Analysis Of Slope Stability Under Rainfall Conditions

For the research rain a condition lower limb the steadiness of the ascent, this text mainly studied saturated homogeneity soil and saturated heterogeneity soil to rain a condition in the dissimilarity under of seepage flow and steadiness;Combine an engineering case analytically unsaturated heterogeneity soil under the situation that the dissimilarity rains of seepage flow and steadiness.Main research result as follows:1.Pore pressure head, total head and amount of precipitation of saturated heterogeneity soil and saturated homogeneity soil become a direct proportion relation;The seepage flow quantity and amount of precipitation of the saturated homogeneity soil becomes line sexual behavior;Under the same rain precipitation condition the amount of seepage flow of the oozing of saturated heterogeneity soil discharge ratio saturated homogeneity soil is small;In the unsaturated heterogeneity soil, the beginning of of each soil layer starts degree of saturation different, but along with rain precipitation into ooze, the degree of saturation arch of of each soil layer is slowly excessive, of the soil layer replenishment water of the supremacy but bottom, bottom layer soil layer degree of saturation increment;The time area concentration diagram and amount of precipitation decides to rain to go into to ooze of depth area curve, the same amount of precipitation rains, go into ooze depth area curve along with the increment in time area concentration diagram but increase;Same time, go into to ooze depth area curve along with the increment of the amount of precipitation but increase.2.Saturated homogeneity soil and saturated heterogeneity soil along with the increment of the amount of precipitation, the cooperation of seepage flow field and stress field was used stress is present an index number growth;The stress index number of saturated heterogeneity soil passes to increase the stress that the partial velocity compares saturated homogeneity soil to pass to increase partial velocity big.And there is the stress variety of a mutation after exerting amount of precipitation, then the arch is slow of index number increment.Saturated heterogeneity soil side slope along with the increment of the amount of precipitation, the safe coefficient presents index number to gradually decrease.3.The dissimilarity rains a condition under, same alike and every moment, the top of slope total amount of the unsaturated heterogeneity soil side slope total moves, toe of slope total amount the total move to present the line increased trend, top of slope and toe of slope to move toward the total amount with the toe of slope level total amount to move line to pass to increase.Light rain and medium rain condition go down slope summit and toe of slope total amount the total move, the move to the total amount and the toe of slope level total amount’s moving is tended to level, but heavy rain and heavy rain condition go down slope a total of summit and toe of slope total amount to move, the move to the total amount and the toe of slope level total amount move a mutation.4.The dissimilarity rains a condition under, top of slope because of positive pore water pressure more big, the top of slope appears negative shearing stress, then pore water pressure dissipation, the top of slope shearing stress changes into just when;Toe of slope shearing stress while raining a beginning because of the rain precipitation cause negative pore water pressure enlarge, the shearing stress increases, the safe coefficient lets up, then in the process of raining in slow-moving increment, but rain the process shearing stress increment speed ratio’s rain precipitation after shearing stress increment of speed;Because the top of slope pore water pressure is big, same alike every moment same rain precipitation condition descending grade summit the shearing stress is smaller than toe of slope shearing stress.5.Unsaturated heterogeneity soil side slope the effective plastic ward run-through rate is in the process of raining center line increment, the effective plastic ward run-through rate presents line to pass to increase after stopping in the rain precipitation;Under the light rain condition and in under rain condition the effective plastic ward run-through rate increase quantity to present line increment and have no obvious of mutation;But under heavy rain and heavy rain condition the effective plastic ward run-through rate increases to mete out to mutate now.Distinguish a side slope steadiness ability one not of led to distinguish from the effective plastic ward run-through, should combine an effective plastic ward run-through rate to increase quantity mutation to distinguish.