Study On Formation Mechanism Of The Slow-inclination Landslide In Red Stratum Region, SiChuan

The red bed is famous for slide-prone stratum. The red beds landslide is widelydistributed over Sichuan, Chongqing, Yunnan and so on. And there are two typicalcases of landslide widespread over the red stratum slow-inclination strata in Sichuan.The one defined as slow-inclination deep-seated rockslide almost occurs in dippingstrata sand and mud interbed, which in the inclination of10°～20°.The other onedefined as slow-inclination shallow soil landslide occurs in ramp slope dipping’sshallow soil, and mostly slides along the bedrock-cover discontinuity. For example,the strong rainstorm in16th September,2011have had been a trigger for thelarge-scale and group-occurring slow-inclination landslide in Nanjiang County,Bazhong City in Sichuan. However it should have been difficult to see landslidearound this kind of area in normal condition. Not to mention the large-scale andgroup-occurring landslide. Thus it could be seen that there must be some formationcondition and formation mechanism extremely special in the landslide. There are alsolots of scholars are researching on the formation mechanism of the gentle\rockstratum landslide, but the object of most of them is the nearly translational landslides（0°～10°). Though there is not much difference between the strata inclination of thistwo kind of landslide, as for geology environment, formation condition and formationmechanism, the two kind of landslide is indeed distinct. Therefore, it is necessary togo deep into the research of the formation mechanism of the slow-inclination redstratum landslide.This thesis, relying on the item of Study on the Mechanics of Rainfall-inducedLandslide and Monitoring Forecast Demonstration Project of Low-Angle Dip BeddedSlope in East Sichuan, targeting at the slow-inclination landslide touched off heavyrainfall in Nanjiang, background of the slow-inclination landslide’s geologyenvironment and several group-occurring landslide touched off heavy rainfall around the area, the study area " slow-inclination deep-seated rockslide" and "slow-inclination shallow soil landslides" were done in-depth research.starting with the slow-inclination deep-seated rockslide’s typical case’s occurredin Yaochangping, Gaoqiao Township, Nanjiang County and Shibangou, JiangyingVillage, Nanjiang County, and Niumachang, Fengyi Township, Nanjiang County,combined with the growth feature and distribution law of17’s slow-inclinationdeep-seated rockslide around the area, carries out research deeply and systematicallyon the slow-inclination deep-seated rockslide inoculation geological environment anddistortion and failure. Based on it, it makes a deep analysis and discussion for theformation mechanism of slow-inclination deep-seated rockslide touched off rainstorm,combined with the laboratory test of the red-bed soft rock turns out to be deteriorationwhen it meets water’s mechanism and the deformation failure mechanism of theslow-inclination deep-seated rockslide’s discrete element numerical simulation, itinquires into the mechanism of slow-inclination deep-seated rockslide. At last, basedon the analysis method of limit equilibrium, it puts forward considering the assessablemethod of the infiltration segment length of the potential sliding surface underdemineralization and the time of the potential sliding surface underdemineralization that is aimed at the slow-inclination deep-seated rockslide touchedoff rainstorm, and as the example of Shibangou,Jiangying Village landslide,appraises the landslide stability based on the rainfall process around the landslide.Starting with the slow-inclination Shallow soil slide’s typical case’s occurred inQilincun, Xialiang Township, Nanjiang County and Erhuangping, GanchangTownship, Nanjiang County，combined with the growth feature and distribution lawof50’s slow-inclination Shallow soil slide around the area, carries out research deeplyand systematically on the slow-inclination Shallow soil slide inoculation geologicalenvironment and deformation disruption model. Based on it, it makes a deep analysisand discussion for the formation mechanism of slow-inclination Shallow soil slidetouched off rainstorm.