CN107100161A - A kind of vacuum bellows fluid injection is pressurized joint grouting and reinforcing super soft ground processing system - Google Patents

Abstract

The invention relates to a vacuum bag type liquid injection pressurization combined with grouting reinforcement ultra-soft ground treatment system, comprising a drainage system and a liquid injection pressurization system, the liquid injection pressurization system includes a liquid injection pressurization bag 10, a horizontal liquid injection Pressure branch pipe 6, water injection valve 4, three-way joint, horizontal liquid injection pressurization main pipe 13 and liquid injection pressurization equipment 1. The liquid injection pressurized bag 10 is made of elastic material that can transmit liquid pressure. The top of the liquid injection pressurized bag 10 is provided with a liquid injection sealing port 5, and the two sides of the upper part are connected with water injection pipes 11, and are connected to the transverse direction through the water injection pipe 11. The liquid injection pressurized branch pipe 6 is provided with a water injection valve 4 on the horizontal liquid injection pressurized branch pipe 6 , and the vertical drainage board 9 is distributed around the liquid injection pressurized bag 10 .

Description

A Vacuum Capsule Liquid Injection Pressurization Combined Grouting Reinforcement Ultra-soft Soil Foundation Treatment System

technical field

The invention provides a treatment method for soft soil and ultra-soft soil foundation, which belongs to the combined treatment technology of vacuum preloading and composite foundation in geotechnical engineering.

Background technique

In recent years, due to the shortage of land resources, land reclamation projects have received more and more attention. As a common foundation treatment method, vacuum preloading method has been widely used in land reclamation projects. The conventional vacuum preloading method is to lay a sand cushion on the surface of the soft soil foundation, set up a plastic drainage board or a sand well, and then use a sealing film to isolate it from the atmosphere. The end of the sealing film is buried with soil. The drainage pipeline of the cushion layer is pumped by vacuum pump or other vacuum means. Under the action of vacuum negative pressure, the negative pressure is gradually formed in the surface sand cushion layer and the vertical drainage channel, and at the same time, the space between the interior of the soil and the drainage channel and the cushion layer A pressure difference is formed. Under the action of this pressure difference, the pore water in the soft soil around the drainage board is continuously discharged from the drainage channel. Due to the dissipation of the pore water pressure in the soil, the effective stress increases accordingly, and the soil gradually consolidates and its strength decreases. will increase accordingly.

With the development of reclamation land reclamation project to "water area, fine-grained, high-efficiency", various types of improvement measures and methods have appeared on the basis of traditional vacuum preloading reinforcement treatment, such as sand-free direct discharge vacuum preloading technology, air pressure splitting, etc. Split vacuum preloading technology, gas injection pressurized vacuum preloading technology, electroosmosis combined vacuum preloading technology, surcharge combined vacuum preloading technology, etc. These improved technologies have achieved certain results in engineering applications.

Although the improved vacuum preloading method can improve the soil reinforcement effect to a certain extent, there are still many shortcomings:

1) For ultra-soft soil foundation, when the vacuum preloading method is used for reinforcement treatment, the drainage volume in the early stage is generally large, and the drainage effect is obvious. In the later stage, the fine-grained silt near the drainage board blocks the drainage board, and the vacuum degree also decreases. , leading to a significant decrease in the drainage rate in the later period, especially the soil far away from the drainage board and the deep layer has not been fully reinforced, which seriously affects the effect of foundation treatment.

2) Although new vacuum preloading technologies such as electroosmosis combined with vacuum preloading technology have improved the drainage efficiency of vacuum preloading to a certain extent, and thus accelerated the soil consolidation rate, this method has a relatively high engineering cost and cannot be used in actual projects. It is difficult to carry out large-scale promotion and application.

3) Adopt air pressure splitting vacuum preloading and air injection pressurized vacuum preloading technology to carry out foundation reinforcement treatment. In engineering practice, it is found that air must be blown into the soil continuously through the pressurized pipe to ensure a stable air pressure difference. Once the gas supply is stopped, the vacuum negative pressure decreases, and the drainage rate decreases immediately, resulting in poor soil reinforcement effect, especially the reinforcement treatment effect of deep foundation soil is not satisfactory.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provide a new type of vacuum preloading reinforcement treatment system suitable for soft soil and ultra-soft soil foundation treatment. It can not only ensure the stable pressure difference between the drainage board and the foundation soil, improve the consolidation rate of vacuum preloading drainage, but also further improve the strength of the soil through later grouting. Technical scheme of the present invention is as follows:

A vacuum bladder type liquid injection pressurization combined grouting reinforcement ultra-soft soil foundation treatment system, including a drainage system and a liquid injection pressurization system, the drainage system includes a plurality of vertical drainage boards (9), bows (8) , horizontal drainage branch pipe (7), tee joint (12), horizontal drainage main pipe (14) and vacuuming equipment (2), wherein, the vertical drainage plate (9) connects with the horizontal drainage branch pipe (7) through the bow tie (8) Connected and connected, the horizontal drainage branch pipe (14) is connected with the horizontal drainage main pipe (14) through the three-way joint (12), and the horizontal drainage main pipe (14) is connected with the vacuum equipment (2) at last, it is characterized in that,

The liquid injection pressurization system includes a liquid injection pressurized bag (10), a horizontal liquid injection pressurized branch pipe (6), a water injection valve (4), a tee joint, a horizontal liquid injection pressurized main pipe (13) and a liquid injection A pressurization device (1), wherein the main body of the liquid injection pressurized bag (10) is an elastic bag capable of transmitting liquid pressure, the top of the elastic bag is provided with a liquid injection sealing port (5), and both sides of the upper part are connected with The water injection pipe (11) is connected to the horizontal liquid injection booster branch pipe (6) through the water injection pipe (11), and the water injection valve (4) is arranged on the horizontal liquid injection booster branch pipe (6), and each horizontal liquid injection booster The branch pipe (6) communicates with the liquid injection pressurization equipment (1) through the horizontal liquid injection pressurized main pipe (13), and the vertical drainage plate (9) is distributed around the periphery of the liquid injection pressurized bag (10); During slurry construction, a grouting pipe (10) is inserted in the elastic capsule.

Preferably, the vertical drainage boards are arranged in a square, and the liquid injection pressurized bag is arranged in the center of the square, the distance between the vertical drainage boards is 0.8-2.0m, and the embedding depth of the liquid injection pressurized bag is higher than the insertion depth of the vertical drainage board 0.5-1m.

The invention aims at the characteristics of conventional vacuum preloading soft soil foundation reinforcement technology, and has the following advantages compared with the prior art:

1 The construction method is simple and easy, and the construction is convenient. While ensuring the construction quality, it can significantly accelerate the soft soil foundation reinforcement process.

2 Similar to the conventional vacuum preloading method, the liquid injection pressurization technology can significantly increase the pressure difference between the drainage board and the foundation soil, and can continuously ensure a stable pressure difference, accelerate drainage and be more conducive to the dissipation of pore pressure, and accelerate Improve the consolidation speed of the soft soil foundation and improve the construction efficiency.

3 After the vacuum liquid injection pressurization stage is over, deep grouting can be carried out directly at the liquid injection pressurized bag, which increases the treatment depth of soft soil foundation, further strengthens the bearing capacity of soft soil foundation, and realizes deep and shallow soft soil foundation Simultaneous processing at the same time.

Two functions: one is to use liquid as the booster mode of vacuum preloading to increase the pressure difference and speed up the consolidation rate and effect; the other is to use the capsule liquid injection device to further grout to form a composite after the vacuum preloading reinforcement treatment is completed. The foundation is strengthened to achieve the effective combination of the two reinforcement effects and the long-term reinforcement treatment effect of the same site, and can achieve the purpose of shallow soft soil or deep and shallow joint reinforcement treatment.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

Fig. 2 is a schematic diagram of the horizontal drainage system and the horizontal liquid injection pressurization system of the present invention.

Fig. 3 is a schematic diagram of the structure of the liquid injection pressurized bag of the present invention.

Fig. 4 is a schematic layout diagram of the vertical drainage plate and the vertical liquid injection pressurization system of the present invention.

Explanation of symbols in the figure: 1. liquid injection pressurization equipment; 2. vacuum pumping equipment; 3. sealing system; 4. water injection valve; 5. liquid injection sealing port; 8. Bow tie; 9. Vertical drainage board; 10. Liquid injection pressurized bag; 11. Water injection pipe; 12. Tee joint; 13. Horizontal liquid injection pressurized supervisor; 14. Horizontal drainage supervisor; 15. Grouting pipe .

detailed description

Referring to Figs. 1-4, the vacuum liquid injection pressurization combined with deep grouting foundation treatment method of the present invention, the drainage system adopted includes a vertical drainage board 9, a bow tie 8, a lateral drainage branch pipe 7, a tee joint 12, a horizontal drainage main pipe 14 and Vacuuming equipment 2, wherein the vertical drainage board 9 is connected and connected to the horizontal drainage branch pipe 7 through a bow tie 8, and the horizontal drainage branch pipe 14 is connected to the horizontal drainage main pipe 14 through a three-way joint 12, and the horizontal drainage main pipe 14 is finally connected to the vacuuming equipment 2 is connected. Among them, the vertical drainage boards (9) are arranged in a square, and a deep liquid injection pressurized bag 10 is arranged at the center of the square. The distance between the vertical drainage boards (9) is 0.8-2.0m. The insertion depth is 0.5-1m higher than the vertical drainage board.

The liquid injection pressurization system includes a liquid injection pressurized bag 10 , a lateral liquid injection pressurized branch pipe 6 , a water injection valve 4 , a tee joint 12 , a horizontal liquid injection pressurized main pipe 13 and a liquid injection pressurized device 1 . Wherein the liquid injection pressurized bag 10 is made of light latex material, which can transmit liquid pressure, and the two sides of the top of the liquid injection pressurized bag 10 are equipped with water injection pipes 11, and are connected to the horizontal liquid injection pressurized branch pipe 6 through the water injection pipe 11 . A water injection valve 4 is installed at the end of the horizontal liquid injection pressurization branch pipe 6, wherein the water injection valve 4 communicates with the liquid injection pressurization device 1. The liquid injection pressurization device 1 is pre-filled with sufficient water, and after the vacuum degree in the soil is stabilized, the liquid injection pressurization device 1 is opened, the liquid injection sealing port 5 is closed, and the water injection valve 4 is opened at the same time, and the water is pressurized from the liquid injection. The device 1 is injected into the liquid injection pressurized bag 10 through the horizontal liquid injection pressurized main pipe 13 and the horizontal liquid injection pressurized branch pipe 6 sequentially, and then the soil near the liquid injection pressurized bag 10 is subjected to the additional liquid pressure applied, and the The pressure difference between the drainage plate and the foundation soil is increased, and the pressure difference is relatively stable, thereby improving the drainage consolidation rate of vacuum preloading. Pressure device 1.

After the vacuum liquid injection pressurization construction is completed, open the liquid injection sealing port 5 provided on the top of the liquid injection pressurization bag 10, insert the grouting pipe 15 into the liquid injection pressurization bag 10, and inject the pre-stirred liquid into the grouting pipe 15. cement grout, after the grout is filled into the liquid injection pressurized bag 10, because the density of the water is less than the grout density, the water will be discharged through the liquid injection sealing port 5, so that a grouting reinforced solid pile is formed, and simultaneously with the grouting Further squeezing the surrounding soil also changes the physical and mechanical properties of the soil and improves the bearing capacity of the soft soil foundation. Wherein the grouting pipe 15 can adjust the height independently.

The combined foundation treatment method of vacuum liquid injection pressurization and deep layer grouting of the present invention comprises the following steps:

1) The first is the arrangement and connection of equipment and devices. After laying a layer of woven cloth on the surface of soft soil or ultra-soft soil, a vertical drainage board 9 and a vertical liquid injection pressurized bag 10 are installed afterwards, and the vertical drainage board 9 is connected with the horizontal drainage branch pipe 7, and the horizontal drainage The branch pipe 7 is connected to the horizontal drainage main pipe 14, and then the vertical liquid injection pressurized bag 10 is connected with the horizontal liquid injection pressurized branch pipe 6 and the horizontal liquid injection pressurized main pipe 13 successively, and two layers of woven cloth, one layer of geotextile, A layer of sealing film constitutes the sealing system 3, and finally the horizontal drainage main pipe 14 is connected to the vacuum equipment 2 for assembly, and the horizontal liquid injection pressurization main pipe 13 is connected with the liquid injection pressurization equipment 1.

2) Vacuum liquid injection pressurization stage. Turn on the vacuuming device 2, and after the vacuum degree in the dredging and filling soil is stable, open the water injection valve 4, and turn on the liquid injection pressurization device 1, and water is injected into the liquid injection pressurization bag 10 through the horizontal liquid injection pressurization system. Hydraulic pressure is applied to the soil around the hydraulic pressurized bag 10 to increase the pressure difference between the drainage board and the foundation soil, thereby increasing the drainage rate of the soft soil foundation and promoting the completion of drainage and consolidation of the deep and shallow soil.

3) After the vacuum liquid injection pressurization stage is over, shut down the liquid injection pressurization equipment 1, close the water injection valve 4 at the same time, open the liquid injection sealing port 5 provided on the top of the liquid injection pressurized bag 10, and inject water into the liquid injection pressurized bag. Insert the grouting pipe 15 into the grouting pipe 10, and inject the pre-stirred cement slurry into the grouting pipe 15. Since the density of the water is lower than the density of the slurry, the water will be discharged through the liquid injection sealing port 5, and the slurry will be filled into the liquid injection pressurized bag After 10, a grouted pile body is formed, which enhances the strength of the deep soil and improves the bearing capacity of the soft soil foundation.

4) When the soft soil foundation reinforcement effect reaches the expected effect, carry out vacuum unloading and equipment removal.

The working principle of the present invention is as follows: firstly, the conventional vacuum preloading method is improved, while applying vacuum negative pressure to the soil body through vacuuming equipment, injecting water into the pre-set liquid injection pressurized bag, and pressurizing through liquid injection The bladder transmits hydraulic pressure to the surrounding soil, significantly increasing the pressure difference between the drainage board and the foundation soil, thereby increasing the drainage rate of the soft soil foundation, and promoting the completion of drainage and consolidation of the deep and shallow soil. After the vacuum liquid injection pressurization is completed, inject cement slurry into the liquid injection pressurized bag through the grouting pipe to form a grouting reinforced solid pile, further squeeze the surrounding soil, and compact the pores in the surrounding soil. The excess pore water in the soil is expelled, the effective stress of the soft soil is increased, the physical and mechanical properties of the soil are changed, the strength of the deep soil is enhanced, and the bearing capacity of the soft soil foundation is improved. In this way, the synergistic reinforcement effect of the two methods in the same field can be realized.

Claims (2)

1. A vacuum capsule type liquid injection pressurization combined grouting reinforcement ultra-soft ground treatment system, comprising a drainage system and a liquid injection pressurization system, the drainage system comprising a plurality of vertical drainage boards (9), bows ( 8), horizontal drainage branch pipe (7), tee joint (12), horizontal drainage main pipe (14) and vacuum equipment (2), wherein, the vertical drainage board (9) is connected with the horizontal drainage branch pipe ( 7) connected and connected, the horizontal drainage branch pipe (14) is connected with the horizontal drainage main pipe (14) through the three-way joint (12), and the horizontal drainage main pipe (14) is finally connected with the vacuum equipment (2), which is characterized in that , The liquid injection pressurization system includes a liquid injection pressurized bag (10), a horizontal liquid injection pressurized branch pipe (6), a water injection valve (4), a tee joint, a horizontal liquid injection pressurized main pipe (13) and a liquid injection A pressurization device (1), wherein the main body of the liquid injection pressurized bag (10) is an elastic bag capable of transmitting liquid pressure, the top of the elastic bag is provided with a liquid injection sealing port (5), and both sides of the upper part are connected with The water injection pipe (11) is connected to the horizontal liquid injection booster branch pipe (6) through the water injection pipe (11), and the water injection valve (4) is arranged on the horizontal liquid injection booster branch pipe (6), and each horizontal liquid injection booster The branch pipe (6) communicates with the liquid injection pressurization equipment (1) through the horizontal liquid injection pressurized main pipe (13), and the vertical drainage plate (9) is distributed around the periphery of the liquid injection pressurized bag (10); During slurry construction, a grouting pipe (10) is inserted in the elastic capsule. 2. The foundation treatment system according to claim 1, characterized in that the vertical drainage boards are arranged in a square, the liquid injection pressurization bladder is arranged in the center of the square, the distance between the vertical drainage boards is 0.8-2.0m, and the liquid injection pressurization The embedding depth of the capsule is 0.5-1m higher than the insertion depth of the vertical drainage board.