Study On Composite Soil Nailing Wall In Soft Soil Area Of Complex Condition With Emphasis On Analysis By Finite Element Analysis

With the rapid development of urban construction, high-rise buildings have emerged in many cities, along with the upside of building higher and higher,the foundation pit digged more deeper than before. The complex condition,deformation and stability of temporary retaining and protecting structure are crucial problems in construction engineering.The composite soil nailing wall used in retaining and protecting for deep foundation pit is developing in recent years, which can work with soil together and keep or enlarge the strength of soil in side of foundation pit, converts the soil that induces loading effect on traditional supporting structure into a part of retaining and protecting structure, which can be effectively applied in special geological condition such as soft soil area. But the r esearch o n b ehavior of composite nailing wall is still insufficient, special in soft soil area,the working of design and construction of composite nailing wall need to be studied continued.Based on the typical projects, the horizontal displacement in depth, horizontal displacement and vertical subsidence of pile top, and settlements of surrounding buildings are monitored with the process on digging of deep foundation pit in soft soil.The diaposing principle of test points are summarized.The resisting force of the soil nails are tested,the primacy test data is gained. The working behavior of composite soil nailing wall is analyzed to posted the arc form of failure surface in side of deep foundation pit in soft soil area .The importance of dynamic construction is shown.According to the data acquired in testing,the study on digging process of foundation pit is analyzed by making use of finite element software.The working behavior of composite soil nailing wall is analyzed to verify the arc form of failure surface in side of deep foundation pit in soft soil area and to point out the inaccuracy of failure model calculation using circular sliding method.Combined with project practice, the process on analyzing composite soil nailing wall is expatiated particularly.The principles how to choose the parameter of soil and the optimizing maens are also discussed .Not only to soil nailing wall and composite soil nailing wall ,but also to similar structure engineering of foundation pit , which is valuable for reference and guilding.