考虑变形滞后效应的高液限土路基模量反算方法  

Back-calculation method for modulus of high liquid limit soil subgrade considering deformation lag effect

作　　者：刘闯[1,2] 张锐[1] 滕煜晟[1] 任天锃 杨博 LIU Chuang;ZHANG Rui;TENG Yusheng;REN Tianzeng;YANG Bo(School of Traffic and Transport Engineering,Changsha University of Science&Technology,Changsha 410114,P.R.China;Department of Traffic and Transportation of Hainan Province,Haikou 570204,P.R.China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,P.R.China)

机构地区：[1]长沙理工大学交通运输工程学院,长沙410114 [2]海南省交通运输厅,海口570204 [3]重庆交通大学土木工程学院,重庆400074

出　　处：《土木与环境工程学报（中英文）》2021年第2期68-75,共8页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51108049、51708071);交通运输部公路工程行业标准制修订项目(JTG-201507)。

摘　　要：为了提高便携式落锤弯沉仪(PFWD)测定高液限土路基回弹模量的精度,考虑变形滞后效应对反算结果的影响,提出了一种基于Kelvin粘弹性模型和准静态动力分析反算模量的方法。通过现场试验,验证了新方法的有效性。研究结果表明:利用高液限土填筑的下路堤模量较低,在PFWD冲击荷载作用下,其顶面竖向位移峰值明显滞后于荷载峰值,且荷载位移曲线非线性显著;基于线弹性模型的常规反算方法使得反算模量远大于实测模量,平均相对误差为52.5%;新方法能较好地反映冲击荷载作用下变形滞后特征,反算相对误差仅为9.2%。随着路基模量增大,路基变形滞后效应不显著,常规方法和新方法反算结果相近,但新方法反算结果的精度更高。In order to improve the accuracy of Portable Falling Weight Deflectometer(PFWD)in measuring the resilient modulus of high liquid limit soil subgrade,the influence of deformation lags effect on the back-calculation result was considered and a new method for back-calculation of the modulus was proposed based on Kelvin viscoelastic model and quasi-static dynamic analysis method.The effectiveness of the new method is verified by field tests.The results show that the measured modulus of the lower embankment filled with high liquid limit soil is lower and the peak vertical displacement of the top surface of the embankment obviously lags behind the peak value of the load under the impact load of PFWD.Furthermore,the load-displacement curve is significantly nonlinear.In addition,the conventional method based on linear elastic model makes the back-calculated modulus much larger than the measured modulus.The average relative error between back-calculated and the measured modulus reaches up to 52.5%.However,the new method can better reflect the deformation lag characteristics under impact load.The average relative error between them is only 9.2%.With increase of subgrade modulus,the lag effect of the deformation is not significant.The back-calculating results via conventional and new methods are similar,but the accuracy of the new method is higher.

关 键 词：道路工程 粘弹性模型 准静态 模量反算 变形滞后 高液限土 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU433[建筑科学—岩土工程]