Chapter 5 Chapter 5 5.1 Bulling asfionandmic forification 5.2 Seismic conceptual design Earthquake Effect and 5.3 Calculation Methodoogy ofsmio Seismic Design principles Configuration Conceptual Design Simpliciry Regularity quirem nts Symmetn Integral Construction Redundancy Objective 贤 度度 -tesdh design methodology 2 Structural detall 器敲盘 Return period (yr)50 475 2475
1 Chapter 5 Earthquake Effect and Seismic Design principles 5.1 Building classification and seismic fortification 5.2 Seismic conceptual design 5.3 Calculation Methodology of seismic action 5.4 Seismic Check of structural members and structural lateral deformations Chapter 5 Review Seismic Conceptual Design Simplicity Regularity Symmetry Integral Construction Redundancy 3 Review Configuration n Configuration characteristics and their effects n Configuration Regularities and Irregularities n Essentials of structural systems for seismic resistance Requirements n Structural Materials n Structural Systems n Connections n Details Review Objective Level 1 Level 2 Level 3 minor earthquake level moderate earthquake level major earthquake level 1) Elastic force 2) Elastic deformation (Stage 1) Structural detailing 1) Elastoplastic deformation (Stage 2) “two-stages and three-levels seismic design methodology” Review Return period (yr) 50 475 2475 Review
Chapter 5 ng00 2.The woanmn Calculation Methods , Seismic Influnce Coefficient Curve When 0.1 <T,<T, When T,T.57, Characteristic Pariods (s)
2 Chapter 5 Building classification and seismic fortification Review 5.3 Calculation Methodology of seismic action Based on the National Code of Seismic design for the Buildings (GB 50011-2010) 5.3.1 General Requirements 1. Seismic calculations should be performed in two directions of the structures; 2. The elements located in the diagonal with the main resistant systems ( angle larger than 15 degrees), should be considered in two directions; 3. If the system with obviously unsymmetrical distribution of mass and stiffness, the torsion effects should be considered; 4. the structures with large spans, long cantilever beams in the 8 or 9 degree areas, or high-rise buildings in the 9 degree areas should be considered of vertical earthquake effects. Calculation Methods n The Response Spectrum Method (RSM) for MDOF System n The Base Shear Method (BSM) for regularity structures with the height is less than 40m n The Time history method (THM) for dynamic analysis of structures, used for the buildings like: in the site of 7,8 and I,II, and with height large than 100m, or in the site of 8 and III, and with the height large than 80m, or in the site of 9 and with the height large than 60m, Seismic Influnce Coefficient Curve GB 50011-2010, Fig. 5.1.5 Seismic Influence Coefficient amax Rare Eq. 0.28 0.50/0.72 0.90/1.20 1.40 Frequently Eq. 0.04 0.08/0.12 0.16/0.24 0.32 Intensity 6 7 8 9 Characteristic Periods（s） 3 0.35 0.45 0.65 0.90 rd Group 2 0.30 0.40 0.55 0.75 nd Group 1 0.25 0.35 0.45 0.65 st Group Site Category I 0 I 1 II III IV 0.20 0.25 0.30 Seismic Influnce Coefficient Curve 2 max g g i T T When T T 5 a h a g = × < < （ ） ： T g 2 1 max i [ 0.2 ( 5 )] When : 5Tg T 6.0 a h h a g T T g s = × × × - < < 2 max 0 Ti When .1 a = h a ： < < Tg
Seismic Influnce Coefficient Curve How to simplify the real building toamodel? The Power Index of the curvilnear decrease sectio In two main direction.Some time sdir.And Ydi 7=0.9+8i of declined slope %=1+80流205 BSM Assumption tical and F1-8 G Efficient Weight RSM 1.Without Torsion vibration For SDOM.G-G .For MDOM.G G,? and Based on G:Represent Weigkt G,=Gu+Lw w(T Bunch or balls
3 Seismic Influnce Coefficient Curve The Adjusting coefficient of declined slope . . . 0 05 0 9 0 3 6 x g x - = + + .0 .0 1 0 5 0 2 4 32 x h x - = + + .0 .0 . 2 0 5 1 0 8 1 6 x h x - = + + The Power Index of the curvilinear decrease section: The damping adjusting factor h2 ³ 0.55 and How to simplify the real building to a model? In two main direction. Some time is X dir. And Y dir. 框架梁 框架梁 框架梁 框架梁 框架柱 PKPM 3D model Simplification of regular structure. 质量 刚度 X 向 X 向 Kx m 质量 刚度 Y 向 Y 向 Ky m BSM Assumption： Regularity in vertical and plan； Height less than 40m； First mode shape is in dominant; High modes effects are concerned。 n n Ek n Ek n j j j i i i Ek eq F F F G H GH F F G d d a D = = - = å= (1 ) 1 1 Geq Efficient Weight n For SDOM, n For MDOM, Geq i =0.85 G n i å Geq 1 =G G i ? Gi Represent Weight Gi =Gki+ L ji ki Live Load combination factor roof loads: 0.0 or 0.5 or 1.0 For floor loads: 0.5 or o.8 hook loads: 0.0 or 0.3 ( Table 5-4) ji RSM q Important and dominant； q Based on Elastic response spectra analysis q Used for elastic structure q Plan regularity q Bunch or balls 1. Without Torsion vibration
Combination of modes Combination of modes ·SRSs ·cac F.=aX.G. sa-oas,s. 8561+2以 P0-T+4k6+广方 ar ofthndtmode With Torsion vibration Only under X dir.Eq. 入 工x,0, 旧 ++8 Bunch of plates Fo=.X,G Fn=《,y,YG =a,yrpG .Undor two directions excited How many modes should be composed?Tota? Combination of two dirction t Sa=5:+0.53,厅 how角any Sm=5+(0.85S,)月 地0
4 Combination of modes § SRSS å å å = = = = = 2 1 2 1 Ek j n i ji i n i ji i j ji j j ji i S S X G X G F X G g a g Combination of modes § CQC å å= = = m j m k S Ek jk S j S k 1 1 r T j k T T j k T T jk l z z l l z z l l r 2 2 2 1.5 (1 ) 4 (1 ) 8 (1 ) - + + + = － coupling factor of i-th and j-th mode . rjk With Torsion vibration q Plan irregularity q Torsion should be concerned carefully q Bunch of plates What’s different between regular and irregular structure? O n ly und e r X d ir. E q . ( ) O n ly und e r Y d ir. E q . ( ) W ith a n a n g le o f θ to X D ir. E q . c o s sin n ji i i 1 tj n 2 2 2 2 ji ji ji i i i 1 n ji i i 1 tj n 2 2 2 2 ji ji ji i i i 1 tj x j yj X G X Y r G Y G X Y r G g f g f g g q g q = = = = = + + = + + = + å å å å tji j tj i ji i Yji j tj ji i Xji j tj ji i F r G F Y G F X G a g j a g a g 2 = = = tj g 2 2 2 2 ( 0 .85 ) ( 0 .85 ) Ek y x Ek x y S S S S S S = + = + n Under two directions excited Combination of two direction excited 1 0.85 How many modes should be composed? The numbers should satisfy that the 90% mass are participant in the vibration. According to some rules, based on the codes or on the required of engineering needed. Total? How many?
THM k THM 三一峰 Tabh512-2eoa辅emp0 aik vele【Gmk力 Vertical Earthquake Action Vertical Earthquake Action To High rise buildie F=G m 0.752 1=0.100.20 Base Shear Force nd structura a-2型 Strength-Capacity The Minimum Base Shear Force Displaceme 00602/02
5 THM 1. Dynamic analysis 2. Elastic THM 3. Elasto-plastic THM Table 5.1.2-2 acceleration peak velue（cm/s2） Intensity 6 7 8 9 Frequently Eq. 18 35/55 70/110 140 Rare Eq. 125 125/220 400/510 620 -0.20 -0.10 0.00 0.10 0.20 10 12 14 16 18 20 22 24 26 28 30 时间(s) 加速度(g) 结构反应记录 一层反应 -0.20 -0.10 0.00 0.10 0.20 10 12 14 16 18 20 22 24 26 28 30 时间(s) 加速度(g) 地面振动记录 台面输入 Responses record Ground motion record Vertical Earthquake Action To High rise building § Regularity in vertical and plan； § First mode shape is in dominant; § Vertical Eq. response spectra almost same to Horizontal Eq. § But, the peak value is 65% of H.Eq. v v,max v v i 1 v,max H,max 0.65 E k eq i i i n E k i i F G GH F F GH a a a = = = = å Geq i =0.75 G n i å Gi Gj Gn Hi Hj FEvk Fvn Fvj Vertical Earthquake Action To Long cantilever beam and the other large span structures Regularity in plan； First mode shape is in dominant; F G vi =lEv i lEv =0.10~0.20 Gi Gj Gn Hi Hj FEvk Fvn Fvj 5.4 Seismic Check of structural members and structural lateral deformations n Strength —— Capacity n Displacement —— Ductility Base Shear Force i n Eki j j V G l = The Minimum Base Shear Force > å 类别 6 7 8 9 Obviously Torsion and T1 less than 3.5s 0.008 0.016/0.024 0.032/0.048 0.064 T1 less than 3.5s only 0.006 0.012/0.024 0.024/0.036 0.048 j i = F n Eki j V = å