路基混凝土施工期温度应力影响因素敏感性分析

Sensibility of factors influencing temperature stress of roadbed concrete during construction period

针对路基混凝土施工期裂缝对路基稳定不利影响的问题,文章以汕(头)湛(江)高速公路云浮至湛江段及支线工程(化州至湛江段)第TJ-29合同段为研究对象,借助ANSYS有限元分析软件,结合工程实测资料以及以往建模经验,建立应力应变场仿真计算模型,系统地分析入仓温度、弹性模量两个因素对温度应力的影响。从分析结果来看:(1)混凝土结构的拉应力增长与温度变化呈指数正相关;(2)拉应力增长与弹性模量变化呈线性正相关;(3)混凝土入仓温度变化对于拉应力场的影响要远大于弹性模量变化引起的影响;(4)最容易形成裂缝的时间段为入仓2 d至5 d。

The concrete cracks during the construction period can undermine the roadbed stability. In this study, with a practical road construction as the example, the author studied the effect of placement temperature and elasticity modulus on the temperature stress with a stress-strain field simulation and calculation model established with ANASYS. It was found that the increase of tensile stress was exponentially positively correlated with the change of temperature,while linearly positively correlated with the change of the elasticity modulus. The effect of the placement temperature on the tensile stress field was much larger than that of elasticity modulus. The cracks were most likely formed during the time from 2 days to 5 days after placement.