DETERMINATION OF LATERAL BEHAVIOUR OF FRAMED TUBE STRUCTURES AND COMPARISION WITH CONVENTIONAL SHEAR WALL STRUCTURES BY L M V KANCHANA DEPARTMENT OF CIVIL ENGINEERING UNIVERSITY OF MORATUWA SRI LANKA DETERMINATION OF LATERAL BEHAVIOUR OF FRAMED TUBE STRUCTURES AND COMPARISION WITH CONVENTIONAL SHEAR WALL STRUCTURES THESIS IS SUBMITTED TO THE DEPARTMENT OF CIVIL ENGINEERING OF UNIVERSITY OF MORATUWA, FOR THE PARTIAL FULFILMENT OF THE DEGREE OF MASTER OF ENGINEERING IN STRUCTURAL ENGINEERING DESIGN By L M V Kanchana Supervised by Prof M T R Jayasinghe DEPARTMENT OF CIVIL ENGINEERING UNIVERSITY OF MORATUWA SRI LANKA December 2010 i DECLARATION I hereby declare that the content of this thesis is the output of original research work carried out at the Department of Civil Engineering, University of Moratuwa. Whenever the work done by others was used, it was mentioned appropriately as a reference. L M V Kanchana ii ABSTRACT Even today, only a very few number of tall buildings are available in Sri Lanka, compared to other countries in the world. However with increase in population and due to the limited space availability the latest trend is to spread buildings vertically than laterally. Nowadays, there is a much greater demand for taller buildings relative to the past. After concrete was introduced to construction world, it gained many improvements within a short time period and because of that concrete buildings spread all over the world. Due to the higher strength ranges that can be achieved by good quality concrete, the section dimensions of members in concrete buildings have reduced drastically in the recent past. The increase in height accompanied with the reduced member sizes formed slender buildings, which require more attention focused on the lateral stability of the building. This problem was however solved by the introduction of various efficient structural forms such as shear walls, shear cores, outriggers, framed tube, etc. in to the building skeleton. The lateral behaviour of framed tube substructure and conventional shear wall structure is observed in this research to a certain extent. 40, 35, 30, 25 and 20 storey framed tube buildings are analysed for different lateral load combinations. The same scenario is carried out for conventional shear wall structure. Mainly the deflection, wind induced acceleration and fundamental period due to lateral loads are observed and analysed. The frame tube structures give 50% reduction in deflection and wind induced acceleration. iii ACKNOWLEDGEMENT My sincere thanks to the project supervisor Prof. M. T. R. Jayasinghe, for devoting his valuable time in guiding me to complete the research study. It is no doubt that without his interest and guidance this would not have been a success. He not only provided direction and guidance through the course of this research, but also inspired me to really learn and understand structural engineering. I wish to thank the Vice Chancellor, Dean of the Faculty of Engineering and Head of the Department of Civil Engineering of the University of Moratuwa, for the permission granted for this research work. Further, I wish to offer my thanks to the Co-ordinator of the Post Graduate research work of Structural Engineering and all the lecturers and staff of the Department of Civil Engineering who helped me in numerous ways. Also I wish to thank the librarian and the staff of the library for the co-operation extended to me for this research work. I am particularly indebted to Eng. A S B Edirisinghe, Managing Director of Anuruddha Edirisinghe Associates, for the encouragement and support given me to success this research work and to prepare this thesis during the period of research. Whole hearted thanks to my husband for the encouragement given from the beginning of the research. The final acknowledgement is to all others helped in various ways for completing the work. iv CONTENTS Declaration i Abstract ii Acknowledgement iii Contents iv List of Figures ix List of Tables xi Chapter 1 Introduction 1.1 General 1 1.2 Objectives 3 1.3 Methodology 3 1.4 Main findings 3 1.5 An overview of the thesis 3 Chapter 2 Literature review 2.1 General 5 2.2 Structural forms 6 2.2.1 Rigid-frame structures 11 2.2.2 Braced frame structures 11 2.2.3 Infilled-frame structures 12 2.2.4 Flat-plate, flat-slab and columns structures 13 2.2.5 Shear wall structures 14 2.2.6 Wall-frame structure 15 2.2.7 Outrigger-braced structures 15 2.2.8 Tube structures 16 2.2.9 Core structures 18 2.2.10 Hybrid structures 18 2.2.11 Height to width ratios of high rise buildings 19 2.3 Structural stability 19 2.3.1 Recommended values 19 v 2.3.2 Drift constraints 20 2.4 Loads on structures 21 2.4.1 Wind loads on structures 21 2.4.2 Human tolerance to wind action 22 2.4.3 Human perception of building motion 23 2.4.4 Perception thresholds 23 2. 5 Structural analysis by software SAP 2000 version 12 24 2.6 Verification of SAP 2000 software by modelling a 10 storey frame and drift calculation 25 2.7 Summary 28 Chapter 3 Structural arrangements and loads applied for case study 3.1 General 30 3.2 Layout of structure 30 3.2.1 Vertical Circulation of the building 30 3.2.2 Service Core and Shear Walls 31 3.2.3 Floor loads 31 3.2.4 Initial member sizing 32 3.3 Material properties of the structure 32 3.3.1 Concrete 32 3.3.2 Reinforcement 33 3.4 Loading to be applied on the structures 33 3.4.1 Dead and Imposed (Live) loads 33 3.4.2 Lateral loads 33 3.4.2.1 Selection of wind speed for high rise buildings in Sri Lanka 34 3.4.2.2 Wind load calculation 35 3.5 Structural forms for case study 35 3.5.1 40 Storeyed building modelled with perimeter tube (Model No 01:- 40 TUBE) 35 3.5.2 40 Storeyed building modelled without perimeter tube (Model No 02:- 40 SHEAR) 38 vi 3.5.3 35 Storeyed building modelled with perimeter tube (Model No 03:- 35 TUBE) 41 3.5.4 35 Storeyed building modelled without perimeter tube (Model No 04:- 35 SHEAR) 44 3.5.5 30 Storeyed building modelled with perimeter tube (Model No 05:- 30 TUBE) 46 3.5.6 30 Storeyed building modelled without perimeter tube (Model No 06:- 30 SHEAR) 49 3.5.7 25 Storeyed building modelled with perimeter tube (Model No 07:- 25 TUBE) 51 3.5.8 25 Storeyed building modelled without perimeter tube (Model No 08:- 25 SHEAR) 53 3.5.9 20 Storeyed building modelled with perimeter tube (Model No 09:- 20 TUBE) 55 3.5.10 20 Storeyed building modelled without perimeter tube (Model No 10:- 20 HEAR) 58 3.6 Summary 60 Chapter 4 Computer modelling and case study 4.1 Computer modelling 61 4.2 Load cases and combinations 61 Chapter 5 Results and observation 5.1 40 storey building 63 5.1.1 Deflection 63 5.1.2 Natural period of frequency and fundamental period 64 5.1.3 Wind induced acceleration 64 5.1.4 Summary of analysis result 64 5.2 35 storey building 65 5.2.1 Deflection 65 5.2.2 Natural period of frequency and fundamental period 66 5.2.3 Wind induced acceleration 66 vii 5.2.4 Summary of analysis result 66 5.3 30 storey building 67 5.3.1 Deflection 67 5.3.2 Natural period of frequency and fundamental period 68 5.3.3 Wind induced acceleration 68 5.3.4 Summary of analysis result 68 5.4 25 storey building 69 5.4.1 Deflection 69 5.4.2 Natural period of frequency and fundamental period 70 5.4.3 Wind induced acceleration 70 5.4.4 Summary of analysis result 70 5.5 20 storey building 71 5.5.1 Deflection 71 5.5.2 Natural period of frequency and fundamental period 72 5.5.3 Wind induced acceleration 72 5.5.4 Summary of analysis result 72 5.6 Summary 73 Chapter 6 Conclusion and future work 6.1 Conclusion 74 6.2 Future work 75 References 76 Appendices Appendix A A.1 Calculations – Selection of structural dimensions of 40 storeyed building 78 A.2 Calculations – Selection of structural dimensions of 35 storeyed building 80 A.3 Calculations – Selection of structural dimensions of 30 storeyed building 82 viii A.4 Calculations – Selection of structural dimensions of 25 storeyed building 84 A.5 Calculations – Selection of structural dimensions of 25 storeyed building 85 Appendix B B.1 Calculations – Determination of number of lifts 87 B.2 Calculations – Sizing of stairway 89 Appendix C Wind load calculation 90 ix List of figures Figure 2.1 Structural systems for concrete buildings 8 Figure 2.2 Interior Structural Forms in High Rise Buildings 9 Figure 2.3 Exterior Structural Forms in High Rise Buildings 10 Figure 2.4 Flat slabs with drop panels and shear walls 13 Figure 2.5 Flat slabs with drop panels and shear walls 13 Figure 2.6 Shear Wall-Frame Interactions 14 Figure 2.7 Exterior braced tube: (a) schematic elevation; (b) plan 18 Figure 2.8 Moment resisting frame with lateral loads 25 Figure 2.9 SAP analysis window of the moment resisting frame 27 Figure 2.10 Height vs. drift in 10 storey moment resisting frame 28 Figure 3.1 Wind zones in Sri Lnka 34 Figure 3.2 Layout of the 40 Storey building with perimeter tube 36 Figure 3.3 Layout of the 40 Storey building without perimeter tube 39 Figure 3.4 Layout of the 35 Storey building with perimeter tube 41 Figure 3.5 Layout of the 35 Storey building without perimeter tube 44 Figure 3.6 Layout of the 30 Storey building with perimeter tube 47 Figure 3.7 Layout of the 30 Storey building without perimeter tube 49 Figure 3.8 Layout of the 25 Storey building with perimeter tube 51 Figure 3.9 Layout of the 25 Storey building without perimeter tube 54 Figure 3.10 Layout of the 20 Storey building with perimeter tube 56 Figure 3.11 Layout of the 20 Storey building without perimeter tube 58 Figure 4.1 Wind directions and selected locations to get results 62 Figure 5.1 Height vs Displacement at location A for the load combination 1.2Gk+1.2Qk+1.2Wk for X direction and Y direction (Models 40 TUBE, 40 SHEAR) 63 Figure 5.2 Height vs Displacement at location A for the load combination 1.0Gk+1.4Wk for X direction and Y direction (Models 40 TUBE, 40 SHEAR) 63 Figure 5.3 Height vs Displacement at location A for the load combination 1.2Gk+1.2Qk+1.2Wk for X direction and Y direction (Models 35 TUBE, 35 SHEAR) 65 x Figure 5.4 Height vs Displacement at location A for the load combination 1.0Gk+1.4Wk for X direction and Y direction (Models 35 TUBE, 35 SHEAR) 65 Figure 5.5 Height vs Displacement at location A for the load combination 1.2Gk+1.2Qk+1.2Wk for X direction and Y direction (Models 30 TUBE, 30 SHEAR) 67 Figure 5.6 Height vs Displacement at location A for the load combination 1.0Gk+1.4Wk for X direction and Y direction (Models 30 TUBE, 30 SHEAR) 67 Figure 5.7 Height vs Displacement at location A for the load combination 1.2Gk+1.2Qk+1.2Wk for X direction and Y direction (Models 25 TUBE, 25 SHEAR) 69 Figure 5.8 Height vs Displacement at location A for the load combination 1.0Gk+1.4Wk for X direction and Y direction (Models 25 TUBE, 25 SHEAR) 69 Figure 5.9 Height vs Displacement at location A for the load combination 1.2Gk+1.2Qk+1.2Wk for X direction and Y direction (Models 20 TUBE, 20 SHEAR) 71 Figure 5.10 Height vs Displacement at location A for the load combination 1.0Gk+1.4Wk for X direction and Y direction (Models 20 TUBE, 20 SHEAR) 71 xi List of tables Table 2.1 Human perception levels 24 Table 2.2 Drift calculation results for 10 storey moment resisting frame 26 Table 2.3 Drift results from SAP 2000 analysis 27 Table 3.1 Grade of concrete and their properties, as per BS8110 33 Table 3.2 Recommended basic wind speed for Sri Lanka 34 Table 3.3 Regional wind speeds - VR (AS/NZS 1170.2: 2002) 43 Table 5.1 Natural period of frequency and fundamental period of 40 storey building 64 Table 5.2 Wind induced acceleration for 40 storey building 64 Table 5.3 Summary of Analysis Results of 40 storey building 64 Table 5.4 Natural period of frequency and fundamental period of 35 storey building 66 Table 5.5 Wind induced acceleration for 35 storey building 66 Table 5.6 Summary of Analysis Results of 35 storey building 66 Table 5.7 Natural period of frequency and fundamental period of 30 storey building 68 Table 5.8 Wind induced acceleration for 30 storey building 68 Table 5.9 Summary of Analysis Results of 30 storey building 68 Table 5.10 Natural period of frequency and fundamental period of 25 storey building 70 Table 5.11 Wind induced acceleration for 25 storey building 70 Table 5.12 Summary of Analysis Results of 25 storey building 70 Table 5.13 Natural period of frequency and fundamental period of 20 storey building 72 Table 5.14 Wind induced acceleration for 20 storey building 72 Table 5.15 Summary of Analysis Results of 20 storey building 72 Table C.1 Calculation of wind force per unit area – 40 storey building 93 Table C.2 Calculation of wind loads on grid locations as point loads in 40 storey building 95 Table C.3 Calculation of wind acceleration – 40 storey building 96 Table C.4 Calculation of wind loads on grid locations in 40 storey building (for wind acceleration) 98 xii Table C.5 Calculation of wind force per unit area – 35 storey building 99 Table C.6 Calculation of wind loads on grid locations as point loads in 35 storey building 101 Table C.7 Calculation of wind acceleration – 35 storey building 102 Table C.8 Calculation of wind loads on grid locations in 35 storey building (for wind acceleration) 104 Table C.9 Calculation of wind force per unit area – 30 storey building 105 Table C.10 Calculation of wind loads on grid locations as point loads in 30 storey building 107 Table C.11 Calculation of wind acceleration – 30 storey building 108 Table C.12 Calculation of wind loads on grid locations in 30 storey building (for wind acceleration) 110 Table C.13 Calculation of wind force per unit area – 25 storey building 111 Table C.14 Calculation of wind loads on grid locations as point loads in 25 storey building 113 Table C.15 Calculation of wind acceleration – 25 storey building 114 Table C.16 Calculation of wind loads on grid locations in 25 storey building (for wind acceleration) 116 Table C.17 Calculation of wind force per unit area – 20 storey building 117 Table C.18 Calculation of wind loads on grid locations as point loads in 20 storey building 118 Table C.19 Calculation of wind acceleration – 20 storey building 119 Table C.20 Calculation of wind loads on grid locations in 20 storey building (for wind acceleration) 121