Research And Application Of Prestressed Anchor Rod Combined With Soil Nailing Teachnology In A Residential Area In The Foundation Engineering

in recent years in order to solve urban land use and traffic congestion problems and etc, more and more high-rise buildings and subway engineering projects are constructed, correspondingly, the deep foundation pit are also increases. Due to complicated engineering geology, hydrology conditions, site constraints, deformation control, and economic benefit, the technologies of deep foundation pit theory, design and construction need continuous research. The type of deep foundation pit supporting structure are various,such as the soil nailing wall support,having the advantages of simple technology and construct convenient, has been widely used. However soil nail wall support is weaker than other supports in the control of deformation.In order to make up for its shot,it's necessary to combine soil nailing soil nailing with micro-pile,anchor and cement soil pile to form composite soil nailed wall support.So we study the prestressed combined anchor soil nail supporting design and stabilily have great significance to ensure the safely of foundation pit construction.According to He fei a deep foundation pit report, this paper adopts computer software calculation and numerical simulation to carry out.The research contents are as follows.1.It studies the reinforcement mechanism of the prestressed anchor composite soil nailing support from to aspect of soil stress soil material change and nature attribute of soil nailing, chemical action and the nail-soil interaction;analizes it from the transmit power of bolt free part,anchoring soil frictional resistance.The composit soil nailing lateral soil pressure distribution charactoristics are reference to the position of anchor embedment,classical soil pressure and the soil pressure of supporting structure are different, the latter has a dynamic and complicated characteristies.Many scholar have different opinion on model of lateral soil pressure.Bolt serves as assist role for the soil nail wall support, it has great importance for the overall stability. The anchoring section generally for stretchas into stable soil beyond the studing surface to improve stability and safty.2.By studying the deep foundation pit calculation software and geotechnical finite element analysis software to solve the practical engineering application,it uses software calculation and simulation to design soil nailing wall. The result slows that has large deformation. Then by adding prestressed anchor to do the simulation again.The result shows that the different position to bury anchor in the soil nailing wall has differenteffects on the deformation of foundation pit,and additional supporting the upper part of the bolt has the most significant effect on the control of the deformation, it can control the largest deformation with the allowable range.All these has effects on the maximum deformation compared with completely soil nailing support.It is concluded that the addition of the upper anchor bolts has better effect on the control of deformation and the maximum settlement of the wall.