东北季冻区灌渠渠底土冻胀力影响因素分析

Analysis of Impacting Factors of Frost Heaving Force of Soil Under Canal in Seasonal Frost Region in Northeast China

为研究东北寒区频发的渠道冻胀问题,针对黑龙江北安二龙山农场灌渠渠底冻胀情况,将其简化为一维冻胀模型,设计并制作了符合一维冻胀工况的试验装置,采用正交试验方法对影响渠底土冻胀力的因素进行分析,结果表明:平均冻胀温度是最主要的影响因素,冻胀力随温度的降低而升高,且在-40℃时(其他因素不变)法向冻胀力最大,为1.49MPa;含水率影响也比较显著,冻胀力随含水率增大而升高,但当含水率超过18%时冻胀力略有下降,含水率为18%时(其他因素不变)冻胀力最大,为1.45 MPa;当含水率为14%、平均冻胀温度为-40℃、预加压力为1 kN、土样孔隙率为62%时,冻胀力最大,冻胀最明显。

In order to investigate the problem of canals＇ frost heaving damage in the cold area of northeast of China,a one-dimensional model of frost heaving was set up and calculated for simulating the bottom of channel in Erlongshan Farm of Beian State Farm in Heilongjiang Province. A testing device conforming to the one-dimensional working condition was designed and fabricated. The factors of influencing the frost heaving force of canal＇s subsoil were analyzed by using of the orthogonal experiment. The results show that the frosting temperature range is the most impacting factor. Frost heaving force increases with the decreasing of temperature. And when the temperature reaches to -40℃, the maximum frost heaving force is 1. 49 MPa. The second important impacting factor is the water ratio. The frost heaving force increases with the increasing of water ratio,however the frost heaving force slightly decreases when the water ratio exceeds 18%. At this point,the maxi-mum frost heaving force is 1. 45 MPa. The maximum frost heaving force can be got on the condition that the water ratio is 14%,the frost temperature is -40℃,the pressure is 1kN and soil porosity is 62%. In this condition,the most obvious frost heaving effect can be arrived.