Dynamic compaction treatment method of deep foundation displacement

Abstract

The invention relates to a construction method of a building foundation treatment technology, in particular to a dynamic compaction treatment method of deep foundation displacement. The method comprises two construction schemes, the first construction scheme adopts a method that sand-gravel pile construction is conducted first, and then dynamic compaction is conducted, pores are formed through a vibration pipe sinking method, piles are formed by stuffing, and local compaction is conducted on soil between the piles; the second construction scheme adopts a method that the dynamic compaction is conducted first, and then the sand-gravel pile construction is conducted, full compaction is conducted on a field, the pores are formed through the vibration pipe sinking method, and the piles are formed by the stuffing. According to the dynamic compaction treatment method of the deep foundation displacement, the advantages of the vibration pipe sinking sand-gravel pile method and the dynamic compaction method on treating soft foundations are combined, and the part displacement of the soft foundations and the dual compaction effects of the dynamic compaction and the vibration are achieved. The dynamic compaction treatment method of the deep foundation displacement has the advantages of being good in treatment effect, low in treatment cost, economical, reasonable and capable of saving resources.

Description

technical field [0001] The invention relates to a construction method of building foundation treatment technology, in particular to a deep foundation replacement dynamic compaction treatment method. Background technique [0002] my country's coastal areas are densely populated, urban development is rapid, and construction land is in short supply. The strata in this area have the following characteristics: the upper soil layer is all under-consolidated soft soil layers such as backfill or dredger fill, with high natural water content and compressibility. Large, low strength, poor permeability, large soil thickness, generally more than 12.0m. Large-scale soft soil sites and local land reclamation require economical and reasonable foundation treatment methods to improve and enhance the soft soil foundation strength, overall stability, reduce its compressibility, and eliminate deep silt and sand layer liquefaction to meet civil engineering requirements. Requirements for construc...

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Problems solved by technology

[0003] At present, there are many methods for foundation treatment, all of which have limitations and economic rationality for this kind of soft soil layer; the traditional sandstone pile method is very suitable for this kind of soft clay foundation, but due to the extremely poor bearing capacity of the upper strata , to meet the requirements of the bearing capacity of the upper structure, it is necessary to arrange the sand and gravel piles very densely, thereby increasing the project cost; due to the low permeability and high sensitivity of soft clay, the excess pore water pressure generated during the pile formation process cannot be quickly Dissipation, the compaction effect is poor, and the natural structure of the soil is destroyed due to disturbance, reducing the shear strength of the soil

After the sandstone pile composite foundation is formed in soft cohesive soil, it needs to be loaded and preloaded to improve the strength and overall stability of the foundation and reduce post-construction settlement; if no preloading is carried out, the soft soil foundation treated with sandstone piles There is still a large deformation and settlement under the load, and it is difficult for buildings with strict settlement requirements to meet the requirements

The dynamic tamping method not only improves the strength of the foundation soil and reduces its compressibility, but also improves its ability to resist vibration and liquefaction and eliminates the collapsibility of the soil. Although the cost of using the dynamic tamping method to treat this kind of foundation is low, its treatment depth cannot reach According to the design requirements, the deep soft soil layer with a depth of more than 12.0m can hardly be affected by the dynamic compaction energy; and if the upper part is a soft clay foundation with high saturation, the treatment effect is very insignificant, especially for silt and muddy soil foundations. worse effect

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