Design of Slender Tall Buildings for Wind & Earthquake
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SMCES Civil Engineering Seminar YTU, Yangon 27 September 2015 Design of Slender Tall Buildings for Wind & Earthquake Presented by Dr. Juneid Qureshi Director (Group Design Division) Meinhardt Singapore Pte Ltd AGENDA 01 02 03 About Definition and Key Meinhardt Trends of Tall Considerations Buildings in the Design of Tall Buildings 04 Structural 05 Systems for Tall Key Buildings Considerations for Seismic Design 06 07 Case Studies & Concluding Innovations Remarks SECTION 01 ABOUT MEINHARDT ABOUT MEINHARDT Largest Global Established in Engineering & PM 1955 (in Australia ) 42 60+ 4000+ 1974 (in Singapore) Offices Years of track Professional staff Company Owned worldwide record and Headquartered in Singapore Start-to-end services ENR 2014 across entire project Largest Independent delivery cycle Engineering Consulting Firm in Asia Group undertakes projects worth US$20 billion annually KEY OFFICES USA EUROPE MENA ASIA AUSTRALIA 40+ 100+ 400+ 3200+ 350+ Staff Strength Staff Strength Staff Strength Staff Strength Staff Strength DIVERSE SECTORS We Have The Credentials And Ability To Deliver Projects Of All Types And Complexities Buildings Industrial and Information Civic . Arts and Culture Manufacturing Technology, . Defense . Commercial Offices . Distribution Centres Research and . Educational . Convention Centres . Healthcare/Hospitals . Hotels and Leisure . Industrial Communications . Pharmaceutical . Public . Mixed-use Developments . Data Centres . Parking Structures . Petrochemical . Life Sciences and Biotech . Residential . Retail / Shopping Malls . Power Systems . Sports Facilities / Stadia . Telecommunications Sustainability Urban Land Infrastructure Transportation . Energy Audits and Development . Environmental . Aviation/Airports Conservation Management . Built Environment . Bridges . Green Buildings and . Energy Generation and . Conservation and . Highways Architecture Distribution Restoration . Ports . Waste Management . Urban Regeneration . Railways/Metros . Water, Wastewater and . Urban Infrastructure . Tunnels Environment HIGH RISE BUILDINGS 610m 385m 385m 360m 358m Mixed-Use Tower, South Capital Market Authority, Worli Development Thamrin Nine Signature Towers East Asia KSA Mumbai, India Jakarta, Indonesia Dubai, UAE 85 & 52 Storey Mixed Use (Office 68 & 58-storey Mixed Use 81 /65/52 Storey Mixed Use (Office & Residential) (Office/Residential) & Residential) C&S Engineering for Specialist structural consultant & International Contractor technical advisor to SBG MEP Engineering & Façade Structural, MEP, Façade Engineering & Lead, Structural, MEP & Façade Traffic Engineering HIGH RISE BUILDINGS 342m 342m 330m 320m 308m 300m Four Seasons Place IFC Project Shanghai Putuo CBD Heartland 66 Ocean Heights ZhuJiang New Town B2-10 Kuala Lumpur, Malaysia Wu Xi, China Shanghai, China Wuhan, China Dubai, UAE Guangzhou, China 76 Storey Mixed Use (Hotel 65 Storey Mixed Use 57-storey Office Tower 64-storey Office Tower 82 Storey Residential 68-storey Office Tower & Residential) (Hotel & Residential) Tower MEP Engineering Structural Engineering MEP Engineering, Structural Engineering MEP Engineering, Façade Structural Engineering Structural Checking HIGH RISE BUILDINGS 300m 298m 290m 290m 280m 267m Dubai Pearl One Island East Tanjong Pagar Nanjing International One Raffles Place Petronas Tower 3, 70-storey Hong Kong Mixed Use Development Commerce Centre Singapore Kuala Lumpur, Malaysia Mixed Use (Office, Hotel, 70 Storey Office Singapore Nanjing, China 63 Storey Office Tower 60 Storey Office Tower Residential, Retail) 64 Storey Mixed Use (Retail, 59-storey Hotel & Office MEP Engineering Office, Hotel, Residential) Tower Structural & MEP Structural Engineering Structural and M&E Engineering Engineering MEP Engineering Structural Engineering HIGH RISE BUILDINGS 261m 254m 251m 258m 245m 245m The Masterpiece, Hyatt Prima Pearl Tower Rialto Towers The River Marina Bay Financial One Raffles Quay, Regency Hotel, K11 Melbourne, Australia Melbourne, Australia Bangkok, Thailand Centre, Singapore Singapore Shopping Mall, Hong 69 Storey Residential 65 Storey Office Tower 74 Storey Residential Towers 67/56/51/50/33 Storey 50/33 Storey Office Towers Kong Tower Mixed Use (Office, 64 Storey Mixed Use Structural Engineering Structural Engineering, Residential & Retail) Structural & MEP (Hotel, Retail, Service Structural Engineering Specialist Lighting Engineering Apartment) Structural & MEP Engineering MEP Engineering SECTION 02 DEFINITION & TRENDS OF TALL BUILDINGS TALL BUILDINGS WHAT IS IT? According to CTBUH, there is no absolute definition . It is a building that exhibits some element of “tallness” in one or more of the following categories: a) Height Relative to Context It is not just about height, but about the context in which it exists. (courtesy of CTBUH) TALL BUILDINGS PROPORTION b) Proportion Again, a tall building is not just about height but also about proportion. (courtesy of CTBUH) TALL BUILDINGS TECHNOLOGIES c) Technologies If a building contains technologies which may be attributed as being a product of “tall”, then this building can be classed as a tall building. (courtesy of CTBUH) TALL BUILDINGS DEFINITION . A structure that, because of its height, is affected by lateral forces due to wind or earthquake to the extent that the forces constitute an important element in structural design. In general 200m: Tall 300m: Super Tall 600m: Mega Tall TALLEST BUILDINGS LOCATION Historically tall buildings have been predominantly in North America. At the end of 2012, 74% of the 100 tallest buildings were located in Asia Courtesy CTBUH TALLEST BUILDINGS FUNCTION Historically tall buildings have been predominantly office buildings. At the end of 2012, 53% of the 100 tallest buildings were either mixed use or residential. Courtesy CTBUH TALLEST BUILDINGS MATERIALS Historically tall buildings have been predominantly in structural steel. At the end of 2012, 82% of the 100 tallest buildings were either concrete or composite. Courtesy CTBUH SECTION 03 KEY CONSIDERATIONS IN THE DESIGN OF TALL BUILDINGS STRUCTURAL DESIGN BALANCING OF NEEDS . Balancing structural needs vs. project demands is always a challenge ….….. specially for tall buildings. Others? Structural Needs Construction Constraints Architectural Vision Developers Requirements STRUCTURAL DESIGN PHILOSOPHY . Tall buildings present special challenges to design & construction. Important considerations include: Efficient structural framing systems Drift control Dynamic behavior & perceived building sway Differential shortening between vertical elements Foundation settlements Wind Engineering Parametric Modeling & Optimization (Geometry > Analysis > Design & Optimization) STRUCTURAL DESIGN PREMIUM FOR HEIGHT Short Buildings: • Generally strength governs design w 16 • Gravity loads predominant 2W Intermediate Buildings: w 2h • Strength / drift governs design W • Gravity / lateral loads h predominant Tall Buildings: M 4M • Generally drift / building motion governs design • Lateral loads predominant ARCHITECTURAL DESIRES NETT:GROSS . In a really efficient tall building, nearly 65% ~ 75% of the building’s volume is useable, whereas as in a well designed low-rise building more than 80% of the space can be sold . The structure should respect the architecture and be designed to minimise any loss of nett : gross Asia Square ~ 75% MBFC Tower 3 ~ 78% Heron Tower – 65% Ocean Financial Centre ~ 73% Swiss Re – 63% Tower 42 – 67% Shard London Bridge Tower – 71% WIND ENGINEERING DYNAMIC RESPONSE . As buildings get taller, wind-induced dynamic response starts to dictates the design . For many tall & slender buildings cross wind response starts to govern loading & acceleration . Building dynamic properties (natural frequencies, mode shapes & damping) greatly effect wind loads & accelerations V(z) = Vg (z/z )α (600m) g g Z α depends on terrain Fluctuating Wind Speed, V(z,t) Mean Wind Speed, V(z) A,B &C V Static Loads, A + Dynamic Loads B &C B &C WIND ENGINEERING INFLUENCING FORM . Thera are a number of approaches to minimize cross-wind response orientation setbacks, varying cross-section Burj Khalifa: initial force balance softened corners predictions indicated 37 milli-g accelerations at the 10 year twisting, tapering Taipei 101: 25% reduction in return period, reduced to 18 introducing porosity base moment due to change in milli-g through shape and geometry of building corners orientation changes WIND ENGINEERING CODE PRESCRIBED WIND LOADS . Shortcomings of Code Analytical Methods Limited range of shapes No aerodynamic interactions between buildings (wake buffeting, channelling) No directional effects & crosswind response Approximate treatment of torsional loads Topographic effects may not be well described Building accelerations are not addressed Can give a false sense of precision WIND ENGINEERING WIND TUNNEL TESTING . Wind tunnel testing is used to optimise & interrogate Building geometry, orientation and form Structural loads Building acceleration sensitivity studies Cladding wind pressures Pedestrian level wind environment Balconies & Terrace environments Signature Tower, Dubai One Raffles Quay MOVEMENTS DEFLECTIONS & ACCELERATIONS . Design of tall buildings is often controlled by building lateral deflection or acceleration (occupant comfort) . Lateral deflection (drift) control necessary to prevent damage to non-structural elements . Lateral acceleration control necessary to prevent annoyance to occupants from perceptible building motions . Careful considerations required