結(jié)構(gòu)動力學(xué)及橋梁的耐震性能評價

1、結(jié)構(gòu)動力學(xué)橋梁的耐震性能評價江西理工大學(xué)江西理工大學(xué)2014年 5月22日Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.spring dashpot mass SDOF struct

2、uresCopyright 2000-2003 MIDAS Information Technology Co., Ltd.自由度 ?靜力超靜定次數(shù) = 5個構(gòu)件 + 9個反力 + 4個剛節(jié)點 2x6個節(jié)點 = 6次超靜定動力超靜定數(shù) = 可能發(fā)生位移的節(jié)點數(shù)(6個節(jié)點)x3(每個節(jié)點的位移數(shù)) 3x3 反力數(shù) = 9次超靜定. 9 自由度動力超靜定次數(shù) = 每個節(jié)點可生成的節(jié)點位移方程數(shù) 已知的方程數(shù)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.) t (pkuucum Inertia Force kufS ucfD um

3、fI Damping Force Restoring Force Copyright 2000-2003 MIDAS Information Technology Co., Ltd.噪音與振動標準地震規(guī)模和等級Copyright 2000-2003 MIDAS Information Technology Co., Ltd.靜力荷載Dead Load,Live Load, Permanent Load, Slowly Varying Load 動力荷載Harmonic,Periodic,Transient,ImpulsiveMachine OperationMachine OperationH

4、uman MotionWindWindWater WavesEarthquakeRail and Road TrafficConstruction WorksConstruction WorksImpactBlast Wave ExplosionLoss of SupportCopyright 2000-2003 MIDAS Information Technology Co., Ltd.-正弦波(sinusoidal wave), 三個參數(shù): 振幅、頻率、位相角-振幅: A peak to peak amplitude = 2A-均方根(roof means square: RMS) = A

5、/ : 用于表現(xiàn)復(fù)雜波形的振幅2最大值正弦波的運動Copyright 2000-2003 MIDAS Information Technology Co., Ltd.- 寬帶隨機振動不規(guī)則振動的表現(xiàn)方式Mean ValueRMS Value (Root-Mean-Square Value)Standard Deviation最大值寬帶(隨即)波時間Copyright 2000-2003 MIDAS Information Technology Co., Ltd.- Amplitude : PGA, EPA- Duration : spectrum intensity, total energy

6、- Frequency ContentsCopyright 2000-2003 MIDAS Information Technology Co., Ltd.FFT快速傅立葉轉(zhuǎn)換Transient LoadEl Centro (NS, 1940) 每個信號均可表現(xiàn)為多個正弦波的和將測試的信號通過測試裝置隨時做傅立葉轉(zhuǎn)換 時間參數(shù) 頻率參數(shù)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-

7、2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.) t (p)u, u(fsucum kufS )u, u(fS Inelastic System inelasticelasticloading unloading reloadingResisting Force ) t (pkuucum Elastic System Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Damp

8、ing Force ) t (pkuucum Aluminum Plexiglass阻尼是隨著時間將振動減弱或停止的能量擴散Viscous DamperCopyright 2000-2003 MIDAS Information Technology Co., Ltd.Damping Force ) t (pkuucum ucfD 速度和阻尼力的關(guān)系能量原理HDSKIEEEEE Copyright 2000-2003 MIDAS Information Technology Co., Ltd.HDSKIEEEEE 能量原理SKEE DEHECopyright 2000-2003 MIDAS In

9、formation Technology Co., Ltd.HDSKIEEEEE SKEE DE彈性非彈性HE彈性能非彈性能能量原理Copyright 2000-2003 MIDAS Information Technology Co., Ltd.umff) t (pDS Newtons Second Laws of MotionsInertia Force 慣性力: 做加速運動的慣性體系內(nèi) 與物體加速度方向相反的假想力) t (pkuucum 靜止/勻速運動加速度運動達朗波特原理 (D Alemberts Principle)行進方向Copyright 2000-2003 MIDAS Inf

10、ormation Technology Co., Ltd.2fCopyright 2000-2003 MIDAS Information Technology Co., Ltd. 墨西哥地震(1985)墨西哥城350 kmCopyright 2000-2003 MIDAS Information Technology Co., Ltd. 墨西哥地震(1985)Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 墨西哥地震(1985)Copyright 2000-2003 MIDAS Information Technology

11、Co., Ltd.A 地震 : 低周期(高頻率)地震 : 支配振動周期=0.5秒 巖石地基、近震、高頻振動、低層建筑受害較重B 地震 : 高周期(低頻)地震 : 支配振動周期=5秒 軟弱地基、遠震、低頻振動、高層建筑受害較重Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Free body Diaphragm ) t (u) t (u) t (ugt - 集中質(zhì)量的慣性力與包含地基運動影響的絕對加速度成比例- 阻尼力與結(jié)構(gòu)地基的相對速度成比例- 彈性恢復(fù)力與地基的相對位移成比例0kuuc)uu(mg effective ear

12、thquake force : horizontal ground motion0)uu(k)uu( cumggt Absolute DisplacementRelative Displacementgumkuucum 地基加速度 : 測量Copyright 2000-2003 MIDAS Information Technology Co., Ltd.1. Classical Methodgumkuucum ) t (pkuucum ) t (u) t (u) t (uPC )t (u)t (u)t (uPC k/ptwsinBtwcosA) t (u0nn or二階線性微分方程2. Duh

13、amels Integral將外力視為由時間間隔非常短的沖擊荷載組成的結(jié)構(gòu)反應(yīng)為對各沖擊荷載反應(yīng)之和Response to impulse 1Response to impulse 2Response to impulse Total ResponseCopyright 2000-2003 MIDAS Information Technology Co., Ltd.4. Numerical Method當外荷載不是周期性荷載時，使用傅立葉變換，用傅立葉積分表示可適用于彈性和非彈性領(lǐng)域, Numerical time stepping methodDirect integration metho

14、d : Wilson- , Newmark- 5. Frequency-Domain Method1/2,1/41/2,1/61平均加速度法 與時間步長無關(guān)，始終收斂1.4/10ntT Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 2 40kuum nnnnnf2,f12T .6,4,2t 2Copyright 2000-2003 MIDAS Information Technology Co., Ltd.0kuucum 0uu2u2nn critical damping coefficientCopyright 2000

15、-2003 MIDAS Information Technology Co., Ltd.0kuucum 0uu2u2nn 0u)m/k(u)m/c (u m/k2 m/cn2 0uun2u2 rtAeu 0rn2r2 mk)m2c(m2cnnr222 mk)m2c(2mk)m2c(2 mk)m2c(2過阻尼: 隨時間振幅祖逐漸衰減，門的衰減裝置隨時間振幅祖逐漸衰減，門的衰減裝置低阻尼: 自然界大部分的動力系統(tǒng)，以特有的頻率振動自然界大部分的動力系統(tǒng)，以特有的頻率振動臨界阻尼: 不做振動的最小的阻尼，根據(jù)初始條件可能發(fā)生振動。不做振動的最小的阻尼，根據(jù)初始條件可能發(fā)生振動。Copyright 2

16、000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Decay of motionCopyright 2000-2003 MIDAS Information Technology Co., Ltd.Logarithmic decrementCopyright 2000-2003 MIDAS Information Technology Co., Ltd.Half-power bandwidthCopyright 2000-2003 MID

17、AS Information Technology Co., Ltd.tsinpkuum0 Non-homogeneous Solutioncomplementary solution, homogeneousparticular solutionCopyright 2000-2003 MIDAS Information Technology Co., Ltd.tsinpkuucum0 Copyright 2000-2003 MIDAS Information Technology Co., Ltd.承受諧振荷載的單自由度結(jié)構(gòu)的非衰減反應(yīng) (a) 自由振動 (b) 正常狀態(tài) (c) 總反應(yīng)承受

18、諧振荷載的單自由度結(jié)構(gòu)的衰減反應(yīng) (a) 自由振動 (b) 正常狀態(tài) (c) 總反應(yīng)Undamped Free-VibrationDamped Free-VibrationSteady-StateSteady-StateCopyright 2000-2003 MIDAS Information Technology Co., Ltd.IF, frequency ratio )TT.,e . i (1/nn Force is “slowly varying” Rd is only slightly larger than 1 and is essentially independent of d

19、ampingkp)u(u00st0 controlled by the stiffness of the system 荷載頻率變小時, 位相角趨近于0: 與荷載方向相同Slowly varying, in phaseCopyright 2000-2003 MIDAS Information Technology Co., Ltd. 荷載頻率增加, 位相角趨近于180度: 與荷載方向相反Rapid varying, out of phaseIF, frequency ratio )TT.,e . i (1/nn Force is “rapidly varying” Rd tends to ze

20、ro as w/wn increases and is essentially unaffected by damping. 2022n0st0mp)u(u controlled by the mass of the systemCopyright 2000-2003 MIDAS Information Technology Co., Ltd.IF, frequency ratio 1/n Rd is very sensitive to dampingn00st0cp2)u(u controlled by the damping of the systemForcing frequency =

21、 natural frequencyCopyright 2000-2003 MIDAS Information Technology Co., Ltd.動力分析時的最大位移靜力分析時的最大位移荷載和結(jié)構(gòu)的頻率比，動力放大系數(shù)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.IF, frequency ratio 1/n Rd is very sensitive to dampingn00st0cp2)u(u controlled by the damping of the system結(jié)構(gòu)的共振現(xiàn)象(SDOF)Copyright

22、 2000-2003 MIDAS Information Technology Co., Ltd.f22 f/1/Tbeating 結(jié)構(gòu)物自振頻率為20Hz, 動力荷載的頻率為19.8Hz時，拍音周期為 T=1/(20-19.8)Hz=5(sec)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.二層剪切變形框架體系的動力方程式Copyright 2000-2003 MIDAS Information Techno

23、logy Co., Ltd.當沒有外力和阻尼時，自由振動的二自由度體系的運動方程式 特征值問題 :固有圓頻率向量模態(tài)向量Copyright 2000-2003 MIDAS Information Technology Co., Ltd.解以上動力方程的自振周期和模態(tài)向量解的二次方程Copyright 2000-2003 MIDAS Information Technology Co., Ltd.計算模態(tài)向量:Copyright 2000-2003 MIDAS Information Technology Co., Ltd.n個自由度體系的n個自振頻率和模態(tài)向量:模態(tài)質(zhì)量矩陣和剛性矩陣的關(guān)系:各

24、特征向量之間滿足正交條件。即，時利用模態(tài)向量的正交性，可生成對角線的質(zhì)量矩陣和剛度矩陣Copyright 2000-2003 MIDAS Information Technology Co., Ltd.歸一化的質(zhì)量矩陣歸一化的剛度矩陣根據(jù)模態(tài)的正交特性 且以上公式將耦聯(lián)的n個自由度體系的動力方程分解為獨立的n個單自由度體系Copyright 2000-2003 MIDAS Information Technology Co., Ltd.將位移u用q來表現(xiàn)，將兩邊用Mn來除，外力項按下面公式，將單自由度體系用D(t)來解，由此可將模態(tài)方程的解用來求。Copyright 2000-2003 MID

25、AS Information Technology Co., Ltd.外力項(模態(tài)參與系數(shù))(有效模態(tài)質(zhì)量)分析時需要滿足Copyright 2000-2003 MIDAS Information Technology Co., Ltd.模態(tài)參與系數(shù)有效模態(tài)質(zhì)量Copyright 2000-2003 MIDAS Information Technology Co., Ltd.有效模態(tài)高度Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Spectral Acceleration ( g )aCaC.520TTCvsT.T20=0

26、sTPeriod (sec)avsC./CT52= (UBC-97)設(shè)計反應(yīng)譜各模態(tài)基底剪力各模態(tài)加速度響應(yīng)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.位移響應(yīng):各模態(tài)傾覆彎矩:(二層最大位移)(一層最大位移)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.結(jié)構(gòu)的阻尼矩陣與質(zhì)量矩陣和剛度矩陣不同，很難構(gòu)成明確的矩陣比例衰減質(zhì)量比例、剛度比例按模態(tài)指定阻尼比(經(jīng)驗)- 不必構(gòu)成阻尼矩陣按模態(tài)指定阻尼比后使用于振型疊加法需要阻尼矩陣的情況非比例衰減、非古典衰減

27、體系非線性分析(直接積分法)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.模態(tài)阻尼比結(jié)構(gòu)的模態(tài)阻尼比是由規(guī)模接近的結(jié)構(gòu)在較強地震期間的響應(yīng)為基礎(chǔ)評價而得的(彈性響應(yīng))目前的資料還不是很充分Copyright 2000-2003 MIDAS Information Technology Co., Ltd.古典阻尼矩陣非古典阻尼矩陣-與質(zhì)量和剛度成比例的阻尼矩陣(比例衰減)-經(jīng)驗決定的阻尼比矩陣-使用模態(tài)向量的正交性分解阻尼矩陣-Rayleigh衰減、Caughey衰減-與質(zhì)量和剛度不成比例-設(shè)置局部阻尼器時，不能與質(zhì)量和剛度成

28、比例 - 非比例衰減體系-將局部阻尼矩陣添加到整體阻尼矩陣中Copyright 2000-2003 MIDAS Information Technology Co., Ltd.與質(zhì)量和剛度成比例的衰減與剛度不同，和質(zhì)量成比例的衰減的可靠度不高Copyright 2000-2003 MIDAS Information Technology Co., Ltd.與質(zhì)量成比例的衰減與質(zhì)量成比例衰減的體系的第n個模態(tài)的阻尼公式模態(tài)阻尼比 - 阻尼比與固有頻率成反比常數(shù) a0 - 決定特定模態(tài)(第i模態(tài))的阻尼比與剛度成比例的衰減與剛度成比例衰減的體系的模態(tài)阻尼比 - 決定常數(shù)a1阻尼比隨著固有頻率線性增

29、加決定特定模態(tài)的n - 決定常數(shù)a1Copyright 2000-2003 MIDAS Information Technology Co., Ltd.單獨的質(zhì)量比例或剛度比例衰減不適合MDF體系中。 -與實際試驗中表現(xiàn)出來的多個模態(tài)具有同樣的阻尼比的情況不一致。 - Rayleigh 阻尼(質(zhì)量比例衰減+剛性比例衰減)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.構(gòu)成與實驗結(jié)果相同的阻尼阻尼第n個模態(tài)的阻尼比用常數(shù) a0、a1求 1、 2 - 用矩陣表示阻尼矩陣 CnCopyright 2000-2003 MIDAS In

30、formation Technology Co., Ltd.第一和第二模態(tài)的阻尼: 假定為 5%決定質(zhì)量和剛度矩陣Copyright 2000-2003 MIDAS Information Technology Co., Ltd.求 a1 和 a2求阻尼矩陣求第三模態(tài)的阻尼比Copyright 2000-2003 MIDAS Information Technology Co., Ltd.考慮第2個模態(tài)以上阻尼比的阻尼矩陣使用Caughey阻尼方法前面兩項與Rayleigh阻尼相同第n模態(tài)的阻尼比系數(shù) al 由 J 個方程式?jīng)Q定(N : 結(jié)構(gòu)的自由度數(shù))Caughey阻尼的問題阻尼的問題- 數(shù)

31、值上的不利(方程式的系數(shù)的階數(shù)不同)- 兩個以上的項包含在Caughey級數(shù)中將生成非對角形矩陣 - 分析時間增加- Rayleigh阻尼更實用一些 Copyright 2000-2003 MIDAS Information Technology Co., Ltd.第一和第二模態(tài)的阻尼: 假定為 5%決定質(zhì)量和剛度矩陣Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDA

32、S Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd. New Experience with an Urban EarthquakeNorthridge (1994.1.17)Kobe (1995.1.17)Workshop Bled

33、97Slovenia (1997.6.24-27)Copyright 2000-2003 MIDAS Information Technology Co., Ltd.加洲北嶺加洲北嶺地震地震 1994年年1月月17日日 04時時30分分- Magnitude : ML=6.7- 人員傷亡人員傷亡 : 57名死亡名死亡- 受災(zāi)人數(shù)受災(zāi)人數(shù) : 約約20,000名名 - 財產(chǎn)損失財產(chǎn)損失 : 400億美元億美元Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 神戶神戶地震地震 1995年年1月月17日日 05點點46分分- Mag

34、nitude : ML=7.2- 人員傷亡人員傷亡 : 5,373名死亡名死亡- 受災(zāi)人數(shù)受災(zāi)人數(shù) : 約約32,000名名- 財產(chǎn)損失財產(chǎn)損失 : 9兆兆9,630億日元億日元Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 提出現(xiàn)有耐震設(shè)計方法存在的問題1994 Northridge1995 Kobe1999 Turkey1999 Taiwan 預(yù)測結(jié)構(gòu)的真實動力反應(yīng) + 確保耐震性能 新的耐震設(shè)計方法的開發(fā) 對現(xiàn)有建筑的抗震性能和水準評價“Workshop on Seismic Design Methodologies

35、for the Next Generation of Codes”Copyright 2000-2003 MIDAS Information Technology Co., Ltd.U.S.-Slovenian Joint Board for Scientific and Technological Cooperation OrganizationWorkshop on Seismic Design Methodologies for the Next Generation of Codes- America, New Zealand, Europe, Japan : About 40 lea

36、ding experts Hugo Bachmann, Vitelmo V. Bertero, Peter Fajfar, Ronald O. Hamburger Yuji Ishiyama, James O. Jirsa, Andreas J. Kappos, Helmut Krawinkler, Eduardo Miranda, Shunsuke Otani, Thomas Paulay, Nigel M.J. Priestley etc. Objective- New methodologies for the seismic design of new building and bri

37、dge structures- For the evaluation and strengthening of existing structures- Seismic design under development in different regions of the worldP. FajfarH. KrawinklerBled, Slovenia, 24-27 June 1997Copyright 2000-2003 MIDAS Information Technology Co., Ltd.U.S.-Japan Joint WorkshopWorkshop on Performan

38、ce-Based Earthquake Engineering Methodology for Reinforced Concrete Building StructuresMaui, Hawaii, 13 September 1999 U.S. SIDE A.Chopra, S.Kunnath, F.Filippou, V.Bertero, J.Moehle, H.Krawinkler, J.Jirsa . U.S. SIDET.Okada, H.Kuramoto, F.Watanabe, M.Maeda, D.Kato, T.Kabeyasawa, M.Teshigawara . - Ea

39、rthquake and Responses- Response of Frame- Modeling of Frame- Seismic Capacity of Frame or Members- Seismic Demands- Design Philosophy- Design of Elements or Code Requirements CONTENTSCopyright 2000-2003 MIDAS Information Technology Co., Ltd. 為了確定結(jié)構(gòu)的真實地震響應(yīng)，使用非線性地震分析Lack of Konwledge onEarthquake Dem

40、andand Building CapacityLinear ElasticBuilding ResponseDisplacementDVdesignVBase Shear?5% Smooth Elastic Design SpectaElastic ForcesReduced for Design by RInelasticResponseCapacity(elastic)DisplacementDDmaxDyieldVdesignVBase ShearR5% Smooth Elastic Design SpectaPerformance PointDemand SpectrumCapaci

41、ty SpectrumSpectral DisplacementSpectral AccelerationSaSdDdesign Historical Approach Traditional Code Basis Performance-Based Design- factors-of-safety- Vdesign=5-10% of Wt- Vdesign= Vmax /R- Reduction justified by expected ductility- Resolution of capacity & demand- Design based on displacement

42、 結(jié)構(gòu)的抵抗能力與對地震作用的要求水準之間的比較BLACK BOXCopyright 2000-2003 MIDAS Information Technology Co., Ltd. 傳統(tǒng)的耐震設(shè)計原理Copyright 2000-2003 MIDAS Information Technology Co., Ltd. Documents- Vision 2000(1995)- ATC-40(1996)- FEMA-273(1997)- SEAOC Blue Book (7th Edition 1999)- ATC-44(1998)- FEMA-356(2000)- ATC-55(2002)Pe

43、rformance PointCopyright 2000-2003 MIDAS Information Technology Co., Ltd.PBSD的基本概念(SEAOC 2000)Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 依據(jù)非線性靜力分析的耐震性能基準評價Copyright 2000-2003 MIDAS Information Technology Co., Ltd. 基于性能的耐震設(shè)計標準基于性能的耐震設(shè)計標準多階段性能基準多階段性能基準SEAOC Vision 20001995. 04. 03SEAOC

44、 Vision 20001995. 04. 03ATC-401996. 01ATC-401996. 01FEMA-273, 2741997. 10FEMA-273, 2741997. 10SEAOC Bluebook1999 7th EditionSEAOC Bluebook1999 7th EditionIBC 20002000. 8IBC 20002000. 8 ( 1997.12 )韓國地震工學(xué)會耐震性能基準 ( 1997.12 ) - Capacity Spectrum : Pushover - Demand Spectrum : UBC-94 - Capacity Spectrum

45、: Pushover - Demand Spectrum : UBC-94UBC-97( 1997.04 )UBC-97( 1997.04 ) - BSSC+ATC+ASCE - Capacity Spectrum : Pushover, Modified Performance Level - Demand Spectrum : UBC-97 - BSSC+ATC+ASCE - Capacity Spectrum : Pushover, Modified Performance Level - Demand Spectrum : UBC-97 - Modified UBC-97+AISC S

46、eismic-97 - Structural Performance Level - Design Ground Motions Definition - Capacity Spectrum Method - Modified UBC-97+AISC Seismic-97 - Structural Performance Level - Design Ground Motions Definition - Capacity Spectrum MethodPerformance Based Seismic Design 1998. 06. 12 1998. 06. 12U.S.AKOREAJAP

47、AN制定建筑基準法Copyright 2000-2003 MIDAS Information Technology Co., Ltd.以性能為基礎(chǔ)的耐震設(shè)計原理以性能為基礎(chǔ)的耐震設(shè)計原理相對于各階段地基運動水準，滿足相應(yīng)的性能目標的設(shè)計Very Rare( 5%-50years )Rare( 10%-50years )Occasional( 20%-50years )Frequent( 50%-50years )NearCollapseLife SafetyFunctionalFullyOperationalUnacceptable Performance( for New Construct

48、ion)Basic ObjectiveEssential / Hazardous ObjectiveSafety Critical ObjectiveEarthquake Design LevelPerformance Level Matrix of Performance Objective (FEMA-273,274) 根據(jù)設(shè)計地震和性能水準確定的建筑性能指標根據(jù)設(shè)計地震和性能水準確定的建筑性能指標: KOREA 韓國耐震性能基準韓國耐震性能基準: 韓國地震工學(xué)會韓國地震工學(xué)會- 根據(jù)重要性分為三個抗震等級- 兩個性能基準兩個性能基準: 履行功能水準、防止坍塌水準- 根據(jù)平均重現(xiàn)周期分為六

49、個階段場地運動水準六個階段場地運動水準- 巖石、沙土、回填土等六個階段場地類型六個階段場地類型Copyright 2000-2003 MIDAS Information Technology Co., Ltd.評價設(shè)計地基運動評價設(shè)計地基運動Spectral Acceleration ( g )aCaC.520TTCvsT.T20=0sTPeriod (sec)avsC./CT52=設(shè)計反應(yīng)譜 (UBC-97)051015202530spectral displacement ( cm )0.00.20.40.6spectral acceleration ( g )Soil = SASoil

50、= SBSoil = SCSoil = SDSoil = SET=0.5 secT=1.0 secT=1.5 secT=2.0 secCopyright 2000-2003 MIDAS Information Technology Co., Ltd.Codes on Performance-Based Seismic Design-1U.S.A1992 SEAOC Vision 2000 委員會決定開始開發(fā)以性能為基準的耐震設(shè)計 1989.10.17 Loma Prieta Earthquake 1994. 1.17 Northridge Earthquake 1994 NEHRP (1991

51、-NEHRP 較大幅度修改) 1994 IBCC (整合 ICBO-UBC, BOCA-NBC, SBCCI-SBC) 1995 ATC-19, 34. SEAOC: PBSE 發(fā)布報告 1996 ATC-40: Seismic Evaluation and Retrofit of Concrete Buildings 1997 FEMA-273,274 NEHRP Guideline for the Seismic Rehabilitation of Buildings NEHRP Commentary on the Guideline for the Seismic Rehabilitat

52、ion of Buildings 1997 FEMA-302,303 . 1997-NEHRP NEHRP Recommended Provisions for the Seismic Regulations for the New Buildings and Other Structures Provisions and Commentary 1999 SEAOC “Blue Book” 7th Edition Recommended Lateral Force Requirements and Commentary 2000 ICC(International Code Council)

53、“2000 International Building Code”Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Codes on Performance-Based Seismic Design-2JAPAN 1968. 5.16 Hachinohe Earthquake . 1971 修改建筑基準法試行板修改建筑基準法試行板 1978. 2.20 Miyagi Earthquake . 1981 即即“新耐震設(shè)計法新耐震設(shè)計法” 1995. 1.17 Hanshin Earthquake . 1998.6.12 修改建筑

54、基準法修改建筑基準法New Zealand NZS 3101: 1995 Concrete Structures Standard, Standards Associations of New Zealand, Wellington, 1995Eurocode 1990 Commission of the European Communities (CEC) 歐共體決定開發(fā) . Structural Eurocode “European Committee for Standardization” CEN 1994 - European Prestandard Eurocode 8: Desi

55、gn Provisions for Earthquake Resistance of Structures NZS 4203: Code of Practice for General Structural Design and Loading for Buildings Standards Associations of New Zealand, Wellington, 1984NZSEECopyright 2000-2003 MIDAS Information Technology Co., Ltd.12th WCEEAuckland, New Zealand6th NCEESeattle

56、, Washington11th WCEEAcapulco, Mexico7th NCEEBoston, Massachusetts 11th ECEE Paris, FranceConference on Earthquake Engineering199620002002199812th ECEELondon, United KingdomCopyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Copyright 2

57、000-2003 MIDAS Information Technology Co., Ltd.Direct Displacement Based Design地震工學(xué)上的迷信和誤區(qū)地震工學(xué)上的迷信和誤區(qū) 設(shè)計和現(xiàn)實之間的矛盾設(shè)計和現(xiàn)實之間的矛盾確立以數(shù)學(xué)分析和大型實驗研究為基礎(chǔ)的新的耐震設(shè)計理念耐震設(shè)計理念的假設(shè)和不正確性指出了設(shè)計與分析的分離的現(xiàn)象彈性反應(yīng)譜的錯誤，對精密分析的迷信，對能量的迷信，對剪切的迷信Copyright 2000-2003 MIDAS Information Technology Co., Ltd.目前強度設(shè)計的問題點目前強度設(shè)計的問題點1. 需要假定固有周期2. 響

58、應(yīng)修正系數(shù)(R)對周期的依賴性3. 由位移(而不是強度)決定非彈性能力響應(yīng)修正系數(shù)(R)-變形延性()n位移法則： R （長周期結(jié)構(gòu)）n能量法則：（長周期結(jié)構(gòu)）n加速度法則：（忽略 ，周期為零）Copyright 2000-2003 MIDAS Information Technology Co., Ltd.彈性-非彈性位移比與的平均位移比Copyright 2000-2003 MIDAS Information Technology Co., Ltd.基于位移設(shè)計的概念基于位移設(shè)計的概念1. 結(jié)構(gòu)的損傷限度與變形極限狀態(tài)有關(guān)聯(lián)2. 構(gòu)件的初期強度只考慮了附加的重要性3. 不應(yīng)使用5%的彈性阻

59、尼比，應(yīng)該使用適合非彈性狀態(tài)的阻尼比4. 可以正確反應(yīng)預(yù)想的柔度水準5. 使用位移反應(yīng)譜基于位移的設(shè)計過程基于位移的設(shè)計過程決定屈服位移y (一般選擇與y=0.005的y ）決定容許塑性位移P 容許最大位移 t = y + P - 位移延性比 sys= m /y決定有效阻尼比(5) 由相應(yīng)于有效阻尼比的位移反應(yīng)譜中決定 Teff、Keff(6) 決定需求屈服強度決定符合需求屈服強度的構(gòu)件尺寸和細部 初期強度: (8) 修改總位移、系統(tǒng)延性、有效阻尼比，反復(fù)迭代計算直到收斂Copyright 2000-2003 MIDAS Information Technology Co., Ltd.位移控制

60、設(shè)計例題位移控制設(shè)計例題Copyright 2000-2003 MIDAS Information Technology Co., Ltd.位移控制設(shè)計例題位移控制設(shè)計例題Copyright 2000-2003 MIDAS Information Technology Co., Ltd.位移控制設(shè)計例題位移控制設(shè)計例題Copyright 2000-2003 MIDAS Information Technology Co., Ltd.Capacity Spectrum Method5% Smooth Elastic Design SpectaPerformance PointDemand Spectru