地下水热效应桩基试验装置的研究和应用

为研究地下水对冻土地区桩基础的影响,针对现有冻土桩基试验设备的不足,对加载系统、位移采集系统等加以改进,并利用可调发热电阻作为热源,研制一套能够模拟地下水热效应的室内桩基模型试验装置,通过标定试验,确定装置模拟地下水热效应时的各项参数。利用该装置,开展不同地下水位置、有无地下水工况下的桩基承载力试验,对地下水热效应对单桩极限承载力的影响进行分析,其试验结果能够与理论模型计算较好的吻合,装置能够良好模拟地下水热效应。

Development of Pile Foundation Test System Simulating Thermal Effect of Groundwater and its Application

In order to study the influence of groundwater on the pile foundation in permafrost area,a new type of indoor pile foundation test system is developed on the basis of the exiting equipment with improved loading system and displacement collection system to simulate the thermal effect of groundwater by using adjustable resistance as heat source. The parameters of the system are determined through calibration test.With the test system,the bearing capacity test of pile foundation at different groundwater level,with or without groundwater condition,is carried out to analyze the influence of thermal effect of groundwater on single pile ultimate bearing capacity. The test result is in good agreement with the theoretical model calculation,showing that the device can well simulate thermal effect of groundwater.