考虑黄土长期蠕变效应的路基沉降预测方法  

Prediction Method of Subgrade Settlement Considering Long-term Creep Effect of Loess

作　　者：董立山 李文强 刘志胜 DONG Li-shan;LI Wen-qiang;LIU Zhi-sheng(Shanxi Transportation Planning Survey and Design Institute Co.Ltd.,Taiyuan 03000,China;Shanxi Jiaoke Highway Survey and Design Institute Co.Ltd.,Taiyuan 030000,China;Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China)

机构地区：[1]山西省交通规划勘察设计院有限公司,太原市03000 [2]山西交科公路勘察设计院有限公司,太原市030000 [3]同济大学道路与交通工程教育部重点实验室,上海市201804

出　　处：《公路》2022年第8期1-7,共7页Highway

基　　金：国家自然科学基金项目,项目编号51808329;山西交通控股集团科技项目,项目编号18-JKKJ-23、20-JKKJ-32;山西省交通科学研究院集团创新发展项目,项目编号20-JKCF-48。

摘　　要：为了研究黄土蠕变变形影响下下伏土洞的黄土路基的沉降特性,基于黄土固结蠕变试验,提出黄土蠕变变形本构模型,研究黄土蠕变变形规律。基于高斯理论曲线提出考虑黄土蠕变变形的下伏土洞的黄土路基沉降预测理论方法,探讨路基沉降的影响因素。结果表明:黄土的蠕变随着蠕变时间的增长而增大,增长速率逐渐趋于缓慢直至趋于稳定,蠕变变形受高含水率与较大的固结压力影响较大;基于“时间硬化”幂函数法则建立的黄土蠕变模型能够较好地模拟黄土的长期蠕变特性,提出的理论预测方法能够较准确地预测黄土土洞周围土体蠕变造成的路基沉降;土洞埋深、高度及宽度对路基沉降影响较大;路基沉降大小及范围随着土洞埋深的增加而减小,随着土洞高度和宽度的增加而增大。In order to study the settlement characteristics of the loess subgrade affected by loess creep deformation, a constitutive model of loess creep deformation is established through loess consolidation creep experiment and the creep deformation law is found out. Based on Gauss theory curve, a theoretical method for predicting the settlement of loess subgrade is established, and the influencing factors of the settlement of loess subgrade are discussed. The results show that the creep of loess increases with the increase of creep time, and the growth rate tends to be slow before it becomes stable. High water content and high consolidation pressure can cause larger creep deformation. The loess creep model based on the power function of“time hardening”can better simulate the long-term creep characteristics of loess,and the theoretical prediction method can accurately predict the subgrade settlement caused by soil creep around loess soil cave.The depth,height and width of soil cave have great influence on the settlement of subgrade.The size and range of subgrade settlement decrease with the increase of soil depth and increase with the increase of soil cave depth and width.

关 键 词：黄土路基 蠕变试验 沉降 预测方法 影响因素 

分 类 号：U416.1[交通运输工程—道路与铁道工程]