Pipe pile-anchor composite foundation and construction technology that can bear bidirectional load in tension and compression

Abstract

The invention provides a pipe pile-anchor rod composite foundation capable of bearing pulling and pressing bidirectional loads and a construction technology of the pipe pile-anchor rod composite foundation. The pipe pile-anchor rod composite foundation comprises a pipe pile and an anchor rod. An anchoring hole is reserved in a foundation bottom plate of a building structure, and a stretching end anchorage device is pre-buried in the anchoring hole. The anchor rod is composed of an anchor cable and a prefabricated anchor head, and the prefabricated anchor head is buried in soil below the foundation bottom plate. The upper end of the anchor cable penetrates out of the pipe pile to stretch into the anchoring hole, and is locked by the stretching end anchorage device after being stretched. The pipe pile is supported between the foundation bottom plate and the prefabricated anchor head, and the lower end of the pipe pile is fixedly connected with the upper end of the prefabricated anchor head. In the pipe pile-anchor rod composite foundation, the prefabricated anchor head is additionally arranged at the lower end of the pipe pile so that the pressure resisting bearing capacity of the pipe pile can be improved; a waterproof curtain is formed by the pipe pile with the two closed ends, the erosion effect of underground water and the like on concrete and steel can be resisted, and the impermeability and durability of the anchor rod, the pipe pile and foundation bottom plate joints can be improved; and structural reliability and stress performance are ensured, meanwhile, project quality can be effectively improved, the construction period can be shortened, and the investment can be saved.

Description

technical field [0001] The invention belongs to the technical field of construction engineering, and relates to an underground multipurpose deep foundation type of geotechnical engineering, in particular to a pipe pile-bolt composite foundation capable of bearing tension and compression bidirectional loads and a construction process. Background technique [0002] In order to develop and utilize underground space and improve land utilization, structures that go deep into the ground continue to appear. Many cities have begun to build comprehensive underground commercial streets, civil air defense, underground parking garages, underground public pipe corridors and subways. The bearing capacity of these underground structures on the structural foundation Higher requirements are put forward for durability and performance. [0003] When the buried depth of the building foundation exceeds the groundwater level, the part below the water level will generate upward buoyancy, which is ...

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Problems solved by technology

[0008] The layout method of the above-mentioned engineering piles solves the difficult problems of foundation compression and tension resistance in engineering, but this method also has certain defects, which are mainly manifested in: (1) Due to the two sets of compression piles and tension (floating) piles The existence of the system greatly increases the pile density on the bottom surface of the building foundation. On the one hand, this greatly increases the project investment and prolongs the construction period. Problems such as inability to press down increase the difficulty of construction work

(2) Tensile (floating) piles have structural weaknesses, such as the joints between the upper end of the pile and the foundation floor, and the joints of prefabricated piles, due to connection structure problems and insufficient tensile strength, they will be damaged due to tension, which will seriously restrict the tensile strength. The performance of the pile is fully exerted

(3) The mechanical performance of the tensile pile is not ideal, because the tensile stress is not uniformly distributed along the pile length (such as Figure 8 (a) and (b)), and the concrete tensile strength is only 1 / 10 to 1 / 20 of the compressive strength, the concrete pile body will crack under the early low tensile force, and the concrete cracking will make The steel bars of the pile body are eroded by groundwater, which will seriously affect the durability of the tensile pile, resulting in a decrease in the reliability of the building structure

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