Foundation pit water-sealing supporting method by using long spiral cement soil mixing structural steel pile

Abstract

A foundation pit water-sealing supporting method by using a long spiral cement soil mixing structural steel pile. Construction steps include that a long spiral drill is used for constructing a cement soil mixing pile; after construction of each cement soil mixing pile, structural steel is inserted into the top end of each cement soil mixing pile; inner supports or detachable anchor rods are used for conducting composite supporting when a foundation pit is deep; pile top beam connecting construction of the cement soil structural steel pile is conducted; the foundation pit is dug, a net is hung on an inner lateral wall of the foundation pit, and concrete is sprayed; and the anchor rods or the inner supports are detached when backfilling of grooves of the foundation pit meets a requirement, and finally the structural steel is removed. The foundation pit water-sealing supporting method has the advantage that the long spiral drill can drill hard soil layers and can reach the designed depth by overcoming the hard soil layers, simultaneously designed pile diameter can be achieved, meshing reliability is guaranteed, and water sealing reliability is guaranteed. The structural steel is inserted later to achieve an effect of supporting the foundation pit, and a two-in-one effect of water sealing and supporting is achieved. Due to recycling of the structural steel and removing of the anchor rods, cost of supporting construction of the foundation pit is greatly reduced, and the method is environment-friendly.

Description

technical field [0001] The invention belongs to a foundation pit water stop support method in building foundation construction, and mainly relates to a long spiral-stirred cement-soil type steel pile and a construction process thereof. It is used for the construction of water-stop (water-proof or cut-off) curtains, slope protection piles or mother piles of slope protection piles. Especially in the hard soil layer in the northern region, the construction has more advantages. Background technique [0002] At present, the SMW (cement-soil mixing wall) construction method is widely used in soft soil areas because of its energy saving, environmental protection and reliable quality. Its design and construction technology is becoming more and more mature, including the extraction and recovery technology of section steel. Many engineering section steel recycling reaches 100%. . Three-shaft mixer equipment is also widely used, with high efficiency and reliable construction. Howeve...

AI Technical Summary

Problems solved by technology

[0004] Cement-soil mixing piles and SMW construction methods are a common method for curtain and foundation pit support in soft soil areas, but construction in hard soil layers in northern areas is incapable, which can be summarized as "unable to stir", especially when encountering sand layers , sand and pebble stratum, and the design depth cannot be reached

no longer applicable

Moreover, the equipment is bulky and heavy, and it is inconvenient to enter and exit the site. During the construction period, the entire supporting equipment occupies a large area, and the mixing station occupies a large area. It is particularly impractical for Beijing metropolises where the site is narrow and "everything is expensive".

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