季节冻土层影响下冻土墙温度场模型试验研究

Experimental Study of the Temperature Field in a Frozen Wall Influenced by a Seasonal Frozen Soil Layer

为了研究季节冻土层对冻土墙温度场的影响,基于相似理论开展了季节冻土层影响下冻土墙温度场模型试验.通过水平冻结管形成季节冻土层,竖向冻结管冻结基坑侧壁土体,进行了6种度条件下季节冻土层温的温度场试验.使用无量纲非线性回归公式对试验结果进行了分析,并推导了季节冻土层作用下冻土墙的厚度扩展速度公式和交圈时间公式.结果表明,季节冻土层温度为-12℃,-3℃和无季节冻土层时冻土墙交圈时间分别为10.2,17.5和21 h,而从交圈到达到设计冻土墙厚度的时间分别为12.8,14.3和24.1 h.说明季节冻土层对减少冻土墙的交圈时间和增加交圈后冻土墙的厚度扩展速度都起到了有利作用.回归系数与季节冻土层温度之间具有明显的规律性,能够合理反应和解释试验现象.

The temperature field during freezing of a soil wall located below a seasonal,frozen layer was studied by constructing a model.The wall was formed by vertical freezing pipes and the seasonal layer was modeled by horizontal freezing pipes.Six different temperatures of the seasonal layer were tested.A non-linear equation describing the width of the frozen wall is presented and two other equations are deduced.The results for seasonal layer temperatures of-12,-3 and 0 degrees Celsius were: Time for vertical fre...