Method for treating high-rise building foundation in non-self-weight collapsible loess area

Abstract

The invention discloses a method for treating a high-rise building foundation in a non-self-weight collapsible loess area. The method comprises the following steps: step one, excavating a foundation pit to a designed elevation, and constructing and arranging compaction piles, wherein the compaction piles are arranged on the outer edge of the foundation within the range of not smaller than 1 / 2 thickness of a collapsible soil layer or within the range of not smaller than 5 m; and the pile diameter of the compaction piles is 300-400 mm, the pile length exceeds the lower limit of the collapsible soil layer by not less than 0.5 m, and the pile spacing of the compaction piles is 2-2.5 times of the pile diameter; step two, constructing and arranging CFG piles, wherein composite foundation of theCFG piles in the middle area of the foundation is designed and constructed according to general areas; step three, constructing and arranging an anti-seepage cushion layer on the top of the compositefoundation; and step four, tamping a foundation trench layer by layer and backfilling lime soil, and paving two pieces of L-shaped cloth and one film. According to the method, outdoor surface water infiltration can be cut off, the situation that the foundation is soaked in water, and consequently foundation collapsing cannot be conducted is avoided, then the composite foundation of CFG piles in the non-self-weight collapsible loess area can be designed according to the general areas, the collapsibility problem does not need to be considered any more, and a large amount of conventionally-adopted compaction pile construction cost is saved.

Description

technical field [0001] The invention belongs to the field of foundation treatment in collapsible loess areas, in particular to a treatment method for high-rise building foundations in non-self-weight collapsible loess areas. Background technique [0002] Collapsible loess has two prerequisites for collapsibility: the foundation soil is collapsible, and the foundation is soaked in water. First of all, the compaction method is generally used to eliminate the collapsibility of the foundation so that it does not meet the first condition for collapsibility. However, the compaction method has limited improvement in the strength of the foundation. Especially when dealing with high-rise building sites, it is necessary to eliminate the collapsibility of the foundation, and to To improve the strength of the foundation, the cost incurred in actual processing is relatively high. At present, the common foundation treatment method for high-rise buildings with collapsible loess foundation...

AI Technical Summary

Problems solved by technology

First of all, the compaction method is generally used to eliminate the collapsibility of the foundation so that it does not meet the first condition for collapsibility. However, the compaction method has limited improvement in the strength of the foundation. Especially when dealing with high-rise building sites, it is necessary to eliminate the collapsibility of the foundation, and to To improve the strength of the foundation, the cost incurred in actual processing is relatively high

At present, the common foundation treatment method for high-rise buildings with collapsible loess foundations is: first construct lime-soil compaction piles to eliminate the collapsibility in the entire foundation range, and then construct CFG pile composite foundations to improve foundation strength, which requires the foundation treatment of the entire site Twice, higher cost

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