Collapsible loess wellpoint presoaking dynamic compaction replacement method

Abstract

The invention discloses a collapsible loess wellpoint presoaking dynamic compaction replacement method, and belongs to a deep collapsible loess foundation treatment method. The method comprises the steps that firstly, the treatment range and the treatment depth of a foundation are determined; secondly, within the foundation treatment range, a cushion material is laid on the whole surface; thirdly, according to the foundation treatment depth, a wellpoint hole is drilled out, a presoaking wellpoint pipe is vertically arranged in the wellpoint hole according to presoaking parameters, and water-pervious holes are evenly distributed in the wall of the pipe stretching into the foundation; fourthly, the presoaking wellpoint pipe is connected with a water injection pipe, and the foundation is subject to presoaking treatment; fifthly, the foundation is subject to dynamic compaction replacement treatment; and sixthly, the foundation quality is tested and is subject to acceptance check. The method is easy and convenient to construct, large in treatment depth, short in construction period and capable of effectively removing collapsibility of the deep collapsible loess foundation, and the bearing force of the foundation obtained after treatment is high.

Description

technical field [0001] The invention relates to a large-area deep collapsible loess foundation treatment method, in particular to a treatment method for well point presoaking combined with cushion material dynamic compaction replacement, and belongs to the technical field of civil engineering. Background technique [0002] Loess is a Quaternary sediment formed under arid and semi-arid climate conditions. It is widely distributed in my country with complete strata, covering an area of ​​about 64×10 4 km 2 , accounting for 6.6% of the total land area, has a thick covering layer, the thickest can reach more than 400m. In the middle reaches of the Yellow River, the area from Helan Mountain in the west to Taihang Mountain in the east, the Great Wall in the north and Qinling in the south is almost completely covered by loess. [0003] Collapsibility is a typical characteristic of loess as a special soil. According to collapsibility, it can be divided into self-weight collapsible...

AI Technical Summary

Problems solved by technology

The pre-soaking method uses the characteristics of self-weight collapsibility of loess after soaking in water. Before construction, a large area of ​​water is soaked to make the soil body pre-generate self-weight collapsibility to eliminate the self-weight collapsibility of the loess soil layer. However, this method consumes a lot of water and the construction period Generally, it should be carried out at least half a year to one year earlier than the official project. After the treatment, the bearing capacity of the foundation is low, and the surface soil layer is soft after pre-soaking, which is difficult to meet the requirements of general construction machinery operations.

[0005] The pre-soaking method, such as patent document CN200610200469.5, provides a "collapsible loess foundation water immersion consolidation method", and patent document CN200610200642.1 provides a "collapsible loess foundation airtight vacuum membrane pressure water consolidation method", If the pre-soaking method is used, a collapsible cavity will be formed at the junction of the pre-soaked water, which will easily cause a sudden collapse of the upper soil.

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