摘要
研究等效线性化方法中土体动力参数不确定性对场地地震反应的影响,提出了可考虑土体动力特征参数间相关性的土体动剪切模量和动阻尼曲线随机样本生成方法,基于Matlab开发一维等效线性化场地地震反应分析计算程序,用于开展场地地震反应随机动力分析。以Ⅱ类成层场地为例建立一维自由场分析模型,采用不同地震设防水准下露头基岩场地加速度反应谱为目标反应谱,合成人工地震记录折半后作为场地下卧基岩处的输入。计算结果表明,考虑土体动力特征参数不确定性对场地地震反应具有较大的影响,且影响程度与地震动强度、频谱成分及场地基本周期均密切相关;场地最大峰值加速度和地表加速度反应谱的波动范围随地震动强度等级的增加而变大,且最大峰值应变和最大峰值加速度的波动范围可达10%和14%;目标反应谱平台段及场地基本周期处对应的场地地表加速度反应谱的波动范围超过20%。
This paper presents a method to generate random samples of soil dynamic shear modulus and dynamic damping curves with full consideration of the correlations of critical soil dynamic parameters to investigate the influence of their uncertainties on the engineering site seismic response in the implementation of equivalent linearization method. A one-dimensional(1D) equivalent linear site seismic response analysis program, which serves stochastic dynamic response analysis of the engineering site, has been developed in Matlab. A 1D free field model for the typical layered engineering sites of site class Ⅱ is established in this study. The target response spectra, which are defined with spectra of the outcrop corresponding to different earthquake return periods based on the acceleration response, are employed to generate artificial seismic records. These records are scaled down by 1/2 and referred to as input motions at the engineering bedrock for the 1D free field model. The numerical results show that the uncertainties of the critical soil dynamic parameters has significant influence on seismic response of engineering sites, which are highly related to the amplitude and the frequency aspects of the input ground motions as well as the fundamental periods of the engineering sites. The variations of the peak shear strain and the peak ground acceleration of the site, which reach 10% and 14%, respectively, increase with the amplitudes of the input ground motions. Besides, the variations of acceleration response spectra corresponding to the plateaus of the target response spectra and the fundamental periods of engineering sites exceed 20% with the consideration of the uncertainties of soil dynamic parameters.
作者
钟紫蓝
史跃波
李锦强
赵密
杜修力
ZHONG Zi-lan;SHI Yue-bo;LI Jin-qiang;ZHAO Mi;DU Xiu-li(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing university of technology,Beijing 100124,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2022年第7期2015-2024,2033,共11页
Rock and Soil Mechanics
基金
国家自然科学基金面上项目(No.51978020)
国家自然科学基金联合基金项目(No.U1839201)
广东省地震工程与应用技术重点实验室开放基金项目(No.2017B030314068)。
关键词
场地地震反应分析
土体动力参数
不确定性
相关性
等效线性化
site seismic response analysis
soil dynamic parameters
uncertainty
correlation
equivalent linear method
