非饱和黄土场地桩-土动力相互作用试验研究  

Experimental study on pile-soil dynamic interaction in unsaturated loess site

作　　者：周敉[1] 冯鹏飞 刘平均 ZHOU Mi;FENG Peng-fei;LIU Ping-jun(Key Laboratory for Old Bridge Detection and Reinforcement Technology of the Ministry of Transportation,Chang'an University,Xi'an 710064,China;China Power Construction Road and Bridge Group Limited Company,Beijing 100160,China)

机构地区：[1]长安大学、旧桥检测与加固技术交通行业重点实验室,陕西西安710064 [2]中电建路桥集团有限公司,北京100160

出　　处：《浙江大学学报（工学版）》2023年第4期824-832,共9页Journal of Zhejiang University：Engineering Science

基　　金：国家重点研发计划资助项目(2021YFB1600300);国家自然科学基金资助项目(51978062);陕西省自然科学基础研究计划项目-联合基金资助项目(2021JLM-47);长安大学中央高校基本科研业务费专项资金资助项目(300102212209)。

摘　　要：为了研究非饱和黄土场地桩-土动力相互作用,利用土工离心机振动台进行桩-土动力模型试验.获得桩身弯矩、桩侧土抗力、桩-土相对位移及动力p-y曲线,分析加速度幅值、桩基埋深对动力p-y曲线的影响.基于非线性文克尔地基梁模型,建立考虑远场阻尼效应、桩-土间隙效应的非线性动力p-y单元,通过有限元分析结果和该试验记录对动力p-y单元的有效性进行验证.结果表明,随着加速度幅值的增加,桩-土体系的耗能增强,土体刚度逐渐退化;桩侧土抗力与桩-土相对位移之间存在滞后性;采用建立的动力p-y单元,能够相对真实地模拟非饱和黄土场地的桩-土动力响应.The pile-soil dynamic model test was conducted by using a geotechnical centrifuge shaking table in order to analyze the pile-soil dynamic interaction in unsaturated loess site.The bending moment along the pile shaft,lateral soil resistance along the pile shaft,pile-soil relative displacement and dynamic p-y curves were obtained.The effects of acceleration amplitude and pile embedment depth on the dynamic p-y curve were analyzed.A nonlinear dynamic p-y element considering the damping effect of far-field and the pile-soil gap effect was established based on the nonlinear Winkler foundation beam model.The effectiveness of the dynamic p-y element was validated by the finite element analysis results and the records of this test.Results show that the energy dissipation of the pile-soil system enhances while the soil stiffness gradually degrades with the increase of acceleration amplitude.A hysteresis exists between the lateral soil resistance of pile shaft and the relative pile-soil displacement.The pile-soil dynamic response in unsaturated loess site can be simulated in a relatively genuine way with the established dynamic p-y element.

关 键 词：非饱和黄土场地 桩-土动力相互作用 离心机振动台试验 动力p-y曲线 动力p-y单元 

分 类 号：TU448[建筑科学—岩土工程]