热力耦合作用对桩及桩间土拱效应的影响研究*

为研究负温对桩侧应力及桩间土拱效应的影响，通过FLAC3D软件模拟热力耦合作用下新型排桩冻结法中桩间土拱效应的变化及温度效应下的桩间距，并根据巴霍尔金单排管冻结稳态温度场解析解，建立冻结壁平均温度区域解。研究结果表明:桩土接触面的应力分量τxy近似线性变化，应力分量σx近似均匀分布，温度降低对应力分量τxy的分布影响较小，但对应力分量σx的影响较大；负温使桩间距发生变化，且整体平均应力的分布也更加均匀化；通过与巴霍尔金解析解对比，证明单排管冻结温度场模型的可行性，在此基础上建立的单排管冻结壁平均温度区域解，其与数值模拟结果相差不超过1 ℃，计算误差满足工程要求；随着冻结时间的增加，单排管冻结壁温度场呈抛物线形式降低。

Study on influence of thermal mechanical coupling effect on pile and soil arch effect between piles

To study the influence of negative temperature on the lateral stress of pile and the soil arch effect between piles,the change of soil arch effect between piles and the pile spacing under temperature effect in the new freezing method of row piles under the thermal mechanical coupling effect were simulated by using the FLAC3D software,and the regional solution of average temperature on the freezing wall was established according to the analytical solution of steady temperature field in the freezing of Barhoergin single row pipe.The results showed that the stress component τxy of the pile soil contact surface presented the approximate linear change,and the stress component σx presented the approximate uniform distribution.The temperature decrease had less influence on the distribution of stress component τxy,but had larger influence on the stress component σx.The negative temperature made the pile spacing change,and the distribution of overall average stress was more uniform.The feasibility of the single row pipe freezing temperature field model was proved by comparing with the Barhoergin analytical solution.On this basis,the regional solution of average temperature on the freezing wall of single row pipe was established,and the difference between it and the numerical simulation results was less than 1 ℃,so the calculation error could meet the engineering requirement.With the increase of freezing time,the temperature field on the freezing wall of single row pipe decreased with the parabolic form.