同济大学：《高层建筑结构》课程教学资源（教案讲稿）Chapter 07 Tube System

2015/6/2 Chapter 7 Tube System Chapter 7 Tabe System 7.1 Characteristic of Tube System 728me6ygcaeuionoiFand 7.3 Design of Framed Tube System Chapter 7 Tube Structural System Characteristic Definition: Tall and rogu 100 Clos Columns and deep Office,hotel, Multiple function Burj Duba Sears Towe framed tubetube in tube braced tube 本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 1 Chapter 7 Tube System Chapter 7 Tube System 7.1 Characteristic of Tube System 7.2 Simplified Calculation of Framed Tube System 7.3 Design of Framed Tube System Chapter 7 Tube Structural System Definition： Tube system is that the perimeter of the building consists of closely spaced columns connected by deep spandrels. The system works quite efficiently as a hollow vertical cantilever wall. There are: framed tube, braced tube, tube in tube, and, bundled tube. Characteristic  Tall and regular the height large than 100m, aspect ratio less than 1:2.5  Closely perimeter Columns and deep beams  Internal space: Large and clear  Office, hotel, Multiple function International Futong Tower Bank of Communication framed tube tube in tube braced tube Sears Tower bundled tube Burj Dubai 本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 Different Types of inner tube systems Characteristic of frame tube In its simplest terms,a framed tube can be defined 向国田用向由回 oined by deep spandrelgirders. varying from about 0.90 to 1.5 m(3 to5f). Characteristics of frame tube Behavior:Shear Lag 30 Fame Behavior:Shear Lag 本课件版权归作者所有，仅供个人学习使用，请勿转载。 2

2015/6/2 2 Different Types of inner tube systems (a) Frame tube (b) Tube with cantilever slabs (c) Tube with bottom truss (e) braced tube (side or exterior braces) (d) Tube with top truss and hanging columns Characteristic of frame tube  In its simplest terms, a framed tube can be defined as a three-dimensional system that engages the entire building perimeter to resist lateral loads. A necessary requirement to create a wall-like three￾dimensional structure is to place columns on the building exterior relatively close to each other, joined by deep spandrel girders.  In practice, columns are placed 4m (10 ft) to as much as 6.1m (20 ft ) apart, with spandrel depths varying from about 0.90 to 1.5 m (3 to 5 ft ). Characteristics of frame tube Behavior : Shear Lag Behavior : Shear Lag Behavior : Shear Lag each successive interior column will experience a smaller deformation and hence a lower stress than the outer ones. 本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 Behavior:Shear Lag Behavior:Shear Lag columns will be less. The stresses in the inner columnslag behind those in he omer hence eteshg Behavior:Shear Lag Load-Carry Because of the effects o and strength of thestructure nurve of the tube is mainly bending 0 Solution? Load-Carrying Characteristics of Limit Height of Tube Horizontal Strengthened Storey Height of Grade A: non-seismic200 m Height of Grade B system,which can decrease the storey drift and the top drift nete 本课件版权归作者所有，仅供个人学习使用，请勿转载。 3

2015/6/2 3  The stresses in the corner column will be greater than those from a pure tubular action, and those in the inner columns will be less.  The stresses in the inner columns lag behind those in the corner columns, hence the term shear lag.  Because the column stresses are distributed less effectively than in an ideal tube, the moment resistance and the flexural rigidity of a tubular building are much less. Behavior : Shear Lag  Dash line: ideal tube  Solid line: Framed tube Behavior : Shear Lag  Because of the effects of shear lag, it does not fully utilize the potential stiffness and strength of the structure, although a framed tube is highly efficient, Behavior : Shear Lag  Because of the effects of shear lag, it does not fully utilize the potential stiffness and strength of the structure, although a framed tube is highly efficient. Solution? Load-Carrying Characteristics of Inner Tube  The RC shear-walls form a closed inner tube located in the core region;  At the bottom of the structure, the inner tube carries large shear force, which causes that the deformation curve of the tube is mainly bending deflection;  The moment caused by lateral loads of the inner tube is comparatively small; Load-Carrying Characteristics of Horizontal Strengthened Storey  Horizontal strengthened storey is the storey with outriggers or belt mega-beams. These floors are mainly used as equipment floors with less available space.  The function of strengthened storey is to connect the inner tube and the outer tube to form a huge anti-lateral loads system, which can decrease the storey drift and the top drift.  Restrain and coordinate the deformation of the frame-tube and the core tube and eliminate the buckling of the slab. Limit Height of Tube Height of Grade A: non-seismic  200 m, 7 degree  150 m, 8 degree  120 m; Height of Grade B: Tube-in-tube, Frame core-tube non-seismic  220 m, 7 degree  180 m, 8 degree  140 m; 本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 Limit Displacement of Tube 7.2 Simplified Calculation of Tube 3D finite element caloulation Spatial linkage-thin-column matrix displacement metho Plane expansion displacement method Equivalent elastic continuous physical volume method 口Finite sliced method 7.3 Basic requirements of Design Design of spandrel beam h and hight-o V.≤0.25Bfh,h0 2)earthquakes g2nao a K≤'(O15Rfhh Tie beam of Frame-tube Shear Capacity of spandrel Beam 4点 sadonmtcamgo Earthquakes: 4 ≤07Au+人兰u 2)Earthquakes 丁 50+听 本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 4 Limit Displacement of Tube  Limit of displacement: RC shear-wall: elastic storey drift angle  1/1000 elasto-plastic drift angle  1/120 7.2 Simplified Calculation of Tube  3D finite element calculation  Spatial linkage-thin-column matrix displacement method  Plane expansion matrix displacement method  Equivalent elastic continuous physical volume method  Finite sliced method 7.3 Basic requirements of Design  Building height should not be less than 60m, and height-to￾width ratio should not be less than 3;  Concrete strength grade >=C30  Transfer beam should be arranged when columns are discontinuous in adjacent storey, and beam depth should be larger than L/6  Rebars should be arranged in two directions with two layers at outer corner of floor slabs  Ratio and diameters of rebars wall should meet the minimum requrement.  Tie beams, especially tie beams of outer frame-tubes, must meet the minimum requirements of shear section. Design of spandrel beam  Requirement of the minimum section： ： 1） No earthquakes ： 2） earthquakes ： shear span ratio >2.5： shear span ratio 2.5 span-depth ratio <=2.5 . sv w t b b0 yv b0 A V 0 7 f b h f h s   ( . ) sv b t b b0 yv b0 RE 1 A V 0 42 f b h f h  s   ( . . ) sv b t b b0 yv b0 RE 1 A V 0 38 f b h 0 9 f h  s   本课件版权归作者所有，仅供个人学习使用，请勿转载

2015/6/2 Design of Outer Frame-Tube Column Design of Outer Frame-Tube Column (thin-wall column) (thin-wall column) Space of columns should not be larger than 4m: Maximum axial force ratio requirement the long side of column's section should be arranged in the according to the frame-wall structure tube-wall direction,and if necessary,T-section beam can be selected; .Requirement of the minimum section: Areas of openings should not be larger than 60%of wall, 1)No earthquakes: V≤0.25 Bfbho Height-to-width ratio of openings should be close to the ratio of storey height to column space: 2)Earthquakes: Area of section of the corner column should be 1 to 2 times shear span ratio >2.5: K≤1(0.20Bfho) of the inner columns. YRE shear span ratio<=2.5: ≤ 0.15B.f.b.h.o)- YRE Design of Wall of Core Tube length of inner tube is suggested as 1/15 to 1/12 and 1/12 of its height for tube-in-tube and frame-tube system respectively. .Wall Openings should not be continuous in horizontal direction.The space should be larger than 1.2m.And the depth-thickness ratio of wall section should be larger than 3. Determine the Reinforced Area of walls Design of Boundary Elements Limits of Axial Force Ratio 宽.How to do .A Tall Building,Height=200m,58 stores,located in 7 degree seismic zone,used as office building. Final Test Time:18:30 Please determine and the main lateral resistant system,materials and the size of these elements. June23,2015 Room:B504 Please try to design it. Question and Suggestion 本课件版权归作者所有，仅供个人学习使用，请勿转载。 5

2015/6/2 5 Design of Outer Frame-Tube Column (thin-wall column)  Space of columns should not be larger than 4m；  the long side of column’s section should be arranged in the tube-wall direction, and if necessary, T-section beam can be selected;  Areas of openings should not be larger than 60％ of wall, Height-to-width ratio of openings should be close to the ratio of storey height to column space；  Area of section of the corner column should be 1 to 2 times of the inner columns. Design of Outer Frame-Tube Column (thin-wall column)  Maximum axial force ratio requirement ： according to the frame-wall structure  Requirement of the minimum section： 1） No earthquakes: 2） Earthquakes: shear span ratio >2.5： shear span ratio<=2.5： . V 0 25 f b h w  c c c c0 ( . ) w c c c c0 RE 1 V 0 20 f b h    ( . ) w c c c c0 RE 1 V 0 15 f b h    Design of Wall of Core Tube  length of inner tube is suggested as 1/15 to 1/12 and 1/12 of its height for tube-in-tube and frame-tube system respectively.  Wall Openings should not be continuous in horizontal direction. The space should be larger than 1.2m. And the depth-thickness ratio of wall section should be larger than 3.  Determine the Reinforced Area of walls  Design of Boundary Elements  Limits of Axial Force Ratio  How to do it?  A Tall Building, Height = 200m, 58 stores, located in 7 degree seismic zone, used as office building.  Please determine and the main lateral resistant system , materials and the size of these elements.  Please try to design it.  Question and Suggestion ? Final Test Time：18:30 June 23，2015 Room：B504 本课件版权归作者所有，仅供个人学习使用，请勿转载