Slope Stability Evaluation And Study Of Support Measures For Cable Platforms Of Yagen Ⅱ Hydropower Of Yalong River

The proposed middle reaches of the Yalong River Hydropower Station is the roottwo planned third cascade hydropower stations, Design gravity maximum height of130m, cable machine platform slope excavation maximum height of more100m. SlopeRock faults, fissures, especially cable platforms along the slope of a group ofdevelopmental Pohuan small faults dip slope under the control of a strong deformation,superficial crack rock relaxation, poor stability, works to open dig slope there aresecurity risks. Therefore, the evaluation of slope stability cable platforms, and researchappropriate support measures to ensure the safe construction and operation of theproject has important practical significance.Based on the project to identify the occurrence of slope and slope of the geologicalenvironment on the basis of the geological characteristics of the rock slope deformationand fracture characteristics of the structure and conduct research to determine the slopedeformation and failure mode, on this basis, the establishment model of slopedeformation and failure mechanisms, the use of geological analysis and limitequilibrium method for slope stability were qualitative and quantitative evaluation,using FLAC3D after excavation (not support) to simulate the slope, slope engineeringbranch support design studies, using MIDAS/GTS supporting the slope after thesimulation, an overall comprehensive judgment on slope stability. Through the abovework and made the following main understanding:(1) cable platforms slope rock mass structure and development, development hasⅡ, Ⅲ, Ⅳ, Ⅴ grade structural plane, which Ⅲ, Ⅳ, Ⅴ level surface for the mainstructure of the surface structure of the cable machine platform slope range. ClaⅡssstructural development has two faces; classⅢ struct ure surface is part of a large-scaleground faults and fault adit exposed, extruded band, there are three groups of structuralplane:①NE towards steep structu ral su rface,②n early EW to steeply dippin gstructural surface,③NW gentle inclination towards structural surface;ⅳ grade structure surface is flat and squeeze cave fault zone, mostly steep angle faultⅤ; gradestructure to face with NW-NNW oriented.(2) by a cable machine platform slope form and slope deformation and failurecharacteristics adits, combined with the development of the law of surface structure,surface structure analysis shows that the slope controlling a group of NW to NE slowtilt angle of the surface structure, steep dip structural plane NWW toward the surface ofthe structure, slow dip structure can be used as the bottom surface slippery surfaces,steep dip structural surface crack as the trailing edge of the slip surface occurs-crackdamage, NE to steeply dipping structural surface and near-surface structure of EWdirection as steep lateral slope deformation and failure of control surfaces, so slip slopefailure mode-crack damage. Of particular note is the F18as a steep angle fault,exposed in the cable machine platform slope slope table, because of its bandwidth is12m, slope of loose material accumulation table, and cable platforms slope slope tableⅤ class rock, very there may be a combination of slow structural plane dip along thebottom boundary of the occurrence of strong curved unloading slip-crack damage.(3) the slope stability calculations show: Natural slope stability factor in naturalconditions better overall slope in a steady state; in storm conditions, slope stability isalso a corresponding decline, but the slope stability sex has little effect on the overallslope is still in stable condition; earthquake conditions, slope stability in limitequilibrium state~stable condition.After the excavation slope stability factor engineering declined slightly, but theoverall slope of the natural condition stable state; in storm conditions, the result will bereduced accordingly under relatively natural state, but has little effect on the slopestability slope overall is still in stable condition; seismic conditions (accidentalconditions), the slope stability in limit equilibrium state~stable condition. Localstability is poor, and more in an unstable state.(4) slope excavation (not support) numerical simulation analysis showed that:With the total displacement during excavation showed a slight upward trend, afterexcavation ANGLED structural surface outcropping shear strain increment focused onANGLED slope table position, the upper part of the slope slope tabⅴle class rock,plastic zone focused on this area.(5) Through the qualitative and quantitative evaluation of slope stability, slopedesign study support measures as follows: a slow winch platform slope outside thestructure and development of the dump slope surface is the controlling factor of slopestability, prestressed anchor be supporting; F18as a steep angle fault, bandwidth is the width of a large, loose body bags piled slope tableⅴ class rock, exposed in the cablemachine platform engineering slope, has its particularity, it is considered a separateframe anchor its support; engineering slope measures the overall use of plain shotcrete;according to engineering slope conditions, slope drainage ditches external works layout,layout engineering slope drains along each level bridleways arranged drainage ditches.(6) through the support of the slope after the numerical simulation results showthat support measures for slope stability and security to meet the requirements.