Analysis On Seepage And Stability Of Spoil Ground Slope Under Heavy Rain

The slope of the spoil yard is mainly composed of unusable earth and stone,construction waste and other materials produced by basic construction projects such as highways,railways,and water conservancy projects,which are formed by certain filling methods.The slope soil of the spoil yard has the characteristics of loose structure,complex soil composition,and large permeability coefficient.Rainfall infiltration is one of the most important reasons for this type of slope landslide.This paper studied large-scale spoil yard in Zhenxiong County,Yunnan Province,Based on the survey and test results,the physical and mechanical property parameters of each soil layer in the abandoned soil site were obtained.The on-site soil staining tracer test was used to directly reflect the influence of the coarse particles of the spoiled soil and the roots of the vegetation on the seepage,and related calculation and analysis were carried out;according to the meteorological data of the study area,different rainstorm intensity,duration and type working conditions were set and selected Based on the SEEP/W module of the professional geotechnical software GEO-studio for the slope section of a typical spoil yard,analyze the seepage flow of the spoil yard slope under the set rainstorm conditions;Finally,the seepage calculation results under various rainstorm conditions were imported into SLOP/W module,and the Morgenstern-Price method in limit equilibrium was used to analyze the slope stability under various rainstorm conditions.The research conclusions can reflect the characteristics and laws of the seepage flow of the spoil yard slope under heavy rain conditions,and can also reveal the relationship between the seepage flow of the spoil yard slope and the stability of the slope.Provide reference for slope seepage prevention and reinforcement.The main conclusions of this paper are as follows:(1)The coarse-grained soil in the slope soil of the spoil yard has an important influence on the rainfall infiltration effect and the depth of infiltration,while the plant roots of the spoil yard can only guide the rainfall infiltration of the soil in a certain depth of the surface.(2)The region where soil saturation,volumetric water content,and pore water pressure change most rapidly on spoil yard slopes under rainstorm conditions is at the foot of the spoil slope at all levels,And the higher the position of the soil on the slope,the greater the range of changes in these values.At the same time,the closer the soil on the slope of the spoilyard is to the slope,the greater the impact of precipitation.(3)The greater the intensity of the rainstorm under certain conditions,the more drastic the changes in soil saturation,pore water pressure,and permeability coefficient within a certain depth range of the spoil yard slope;the longer the rainstorm lasts under the same intensity of the rainstorm,the impact of the rainstorm The maximum depth of the soil in the spoil yard is larger;the impact of different types of heavy rain on the seepage depth of the slope soil is also inconsistent.(4)Under rainstorm conditions,the vertical direction of the permeability change characteristics of the spoil yard slope soil: under the same rainstorm intensity,as the rainstorm duration increases,the position of the peak permeability point continues to move downward,and the longer the rainstorm lasts,the permeability The location of the peak point is deeper;under certain conditions of the duration of the rainstorm,the greater the intensity of the rainstorm,the faster the downward movement of the peak point of permeability,and the greater the depth of the peak point;the two cases are stable to the deep layer of the spoil yard slope Both are unfavorable.(5)Under the condition of the same rainstorm intensity,the slope safety factor of the abandoned soil site shows a downward trend with the increase of rainfall duration.Among them,the descent speed is slow in the early stage of the rainstorm and fast in the latter stage;the rainstorm duration is the same under the same conditions.The greater the intensity,the greater the drop in the slope safety factor of the spoil yard,and the lower the stability factor at the end of the rainstorm.Different rainstorm intensity,rainstorm duration,and rain conditions before and after rainstorm result in different overall safety factors of spoil yard slopes,different areas of critical sliding surfaces and maximum depth of sliding surfaces.(6)Through calculation and analysis,under various set rainstorm conditions,the overall stability of the spoil yard slope is in a stable state.