top floors framing around the triangular cut-out have been modelled and analysed as a traditional RC structure, with framed floors and columns/shear walls. During the next stage this may be changed to structural steelwork in order to make it more buildable and at the same time make it lighter so that the global dynamic response would improve.

4.5    Differential Column Shortening

For tall concrete structures (more than about 30 storeys), the effects of elastic column shortening as well as long term shortening due to creep and shrinkage become significant. This happens mainly due to the fact that columns are usually much more heavily stressed than the shear/core walls. This then leads to increasingly differential “settlement” between the columns and the walls, with beams and slabs ending up at a slope. The best way to mitigate this effect is by stress balancing between columns and adjacent walls- however this is not always possible (due to lateral stability requirements), so a detailed and complex analysis is normally required during the PD and DD stages in order to work out and specify “super-elevations” at every 5-10 floors.

With this, the floors/beams are deliberately cast at a negative/reverse slope, with the idea that in due time they would revert to the horizontal.

4.6    Differential Temperature Effects

In tall structures (more than about 30-40 storeys), the effects of differential temperature gain/loss between the external envelope and the internal structure become significant, as this leads to secondary stresses within  the connecting members (beams, floors, etc). This aspect will need to be carefully assessed and catered for during the PD and DD stages.

5.0       Design codes

The design will be done in accordance with the following main codes and standards:

BS 8110   Structural use of concrete
  Part 1: Code of practice for design and construction
  Part 2: Code of practice for special circumstances
BS 5950   Structural use of steelwork in building
 
Part 1: Code of practice for design in simple and continuous construction: hot rolled sections
S 6399   Loadings for Buildings
  Part 1: Code of practice for dead and imposed loads
  Part 3: Code of practice for imposed roof loads
BS 8004:   Foundations
BS 8102:   Protection of structures against water from the ground
BS 8007:   Design of concrete structures for retaining Aqueous Liquid
BS 5628:   The structural use of masonry
ASCE 7-05   Wind loads in concept design phase
ACI 363R-92   Report on High Strength Concrete
ETABS Modes of Vibration 1, 2, 3 and 4

ACI 441-R96

  High Strength Concrete
UBC Code 1997 & ACI 318-05   Seismic design
NFPA 5000   Fire Resistance

Note: All current Kuwait Regulations will be complied with and will take precedence should they conflict, unless specifically waived by the Municipal engineers

6.0     Dead and Imposed Loads

6.1  Dead Loads                                            

Screed Density = 20 kN/m3
Concrete + in-situ topping Density = 24 kN/m3
Lightweight concrete Density = 13 kN/m3
Service and suspended ceiling Density = 0.3 kN/m2
200mm light weight block work partitions 1.8 kN/m2 (on elevation)
100m light weight block work partitions 1.2 kN/m2 (on elevation)
Dry wall partition 0.9 kN/m2 (on elevation)
Cladding (glass and aluminium) 1.0 kN/m2 (on elevation)

 

6.2  Imposed loads

Residential areas 2.0 kN/m2
Office areas (including movable partitions) 3.5 kN/m2
Plant, mechanical/electrical room areas 7.5 kN/m2
Stores, corridors, lift lobbies and staircase 4.0 kN/m2
 

Car park areas

3.0 kN/m2
Retail areas 5.0 kN/m2
Balconies 3.0 kN/m2
Transformer rooms 10.0 kN/m2
Roofs (unless noted otherwise) 1.5 kN/m2
Landscaping (to be confirmed) 16.0 kN/m2

 

Note: Codified live load reduction factors will be used where applicable.

7.0       Wind Loads

The basic wind speed will be established by the wind specialist based on the meteorological data for Kuwait. For the concept stage designs, following data, per ASCE 7-05 will be used to estimate the wind load on structure. The wind tunnel test results will be used for the preliminary and detailed design stages.

 

Basic wind speed V = 40 m/s 3 second gust wind speed for Kuwait
Velocity Pressure Exposure Coefficient. Exposure D Open area (for a tall building located at sea shore) outside hurricane prone regions
Topographic Factor Kzt = 1.0 Flat coastal fringe.
Wind Directionality Kd = 0.85 Main Wind Force Resisting System
Importance Factor I = 1.0 Category II building

 

 

8.0       Seismic Loads

Load factors for seismic design shall be in accordance with UBC 1997 Ch.16

Seismic Zone 1 Z = 0.075
Soil profile factor Sc  
Occupancy category   I = 1.0
Ductility factor   R=5.5 for concrete frame system

 

9.0       Load Combinations

The following combinations will be used in design:

9.1   Serviceability Limit State

–           1.0 DL + 1.0 LL

–           1.0 DL +/- 1.0W

–           0.8 (DL + LL +/- W)

–           0.9 DL + UPL

 

9.2       Ultimate Limit State

–           1.4 DL + 1.6LL

–           1.2 DL + LL +/- E

–           0.9 DL +/- E

–           1.2 DL + 1.2LL +/- 1.2W

–           1.4 DL +/- 1.4W

–           0.9 DL +/- 1.4W

 

9.3       Piles and Foundations

–           1.0 DL + 1.0LL

–           0.8 (DL + LL +/- W)

–           0.75 (DL + LL +/- E/1.4)

–           0.9D +/- E/1.4

 

Where:             DL: Dead Load.                                                                                                                                              LL: Live Load.                                                                                                                                               E: SRSS Seismic load from Response spectrum analysis.                                                                             W: Wind Load in any direction.                                                                                                                     UPL: Uplift Load.

10.0     Robustness

Disproportionate and progressive collapses are important considerations for a building such as this. The structural system adopted has inherent robustness and redundancy, as evident from the removal of one column at ground level (on gridline 11, at the main hotel entrance) without the need for a heavy transfer structure.

The provisions of BS 8110 for structural robustness will be met by providing vertical and horizontal ties and careful attention to rebar detailing.

 

11.0     Damping Values

2% damping value will be considered appropriate for serviceability and ultimate limit states under 50 year return period wind loads. The estimation of the occupant comfort (10 year return period wind) will be performed with a structural damping ratio of 1.5% for the concrete structures. A 5% damping value will be used for seismic loads in ultimate limit state.

12.0     Occupants Comfort

Wind tunnel test studies will be carried out to assess the occupancy comfort. The maximum peak acceleration for 10 year return period wind shall not exceed 15 mg at the top occupied floor for residential units and 20 mg for the top office floor.  An assessment as to whether the tower is stiff enough to obviate such problems is to study the first 3 or 4 natural modes of vibration. If the first and second modes are within the limits of n/10 seconds or H/60, where n= number of storeys and H= overall height of tower, then this is sufficient evidence at this stage of the design. The images and table below shows the mode shapes and the time periods for the first 4 modes and they are all within expected limits.

However, the shape of the tower makes it susceptible to cross-wind excitement and this aspect will be studied in more detail after receipt of the wind tunnel test results.

13.0     Wind Drifts

A normally acceptable wind drift ratio is H/400 to H/500 for a 50 year return period of wind. This wind drift will be calculated for service load combinations with wind loads from the wind tunnel tests. Based on the code wind loads, the preliminary analysis shows that the tower is stiff enough to fall within the above limits.

14.0     P-delta Effects

P-Delta analysis requirement for the seismic analysis will be verified and included, as per clause 1630.1.3 of UBC-97.

P-Delta analysis requirement for the wind analysis will be verified and included, if necessary, at the detailed design stage, as per Clause 12.8.7 ASCE 7-05.

15.0     Foundations

15.1     Tower Foundation

Although no soil investigation report is available for the project site yet, it is envisaged that a piled raft foundation will be required to carry column and wall loads of the towers. The raft thickness is expected to be about 4m under the tower at one end, reducing to about 3m at the other end.

15.2     Podium Foundation

The excavation for foundation and basement construction will be carried out either by an open excavation or by a temporary soil retention system such as diaphragm wall or contiguous wall systems, depending on the ground water condition at the reclamation land. As the whole site is covered by basements, the foundation for the Podium will also be a raft (1.5-2.0m thickness) on piles.  The selection of the final systems will be made after a detailed review on the information provided by the soil investigation report.

15.3     Basement Walls

The basement walls will be designed as water retaining and in addition there will be external waterproofing/tanking. The walls will be 600mm thick for B4 and B3 and can reduce to 400mm thick for B2 and B1.

16.0     Movement Joints

As the site is quite large, joints will be required in order to accommodate temperature movements during construction and during service. The normal criterion is to space these at between 50-75m but, with suitable design and detailing, the joint spacing can be extended up to 100-120m, especially in those floors that are below ground or subject to little temperature change during service due to a controlled environment.

Due to expected differential settlement between the tower and the podium, a movement joint adjacent to gridline P will be provided to separate the tower from the podium. However, this will result in potential pounding problems from seismic sway, so the width of the joint will need to be carefully assessed during the preliminary design stage.

17.0     Materials

Concrete will typically be Grade C45 to C80 depending on the strength requirements. The high strength concrete will be used for the walls and columns at the lower levels of the towers. High strength concrete will be achieved by the addition of silica fume to the mix and use of super-plasticizer to achieve a low free water to cement ratio, typically below 0.40.  A durable low heat of hydration concrete for the raft slabs and basement walls will be achieved using a mix of OPC and GGBFS.

Concrete for piling may be triple blend comprising the ordinary Portland cement (OPC), the ground granulated blast furnace slag (GGFBS) and the micro-silica.

Reinforcement will be high yield deformed bars fy = 460N/mm2

Block work walls will generally be constructed using lightweight concrete blocks with a density not exceeding 600 kg/m3. A study was conducted to compare 3 different types of blocks available in Kuwait and from this it is clear that the lighter blocks have an advantage as they can reduce the overall dead loading per floor by as much as 10%, which will have a significant affect on the sizing of columns and foundations.

Structural steelwork will comply with BS5950 and will be Grade S275, S355, or S460 as required.

18.0     Durability

The design life for the concrete is 50 years. The extreme climate and presence of chlorides and sulphates in the ground and the atmosphere create an onerous requirement for concrete durability which will be achieved by adopting a combination of the following measures:

  • Specifying high quality, dense, low permeability concrete.
  • Specifying adequate cover to reinforcement.
  • Application of external tanking below ground and external protection above ground.

 

The following concert covers for rebar will be specified to achieve the more onerous requirement for either durability or fire protection:

  • 35 to 60mm for internal surfaces
  • 50 to 60mm for external/exposed elements
  • 75mm for pile caps
  • 100mm for piles

 

Concrete below ground will be designed as water excluding, both to prevent ingress of water and also to prevent aggressive ground water penetrating the concrete, causing corrosion of the reinforcement. The design shall be to BS 8102 Type B using BS 8007 with a 0.2 mm crack width for the inner faces of raft and retaining walls & 0.3 mm for the other faces.  This should provide a Grade 3 environment within the building (dry environment).

External water bars will be provided at all construction joints in concrete below ground (‘ground’ defined as the level of backfilling behind the external walls of the building on completion).

The waterproofing system (membranes, protection boards, water bars, joint fillers, sealants etc) will be specified to be from a single manufacturer’s product range to ensure compatibility and to be applied strictly in accordance with the manufacturer’s instructions. Details will be developed with potential suppliers during the design stage.

19.0     Fire Resistance

As per the requirements of NFPA 5000, the fire resistance shall be 2 hours for floor plates system and between 3 and 4 hours for primary framing members, transfer structures, columns and walls, depending on different levels. For any steel structures the appropriate fire rating will be achieved by providing a spray applied cementitious, vermiculite or other polyvinyl coats, while the vertical steel elements within residential or office units would have a dual fire protection system consisting of a thinner spray-on system boxed out with gypsum board.

During the next phase of design the performance of high strength concrete elements subjected to high temperatures will be investigated as these are prone to explosive spalling failure which can be overcome by adding polypropylene fibres to the concrete mix.

20.0     Construction Methods and Sequence

These aspects will be considered during the PD stage, in consultation with buildability experts as well as with the involvement of the potential main contractor. At this stage, the scheme as proposed does not pose any undue challenges, apart from the great height, as the construction materials and structural system selected are appropriate for Kuwait.

21.0     The Next Step- the Preliminary Design Stage

During the preliminary design stage, all structural members will be optimised for gravity loading and the lateral stability systems will be optimised based on wind tunnel test results. The foundations will be optimised based on results of the GI results and the ultimate aim of this activity will be to minimise concrete and rebar quantities but at the same time to ensure buildability for fast construction and a quick floor-to-floor cycle for the tower. Key issues that will require attention are:

  • Ground Investigations
  • Enabling works package
  • Consultation with contractors and buildability experts
  • Detailed Wind Tunnel Tests after the structure has been optimised and fully coordinated with the other disciplines (architecture, MEP, landscape, etc)
  • Second order effects (elastic, creep, temperature, shrinkage and p-delta).
  • Foundation design after receipt of the GI factual and Engineering report
  • Piling package

 

22.0     Acknowledgements

The author would like to acknowledge the engineering and architectural teams at Atkins Bahrain office for their contribution to the design of this iconic building, and also notes that the artist’s image of the tower is Atkins Copyright.

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