地下超长结构环境温度效应数值模拟分析

Numerical simulation of ambient temperature effect on underground over-long structure

为分析环境温度对地下隧道结构温度场、温度应力场及变形的影响,基于对隧道超长钢筋混凝土结构使用阶段结构变形实测数据,利用ANSYS10.0软件对南京玄武湖隧道90m长无缝结构的环境温度效应进行数值计算分析。结果表明,环境温度作用下隧道结构温度由内壁向外围土体形成明显的温度梯度,结构温度随环境气温波动,而且波动存在滞后相位;负温差作用下结构沿纵向产生拉应力,由内壁至外壁逐渐减小,最大拉应力位于中间截面;负温差作用下结构沿纵向收缩变形,且变形大小与结构内温差呈线性关系,最大位移位于结构无缝段端部截面,其值比实测值略大。环境温度效应对地下超长混凝土隧道结构的影响不容忽视。

To analyze the ambient temperature effect on the temperature field,thermal stress field and the deformation of reinforced concrete tunnel structure,numerical simulation was processed based on the actual measurement of the 90m jointless structure deformation in using age,by using ANSYS10.0 software.The results show that,there is obvious temperature gradient from the internal wall of the tunnel structure to the outside soil mass,and the structure temperature fluctuates with the change of the ambient temperature,only with lagging phase.Under the negative temperature difference tensile stress exists along the long direction of the tunnel structure,which decreases from internal wall to out wall,the largest of which is located in the middle section.The tunnel structure shrinks along the long direction,and the deformation is linear with the inner structure temperature difference,the largest of which,bigger than the value of actual measurement,is located in the terminal section of the structure,under the negative temperature difference.Therefore,the ambient temperature effect on the over-long tunnel structure can＇t be ignored.