Method for reinforcing high-moisture content hydraulically filled soft soil through chemical and horizontal vacuum preloading drainage-combined mode

Abstract

The invention belongs to the technical field of geotechnical engineering and hydraulic engineering research, and discloses a method for reinforcing high-moisture content hydraulically filled soft soilthrough a chemical and horizontal vacuum preloading drainage-combined mode. According to the method, a sand cushion layer is not required to be laid, and therefore, construction costs can be greatlyreduced; horizontal drainage boards are adopted, so that the problem of the proneness of traditional vertical drainage boards to bending and the disturbance of soil around the drainage boards can be solved, and therefore, the transmission efficiency of vacuum load in the drainage boards can be improved, drainage can be realized by means of the weight of the soil itself, and drainage efficiency canbe improved; and a flocculant is adopted during a hydraulic fill process, and therefore, the permeability of the soil can be increased, the particle size of the soil can be increased by means of flocculation and lumping, the clogging of the drainage boards can be alleviated, the transmission efficiency of the vacuum load in the soil can be improved, a soil drainage consolidation rate can be improved, construction time can be shortened, and construction costs can be saved.

Description

technical field [0001] The invention belongs to the related technical fields of geotechnical engineering and water conservancy engineering research, and in particular relates to a method for reinforcing high moisture content blown-filled soft soil with chemical agent combined with horizontal drainage board-vacuum preloading. Background technique [0002] In recent years, there have been increasing land reclamation projects and dredging projects, involving the dredging, filling and reinforcement of soft soil (silt). How to quickly realize the dehydration and reinforcement of soft soil (silt) is crucial to the subsequent scientific planning of soft soil foundations. Design and construction are of great significance. At present, there are many reinforcement techniques for saturated soft soil, and the vacuum preloading method is commonly used in practical engineering. Many scholars at home and abroad have studied and analyzed the vacuum preloading reinforcement method through t...

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Problems solved by technology

[0003] However, the traditional vacuum preloading reinforcement method still has some defects in practical engineering applications, as follows: (1) For the traditional vacuum preloading reinforcement method, it is often necessary to lay a sand cushion on the construction site, which greatly increases the construction cost, especially For large-scale reclamation projects or construction areas where sand resources are scarce near the site; (2) Since the initial strength of the dredged silt is almost zero, construction personnel and equipment cannot directly enter the site after the completion of the dredging and filling, and must be dried for a period of time after the completion of the dredging and filling (ranging from several weeks to several years) before the drainage board can be installed and then the reinforcement can be started. The dredging and filling process is completely separated from the reinforcement process, resulting in the overall efficiency of the vacuum drainage reinforcement method is not high; (3) With the progress of vacuum reinforcement, The fine particles of the soil around the vertical drainage board gather, and the drainage board silts up, making the later drainage very difficult; (4) The traditional vacuum preloading reinforcement method uses the vertical drainage board, and after the soft soil undergoes large deformation and settlement, the vertical Drainage boards are prone to severe bending, which will greatly reduce the transmission efficiency of vacuum loads, and lead to poor reinforcement effects in deep soft soil, reducing the overall drainage efficiency and reinforcement effect; (5) The insertion process of vertical drainage boards will affect the The soil around the drainage board causes disturbance (that is, the smear area is formed), and the soil in the smear area has poor permeability and is easy to cause drainage board silting, especially in the treatment process of saturated soft soil with high clay content or poor permeability In the middle, the clogging phenomenon is more serious

Existing studies have shown that clogging is the most important factor leading to the inefficiency of the current vacuum preloading reinforcement methods; (6) Most of the current vacuum preloading reinforcement methods will leave the vertical drainage boards in the soil after construction, resulting in The pore water in the underlying deep soft soil layer is continuously discharged through the drainage channel, and the site is prone to large post-construction settlement

The above defects have limited the application of traditional vacuum preloading reinforcement methods in practical engineering.

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