地震工程学报
地震工程學報
지진공정학보
China Earthquake Engineering Journal
2015年
2期
565-570,584
,共7页
地震反应分析%LSSRLI-1%精确解%土表反应谱%土体剪应变
地震反應分析%LSSRLI-1%精確解%土錶反應譜%土體剪應變
지진반응분석%LSSRLI-1%정학해%토표반응보%토체전응변
seismic response analysis%LSSRLI-1%exact solution%response spectrum of soil sur-face%soil shear strain
基于谐波入射下的波动理论频域精确解,导出线性时域精确解,并在 Matlab 环境中编制相应的计算程序;选取8个简化的中硬场地剖面,用 LSSRLI-1、精确解和 SHAKE2000三种方法计算各场地在不同输入条件下的地震反应。结果表明:程序计算所得地表反应谱和土体剪应变分布与SHAKE2000结果一致;LSSRLI-1方法得到的地表反应谱与前二者结果一致;LSSRLI-1方法在某些情况下得到的土体剪应变分布与另外二者结果存在较大偏差,该偏差对地表反应谱有着不可忽略甚至非常显著的影响。
基于諧波入射下的波動理論頻域精確解,導齣線性時域精確解,併在 Matlab 環境中編製相應的計算程序;選取8箇簡化的中硬場地剖麵,用 LSSRLI-1、精確解和 SHAKE2000三種方法計算各場地在不同輸入條件下的地震反應。結果錶明:程序計算所得地錶反應譜和土體剪應變分佈與SHAKE2000結果一緻;LSSRLI-1方法得到的地錶反應譜與前二者結果一緻;LSSRLI-1方法在某些情況下得到的土體剪應變分佈與另外二者結果存在較大偏差,該偏差對地錶反應譜有著不可忽略甚至非常顯著的影響。
기우해파입사하적파동이론빈역정학해,도출선성시역정학해,병재 Matlab 배경중편제상응적계산정서;선취8개간화적중경장지부면,용 LSSRLI-1、정학해화 SHAKE2000삼충방법계산각장지재불동수입조건하적지진반응。결과표명:정서계산소득지표반응보화토체전응변분포여SHAKE2000결과일치;LSSRLI-1방법득도적지표반응보여전이자결과일치;LSSRLI-1방법재모사정황하득도적토체전응변분포여령외이자결과존재교대편차,해편차대지표반응보유착불가홀략심지비상현저적영향。
Earthquake ground motions can significantly affect buildings when they are amplified in surface soil layers.Therefore,in order to estimate the behavior of buildings during severe earth-quakes,it is essential to evaluate those characteristics of amplification.Although investigations have been carried out,many problems remain unsolved with regard to those characteristics. Ground response analysis typically involves predictions of surface ground motions,developing a spectrum of design responses,determining dynamic stress and strain,and evaluating the potential for liquefaction.Methods used to calculate the ground response are commonly divided into linear, nonlinear,and equivalent linear concepts.The linear analysis assumes that the shear modulus as constant.However,soils often exhibit nonlinear behavior,even at low levels of strain.The nonlin-ear method is time consuming.The equivalent linear method,represented by the SHAKE model,is one of the most frequently used methods for analysis of ground responses to earthquakes.This method is used primarily for approximations because it uses effective strain to define the material property for analysis.However,the equivalent linear method remains the most popular method of seismic response analysis.It has been 20 years since the safety evaluation program LSSRLI-1 was developed and was used for seismic response analysis.At the time,LSSRLI-1 represented the most advanced method and contributed greatly to earthquake preparedness and disaster reduction for China.However,some deficiencies in the model were identified.Based on its focus in the frequency domain with a harmonic wave incident,the exact linear solution was deduced in the time domain, and compiled into a program in the Matlab environment.For the study,eight sites with medium-hard soils were chosen.Seismic responses were calculated using three different methods:the LSS-RLI-1,exact solution,and SHAKE2000.The results show that the ground response spectrums and distribution of soil shear strain,calculated using the exact solution and SHAKE2000 methods,are in agreement with each other.The ground response spectrums,calculated using LSSRLI-1,were consistent with the other two methods.However,in some cases,the distribution of soil shear strain,calculated using LSSRLI-1,showed a relatively large deviation from the SHAKE2000 and exact solution methods.The extent of these differences may significantly affect the estimates of ground motion,and cannot be ignored.