Collapsible loess deep presoaked water dynamic compaction method

Abstract

The invention relates to a deep pre-wetting dynamic consolidation method for collapsible loess. The method includes the steps of 1, analyzing and determining the smallest treatment depth and the treatment range of removing the collapsibility of the loess partially or completely according to the geological exploration and design requirements; 2, uniformly distributing water injection holes within the treatment range, placing water injection guide pipes into the holes and carrying out pre-wetting treatment on the deep areas of the drill holes until deep soil is basically saturate and the collapsibility is removed; and 3, carrying out dynamic compaction treatment on a shallow soil layer of a site, removing the collapsibility of the shallow soil layer and improving the bearing capacity of a foundation. According to the method, the treatment problem of increasing deep collapsible loess sites or foundations recently formed by mountain digging and valley filling can be effectively solved, and the collapsibility of collapsible loess strata of any thickness can be completely removed at a time. The method has the advantages that the technology is simple, the construction period is short and the cost is low.

Description

technical field [0001] The invention relates to a site or foundation treatment method, in particular to a deep pre-soaked dynamic compaction method for collapsible loess. Background technique [0002] Loess is widely distributed on the earth, covering an area of ​​13 million km 2 , accounting for about 9.3% of the total land area. The distribution area of ​​loess in my country is about 630,000 km 2 , concentrated in Shaanxi, Gansu, Shanxi, Ningxia and other provinces known as the Central Loess Plateau, especially northern Shaanxi and Guanzhong are the most representative. Collapsible loess is a kind of unsaturated under-pressure dense soil with large pores and vertical joints. Under natural humidity, its compressibility is low and its strength is high, but when it is wetted by water, the strength of the soil is significantly reduced. Collapse deformation caused by additional pressure or under the pressure of additional pressure and soil self-weight is a kind of unstable d...

AI Technical Summary

Problems solved by technology

However, with the rapid development of economic construction, there are more and more loess sites with large areas and high fill (thickness greater than 20m) newly formed by the method of "digging mountains and filling valleys", and their collapsibility characteristics are generally relatively balanced from top to bottom. They are all quite serious, resulting in the minimum treatment thickness under the control of the standard "the remaining collapsible amount of the untreated collapsible loess layer should not be greater than 150mm (for Class B buildings) and 200mm (for Class C buildings)" is much greater than the 4 ~6m, which is close to the depth of the entire collapsible loess layer, which leads to the confusion of various common treatment methods for collapsible loess foundations, or high treatment costs and long treatment periods

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