Study On The Design And Construction Of Indoor Deep Excavation

In recent years, with the continuous improvement of people's living standards, demands for the use of the buildings are increasing. More and more buildings are difficult to meet requirements for the rapid developments.So we need many adaptive transformations for the buildings. We often encounter many technical problems,when we excavae deep foundation pits inside the existing buildings.The deep foundation pit indoor is always close to the original foundation.In addition to,excavation of the deep foundation pit indoor has the following characteristics: complex environments around the pit, the complexities of supporting structures and sealing structures, the limits of working space and so on. The deep foundation pit indoor should provide a suitable space to meet the safe construction of the new structure, the same time, the existing building is safe and normal. Generally, the excavation technology of the deep foundation pit indoor is relatively difficult.In this paper, deep excavation for the National Stadium, Vice Pavilion indoor arena station warehouse project is close to the edge of the existing building foundation, we can not excavate and slope. We sloped it vertically under the protection of supporting structure. The cantilever piles or cantilever piles with anchorsa were applied to support the deep foundation ditch in this project. The constrtucion scheme not only reflected characteristics to the supporting piles, but also exerted advantages of building materials. The rotary jet grouting piles and slope protection piles were used to become the water-seal drapery for high-pressure spiral spraying piles.We adjusted the pile length,the pile diameter,the pile spacing, the bolt length,the bolt position and the bolt numbers to optimize the construction scheme. It saved about 128,000 yuan, i.e. 16 percent of the total cost by above the optimizations.The construction work space was limited, and the construction efficiency would be reduced. The construction technology of the reinforced bar was used in the pumping concrete through the use of a long spiral drill. The measure did not produce waste muds. We had shorted the construction period.Finally, construction monitoring datas showed that vertical and horizontal displacement of the retaining structure meeted specification limits of the deep foundation pit deformations. The smaller sedimentation values of existing the building ensured the normal use and safety. The deep foundation pit excavation technology has provided valuable experiences for similar projects in the future.