Coupling Study Of Seepage Stress Of Laterite Dam After Alkali Erosion

As a kind of time-honored dam,earth-rock dam is widely used in construction of water conservancy engineering and tailings dam because of its simple construction,low construction technology and low cost.In areas covered by laterite,mainly taking blocky and granular red soil as the raw material of dam shell and anti-seepage body.From the perspective of disaster geology,the earth-rock dam belongs to artificial geological body.Because of the technical and historical reasons,such dams often appear the danger of leakage,collapse,landslide and breach,which cause serious threat to people's life and property safety.So far,the repair technology of the general earth-rock dam is widely used in the reinforcement of red clay dam,ignoring the long-term erosion of the reinforcement material on the laterite of dam,resuting in the strange phenomenon that the reinforcement of dam exacerbates its dangerous situation.In the earth-rock dam subjected to alkaline material erosion,the interaction of seepage and stress has a significant deterioration effect on the stability of the wading slope,so this paper used the method of seepage-stress coupling to analyze the safety performance of dangerous earth-rock dam.The preliminary conclusions are as follows:Under the alkali material erosion,the original chemical bond is destroyed,the cementation material is consumed unceasingly;the soil particles are gradually decomposed and bringed out of the soil by pressure water,so the pores between the particles increased,appering overhead phenomenon and leakage channels.With the deepening of chemical reaction,the loss of Al,Ti and SiO2 in the dam material increased,permeability coefficient and compression coefficient increased significantly,and the cohesion,specific gravity and internal friction angle decreased.So this paper considers that alkaline matter reacts with red clay,and which is the basic reason of deterioration of dam material index.With the increase of alkali erosion,the saturation line and saturation point of the dam obviously rised,the seepage flow increase,and the displacement and stress of the dam increase.Due to the deterioration of physical mechanics indexes of dam material,the adverse effects such as seepage uplift pressure,seepage pressure,lubrication,corrosion are more obvious,the stability of the dam slope is significantly decreased.Using the method of seepage-stress coupling to analyze the safety performance of LongLin dam,and the results are consistent with dam safety identification.The interaction of seepage and stress has a significant deterioration effect on the stability of the wading slope after alkaline material erosion,so the coupling analysis method of seepage-stress can provide reference for the safety identification of laterite dam after alkaline erosion.