土层非线性非平稳有效应力动力响应可靠度分析
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摘要
在非平稳一致地震输入下对非线性土层进行了有效应力动力响应可靠度分析。通过虚拟激励法,将非平稳地震加速度功率谱密度作为基岩上的虚拟输入,并利用Hardin-Drnevich双曲线模型考虑土层的非线性特性,迭代计算得到土单元的剪切模量与阻尼比。在此基础上,运用有限元方法对土层进行了地震响应分析,通过比较4种方法获得等效峰值剪应力和剪应变来计算等效动力剪切模量和振动孔压。结果表明,采用基于概率平均法的插值方法与确定性分析所得的平均值较为接近,说明由于孔压的不断上升与土层有效应力的降低,可液化地基的地震响应变为非平稳随机过程。
The nonstationary probabilistic seismic response was carried out via pseudo excitation algorithm combined with finite element method under uniform nonstationary seismic environment. The evolutionary power spectral density (PSD) of acceleration at the engineering bedrock was handled as the nonstationary pseudo input. Shear modulus and damping ratio were obtained iteratively from the Hardin-Drnevich constitute relationship accounting for the nonlinearity of soil and the effect of pore pressure. Also,the performance of four techniques,using different approximations to estimate the equivalent peak value of shear stress and strain,were investigated for the purpose of determining the equivalent shear modulus,damping and excess pore water pressure induced by seismic loading,in which the equivalent peak value is computed in terms of its standard deviation and the corresponding peak factor. It is found that the interpolation method based on probabilistic average approach is appropriate compared to the deterministic method. The analytic results indicate that the dynamic response of liquefiable soil is time-dependent due to the cumulation of the excess water pore pressure and should be considered as nonstationary process.
The nonstationary probabilistic seismic response was carried out via pseudo excitation algorithm combined with finite element method under uniform nonstationary seismic environment. The evolutionary power spectral density (PSD) of acceleration at the engineering bedrock was handled as the nonstationary pseudo input. Shear modulus and damping ratio were obtained iteratively from the Hardin-Drnevich constitute relationship accounting for the nonlinearity of soil and the effect of pore pressure. Also,the performance of four techniques,using different approximations to estimate the equivalent peak value of shear stress and strain,were investigated for the purpose of determining the equivalent shear modulus,damping and excess pore water pressure induced by seismic loading,in which the equivalent peak value is computed in terms of its standard deviation and the corresponding peak factor. It is found that the interpolation method based on probabilistic average approach is appropriate compared to the deterministic method. The analytic results indicate that the dynamic response of liquefiable soil is time-dependent due to the cumulation of the excess water pore pressure and should be considered as nonstationary process.
引文
[1]Loh C H,Cheng C R,Wen Y K.Probabilistic evaluation of liquefaction potential under earthquake loading[J].Soil Dynamics andEarthquake Engineering,1995,14:269–278.
[2]刘汉龙.随机地震作用下地基及土石坝永久变形分析[J].岩土工程学报,1996,18(3):19–27.(Liu Hanlong.Permanent deformation of foundation and embankment dam due to stochastic seismic excitation[J].Chinese Journal of Geotechnical Engineering,1996,18(3):19–27.(in Chinese))
[3]陈国兴,谢君斐,张克绪.土坝地震性能二维随机分析方法[J].地震工程与工程振动,1994,14(3):81–90.(Chen Guoxing,Xie Junfei,Zhang Kexu.A method of2D random response analysis of earth dam earthquake performance[J].Earthquake Engineering and Engineering Vibration,1994,14(3):81–90.(in Chinese))
[4]严松宏,梁波,高峰,等.考虑地震非平稳性的隧道纵向抗震可靠度分析[J].岩石力学与工程学报,2005,24(5):818–822.(Yan Songhong,Liang Bo,Gao Feng,et al.Dynamic reliability analysis of resistance of tunnels to longitudinal nonstationary earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(5):818–822.(in Chinese))
[5]吴再光,林皋,韩国城.土层非平稳有效应力随机地震反应分析[J].水利学报,1991,(9):25–32.(Wu Zaiguang,Lin Gao,Han Guocheng.Nonstationary stochastic seismic response analysis of effective stress for saturated soil layer[J].Journal of Hydraulic Engineering,1991,(9):25–32.(in Chinese))
[6]林家浩.非平稳随机地震响应的精确高效算法[J].地震工程与工程振动,1993,13(1):24–29.(Lin Jiahao.An accurate and efficient algorithm of nonstationary stochastic seismic responses[J].Earthquake Engineering and Engineering Vibration,1993,13(1):24–29.(in Chinese))
[7]Clough R W,Penzien J.Dynamics of Structures[M].New York:McGraw-Hill Inc.,1975.
[8]Hardin B O,Drnevich V P.Shear modulus and damping in soils:design equations and curves[J].Journal of the Soil Mechanics and Foundations Division,1972,(7):667–692.
[9]Seed H B.Representation of irregular stress time histories by equivalent uniform stress series in liquefaction analysis[R].Berkeley:University of California,1975.
[10]Romo-Organista,Miguel P.PLUSH:A computer program for probabilistic finite element analysis of seismic soil structure interaction[M].Berkeley:Univ of California,1980.
[11]冯启民.地震动随机场分析[博士学位论文][D].哈尔滨:国家地震局工程力学研究所,1986.(Feng Qimin.Random field analysis of ground motions[Ph.D.Thesis][D].Harbin:Harbin Institute of Engineering Mechanics of State Seismological Bureau,1986.(in Chinese))
[12]吴再光.土层随机地震反应的一种改进算法[J].振动工程学报,1990,3(1):56–59.(Wu Zaiguang.A modified method for the computation of stochastic seismic responses of soil layers[J].Journal of Vibration Engineering,1990,3(1):56–59.(in Chinese))
[13]Perotti F.Structural response to nonstationary multiplesupport random excitation[J].Earthquake Engineering and Structural Dynamics,1990,19(6):513–527.
[14]Gasparini D A,Amitabha D.Dynamic response to nonstationary nonwhite excitation[J].Journal of the Engineering Mechanics Division,1980,106(6):1233–1248.
[15]潘晓东,徐长节,蔡袁强.水泥搅拌桩加固坝基动力响应分析[J].振动工程学报,2001,14(3):359–363.(Pan Xiaodong,Xu Changjie,Cai Yuanqiang.Dynamic response analysis of foundation with cement mixing piles of a dam[J].Journal of Vibration Engineering,2001,14(3):359–363.(in Chinese))
[16]蔡袁强,钱磊,凌道盛,等.钱塘江防洪堤地震液化及稳定分析[J].水利学报,2001,(1):57–61.(Cai Yuanqiang,Qian Lei,Lin Daosheng,et al.Seismic liquefaction and stability analysis of Qiantang River embankment[J].Journal of Hydraulic Engineering,2001,(1):57–61.(in Chinese))
[2]刘汉龙.随机地震作用下地基及土石坝永久变形分析[J].岩土工程学报,1996,18(3):19–27.(Liu Hanlong.Permanent deformation of foundation and embankment dam due to stochastic seismic excitation[J].Chinese Journal of Geotechnical Engineering,1996,18(3):19–27.(in Chinese))
[3]陈国兴,谢君斐,张克绪.土坝地震性能二维随机分析方法[J].地震工程与工程振动,1994,14(3):81–90.(Chen Guoxing,Xie Junfei,Zhang Kexu.A method of2D random response analysis of earth dam earthquake performance[J].Earthquake Engineering and Engineering Vibration,1994,14(3):81–90.(in Chinese))
[4]严松宏,梁波,高峰,等.考虑地震非平稳性的隧道纵向抗震可靠度分析[J].岩石力学与工程学报,2005,24(5):818–822.(Yan Songhong,Liang Bo,Gao Feng,et al.Dynamic reliability analysis of resistance of tunnels to longitudinal nonstationary earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(5):818–822.(in Chinese))
[5]吴再光,林皋,韩国城.土层非平稳有效应力随机地震反应分析[J].水利学报,1991,(9):25–32.(Wu Zaiguang,Lin Gao,Han Guocheng.Nonstationary stochastic seismic response analysis of effective stress for saturated soil layer[J].Journal of Hydraulic Engineering,1991,(9):25–32.(in Chinese))
[6]林家浩.非平稳随机地震响应的精确高效算法[J].地震工程与工程振动,1993,13(1):24–29.(Lin Jiahao.An accurate and efficient algorithm of nonstationary stochastic seismic responses[J].Earthquake Engineering and Engineering Vibration,1993,13(1):24–29.(in Chinese))
[7]Clough R W,Penzien J.Dynamics of Structures[M].New York:McGraw-Hill Inc.,1975.
[8]Hardin B O,Drnevich V P.Shear modulus and damping in soils:design equations and curves[J].Journal of the Soil Mechanics and Foundations Division,1972,(7):667–692.
[9]Seed H B.Representation of irregular stress time histories by equivalent uniform stress series in liquefaction analysis[R].Berkeley:University of California,1975.
[10]Romo-Organista,Miguel P.PLUSH:A computer program for probabilistic finite element analysis of seismic soil structure interaction[M].Berkeley:Univ of California,1980.
[11]冯启民.地震动随机场分析[博士学位论文][D].哈尔滨:国家地震局工程力学研究所,1986.(Feng Qimin.Random field analysis of ground motions[Ph.D.Thesis][D].Harbin:Harbin Institute of Engineering Mechanics of State Seismological Bureau,1986.(in Chinese))
[12]吴再光.土层随机地震反应的一种改进算法[J].振动工程学报,1990,3(1):56–59.(Wu Zaiguang.A modified method for the computation of stochastic seismic responses of soil layers[J].Journal of Vibration Engineering,1990,3(1):56–59.(in Chinese))
[13]Perotti F.Structural response to nonstationary multiplesupport random excitation[J].Earthquake Engineering and Structural Dynamics,1990,19(6):513–527.
[14]Gasparini D A,Amitabha D.Dynamic response to nonstationary nonwhite excitation[J].Journal of the Engineering Mechanics Division,1980,106(6):1233–1248.
[15]潘晓东,徐长节,蔡袁强.水泥搅拌桩加固坝基动力响应分析[J].振动工程学报,2001,14(3):359–363.(Pan Xiaodong,Xu Changjie,Cai Yuanqiang.Dynamic response analysis of foundation with cement mixing piles of a dam[J].Journal of Vibration Engineering,2001,14(3):359–363.(in Chinese))
[16]蔡袁强,钱磊,凌道盛,等.钱塘江防洪堤地震液化及稳定分析[J].水利学报,2001,(1):57–61.(Cai Yuanqiang,Qian Lei,Lin Daosheng,et al.Seismic liquefaction and stability analysis of Qiantang River embankment[J].Journal of Hydraulic Engineering,2001,(1):57–61.(in Chinese))
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