Construction method for piling prestressed concrete hollow pile into thick-layer soft soil processed by cement mixing piles

Abstract

The invention discloses a construction method for piling a prestressed concrete hollow pile into thick-layer soft soil processed by cement mixing piles, belonging to a technical field of piling and civil engineering. Process of the method comprises: drilling a dewatering well on the edge of a pile region; carrying out construction of a cement stirring pile at the middle points of connection lines of centers of the arranged prestressed concrete hollow pile after the water level reduces 5-6 meters; piling the prestressed concrete hollow pile after the construction of the cement stirring pile is completed for 7days, wherein the piling adopts a method of piling the same hollow pile at different times and a method of piling the nonadjacent piles successively. The method provided in the invention has the advantages that: schemes of well-point dewatering and cement stirring pile piling can effectively reduce hole water pressure in the soft soil and improve foundation strength; the adopted method of piling the same hollow pile at different times and the method of piling the nonadjacent piles successively develop two ways for dissipation of water pressure in holes in time and space, and fully guarantee stability of prestressed concrete hollow pile piling in the thick-layer soft soil after processing by the cement stirring pile.With the method, a requirement of construction quality and a requirement of bearing capacity can be reached.

Description

technical field [0001] The invention relates to a construction method for driving a prestressed concrete hollow pile into thick soft soil treated with cement mixing piles, and belongs to the technical field of civil engineering piling. Background technique [0002] The thick layer of soft soil refers to the fine-grained soil with a natural void ratio e≥1.0 and a natural water content greater than the liquid limit. The soil includes silt, muddy soil, peat, and peaty soil, and the general thickness of the soil layer is ≥5m . [0003] Studies have shown that when piling in thick soft soil, due to the low permeability of saturated soft clay, the excess pore water pressure generated cannot be dissipated in time. If the design and construction are improper, there will be an obvious soil squeezing effect, resulting in the ground Uplift, pile upwelling, skewing or even fracture, thereby reducing the bearing capacity of the pile, and sometimes damaging adjacent buildings; after the ...

AI Technical Summary

Problems solved by technology

[0003] Studies have shown that when piling in thick soft soil, due to the low permeability of saturated soft clay, the excess pore water pressure generated cannot be dissipated in time. If the design and construction are improper, there will be an obvious soil squeezing effect, resulting in the ground Uplift, pile upwelling, skewing or even fracture, thereby reducing the bearing capacity of the pile, and sometimes damaging adjacent buildings; after the construction of the pile foundation, the pore water pressure in the saturated soft soil may also dissipate, and the soil layer may re-consolidate and settle. Make the pile produce negative friction resistance, reduce the bearing capacity of the pile foundation, and increase the settlement of the pile foundation

Therefore, if there is no corresponding engineering countermeasure to deal with soft soil foundation, it will seriously limit the application of pipe pile foundation with great technical advantages

Images