考虑温度影响的软黏土长期动孔压模型研究

以宁波轨道交通④层淤泥质黏土为对象,开展了不同温度、动应力、初始偏应力、围压作用下的动三轴试验,获得了不同试验条件对孔压的影响规律。在此基础上,对现有的孔压-振动次数双曲线模型进行改进,建立了考虑温度影响的动孔压-振动次数模型;其次,利用孔压试验结果对模型进行验证,并给出了不同试验工况下的模型参数;最后,基于动态平衡假设,建立了长期动荷载作用下考虑温度影响的归一化孔压预测模型,模型预测值与试验结果吻合性较好,可以为轨道交通设计和施工提供理论依据。

Study on long-term dynamic pore pressure model of soft clay considering temperature effect

Taking the ④ layers of silty clay in Ningbo Rail Transit as the object, the dynamic triaxial tests under different temperature, dynamic stress, initial deviatoric stress and confining pressure were carried out, and the influence of different test conditions on the pore pressure was obtained. On this basis, the existing hyperbolic model of pore pressure-vibration times is improved, and furthermore, the dynamic pore pressure-vibration number model considering the influence of temperature is established. Secondly, the model is verified by the pore pressure test results, and the models under different test conditions are given. Finally, based on the dynamic equilibrium assumption, a normalized pore pressure prediction model considering the temperature influence under long-term dynamic loading is presented. The prediction value of model is in good agreement with the experimental results, which can provide a theoretical basis for rail transit design and construction.