| This paper relies on the public welfare industry special funds scientific research project from Ministry of Water Resources,and the name of the project is "Evaluation of bank slope safety life cycle diagnosis and demonstration of the new protective technology".Based on the typical case of Muyubao landslide which is located in Shazhenxi town in the Three Gorges Reservoir area reservoir,I use analysis of geological data and monitoring data,laboratory test,numerical simulation and theoretical research to study the formation mechanism,deformation features,evolution laws,rock soil mechanics parameters aging deterioration model,landslide stability prediction model,the factors affecting the stability of landslide,slope safety lifecycle diagnosis and evaluation system and diagnostic methods with the comprehensive ways of geological data and monitoring data analysis.I have got main research achievements as follows:(1)According to the evolution stages of landslide,I have analyzed the gravity anticline phenomenon of the Muyubao landslide and predicted that Muyubao landslide will gradually evolve into a consequent accumulation landslide.Combining the characteristics of water rock interaction with the reservoir water level's circulating fluctuation in different periods,I have analyzed the variation characteristics of the monthly average horizontal displacement between different monitoring points with time,and I also have compared with various factors on landslide slope failure from the displacement orders of the monitoring points in different stages.According to the deformation characteristics of the landslide,I propose the developmental status of transverse cracks and longitudinal cracks as an engineering method to recognize the feature of slope deformation.(2)I have analyzed the dry-wet effect of rock mass in hydro-fluctuation belt with the water level fluctuation,the hot-wet effect of bare rock suffering high temperature-rainfall and day and night in high temperature season.According to the data in hand from 2006 to 2012,I use mathematical statistics methods to get the results that the reservoir water level fluctuation occurs one time every year,day and night action in high temperature season occurs 40 times every year,high temperature-rainfall occurs 11 times every year.Then I take the results to establish the deterioration model of rock shear strength parameters with time in the following contents.(3)Quoting the indoor test results of soil rock mixture by Professor Deng Huafeng,I establish the relationship the deterioration quantity of the shear strength parameters of soil rock mixture and moisture content.And I also establish the degradation model of rock shear strength parameters with dry-wet cycling times under the water rock interaction condition.According to back analysis method,I establish the relationship between rock mass shear strength parameters deterioration model and rock shear strength parameters deterioration model to apply to slope stability analysis.(4)By using YZW100 type microcomputer direct shear apparatus,I conduct the direct shear tests of sandstone absorbing water and soaked in water under high temperature.According to the tests,I get the relationship between rock quality and water absorption rate,I also get the law of crack growing.Then I establish deterioration law of the rock shear strength parameters under the two conditions above.I propose bisection method and equivalent method and applied rock deterioration law into practical engineering.Additionally,I analyze the depth and time effects of rock strength with weathering to provide basis for practical application from the experiment outcomes.(5)According to reservoir fluctuation,rainfall and seepage field changing in the rock,I divide the slope influence range suffering related factors.I establish the deterioration equivalent model of rock shear strength parameters in each area with time.With the help of GEO-STUDIO,I get the transient stability diagnosis in natural condition and operation condition of Muyubao landslide in different time to establish the corresponding stability prediction model.(6)According to the sensitivity analysis results of Muyubao landslide in different influential region and the change of potential sliding model under the water rock interaction,I divide the safety lifecycle of Muyubao landslide into four stages.The rock and soil material shear strength parameters degradation ratio of the water rock interaction region(hereafter referred to as study area)are 0-40%,40%-70%,70%-80%and 80%to slope safety lifecycle ending.According to the potential failure mode of each stage,it can be seen that landslide revival time depends on the extinction degree of the resistance sliding function in sliding resistance region.I put forward the derivation based on the classical theory formula.To the different stage nodes in the Muyubao landslide safety life cycle,I analyze the inner diagnosis factors influenced the stability of landslide by cohesion,internal friction angle,severe,sliding surface slope angle and pore water pressure.I get the obtaining the sensitivity values of all the inner diagnostic factors in different stages.I also get the sensitivity values of external diagnostic factors in different stages by traditional sensitivity method.(7)Basing on fuzzy mathematics theory and combining with the deterioration law of diagnostic factors,I establish the safety lifecycle diagnosis system which adapting to prescriptive factors effect on the bank slope's stability.After selecting the reasonable evaluation factors,classifying them according to certain attributes and according to the values of sensitivity to quantify the weight of each factor,I conduct a comprehensive diagnosis of the safety life cycle stability in different stage nodes,which forms a relatively complete bank slope safety life cycle diagnosis chain. |
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