Slope Stability Analysis Of Coal Mine Dump In Arid Desert Area Of Northwest China Under Infiltration Condition

The seepage mechanics theory was combined with soil mechanics theory to let on the fluid-solid coupling mechanics mechanism of landslides on the high and steep slope of coal mine dump under irrigation in an arid desert region of Northwest China.Concurrently,the Darcy and mass conservation law,both were introduced to derive the fluid-solid coupling analysis method.Taking Xinxing coal mine of Wuhai city as a sample,the finite element software ABAQUS was used to examine the slope stability of unsaturated soil under the fluid-solid coupling theory.Twelve types of irrigation schemes were observed by choosing four types of irrigation intensity(i.e.,5,20,45 and 70 mm/h)and three sorts of continuous irrgation times(i.e.,2,9 and 15 h)according to the water requirement of vegetation and rainfall intensity,respectively;Aiming at four different initial water content,two equivalent rainfall intensities,68 mm/h and 18 mm/h,were selected for 1 h and 24 h maximum rainfall of super-standard high-steep slope and standard slope,and 16 rainfall schemes were formed.The variation law of slope stability is discussed comprehensively from four aspects:including vertical deformation,pore water pressure distribution,equivalent plastic strain,and safety factor.The stability and rationality of this kind of high and steep slope are studied by comparing with the standard slope.The main results are as follows:(1)Through numerical analysis,infiltration water is easily stored in shallow slope area.The water is concentrated in the surface of the slope and has minimal impact on the bottom of the slope.When the total infiltration water volume is too large,it is easy to form water accumulation inside the slope,increasing the gravity of the rock mass itself,thereby inducing the instability of the slope.(2)The slope top and slope surface should be cut off and drained to prevent the runoff caused by irrigation and rainfall from forming a confluence on the bottom slope.(3)When the greening measures for slope irrigation are carried out,the irrigation intensity should be controlled under the premise of ensuring the stability of the slope,meeting the vegetation requirements and water conservation,and adopting short-term and interval irrigation to reduce the slope.The possibility of runoff.(4)When short-term high-intensity rainfall occurs,the initial water content of the slope is increased,and the slope will develop in a stable direction;when long-term low-intensity rainfall occurs,the initial moisture content of the slope is too high and too low.Will lead to a decline in slope stability.(5)The slope height and slope angle of the slope seriously affect the stability of the slope,and the instability of the slope starts from the foot of the slope and extends from the inside along the slope until the equivalent plastic strain zone penetrates,forming a continuous sliding surface and causing the loss.Steady destruction.For such super-standard high-steep slopes,reinforcement is required at the slopes and slopes,such as masonry skeletons and anti-slide piles.Through the above analysis,it can provide reference and guidance for the greening irrigation in such areas,and prevent sudden and extreme rainfall from causing instability and collapse of the slope.