砂性冻土堤防冻融作用下水分迁移试验研究

以工程实际环境为研究基础,阐述砂性土堤防在冻融作用下的破坏机理,并介绍一种新型研究水分迁移试验装置,利用该装置测量黑龙江干流堤防典型砂性土试样在冻融循环作用下的温度场、水分场、应力场的时空分布。试验结果表明:堤顶公路破坏与堤身不均匀沉降有关,温度变化引起含水率出现梯度变化,从而出现应力场变化,且温度梯度含水率梯度呈线性关系。冻结初期土柱顶部出现应力增加,稳定后应力减小,稳定冻结深度1 m左右。

Experimental Study of Moisture Migration of Sandy Frozen Soil Embankment under Freeze-Thaw Cycles

Based on a practical project environment, in this study, we studied the failure mechanism of a sandy soil embankment subjected to freeze-thaw cycles, and introduced a novel moisture-transfer test device. We used this device to measure the space-time distribution of the temperature, water, and stress fields of typical sandy soil specimens from the main dike of the Heilongjiang River during freeze-thaw cycles. The test results show that the damage to the embankment is related to its uneven settlement. We found the change in the water content gradient to be due to the temperature change, which changes the stress field, and the water content and temperature gradients have a linear relation. The stress increases at the top of the soil column during the initial freezing period and decreases after it has stabilized, with the stable freezing depth occurring at about 1 m.