| XinYan landslide near Yanji city is located in the K58+750~K59+30biddingsection of Wangqing-Yanji highway under construction, which is characterized by aswell soft rock landslide. The slope failure is caused by many factors especially therole of water. The stability of slope will be affected when there is a rainfall making theseepage field of slope redistribution which causes the variation of water content andstrength in unsaturated soil. Relaying on the project of mechanism and governanceresearch of Wangqing-Yanji soft base road, the seepage properties of rock and soilmass is studied in this paper, in the meantime, basing on saturated-unsaturatedseepage theory and rainfall infiltration theory, numerical simulation(SEEP/W finiteelement sofrware) is applied to analyze the affection of seepage field under differentfactors. Then the calculated transient seepage field is used to analyze stability of slope,which the stability analysis method is limit equilibrium taking unsaturated soil shearstrength into consideration, and different factors are discussed to the influence ofstability. There are some conclusions in our research.(1) The main character of XinYan swell soft rock landslide is multi-cracks. Themajority type of crack are extensive, few is bulged.(2) The swell laboratory test of rock and soil mass shows that it belongs to weakexpansive soil and has stronger swelling force. High contents of montmorilloniteminal, exchangeable cation and fine pore are its features.(3) Basing on previous researcher’s result, the parameter of Fredlund-XingSWCC on rock and mass of slope a, n and m are predicted by physical propertyindex. The result shows filled soil(porosity, breaking) and whole weatheredsandstone have lower AEV, lower residual suction and fine water capacity in mediumsuction region. Infiltration test figures that the saturated infiltration coefficient(m/s)of filled soil(porosity, breaking) and whole weathered are in the magnitudes of10-6,while filled soil(compacting), silty clay and whole weathered mudstone are10-8, andthe least is strong weathered clay, it is only in the magnitude of10-8.(4) SEEP/W software is applied to simulate transient seepage field under rainfall infiltration and make influence factors analysis. The result shows the affection ofrainfall intensity, duration time and max negative pressure head are relative obvious,while rainfall type is little.(5) The SLOPE/W analysis which is introducted pore water pressure from transientseepage field shows matric suction, rainfall intensity, duration time and max negativepressure head all have influences. |
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