饱和砂土液化Finn模型的关键参数  

Key Parameters for the Finn Liquefaction Constitutive Model of Saturated Sand

作　　者：关振长[1] 张浩浩 苏拯弘 黄博洋 宁茂权[2,3] Guan Zhenchang;Zhang Haohao;Su Zhenghong;Huang Boyang;Ning Maoquan(College of Civil Engineering,Fuzhou University,Fuzhou 350116,P.R.China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430064,P.R.China;Haixia(Fujian)Transportation Engineering Design Co.,Ltd.,Fuzhou 350004,P.R.China)

机构地区：[1]福州大学土木工程学院,福州350116 [2]中铁第四勘察设计院集团有限公司,武汉430064 [3]海峡(福建)交通工程设计有限公司,福州350004

出　　处：《地下空间与工程学报》2024年第2期419-425,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51678155);铁四院科技研究开发项目(2019K107)。

摘　　要：以闽江中细砂层为对象,开展三因素三水平正交设计的小型振动台试验,定性探讨闽江砂土液化特性;同时基于Finn模型,在FLAC3D数值平台上对典型试验过程开展动力时程数值模拟。结果表明:Finn模型可有效模拟地震动作用下饱和砂土孔压的增长与有效应力的降低,能较为准确地反映饱和砂土的液化效应,Finn模型中的关键参数C_(1)、C_(2)对计算结果影响显著。以超孔压比峰值及超孔压比稳定值为指标,通过大量数值模拟结果与试验结果的对比,对上述关键参数进行标定,建议闽江饱和砂土液化Finn模型的关键参数取值为C_(1)=1.30、C_(2)=0.31。饱和砂土激振过程中呈现出轻微剪胀趋势,大致与液化现象同步出现。Taking the medium-fine sand layer along Minjiang River as prototype,small-scale shaking table tests based on 3 factors and 3 levels orthogonal design were conducted to discuss the liquefaction characteristic qualitatively.Meanwhile,the dynamic numerical simulations for the typical excitation time-history were carried out upon the FLAC3D numerical platform by using Finn liquefaction constitutive model.The simulation results showed that the Finn constitutive model could well reflect the increase of pore pressure,the decrease of effective stress and the liquefaction characteristic of saturated sand under seismic excitation.On the other hand,the key parameters C_(1)and C_(2)in the Finn liquefaction constitutive model might influence the simulation results significantly.A large number of numerical simulations with different key parameters were carried out sequentially.The peak value and the stable value in the time-history of excess pore pressure ratio were focused and compared with experimental results.Therefore,the key parameters C_(1)and C_(2)for the Finn liquefaction constitutive model of Minjiang saturated sand were calibrated and suggested as 1.30 and 0.31,respectively.Meanwhile,the saturated sand also tended to dilate slightly during excitation time-history,which appeared synchronously with liquefaction.

关 键 词：砂土液化Finn模型 振动台试验 数值模拟 关键参数标定 

分 类 号：TU43[建筑科学—岩土工程]