桩承式路堤桩帽顶面土压测试代表性分析  

Representative Analysis of Soil Pressure Test on Top Surface of Pile Cap of Piled Embankment

作　　者：姜彦彬 何斌[2] 王艳芳[1,2] 陈盛原 何宁[2] JIANG Yan-bin;HE Bin;WANG Yan-fang;CHEN Sheng-yuan;HE Ning(School of Architectural Engineering,Jinling Institute of Technology,Nanjing 211169,China;Department of Geotechnical Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]金陵科技学院建筑工程学院,南京市211169 [2]南京水利科学研究院岩土工程研究所,南京市210029

出　　处：《公路》2022年第4期1-7,共7页Highway

基　　金：金陵科技学院高层次人才科研项目,项目编号jit-b-202130;国家重点研发计划课题,项目编号2018YFC1508505;国家自然科学基金青年科学基金项目,项目编号51908278;江苏省高校自然科学基金面上项目,项目编号19KJD410002。

摘　　要：准确获取桩帽顶面的土压力是评价桩承式路堤土拱效应的关键,而如何量化分析桩帽顶面点式土压测试的均值代表性往往被忽视。建立了单桩加固范围的三维有限元模型,提出土压测试代表性系数λ,探讨平面布桩、传感置换率α、路堤填高H_(e)及刚度等对桩帽顶面土压测试代表性的影响。结果表明,桩承式路堤桩帽顶面土压力不均匀分布特征显著,导致点式土压测值的均值代表性较差。λ对H_(e)及α的变化较为敏感,α及H_(e)越小时,点式土压测值的均值代表性越差;H_(e)较大时,λ对路堤填土刚度的变化不敏感。改变布桩的平面几何数值时,λ仅与桩帽直径相关,而与桩间距无关。新型分布式光纤土压测试方法的提出,有助于提升桩帽顶面土压测试的准确性。研究成果可为土压测试代表性研究提供一定参考。Accurately obtaining the soil pressure on the top surface of pile cap(TSPC)is the key to evaluate the soil arching effect of piled embankment,and how to quantify the mean value representativeness(MVR)of the point soil pressure test(PSPT)on the top surface of the pile cap(PSPT)is often ignored.In this paper,three-dimensional finite element models of the single-pile reinforcement area are established,the representative coefficient,λ,is also proposed to discuss the influence of pile arrangement,sensor replacement ratioα,embankment filling height H_(e)and stiffness on the MVR of PSPT on TSPC.The results show that the uneven distribution of soil pressure on TSPC of the piled embankment is significant,resulting in poor MVR of PSPT on TSPC.The smaller theαand H_(e),the worse the MVR,and it is more sensitive ofλto the change ofαand H_(e).When H_(e)is large,λbecomes insensitive to the change of embankment fill stiffness.When changing the plane geometry of the pile layout,λis only related to the diameter of the pile cap,but not to the pile spacing.The proposal of a new distributed optical fiber soil pressure testing method helps to improve the accuracy of soil pressure testing on TSPC.This paper provides an important reference for representative studies of soil pressure testing.

关 键 词：土压力 点式土压测试 代表性系数 传感置换率 有限元数值模拟 分布式光纤 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU472.3[建筑科学—结构工程]