Method for treating soft soil foundation through deep compound vacuum pre-compaction

Abstract

The invention relates to a method for treating soft soil foundation through deep compound vacuum pre-compaction. According to the method, a pressurizing system is improved on the basis of pressurized vacuum pre-compaction, a plastic draining plate substitutes a pressurizing filtration pipe, and a steel wire soft pipe substitutes a PVC (polyvinyl chloride) pipe in a transverse pressurizing system. The problems of difficulty in driving the pressurizing filtration pipe, difficulty in controlling perpendicularity and the like when a deep soil body is pressurized are mainly solved. The atmospheric pressure difference between a vertical draining plate in the pressurizing system and a vertical draining plate in a vacuumizing system is increased by pressurizing the deep soil body by the vertical draining plate in the pressurizing system, so that the radial seepage velocity of pore water is increased; furthermore, due to the fact that the pressurizing effect back flushes a sludge layer with relatively dense texture formed nearby the vertical draining plate during a vacuumizing period, the permeability is improved; meanwhile, due to the fact that mud particles contained in a membrane filtering pore of the vertical draining plate can also be reversely blown out through the pressurizing effect, the water permeability of the vertical draining plate is enhanced. The soft soil foundation can be relatively well treated.

Description

technical field [0001] The invention belongs to the field of soft soil foundation treatment, and more specifically relates to a method for deep-layer compound vacuum preloading treatment of soft soil foundation, which is suitable for drainage and consolidation treatment of soft soil foundation and silt. Background technique [0002] A large amount of soft soil is distributed along the river and coastal areas of our country. Today, with the increasingly tight construction land, how to deal with these soft soils to meet the needs of engineering construction has always been a technical problem. In particular, the treatment of dredging fill in the southeast coastal areas has become a key technology for ports, transportation and urban construction in coastal areas. [0003] Since the 1980s, my country began to propose and apply the method of vacuum preloading to treat soft soil foundations. Through continuous improvement and innovation in engineering practice, the theory and tech...

AI Technical Summary

Problems solved by technology

Therefore, when using this kind of pressurized filter pipe to carry out shallow treatment of dredged fill, one section of the pressurized filter pipe can be used to meet the pressurization requirements, but when the treatment depth is deep, some problems will arise: first, increase The pressure filter tube has a certain degree of elasticity. When the depth of drilling is increased, it will produce a large longitudinal elongation deformation under the action of friction between the soil and the soil. Under the action of its own elasticity, it shrinks and deforms, and it is difficult to ensure that the setting position is exactly the same as the design position; second, when the treatment depth is large, it is necessary to use multi-section filter tubes to connect once through the matable screw joints and then insert them into the soil. body, which may become disjointed under the action of friction

It is difficult to ensure the reliability of the connection of each section of the hose; third, the rigidity of the pressurized filter pipe is small, and it is difficult to ensure the verticality of the pressurized filter pipe when the depth is large. The distance between the pressure filter tubes is relatively small, generally between 40-60cm. If the pressurized filter tube cannot be installed with a high verticality, or the pressurized filter tube is not uniform in the soil during the vacuum preloading period. Larger deformation under the action of radial stress will further reduce the distance between the pressurized filter tube and the plastic drainage plate, and even contact phenomenon will occur, which will not only reduce the efficiency of post-pressurization, but also increase the The pressure effect reduces the vacuum degree at the plastic drainage board and reduces the radial drainage effect; fourth, due to the different structures of the pressurized filter pipe and the plastic drainage board, the mechanical equipment used in construction is also different, which gives Construction brings certain troubles; Fifth, since the pressurized filter tube is a hollow hose, it is more suitable as a pressurized channel, but it cannot also be used as a drainage channel. If it is connected to a vacuum pump for vacuuming , the pore water that penetrates radially will accumulate in the pressurized filter tube, and the pore water accumulated here can only be discharged through the upward seepage of the pressurized filter tube wall, so the drainage effect is poor, and it is not suitable for vacuuming, resulting in material waste of use

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