寒区公路土质边坡冻融界面的抗剪强度试验

Experimental study on shear strength deterioration of the freezing and thawing interface of soil slope in seasonal frozen regions

季节冻土地区公路土质边坡在春季融化期经常发生浅层滑坡,对公路运输造成了严重的潜在威胁。冻融界面处的土体抗剪强度是发生滑坡的直接影响因素,采用不同的材料配比设计冻融界面的抗剪强度模型试验,该试验针对不同的土体含水量以及冻融循环次数进行剪应力测试,通过试验获得界面抗剪强度与冻融循环次数间的关系,基于数据得到冻融界面土体抗剪强度的损伤模型。考虑到正融土质边坡发生失稳破坏时其抗剪强度与土体内部的受力条件及边坡的几何尺寸有关,因此通过试验得到土体剪切强度后,可为评价季节冰冻区边坡稳定性提供直接数据参考,也可为季节冰冻区土质边坡的设计以及稳定性分析提供借鉴。

In seasonal frozen regions,shallow landslide hazards in soil slopes usually happen,which pose a serious threat to road safety operations.The direct influence factor of soil slope failure is the shear strength of the soil between the freezing and thawing surface.This paper designsa model experiment of freeze-thaw soil interface with different aggregate materials,by alternating the freeze-thaw cycle times and the water content of soil,then obtains the relationship between shear strength and freeze-thaw cycle times.Finally the shear strength deterioration modal of the soil surface is put forward.The main parameters and influence factors of melting soil slope failure are relate to the soil inner stress and geometry form of the slope.So based on the fully understand of the soil shear strength,the result can not only present the reference to fix on the soil slope landslide surface position,but also offer the slope design and stability analysis in seasonal frozen regions.