Vacuum preloading seepage consolidation combined with precipitation preloading consolidation method for ultra-soft foundation

Abstract

The invention relates to a super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading. The super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading is characterized by comprising the following steps that step one, an integrated well point plastic drain vacuum system is arranged, specifically, 1.1, integrated well point plastic drain pipes are subjected to insertion construction to form an integrated well point plastic drain pipe grid, and 1.2, the integrated well point plastic drain vacuum system is formed by connecting the integrated well point plastic drain pipe grid with a header pipe and a vacuum pump; step two, vacuum preloading is conducted; and step three, vacuum dewatering preloading is conducted. The super-soft foundation seepage consolidation method combining vacuum preloading and dewatering preloading has the advantages of being easy to operate, low in cost and good in construction effect.

Description

technical field [0001] The invention relates to an underwater foundation treatment method, in particular to a supersoft foundation vacuum preloading seepage consolidation combined with precipitation preloading consolidation method. Background technique [0002] 1. Conventional ultra-soft foundations, on which mechanical equipment cannot walk for construction, often use manual insertion of shallow plastic drainage boards, manual laying of sand cushions and geotextile sealing membranes for vacuum preloading reinforcement, but there are the following disadvantages: [0003] 1. The construction of large-area sealing membranes is difficult, and onshore vacuum preloading requires a lot of manual laying membranes with a low degree of mechanization; [0004] 2. The PVC sealing film has low strength and is easy to be damaged and leak air. The cost of the second layer of sealing film and the first layer of geotextile is high, and it is difficult to find the air leakage point; [0005...

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Problems solved by technology

[0002] 1. Conventional ultra-soft foundations, on which mechanical equipment cannot walk for construction, often use manual insertion of shallow plastic drainage boards, manual laying of sand cushions and geotextile sealing membranes for vacuum preloading reinforcement, but there are the following disadvantages:

[0003] 1. The construction of large-area sealing membranes is difficult, and onshore vacuum preloading requires a lot of manual laying membranes with a low degree of mechanization;

[0004] 2. The PVC sealing film has low strength and is easy to be damaged and leak air. The cost of the second layer of sealing film and the first layer of geotextile is high, and it is difficult to find the air leakage point;

[0005] 3. A large number of PVC sealing films are not environmentally friendly;

[0006] 4. The surface under the film can reach a maximum negative pressure of 80kPa, and the negative pressure transmission loss to the deep part of the soil layer is fast. Generally, the loss of negative pressure per meter to the deep part is about 10kPa. The effective reinforcement depth is shallow;

[0007] 5. The loading surface is on the original ground surface or the backfilled land surface. Even if the surface sealing film does not leak, the slow air leakage of the shallow soil around the reinforcement area cannot be ignored, especially in the case of long-term loading for about 90 days, when the groundwater level drops to The degree of air leakage in shallow soil around a certain degree of reinforcement area is even more worrying

[0009] 1. The sand-removing cushion layer is changed to the mode of direct connection of plastic slabs with hand-shaped joints, and the mode of indirect negative pressure transmission is changed to direct negative pressure transmission mode, but it still needs a sealing film, and the maximum negative pressure loading surface is still on the surface;

[0010] 2. The sealing layer is formed by blowing and filling mud, or the vacuum branch pipe is directly connected to the plastic discharge into the soil for about 1.5 meters, or the vacuum filter tube is about 3 meters underground, and the side blister row replaces the sealing film. The dredging fill mud loses water, consolidates and cracks, the groundwater level drops rapidly, and the sealing effect is greatly reduced;

[0011] 3. The ultra-soft soil for land reclamation cannot be mechanically constructed. First, artificially insert the shallow layer of plastic drainage vacuum preloading, and then do deep vacuum preloading after the foundation strength is suitable for mechanical construction. The principle and process of conventional vacuum preloading are almost the same, only the simple difference between manual and mechanical, the process is more complicated, the cost is high, and the efficiency is low;

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