MahaNakhon Tower History of a Design & Build. Dr. Kanokpat Chanvaivit, Senior Design Manger, Bouygues-Thai Ltd.

Transcription

1 MahaNakhon Tower History of a Design & Build Dr. Kanokpat Chanvaivit, Senior Design Manger, Bouygues-Thai Ltd.

2 MahaNakhon Tower History of a Design & Build Ī Source image courtesy of Bouygues-Thai

3 TOPICS [1] MahaNakhon Tower [2] Structural system and construction method (2.1) Mat foundation (2.2) Mega-columns and core walls (2.3) Outriggers (2.4) Floor plates (2.5) Tower Pre-setting [3] Presentation Wrap-up Ī Source image courtesy of Bouygues-Thai

4 (1) MahaNakhon Tower The tallest tower of Thailand

5 MahaNakhon Tower 77 Stories: 76 superstructure levels 1basement. 314 m Height + 5 m basement: Tallest building in Thailand. Ī Source image courtesy of PACE Development PLC

6 MahaNakhon Tower 30%of floor plates: Cantilever spans range from 4.00m to 11.00m. PIXELATION Imitation of Digital Pixel. Ī Source image courtesy of PACE Development PLC

7 Sky bar Ritz Carlton Sky Residences Ritz Carlton Residences Hotel Marriott EDITION Retail & Car Parking Ī Source image courtesy of PACE Development PLC

8 Structural Conceptual Design: -ARUP Beijing Structural & Geotechnical Design Development (Design and Build) Construction Stage: -Warnes Associates - ARUP Australia - Coffey - Bouygues-Thai - Bouygues Batiment International Structural Design Peer Review: - Robert Bird (Australia). - Aurecon Ī Source image courtesy of PACE Development PLC

9 Why Design & Build? Value-added of" Design & Build

10 Design & Build by Bouygues-Thai Studying the design in parallel with the construction stage Designs dedicate for construction More integrated solution Details are developed with the production team Safer for the methods Essence of method statements More economical Cost controlling is active during the design stage Faster construction Fast-track design schedule

11 (2) Structural system and construction method

12 (2.1) Mat foundation

13 Piling 129 Barrettes 1.20m x 3.00m Tip level at -65m. Safe working load = 2,900 ton Ī Source image courtesy of Bouygues-Thai

14 Piling model As deep as 120m soil layers in the finite element model for soil structure interaction iteration between PLAXIS and ETABS Ī Source image courtesy of Bouygues-Thai

15 Mat Foundation 8.75m/4.5m Thick 22,000 m 3 of concrete Ī Source image courtesy of Bouygues-Thai 3,200 T of steel rebars Ī Source image courtesy of Bouygues-Thai

16 Mat foundation casting sequence Constraints : Thickness = 8.75m Quantity of concrete to be brought in the central of business district of Bangkok Concrete temperature control Aggregate quality Ī Source image courtesy of Bouygues-Thai

17 Concrete mock-up test Picture credit : K. SOMPHOB, Punpueng (BYTHAI) <S.Punpueng@bythai.bouygues-construction.com> 3070m Ī Source image courtesy of Bouygues-Thai Concrete Temperature (H=1.50 m) Concrete Temperature (H=0.50 m) 2070"m 2070"m 2070"m

18 Casting sequence 6 layers in the central part 12 pours in total 2 months duration Ī Source image courtesy of Bouygues-Thai

19 Mat foundation casting sequence Constraints : Thickness : 8.75m Quantity of concrete to be brought at the same time in inner city Bangkok Early age thermal effect Ī Source image courtesy of PACE Development PLC

20 Ī Source image courtesy of Bouygues-Thai

21 Concrete temperature monitoring Ī Source image courtesy of Bouygues-Thai

22 (2.2) Mega columns and core walls

23 IBC 2006/ ASCE ACI AISC 2005 ISO137 or ISO-6897 DPT AS3600 CTBUH 2008 Codes, Standards, Guidelines and Recommendations Seismic Design Building Code Requirements for RC design and detailing Design and detailing of structural steel members and joints Vibration and human comfort Performance of the tower under wind load. Relative shortening of vertical components and compensation. Recommendations for the seismic design of High-rise building: for performance based design/ evaluation of the tower (Appendix B)

24 Wind Tunnel Test by Dr. Virote Boonyapinyo of Thammasat University (March, 2009) Updated on December 2012 by Dr Nakhorn Poovarodom Wind Design Speed Damping ratio Material properties Lateral Performance Wind analysis V = m/ 10m / 50 years return period V = m/ 10m / 10 years return period z = 1.00% for service level (10 year return period) z= 1.50% for ultimate level (50 year return period) Short term material properties for assessing wind acceleration and movement acceptability. Overall Maximum Deflection: H/ 500 (H = building height) under the 10 year wind. Interstorey drift: h/ 200 (h = story height) under the 10 year wind. Acceleration: 15 mg under the 10 year wind event (DPT ).

25 Thai Local Code (¾² ¼." ) 475 year return period Seismic analysis CTBUH Appendix B 2475 year return period

26 Parameters Thai Local Code CTBUH 2008 Appendix B Difference Analysis Wind method Tunnel Test by Dr. Virote Boonyapinyo of Thammasat Modal University analysis (March, 2009) - Response Updated Spectrum on December 2012 Site by Specific Dr Nakhorn. Seismic Hazard Assessment - V = m/ / 50 years return period Return Wind period Design Speed 475 V = year return m/ s / 10 years 2475 return year period return period x 1.50 times Damping ratio 5% z = 1.00%for service level (10 2% year return period) (Arup s advice) x 1.25 times Damping ratio ζ = 1.50%for ultimate level (50 year return period) (Arup s advice) 4 1 x 4.00 times Response Modification Factor (R) Seismic Mass DL + SDL+ 0.25LL = 241,400 Ton - Material properties Short term material properties for assessing wind acceleration and movement acceptability. Demand to Capacity x 0.50 times Ratio (D/ C) Overall Maximum Deflection: H/ 500 (H = building height) (62cm) under the 10 year wind. Phi (Ø, Reduction factor) 0.70 to x 0.80 times Interstorey drift: h/ 300 (h = story height) under the 10 year wind. Lateral Performance Material over-strength 1.0 Acceleration: 15 mg under the Force 10 year Control wind Action event (P (DPT & V) [5]). x 1.00 times ratio = No material over strength ratio (min) Deformation Control Action (M & T) 1.50 for concrete 1.25 for steel Ī Source image courtesy of Bouygues-Thai Summary x 3.00 times (Approx.)

27 Core walls / mega-columns design 9 Finite element models / complex design procedures 4 finite element models for actual construction sequences (Flexible foundation, short term) (Flexible foundation, long term) (Rigid foundation, short term) (Rigid foundation, long term) 4 finite element models for lateral loads (Flexible foundation, 475 Years RP seismic) (Flexible foundation, 2475 Years RP seismic) (Rigid foundation, 475 Years RP seismic) (Rigid foundation, 2475 Years RP seismic) 1 finite element model for serviceability analysis Performance based design for seismic based on CTBUH recommendations 36 directions of wind loads from wind tunnel test Ī Source image courtesy of Bouygues-Thai

28 Core walls 22m x 14m from the L52 to Top. 22m x 17m from the L21 to L52. 22m x 22m from the B1 to L20. Ī Source image courtesy of Bouygues-Thai

29 Columns 12 Mega-columns around the center core wall Concrete strength 60 MPa

30 Ī Source image courtesy of Bouygues-Thai

31 (2.3) Outriggers

32 Outrigger Outriggers are made of double floor height reinforced concrete walls to stabilize the tower globally and locally ( kinked mega-columns on level 19-20)

33 Differential axial shortening between columns and core wall Gravitational stresses : Strength : columns >> core wall columns << core wall The result is the differential axial shortening :

34 Staged analysis for system with outriggers Stage Analysis Model Full Model in one go

35 Innovation at Bouygues Construction

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37 Ī Source image courtesy of PACE Development PLC

38 (2.4) Floor plates

39 Ī Source image courtesy of PACE Development PLC

40 Pixel effect : challenging floor plate design and build! 30%of the slabs in cantilever Pixel areas Slabs in cantilever : difficult to design / deflection for facade Pixel area : difficult to construct Ī Source image courtesy of Bouygues-Thai

41 Ī Source image courtesy of Bouygues-Thai

42 Ī Source image courtesy of Bouygues-Thai

43 Ī Source image courtesy of Bouygues-Thai

44 (2.5) Tower Pre-setting

45 Tower pre-setting... Why?

46 Unbalanced tower load This architectural design of the top of the tower affects the centre of the gravity of the upper floor to shift westward. This is called unbalanced tower loads.

47 Concrete Elastic modulus and Creep tests This pre-setting calculation was originally based on the ACI creep assumption without any specific data available in Thailand. Bouygues - Thai worked with King Mongkut University of Technology Thonburi to develop a creep testing machines and a creep testing room according to ASTM C512 standard. The temperature was controlled at 23 C ±1 C with the controlled relative humidity at 50% ±4%. It can be found that the elastic modulus of all concrete specimens were higher than the code models approximately by 15% to 30% while the creep strains were relatively lower than the code recommendations. The higher concrete strength had the lower creep strain. ACI Laboratory Concrete Applied stresses Elastic strains based Creep & Shrinkage Actual long term creep Elastic Elastic strength (40% of compressive on ACI elastic strains from test coefficients (based on modulus modulus (MPa) strength, MPa) modulus (x10-6) results (x10-6) ACI elastic modulus) (MPa) (MPa) 35 29,910 40, ,975 40, ,750 44, ,162 47,

48 Tower pre-setting Ī Source image courtesy of Bouygues-Thai Design BTL - Casting STS - Current Longterm

49 (3) Presentation Wrap-up

50 PRESENTATION WRAP-UP [1] MahaNakhon Tower Tallest tower in Thailand / High end Luxury mixed uses [2] Structural system and construction method (2.1) Mat foundation (2.2) Mega-columns and core walls (2.3) Outriggers (2.4) Floor plates (2.5) Tower Pre-setting [3] Conclusion The design and build process leads the structural designers to work in full conjunction with the construction teams. Design is adapted to methods and vise versa. This is how Bouygues-Thai achieves success and efficiency. Ī Source image courtesy of Bouygues-Thai