摘要
以西南地区穿越典型地形地貌和地基土大类的某线路工程为例,首先通过震害调研获得地震作用下输电线路震害特征。然后采用FLAD 3D有限差分软件建立斜坡桩-土体系分析模型,通过模拟明确了动力荷载作用下,斜坡场地永久位移、场地加速度放大系数以及桩身位移、桩身包络弯矩、桩身峰值加速度的动力响应特征。结果表明:坡肩处的场地位移、加速度放大系数以放大为主,全坡面位移平均放大系数范围为1.0~5.0、加速度最大放大系数约为1.2~1.5;而桩基地震响应表征参数中桩基础的加速度、位移、内力受地震荷载影响明显,但由于斜坡坡度的影响,一定深度上、下土层差异性逐渐加大,斜坡上部土体丧失了抵抗强度使桩产生了明显的响应突变。
Taking a line project crossing typical landform and foundation soil in Southwest China as an example,the seismic damage characteristics of transmission line under earthquake action are obtained through seismic damage investigation.Then,the analysis model of slope pile-soil system is established by using FLAD 3 D finite difference software.Through simulation,the dynamic response characteristics of the permanent displacement of the slope,the amplification coefficient of the site acceleration,the pile displacement,the pile envelope bending moment and the peak acceleration of the pile under dynamic load are determined.The results show that the amplification coefficients of site displacement and acceleration at the slope shoulder are amplified.The average amplification coefficient of slope displacement ranges from 1.0 to 5.0,and the maximum amplification coefficient of acceleration ranges from 1.2 to 1.5.The acceleration,displacement and internal force of the pile foundation are affected by the seismic load.However,due to the influence of slope gradient,the difference between upper and lower soil layers increases gradually at a certain depth,and the soil at the upper part of the slope loses its resistance strength,resulting in abrupt response of pile.
作者
杨薇薇
YANG Wei-wei(Zhongtong Service Consulting Design&Research Institute Co.,Ltd.,Nanjing 210003,Jiangsu,China)
出处
《地基处理》
2021年第5期409-414,共6页
Journal of Ground Improvement
关键词
斜坡
场地
桩基
地震响应
数值分析
slope
site
pile foundation
seismic response
numerical analysis
