Synergy Performance Analysis Of The Soil Nailed Wall And Pile Anchor Combined Support Structure

More and more deep foundation pits come forth with the rapid development of cityconstruction, and the supporting types develop form single structure to combined supporting,such as: pile-anchor composite support, soil-nail and priestesses anchor composite support,pile-anchor and soil-nail composite support, and it has become an inevitable choice. Stressanalysis of various support forms is in-depth study; however, soil-nail wall support has foundwider and wider application because of its advantages, such as: light structure, large flexible,simple construction equipment, and good economic returns. Soil-nail wall is a kind ofpassive support, which leads to large horizontal and vertical displacement, and theapplication of soil-nail wall subjects to certain restrictions, because it is difficult to adapt tothe deep and complex foundation pit. Pile-anchor (priestess) composite support is a kind ofactive support, which has little horizontal and vertical displacement, therefore it adapts tovaried construction site with complex geological conditions and surrounding environment,however, as a provisional project, its cost is much higher than that of soil-nail wall. Therefore,in order to realize target control among technology, economy and environment, the upperpart is supported by soil-nail and the lower part is supported by pile-anchor, and thecomposite support can be used.Stress mechanism of soil-nail and pile-anchor composite support should be furtherstudied; in particular each cooperative relationship of force in composite support is lackof knowledge. In the current standard condition, cooperative relationship of forcebetween soil-nail and pile-anchor is not considered in design of soil-nail and pile-anchorcomposite support, which leads to conservative design and some waste. In this paper,the author research soil-nail and pile-anchor composite support, and puts forward thetheoretical calculation method of composite support by theoretical analysis, andanalyses the results between theoretical formula and numerical simulation to deserverules of cooperative relationship of force between soil-nail and pile-anchor with theinternal friction angle and cohesive strength, and put s forward correction coefficientcalculation formula by simplifying and rectifying the theoretical calculation method,which may be used and referenced for designers. Mutual cooperation relationshipbetween soil behind of pile and pile in the soil arching effect is analyzed and researchedin the paper, and the relationship between soil arching effect and pile distance is deserved. A deep foundation pit in Baotou city is designed by calculation method in thepaper. At present, the project has been the main completion, and the method is reliableand economic by analyzing deformation data of foundation pit.