Vacuum preloading method for non-water discharge sand cushion

Abstract

The invention relates to a treatment method of large-area soft ground, in particular to a non-discharge sand cushion layer vacuum preloading method. The invention comprises the following steps: 1) installing drainage plates in a style of quincuncial piles in a treatment site; 2) replacing the horizontal discharging system of medium coarse sand cushion layer used in previous vacuum preloading construction with one of the two paving methods; 3) connecting the main pipe of the horizontal discharging system to a vacuum device, and carrying out vacuum pumping construction. The non-discharge sand cushion layer vacuum preloading method of the invention is suitable for reinforcement of large-area soft ground, more particularly have rather good effect on the reinforcement of dredger fill and recently deposited super soft soil; besides, the invention saves the investment of paving sand cushion layer, has good effect of vacuity transmitting; wherein, the horizontal discharging system with a paving way of combination of a steel spring tube, a tube plate connector and the drainage plates can realize large-scale finished product, normalized construction, short paving time, can be recycled and reused, and has the unique advantages of short construction period and being economical.

Description

Technical field: [0001] The invention relates to a large-area soft ground treatment method, in particular to a non-drainage sand cushion vacuum preloading method, which belongs to the innovative technology of the large-area soft ground treatment method. Background technique: [0002] With the acceleration of my country's modernization process, in the process of (coastal) city construction, a large number of soft soil foundations need to be treated. At present, the following three methods are widely used for soft foundation treatment: [0003] 1. Vacuum preloading method: This method uses atmospheric preloading as the preloading load. First, a layer of drainage cushion is laid on the ground, and then plastic drainage boards are inserted according to the designed spacing using a plugging machine, and then one to two covers are covered on it. A layer of airtight sealing film, and then use a vacuum pump to pump air to maintain a high degree of vacuum in the permeable material, g...

AI Technical Summary

Problems solved by technology

[0005] (1) Drainage sand cushions need to be laid. Generally, medium-coarse sand with a mud content of less than 5% must be strictly used. Generally, about 50 cm should be laid. For dredging or newly deposited ultra-soft soil and underwater vacuum preloading, It is even necessary to lay a cushion layer with a thickness of more than 100cm. The cost of laying a sand cushion layer will greatly increase the investment in the entire soft foundation treatment project.

[0006] (2) The vacuum degree provided by the vacuum pump must be transmitted to the soft soil layer through the permeable sand and gravel layer. Soil consolidation is slow and the treatment effect is not good

[0007] (3) After the construction of the vertical drainage system is completed, multiple main pipes and filter pipes must be laid as the transmission channels for vacuum degree, which consumes a lot of pipe materials

[0008] 2. Surcharge preloading method: Filling a certain thickness of filling layer on the site as a preloading load to achieve the purpose of reinforcing the underlying soft soil layer, but the amount of earthwork is huge and the processing time is long

This processing method has high construction cost and long construction period.

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