热-力耦合下能源桩沉降和荷载传递特性的数值分析

Numerical Analysis of Settlement and Load Transfer Characteristics of Energy Pile under Thermal-force Coupling

在热—力耦合下,能源桩荷载传递及其沉降规律是能源桩的研究热点。通过FLAC 3D有限差分软件研究能源桩在冬季运行工况下的沉降和荷载传递特性,并用London试验验证数值计算结果的合理性和正确性。通过研究温度对桩身轴力以及桩体和桩侧土体的沉降的影响,发现热—力耦合作用下桩体的轴力大于仅荷载作用时;桩体因自身温度升高而膨胀,桩体的上半部分相对于桩侧土体向上运动,桩体的下半部分相对于桩侧土体向下移动,使得桩体顶部的沉降量减小,热—力耦合作用下桩侧土体的沉降量小于仅荷载作用时。

Under thermal-mechanical coupling,the load transfer of energy pile and its settlement law are the research hotspot of energy pile.FLAC 3D finite difference software was used to study the settlement and load transfer characteristics of energy pile in winter,and rationality and correctness of numerical calculation results were verified by London experiment.By studying the influence of temperature on axial force of pile and settlement of pile and soil,it is found that the axial force of pile under thermal-mechanical coupling is greater than that under load alone.The pile expands due to the increase of its own temperature.The upper part of pile moves upward relative to soil on the pile side,while the lower part of pile body moves downward relative to soil on the pile side,which reduces the settlement amount on the top of pile.The settlement amount of soil on the pile side under the action of thermal-mechanical coupling is less than that under load alone.