Study On Process Control Of Talus Slide Run-out Promoting Treatment By Reservoir Level Fluctuation

With the fast-developing of hydroelectricity power industry in southwesternChina, the large scale catastrophic landslides in reservoir have raised people’sattention for the the totally or partly reactivation of ancient landslide under water levelfluctuating condition. The large talus slide sometimes become revivatory because ofthe unceasing expansion of construction scale of hydropower engineering. So theslope protection projects will be more and more difficult, the cost is also growing.However, only a few of slope can take project controlling because of the restriction ofthe various factors such as economic development. In addition, the conventionalcountermeasure such as slope drainage, landslide scaling, fixed retaining, defensiveavoidance can hardly receive the prospective protection result in some slopeprotection projects. In some cases, the poject will be very huge and expensive. It’s anew subject of the engineering designers that how to treat the large talus slideeconomic and efficient. Countries like Australia have already done some effectiveprotection of the slip acceleration by adopting the scientific technology to master thelandslide formation mechanism and the deformation response mechanism of how theslide affect the resevior.The methods of slip acceleration treatment is a key frontiernew technical problems, but it can provide more choices for future reservoir landslideprevention.The Heishui river that in our study area is located in Heishui and maoxian countyAba prefecture, the cascade hydropower stations group, mainly medium-sizedhydropower stations has been built over the river, but both coasts of the Erosionincised valley steep rugged terrain,along mountain the surface of bedrock crushing,thelandslide that consists of a large number of weathering, cracked residual or colluvialdeposits become the most typical geological disaster after the reservoiroperation.Xierguazi landslide,a typical loose pieces of rubble mound Talus landslideof Maoergai reservoir area, it is located in the right bank of Heishui river fromMaoergai dam3km.The total volume of Xierguazi landslide amount to13.41millionm3, the Beier tunnel which parallel across the lower part of landslide and new Mawojitown that adjacent to landslide become the most direct harm objects, After the wenchuan earthquake, with normal water storage of power station dam, the ancientlandslide front has obvious cutted deformation, more than ever it is near dam area, sothe power station operation manager pay more attention to the effective governance ofit.This paper will take the Xierguazi landslide stability and prevention project asthe study case, by exploring the use of process control theory, etc to study on processcontrol of talus slide run-out promoting treatment by reservoir level fluctuation, inorder to form a technique method system with a certain theoretical value and aguiding significance to landslide control. Firstly, this paper based on the theory ofgeological disaster governance design which upon the deformation theory, extract thethe most basic thought of process control, namely use process control theory to studythe landslide deformation and slip velocity, guiding the rational design water level. Onthe basis of the basic point, put the process control and optimization theory, flow-solid interaction theory and theory of computational fluid dynamics theory connect asthe basic of landslide run-out promotion treatment design theoretical system; thenbased on these theories, this paper has summarized two basic methods,including theprocess simulation technology to run-out promoting starting up, the landslidemovement accumulation and a surge of simulation technology, which contribute to thepreventive treatment and design. Lastly, put forward key points of specific process torealize landslide run-out promoting treatment design which base on reservoirscheduling.This paper use the proposed process control method system of landslide run-outpromoting treatment, and apply run-out promoting treatment design to Xierguazilandslide control issues, and systematic study the following aspects:(1) Studies on the engineering geological environmental conditions andengineering geological characteristics of landslide.In this study, the basic form ofdeposit slope, the composition and distribution of material, and the physical andmechanical characteristics of Xierguazi landslide are analyzed, which provide thebasic data for a calculation model of seepage field and stress field coupling analysis.(2) Doing deep analysis on the change of the surface deformation phenomenon,material composition and morphology characteristics; dividing the deformation oflandslide into different period and part; generalizing the formation mechanism andrevival mechanism of landslide; establishing conceptual model of the formationmechanism and revival mechanism of landslide. (3)Based on the existing landslide monitoring data and the characteristics of thereservoir operational water level, the response of landslide deformation under theaction of water are analyzed. Rigid limiting equilibrium method is used to analyze thelandslide stability. After conducting a correlation analysis of surface deformation andthe rise and fall of reservoir water, a multiple regression model is built to predict thelong-term stability of reservoir under the action of reservoir water and the reservoirscheduling scheme in run-out promotion treatment. At last, the conceptions and initialdesign scheme of run-out promotion treatment are presented.(4) Based on process control theory, studing the control of the landslide run-outpromoting and starting up, puts forward basic requirements for the deformation oflandslide control first, with division to control the amount of slide, falling to predicttime to control the reservoir water level when slide into the water.The engineeringgeology–seepage mechanics model is set up for fluid-structure interaction simulateanalysis of landslide run-out promoting deformation,and find out promote the slipdeformation simulation analysis, find out the water level scheduling scheme that canensure to control the deformation of the langslide.(5) This paper researches on the landslide movement and surge process control,based on the theory of process control.It puts forward basic requirements about thelandslide movement accumulation control, then so does basic requirements forlandslide surge height control. After calculating fluid dynamics index, we analyzedmovement of landslide accumulation and landslide surge.Then it validates thevelocity and the initial maximum of height when sliding body gets into water. Basedon former results, we find out the water level scheduling scheme of reservoir that cancontrol the landslide movement surge.(6) In combination with the evaluation results of each control target layer,optimization theory is used to determine the reservoir scheduling scheme in run-outpromotion treatment of landslide.I established influence and effect evaluation systemof run-out promotion treatment, thus comprehensively estimating the local and macroeffect of landslide in run-out promotion treatment. In view of the analysis of treatmenteffect, the slope later period stability and the environmental, economic, social benefit,all of them should be taken into consideration. Finally according to the result ofinfluence and effect evaluation of run-out promotion treatment, feedbacking theevaluation conclusion to the optimum design of sliding of the promoting.