Study On Design Of Construction Scheme Of Soil Nailing Wall Combined Pile-anchor Supporting

Deep foundation pit is the underground space which is formed from the ground down through supporting and strengthening. Since 20th Century, the development of high-rise buildings and super-high-rise buildings in China and abroad is very fast, especially in the last twenty years, the development of building technology has led to the rapid development of high-rise buildings and high utilization of underground space, which provides the development of the designing and construction of deep foundation pit supporting engineering. With the characteristics temporary, high risk and poor safety, in the process of designing and construction of the foundation pit supporting engineering, we must pay enough attention, especially for the deep foundation pit supporting structure. The retaining structure of the soil nailing wall is a gravity retaining wall, which is formed by setting up soil nailing in the slope. The retaining structure of the pile-anchor supporting structure is made of row pile and the support system is made of prestressed anchor. Therefore, This kind of supporting system is also known as the row piles with prestressed anchor bolts. Soil nailing wall combined pile-anchor supporting structure has the advantages of both of soil nailing wall supporting structure and pile-anchor supporting structure. With the characteristics of convenient construction, saving cost, safe and reliable and low cost, the soil nailing wall combined pile-anchor supporting structure has been used more and moer widely in the practical engineering.China children’s science and technology training base is located in Haidian District, Beijing. On its eastern side is a temporary road and urban green space. On the west, near the four third ring road,is Yuanxitang residential quarters. On the south is Yuyuantan Road. On the north are abandoned mound and Bayi Lake. The project of the foundation pit is 147.5 meters long and 139.4 meters wide, which covers an area of about 21000 square meters. The excavation depth of the project is 14.80 meters in the north part of the pit, and the depth of the other part is 8.35 meters to 14.80 meters. Considering the buildings and v around the foundation pit, we have made further research on construction method, construction technology, materials, parameters, equipment, organization and coordination and decide to choose the Soil nailing wall combined pile-anchor supporting structure as the final construction scheme. According to the practical engineering experience, the construction scheme is formed, which provides valuable experience and reference for the design, construction and management of the similar projects in the future.As a kind of passive supporting structure, the structure of soil nailing wall’working needed the support the deformation of the soil to made the soil nailing work. However, this structure cannot meet the requirements of the stability of the slope and controll the deformation of the slope at the same time in beyond a certain depth. On the other hand, the pile-anchor supporting structure has good ability of flexibility, which can made the soil nailing supporting structure used Combined with the pile-anchor supporting structure to overcome the shortcomings on the aspect of foundation pit depth. Soil nailing wall and combined pile-anchor supporting structure is a kind of structure that supports the upper soil layer with structure of the soil nailing wall and the lower soil layer with the pile-anchor supporting structure, which is the improvement and optimization for two kinds of supporting structures. This kind of combined supporting structure can not only effectively use the self standing height soil to save cost, but also can effectively control the stability and deformation of the slope. In This paper, through the strict construction process, deformation monitoring, security protection and other construction organization measures, We have carried out control engineering construction quality in a full range and process, to ensure the construction quality. According to this construction scheme, the construction of deep foundation pit supporting engineering is accomplished successfully. And the construction scheme provides valuable experience and reference for theoretical research and engineering practice.