桩-红黏土接触面温控测试及应力-应变关系研究

在对能量桩承载特性进行设计与计算时，能量桩桩-土接触面力学特性十分重要；已有桩-土接触面力学特性研究中考虑温度效应的仍相对较少。采用重庆地区重塑红黏土，通过室内温控直剪试验测试其桩-土接触面力学特性，并与土体本身直剪强度特性进行对比；基于能量耗散原理推导的桩-土接触面模型，分析红黏土温度效应试验结果，归纳形成两个温度因子?1、?2，建立考虑温度效应的桩-红黏土接触面模型。通过新模型模拟结果与实测值的对比，验证文中所建立的桩-红黏土接触面温度效应模型的准确性和可靠性。研究结果表明，文中试验条件下，温度升高，桩-红黏土接触面的剪切强度略有增大；桩-红黏土接触面温度效应模型可以较好地模拟不同法向应力下的接触面应力-应变曲线，并且可以在一定程度上反映温度对接触面力学特性的影响。

Study of temperature-controlled pile-red clay interface tests and#br# stress-strain relationship

The mechanical properties of pile-soil interface have important influence on the design and calculation of bearing capacity of energy piles. However, there are relatively few studies on the mechanical properties of pile-soil interface considering the influence of temperature. The remodeling red clay from Chongqing was used to conduct the temperature-controlled direct shear test to study the mechanical properties of pile-soil interface. The results of the interface tests were compared with that of soil as well. Based on the potential energy dissipation principle, two temperature factors ?1、 ?2 were concluded to established the pile-soil interface model considering temperature effects. The accuracy and reliability of the new model were verified trough the comparison of the simulation results with the measured data. The results show that the shear strength of pile-red clay interface increases slightly with temperature in this test. The new model of pile-red clay interface considering temperature effects can simulate the stress-strain curves under different normal loadings, and to a certain extent the temperature influence on the interface mechanical properties can be reflected.