列车移动荷载下饱和软黏土地基的长期沉降计算  

Long-term settlement calculation of saturated soft clay foundation under train moving loads

作　　者：陶明安[1,2] 沈扬[1] 王鑫[1] 王保光[1] 杜文汉[1] TAO Mingan SHEN Yang WANG Xin WANG Baoguang DU Wenhan(Key Laboratory of Geomechanics and Embankment Engineering of Ministry of Education, Hohai University, Nanjing 210098, China The Third Railway Survey and Design Institute Group Corporation, Tianjin 300142, China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]铁道第三勘察设计院集团有限公司,天津300142

出　　处：《中南大学学报（自然科学版）》2016年第12期4206-4215,共10页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51479060;U1134207);中央高校基本科研业务费专项资金资助项目(B15020060)~~

摘　　要：借助空心圆柱扭剪仪开展偏应力空间中主应力轴心形线旋转路径的室内模拟,建立列车移动荷载引发的主应力轴心形旋转路径下土体的塑性累积模型和孔压模型;在动力有限元中引入等效移动列车荷载,并结合分层总和法的思想,建立高速列车移动荷载作用下饱和软黏土地基的长期沉降计算方法,进一步研究交通荷载下地基软土的长期变形规律。研究结果表明:总沉降量随着振次的增加而增大,其增大速率迅速减小,并在振动约250万次时出现拐点,总沉降速率趋于稳定,此时沉降量占4 a总沉降量的90%以上;土体总沉降量随着深度的增加而不断减小,整体沉降主要发生在距地面5 m以上部分,该部分的沉降量占总沉降量的95%以上;随着列车运行速度的增大,地基土层的总沉降增大,当列车速度超过临界速度时,地基的总沉降量反而大幅度减小。The hollow cylinder apparatus was utilized to simulate the heart-shaped line path in the maximum shear stress pace. The cumulative model of strain and pore water pressure were established for saturated soft clay under train load. The equivalent moving train load was introduced to obtain the distribution of soil dynamic stress levels in dynamic FEM. Combined with the layer-wise summation method, the method of calculating soft clay foundation settlement was established under the high-speed train moving loads. The results show that with the increase of the cycles, the total settlement increases gradually while the rate decreases rapidly. The inflection point occurs when the number of cycles exceeds 2.5 million. In addition, the rate of total settlement tends to be stable while the settlement of the first year exceeds 90% of the total settlement. The total settlement of soil decreases with the increase of depth; the whole settlement mainly occurs within 5 m below the ground while the settlement occupies more than 95% of the total settlement. With the increase of train speed, the total settlement of foundation soil is not always increased. The total settlement will decrease when speed exceeds the critical value.

关 键 词：列车 移动荷载 主应力轴心形旋转 塑性累积模型 孔压模型 长期沉降 

分 类 号：TU43[建筑科学—岩土工程]