基于混合试验的桩承式加筋路堤参数影响分析  

Parametric analysis of geosynthetic-reinforced pile-supported embankments using hybrid tests

作　　者：芮瑞[1] 贺世开 刘浩[2] 裴宇豪 陈成 张磊 RUI Rui;HE Shikai;LIU Hao;PEI Yuhao;CHEN Cheng;ZHANG Lei(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan,Hubei 430070,China;Huadong Branch of China Construction Second Engineering Bureau Co.,Lid,Shanghai 200135,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]中国建筑第二工程局有限公司华东公司,上海200135

出　　处：《岩石力学与工程学报》2022年第7期1476-1487,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金青年基金项目(51208403,51708438);中国建筑第二工程局有限公司科技资助计划(CSCEC–2019–Z–29)。

摘　　要：桩承式加筋路堤的路堤土拱效应、加筋体张拉膜效应以及桩土地基承载效应之间存在着较为复杂的耦合效应,由于土拱效应随路堤加载与桩间土下沉的演化,目前的计算理论与方法难以真实地评价桩承式路堤荷载调节与沉降稳定的全过程。引入混合试验的技术思路,开发一套阵列式多活动门试验装置及桩土地基混合试验方法,实现加筋垫层路堤物理模型与桩土地基数值模型的适时数据交换,开展9组不同路堤高度与加筋体拉伸模量的参数影响试验。试验结果表明:所建立的混合试验方法能够较好地实现桩承式加筋路堤的全组件参与、全效应耦合工作性能模拟,大大地节省了试验成本和时间,为桩承式加筋路堤的长期承载性能演化以及沉降预测提供了一种新的试验手段。同心圆力学模型能够较为准确地评价路堤的最大土拱效应。当路堤高度较低时,采用拉伸模量较高的加筋体能够提高桩的荷载分担比。采用拉伸模量较高的加筋体,在不同的加筋高度条件下均能够显著地降低桩间土沉降与桩土差异沉降。随着路堤高度的增加,不同加筋体模量试验的桩、土荷载分担比趋于一致,采用地基反力系数法不能可靠地反映桩间土的真实承载机制。There is a complex coupling effect among soil arching effect of the embankments,the tensile membrane effect of the geosynthetic reinforcement and the load bearing effect of the soft ground in geosynthetic-reinforced pile-supported(GRPS) embankments. Due to the evolution of soil arching with embankment loading and soil settlement between piles,the current calculation theories and methods are challenging to evaluate the whole process of load regulation and settlement stability of GRPS embankments. By introducing the technical idea of the hybrid test,a set of array multi trapdoor test devices and pile-soil foundation hybrid test methods were developed. The timely data exchange between the physical model of reinforced cushion embankment and the numerical model of pile-soil foundation was realized. Nine groups of hybrid tests with different embankment heights and tensile stiffness of reinforcement were carried out. The test results show that the established hybrid test method could well model the full component participation and full effect coupling working performance of GRPS embankments,greatly save the test cost and time,which provides an innovative evaluation method for the long-term bearing performance and settlement prediction of GRPS embankments. The concentric arch model can accurately evaluate the maximum soil arching effect of GRPS embankments. When the embankment height is low,the geosynthetic reinforcement with high tensile stiffness can improve the loading efficacy of piles. The geosynthetic reinforcement with high tensile stiffness can significantly reduce the settlement and the differential settlement between piles and soil under different embankment heights. With the increase of embankment height, the pile and soil efficacies with different reinforcement stiffness tend to be consistent,which reflects that the subgrade reaction coefficient method cannot reliably reflect the actual load-bearing mechanism of soil between piles.

关 键 词：桩基工程 桩承式加筋路堤 混合试验 土拱效应 沉降 长期性能 

分 类 号：TU47[建筑科学—结构工程]