Long auger rotary-jet mixing steel reinforced cement-soil pile foundation pit water-resisting and supporting method

Abstract

The invention relates to a long auger rotary-jet mixing steel reinforced cement-soil pile foundation pit water-resisting and supporting method. An undisturbed soil layer is subjected to rotary-jet mixing on the spot through using the characteristic that a transformed long auger drilling tool with a bit is more adaptive to harder pans, the undisturbed soil layer is stirred and filled with grout at the same time to the designed elevation, the long auger drilling tool is pulled out to finish the construction of the cement-soil piles, and then reinforced materials such as shape steel are inserted into the top ends of the cement-soil piles to form columnar reinforced cement-soil pile bodies with certain strength and anti-permeability performance. The method has the advantages that the pile bodies can be driven in the harder pans to the designed depth and the designed pile diameter; through the occlusion of the pile bodies, the closed continuous pile wall body can be formed, and the reliability of a waterproof curtain is improved; and in order to increase the rigidity and the strength of the pile wall body, cement-soil is mixed and then inserted into the reinforced materials such as the shape steel, so as to ensure water-resistance reliability and the foundation pit safety. The method is applied to wide stratum ranges, and has superior advantages in harder pans in northern areas. The shape steel, an anchor rod or an inner support can be recycled, so that the cost is reduced.

Description

technical field [0001] The invention belongs to foundation pit support method (including subway foundation pit) in building foundation construction, and particularly relates to long helical rotary spraying and stirring cement-soil shaped steel piles and construction technology thereof, which can form pile walls and be used for water-stopping (water-proof or Water interception) curtain and slope protection pile or its parent pile, in the water-rich stratum, the excavation of the foundation pit may not be dewatered. The invention is applicable to a wide range of formations, especially in relatively hard soil formations such as dense sand and pebble formations in northern regions. 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. The rate can generally reach 100%. The three-axis mixer equipment has high power, high effici...

AI Technical Summary

Problems solved by technology

[0003] Cement-soil mixing piles are widely used in the fields of foundation pit support, water-stop curtain and foundation treatment because of their simple construction and low cost. Restrictions, especially the mixing sand layer or sand pebble layer is impossible to implement

Cement-soil rotary grouting piles include single-pipe, double-pipe and triple-pipe. Although they have been successfully applied in the fields of foundation pit support, water-stop curtain and foundation treatment in soft soil areas, they are also subject to extreme pressure when constructing hard soil layers. Large restrictions, especially when encountering sand layers or sand and pebble layers, it is also impossible to implement

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