Text Studying And Numerical Simulation Of The Prestressed Anchor Cable Composite Soil Nailing Wall

Soil nail supporting is broadly used in undergroundengineering, especially used in foundation pit because of itsnumerous advantages such as fast construction, economicsecurity and so on. However, the generalization of soil nail islimited by itself applied conditions. Since composite soil nailsupporting has been gradually used in retaining and protectingfor foundation excavation,Practice has showed its economicadvantage.The prestressed anchor cable composite soil nail, acommon and effective method of composite soil nailingsupporting, adopts soil nailing and prestressed anchor nail. Itcan control the deformation of foundation ditch effectively andimprove the stability of earth slope greatly. But compared withapplication of composite soil nail, theoretic study for compositesoil nail is comparatively laggard, so as to many engineeringaccidents, which had brought biggish economic losses andharmful effect to society, happened because of incompletedesign method, absent test study etc. Therefore, study for workmechanism, design method and construction technology ofcomposite soil nail is useful of technically perfection, and alsouseful of broadly application of this technology.In this paper, author back up Shenzhen Holiday PlazaProject, use combinative method for theory guidance, test study,simulation analysis, project application and so on, entirely anddeeply study prestressed anchor cable composite soil nail, andalso make a pilot study for deformation of pile anchor compositesoil nail. Author proceeds with the evolvement course from soilnail to composite soil nail, introduces actual study anddevelopment to soil nail and composite soil nail, and points outsome existent problems about composite soil nail in theoreticstudy. Brief introduces all kinds of composite soil nail supportingstructure and their construction technique. Lots of entirelysitu-test study for prestressed anchor cable composite soil nailhas been made. According to test results, author analysesdeformation characters and its rules of prestressed anchor cablecomposite soil nail supporting and pile anchor composite soil nailsupporting, studies work mechanism of prestressed anchorcable composite soil nail supporting structure, explores changeregularity of inner force of soil nail and anchor cable, soilpressure of surface, and pore water pressure, especially studiesdistribution and change of inner force of supporting structurealong with change of exterior factors, such as foundationexcavation, underground water, rainfall, load-on/load-off on thetop of foundation pit, tension of anchor cable, explosion vibrationetc, illustrates mutual action among nail, anchor cable and soil,indicates the effect for soil parameter , which exerted bysupporting and high-pressure injection grout, and analysesdestroy form and stability of prestressed anchor cable compositesoil nail supporting and pile anchor composite soil nailsupporting. Combined with FLAC 3D software, authorestablishes three-dimensional finite difference model, andsimulates construction process of prestressed anchor cablecomposite soil nail supporting. In the process of simulation,neural network back analysis is used, in order to obtain exactersimulation and forecast, and guide information construction.Detailed analyses construction technology and gist ofprestressed anchor cable composite soil nail, indicates disposalmethod of especial condition in the process of construction,discusses flexible application of information construction anddynamic design in the process of foundation excavation,analyses the causations of some engineering accidents.