冻土区桩侧水热效应对桩基稳定性影响的模型试验研究

为了研究冻土区桩侧水热效应对桩基稳定性的影响,采用电阻热源模拟桩侧水热效应,并利用高低温试验箱进行单桩模型试验,通过设定有、无桩侧水两种环境因素,对比分析了桩侧水热效应对桩身应变、桩侧冻结应力、桩土相对位移、桩基的极限承载力和桩侧冻结应力与桩顶位移的流变特性的影响。试验表明,冻土区桩侧水热效应能使桩侧冻结应力减弱,造成桩身应变与桩顶位移增大,桩-土相对位移增加,同时加速桩基沉降,导致桩基极限承载力降幅达16%,且上述影响随着荷载等级的提高而增强,造成桩基承载力严重下降。

Model test study of pile - side hydrothermal effect on pile stabilityin permafrost region

In order to study the influence of the pile side effect on the stability of pile foundation, the thermal effect of the pile side is simulated by the resistance heat source, and the single pile model test is carried out by using the high and low temperature test box. By setting with and without water pile two environmental factors, comparing and analysing the pile side water thermal effect on the strain of the pile, pile frozen limit force and pile-soil relative displacement, pile bearing capacity of pile and rheological behavior of pile side freezing stress and pile top displacement. The test shows that thermal effect of pile side water in permafrost region can weaken the stress of the pile side., which caused the pile strain and the pile top displacement increase, the pile soil relative displacement increases, and the pile foundation settlement is accelerated, resulting in the decrease of the ultimate bearing capacity of pile foundation by 16%,and The above effects are enhanced with the increasing of the load level, and the bearing capacity of pile foundation is decreased.