填筑速率对高等级公路加宽工程路基变形影响的数值分析

根据同三高速公路方正—哈尔滨段公路扩建项目实际情况,采用Plasix有限元分析软件,对新填路基以10、20、30 cm/d填筑速率施工时的路基变形进行了数值模拟计算,研究了填筑速率对高等级公路加宽工程路基变形的影响规律。结果表明,填筑速率越大,施工期越短,竣工时荷载作用时间就越短。尽管初始阶段的沉降速率较大,但沉降相对比较小,一部分沉降在填筑结束后完成,工后沉降和路面差异沉降越大。随着填筑速率的增大,相同时间内荷载增量越大,侧向变形量也越大,且对地基浅层影响较大。填土高度不变时,填筑速率的变化不能改变加载总量,时间效应是影响变形的主要因素。

Numerical Analysis of Effects of Filling Velocity on Subgrade Deformation in Widening Project of High-Grade Highway

According to the actual situation of the expansion project from Fangzheng to Harbin along Tongjiang-Sanya Highway,Plaxis software for finite element analysis was applied to make a numerical simulation of subgrade deformation under different filling velocities(10,20 and 30 cm/d) during construction.The influence of filling velocity on subgrade deformation in widening project of high-grade highway was studied.Results showed that the construction period and the duration of load decreased with increasing filling velocity.Although the subsidence rate was larger at the initial stage,the settlement was relatively small.A part of the settlement finished after filling,and then the post-construction settlement and the differential subsidence of pavement increased.Load accumulation and lateral deformation increased with increasing filling velocity in the same period of time,which had an obvious effect on the shallow foundation.If the filling height keeps unchanged,the alteration of filling velocity cannot change the loading amount,so time effect is the main factor influencing deformation.