温控软土地基模型试验装置研发及其应用

Development and application of a temperature-controlled model test device for soft soil ground

温度荷载(升温)对岩土体和工程场地力学特性的影响是近年来岩土工程领域的一个重要研究课题。为了测试温度荷载对软土和软土地基力学特性的影响,在调研国内外相关仪器设备基础之上,设计研发了两种带升温装置的软土地基模型试验装置。第一种方案通过在模型桶内设置螺旋电热丝,实现在模型地基内对地基土进行直接加热;第二种方案利用热水循环仪对空腔式模型桶壁进行加热,实现在模型地基外围对地基土进行加热。测试并对比分析了两套装置的加热效果和可操作性,发现后者性能良好,达到了温控试验装置研发的目标。在此基础上,开展耦合温度的软土地基模型试验。结果表明:温度荷载对软土地基的孔压和沉降均有明显影响;考虑温度的软土地基固结机理及其固结沉降计算均有必要开展进一步研究。

The influence of temperature load on the mechanical properties of soil and foundation is one of the major research topics in geotechnical engineering in recent years. Aiming at studying the influence of temperature load on the mechanical properties of soft soil and soft ground,two model test equipments with heating device for soft soil foundation were set up based on the domestic and foreign related research. Direct heating was formed for the first scheme by setting a spiral electric heating wire in the model bucket. The second scheme applied a hot water circulation machine to heat the cavity of the cavity type mold,and then to heat the ground soil. The heating effect and maneuverability of the two devices were tested and compared. It is found that the second scheme with high performance suits the goal that developing test equipment with temperature control function. On this basis,model test for soft ground with loading and temperature was carried out. The results show that the temperature has obvious influence on the development of pore water pressure and settlement of the soft foundation model. It is thus concluded that it is necessary to further study the consolidation mechanism and the settlement calculation of the soft soil foundation considering the temperature effect.