Optimum Design And Numerical Simulation Of Foundation Pit Support About BaiShiDa Garden

The foundation pit project is the geotechnical engineering focus point that all very much pay attention to now .It is a synthesizing problem of geotechnical technique .Include the typical strength ,stability and transform,it still involves the common function of the soil and structure.Deep foundation pit construction has a lot of forms,and each has its own suitable conditions,different designs and different calculations. Despite foundation pit support technical has much monograph, but the most talk about basis of theory, design and calculation, theoretical content. But the books are lack about targeting a specific object with geological conditions, surroundings and functional requirements, how to choose a reasonable both economic and safe, effective and simple support program.Because of complexity of foundation pit engineering,unsuitable design and construction,the frequency of foundation pit engineering accident is high,which makes people living and the nation economic loss. In actual projects, the sizes, excavation depth, hydrogeology conditions, and the surrounding environment with each foundation are not the same. In order to solve complex engineering problems, it often requires integrated applications multiple technologies. So carrying out the design of specific foundation is necessary.In the paper,we first analyze the present condition of foundation pit engineering,then summarize characteristics and suitable conditions of all supporting forms.Besides these,we emphases the theories and calculations of united supporting which pile-anchor and soil-nailed wall were united simultaneity.According to fact of foundation pit in BaiShiDa Garden,we start with optimized project and analyze applicability of the every supporting forms for this engeering,then we adopt equivalent beam and m methods to calculate and optimize the design,which is the most economic and reasonable and which is the most suitable design.The result of the design,calculation and construction shows that the united supporting which pile-anchor and soil-nailed wall were united is successful in this engineering.The design ensures foundation pit safety without big transforming and displacement.On the one hand,soil-nailed wall is the most economicsupporting form,and the united supporting saved the engineering spending.On the other hand,pile-anchor and soil nail can dig synchronously with earthwork without impropriating the time additionally.In conclusion,the united supporting has innovative meaning.We can adopt different supporting forms according to different situations.And problem occurred in this engineering can arose engineer attention for the future.The key content and study as follows:The selection of support system will think over the security, the economy, facilitate construction according to the special condition. When the program is designed, on the basis different conditions for a variety of support structures, we summed up the select program for the foundation pit works. the foundation pit is high in west and low in east,the max depth is 17.7m and the min is 13.2m. The construction site is located in the business district, This design will use pile anchors and soil-nailed wall support program. Basing on the prospecting data, and weighing all the pros and cons of structural endogenous force calculation, this paper count simply through traditional equivalent beam to get the anchor power and the greatest moment.Using m to optimize the calculation result,then we adopted equivalent beam method to design minutely.Based on the design principles and formula of the anchor, we givenpreliminaryresultsofthefixedlength,thefreelength,inclination,distance,anchor diameter. Based on length and parameter of the pile, calculated the cross-sectional area, number the steel etc. According to the size and other data, combining the design result of pile and anchor, got the number of the piles along long margin, short margin and the overall number of piles, gave the furnished tables the anchor and the layout map of the pile, the profile and node map of the anchor. Checking the resist-rise stability and the overall stability of the pit, certificated fully the pit is stable and the design is reasonable.The basic principles of numerical simulation methods and Lagrangian are introduced. The FLAC is given a brief statement. FLAC then applied to the excavation process of excavation and support of the numerical simulation, the results were analyzed, proceed with the actual monitoring results, it is indicated for use FLAC pit simulation analysis is feasible. After the excavation for a project designed to provide a supplemental means.