【作者】 樊建利；

【导师】 李天斌；

【作者基本信息】 成都理工大学 ， 地质工程， 2008， 硕士

【摘要】 自然界中,滑坡体上经常因变形产生拉张裂缝,降雨形成的地表径流通过裂缝入渗进入滑坡体对滑坡的稳定性产生影响。本文以这种普遍现象为线索,采用室内试验研究土质滑坡裂缝充水对其稳定性产生的定量(或半定量)影响,为滑坡预测预报及其防治研究提供新思路。本项研究首先针对滑坡中的单条裂缝,研究其充水情况下的流线分布特征、入渗量及入渗强度等;然后根据单裂缝水的入渗特征,对具有多条裂缝的滑坡稳定性进行试验与评价。通过研究,获得的主要认识和结论如下:(1)根据自然界土质滑坡的物质组成特征,选择粘土、细砂、粗砂、石子及水作为基础材料,按一定的质量比例配制出三种滑坡体材料及四种滑带材料。对滑体材料及滑带材料进行相关参数的测定,并对滑带材料进行不同饱和度下的抗剪强度测试,得出抗剪强度与材料饱和度之间呈线性趋势变化关系。(2)在设计的测试设备内制作单裂缝试验模型,然后向裂缝内充水,并观察和测试水在试验模型内的渗流情况和不同时刻流线的分布特征。根据流线分布计算出入渗量。改变裂缝深度、裂缝内水位高度及试验材料,研究入渗量与这些试验条件的关系,得出裂缝内水的入渗特征曲线。研究揭示,裂缝水的入渗量及平均入渗速率与入渗时间呈对数函数趋势关系;入渗量与裂缝内水位高度的二次方呈正比关系,与试验材料渗透系数呈正比关系。综合以上关系,得出入渗量与裂缝内水位高度、材料渗透系数及裂缝深度的关系表达式。(3)选择配制的一种滑体材料及滑带材料进行裂缝充水对土质滑坡稳定性影响的综合试验。按滑坡体上裂缝数量多少共进行了四次试验,根据试验结果归纳出滑坡存在多条裂缝下裂缝内水的入渗特征,即,相同时间下入渗量随滑坡体上裂缝数量的增加而增加,平均入渗速率也随裂缝数量的增加而加快。入渗量及平均入渗速率与入渗时间呈对数函数趋势关系。(4)通过裂缝充水对滑坡稳定性相关因子影响的研究,对滑坡稳定性进行分时段综合评价,得出滑坡从试验开始到试验结束的稳定性变化过程,即滑坡稳定性随裂缝内水的入渗时间增加而不断降低,在裂缝充水结束后,滑坡稳定性逐渐提高。根据综合试验结果,推出滑坡稳定性系数与裂缝内水的入渗量的半定量函数关系表达式。并得出裂缝充水特征通过控制入渗量间接控制滑坡的稳定性,裂缝内水产生的静水压力对滑坡的稳定性具有明显的不利影响。更多还原

【Abstract】 In nature, some pull cracks are caused frequently by landslide mass deformed; running water on the earth’s surface bringed by rainfall will flow into cracks and infiltrate into landslide mass and influence landslide’s stability. This paper bases on this kind of common phenomenon, research quantity (or half quantify) influencing to soil landside’s stability by means of test in home. This research can supply new train of thought in research of landslide’s forecast and prevention and cure. Firstly, this research directed towards single crack, to research distributing feature of streamline and infiltrating amount and infiltrating strength etc. Then base on infiltrating feature of single crack, to test and assess landslide’s stability with more cracks. through research, some recognizing and conclusion as follows:(1)According to substance component feature of soil landslide in nature, choosing clay, fine sand, coarse sand, cobblestone and water as basic materials; with these materials, three types of landslide mass materials and four types of sliding zone materials are compounded. Then test the parameters of landslide mass materials and sliding zone materials. At the same time, sliding zone cutting strength is tested at different saturation, by this means, obtain the result that cutting strength have linearity trend in changing with saturation.(2)Making single crack testing model in the equipment, fill crack with water then observe and test water’s seeping and streamline’s distributing feature in different time. With the distributing feature of streamline, amount of infiltration can be counted. Change the depth of crack and water level and material, researching the relationship between amount of infiltration with above factors and then drawing the curve by feature of infiltration. From research finding that the amount of infiltration and average rate of infiltration have relationship of logarithm function to infiltration time; amount of infiltration is directly proportional to the water level’ height’s square and directly proportional to material’s infiltration coefficient. Sum up relations above, we get the expression of amount of infiltration and water level’s height and depth of crack and infiltration coefficient.(3)With one of landslide mass material and sliding zone material to test landslide’s stability synthetically. Testing is divided into four times by the number of cracks in landslide mass. with the results from testing of infiltration in single crack, we can conclude distributing feature of streamline in landslide mass and features of infiltration with more cracks in landslide mass. Namely, in identical time, amount of infiltration will increase with the increasing of cracks’ number, in the same way average rate of infiltration will increase. Amount of infiltration and average rate of infiltration have relation of logarithm function trend between hours of infiltration.(4)Through research about influence to factors relation to landslide’s stability effect by crack water, we compute the landslide’s stability in synthesis and work out the process of landslide’s stability chang. Namely, landslide’s stability reduces on and on following the increasing of infiltration time of crack water; when no water in crack, landslide’s stability will rise gradually. On the basis of consequence of the synthesis test, we get half quantify relation expression of landslide’s stability and amount of infiltration of crack water, and get conclusion that feature of water level in crack will control landslide’s stability indirectly by controlling amount of infiltration;pressure of still water in crack has obvious harmful influence to landslide’s stability;更多还原