液化土中斜群桩承台动力响应特性及桩身弯矩分布规律研究  

Dynamic response of pile cap and distribution law of pile bending moment for batter pile group in liquefied soil

作　　者：张健 李雨润 戎贤 师庆晓 贺书云 ZHANG Jian;LI Yurun;RONG Xian;SHI Qingxiao;HE Shuyun(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Civil Engineering Technology Research Center of Hebei Province,Tianjin 300401,China;Tianjin Dagang Oilfield Group Engineering Construction Co.,Ltd.,Tianjin 300280,China;CSCEC Road and Bridge Group Co.,Ltd.,Shijiazhuang 050000,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]河北省土木工程技术研究中心,天津300401 [3]天津大港油田集团工程建设有限责任公司,天津300280 [4]中建路桥集团有限公司,河北石家庄050000

出　　处：《地震工程与工程振动》2021年第3期235-244,共10页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51778207);河北省自然科学基金项目(E2018202107);邢台市重点研发计划项目(2020ZC140)。

摘　　要：为研究动荷载作用下饱和砂土发生液化前后斜群桩的动力响应相关问题,利用土工离心机振动台进行了饱和砂土场地条件下的斜群桩物理模型试验。通过试验分别对土层响应、桩身弯矩以及桩顶承台加速度和位移等进行了详细分析,得到了如下结论:不同荷载作用下土层液化范围的改变导致了土层加速度峰值出现了不同程度的放大或缩小现象;砂土液化前后桩身动弯矩和残余弯矩对整个桩身的影响程度发生了显著变化,尤其在砂土大范围液化后残余弯矩相比动弯矩的影响明显减弱;当输入加速度峰值较小时,桩顶承台水平加速度峰值与振动台台面比较出现了明显的放大现象。而随着输入加速度峰值的增加,在振动后期承台水平加速度峰值出现了缩小的现象,同时在振动结束后承台产生了明显的动态残余位移。本研究取得的相关结论为液化土中斜群桩的相关研究以及工程设计提供参考。In order to study the dynamic response of the batter pile group before and after the saturated sand liquefaction under the seismic and cyclic loads,the physical model experiment of the batter pile group under the saturated sand field was carried out using a geotechnical centrifuge shaking table.A detailed analysis of soil response,pile bending moment,acceleration and displacement of pile cap and other factors were carried out,and the following conclusions were obtained:The change of liquefaction range have led to different degrees of enlargement or reduction of the peak acceleration in soil layers at different depths.Before and after sand liquefaction,the influence of the dynamic bending moment and residual bending moment on the total bending moment has changed significantly,especially after the large-scale liquefaction of the sand,the influence of the residual bending moment is significantly weaker than the dynamic bending moment.When themotionintensity is small,the peak acceleration of the pile cap is obviously amplified.With the increase of the motion intensity,the peak acceleration of the pile cap in the later stage of motion has been reduced.At the same time,after the end of the vibration,the pile cap produced obvious dynamic residual displacement.Theconclusions obtained in this study provide references for the related research and engineering design of batter pile groups in liquefied soil.

关 键 词：液化土 斜群桩 离心机振动台 动力响应 桩身弯矩 

分 类 号：TU435[建筑科学—岩土工程]