| Zhaojiagou landslide draws great attention of many domestic and overseasscholars due to some special phenomena. Unlike general landslide, Zhaojiagoulandslide happened suddenly during the non-flood season without a strong rainfallprocesses and the occurrence site was not a danger area in conventional conception..What are the factors that trigger Zhaojiagou landslides? Start landslide mechanismand start the process is what? Why is there such a stacked form after landslide? Withthese questions, the author under the guidance of instructors to Zhaojiagou landslidein the title, its start-up and movement characteristics were studied. This paperobtained the following results:(1) According landslide development, movement and accumulationcharacteristics of the landslide, zone the landslide as source area(zone I), flowarea(zone II) and slide cover area(zone III). Zone II starts to form three regions. ZoneII is the flow area and Zone III is the slide cover area. Through the landslide zoningand careful description of the district, the more comprehensive display of the entiremovement landslide characteristics.(2)Zhaojiagou landslide is formed by the accumulation of landslide. Combinedscreening test drilling by means of landslide material composition of the basicformations and have a more clear understanding. Landslide cut at the exit of pebblysilty clay, permeability coefficient of8.57×10-7m/s, the permeability of aquitard,water blocking role to play in front of the sliding body. The main body of the slideclamp pebbly silty clay gravel, permeability coefficient of6.60×10-5m/s, permeabilityis moderate flooding. Slip band is pebbly silty clay, permeability coefficient of9.27×10-7m/s, the permeability of aquitard, water blocking role to play in the bottomof the slide body. Such geological structures conducive to groundwater in the slidebody has brought about an adverse impact on the stability of the landslide.(3) Although the rains lasted40days, but rainfall is only3mm/d, is notsufficient to directly cause landslides, and not the direct cause of the landslide. The higher the position of the platform behind the landslide landslide groundwaterinfiltration can sink the water, so rain caused landslides indirect rather than direct. Formining, the authors believe that the mining process is a long term stress redistributionof the current gob section, there will be local deformation of the upper structure maycause the formation of cracks or loose change seepage upper bedrock, which is along-term deformation process, and deformation results may lead to the formation ofthe mountain fissures, cracks that form if the mountain will form a landslide againstgroundwater infiltration channels, adversely affected by the landslide started.(4) Numerical simulation of flow using the finite element method fixed head, bychanging the permeability coefficient to simulate changes in the mountain aftermountain produce fissures, in order to simulate the change of groundwater. Theresults of numerical simulations of the mountain increased permeability would indeedmake the water line to rise, and with the water level to rise, showing a typicallandslide creep-crack deformation characteristics. This paper also simulates therising water level changes in the landslide body of stress and strain, according to thesimulation results of the landslide is divided into four stages start:①groundwaterinfiltration stage,②surface creep stage,③progressive failure stage,④landslidestart-up phase. Also four stages were described, which analyzes the effect of saturatedwater softening slip bands, respectively, from the formation of slip bands and slip withmineral composition analysis of the effect, but also the design of the correspondingtest in saturated water softening conducted a direct verification, test results, said thelandslide in enough water for7days,54%reduction in cohesion and internal frictionangle decreases. In this paper, scratches slope landslide after exercise, start-up speedof the landslide was estimated, estimates of11.75m/s, belongs to the high-speedstart-up. For high-speed landslide started this article with a theory of excess porewater pressure were analyzed, it was calculated excess pore water pressure, thecalculations show that when the landslide started, mechanical parameters decreased49.9%.(5) Survey methods use the window on the entire range investigated landslideaccumulation and analysis found the landslide accumulation characteristics and lawsof debris flow streams. According to the accumulation of debris flow movementcharacteristics and features, the entire process of landslide movement divided intothree stages:①landslide startup phase,②debris flow of high-speed streams slipperystage,③debris flow stagnation phase. In-depth analysis of the characteristics of eachstage, and calculated in the pore water pressure of landslide startup speed. By momentum transfer method, energy method were calculated maximum speedZhaojiagou landslide movement were26.98m/s,36.6m/s, high-speed remote landslide.And landslides along the speed of calculation. Energy method which takes intoaccount the unique Zhaojiagou landslide "cushion" effect on the speed of the landslidecorrection calculation. Also made a landslide along Zhaojiagou speed estimation map.Analyze and summarize the reasons for the high-speed bovine jugular groovelandslide generated, including the high potential landslide terrain, debris flow effectbeneficial,"cushion" effect and landslides substances. |
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