滑坡防治前后滑带土基质吸力特征研究

降雨使坡内地下水位上升,坡体的基质吸力和暂态孔隙水压力会随着降雨过程和时间呈现不同的变化趋势。采用抗滑桩、挡墙等工程防治后,针对滑坡体滑带土的性质变化以及抗滑结构的设置是否会影响到滑坡体的自然排水通道,导致坡体地下水位的抬升,从而影响滑坡防治效果等问题进行了研究。以鹰厦线K290滑坡为主线,通过开展滑坡饱和-非饱和渗流模型试验与数值分析,探讨了降雨入渗及地下水位变化下滑坡体及滑带土体积含水率与基质吸力的变化规律,以及其对滑坡防治前后坡体渗流场的影响。在此基础上,探讨了滑带土基质吸力对抗剪强度的贡献。研究表明:防治前后滑坡体及滑带土基质吸力受降雨强度等条件影响明显,不同深度处滑带土基质吸力变化呈现不同的变化规律,在土质滑坡的防治中应考虑抗滑桩的布置对滑带土性质的影响。

Study of characteristics of matric suction in landslide slip soils before and after landslide control

During the period of rainfall, groundwater level in the slope will rise; the matric suction and the temporary pore water pressure will change with time and rainfal1; after constructed the anti-slide piles, retaining wall or drainage structures, the change of the nature of slip zone and anti-slide structure settings whether affect the natural drainage channel of landslides, which lead to the groundwater table rising of landslide, then affect the effectiveness of landslide control. This paper discusses variable rule of volumetric water content and matric suction and seepage-field in the landslide under different conditions of rainfall infiltration and groundwater level change that on the saturated-unsaturated seepage model test and analysis of number value. On this basis, the contribution of matric suction to shear strength is considered. Studies have suggested: The matric suction in the landslide influenced by conditions such as the rainfall intensity, etc.; different change laws appear at different depths. So it should be considered that the anti-slide pile projects affect soil property in prevention and cure that soil landslide.