CN111851460A

CN111851460A - Dehydration and consolidation device for slurry treatment of geotechnical pipe bag and working method thereof

Info

Publication number: CN111851460A
Application number: CN202010684057.3A
Authority: CN
Inventors: 吴海民; 程醒; 田振宇; 张茂雪; 冯路明; 莫岱辉
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2020-10-30

Abstract

The invention discloses a dehydration and consolidation device for slurry treatment of a geotube bag, which comprises a geotube bag, wherein a plurality of blind pipes are arranged in the geotube bag along the length direction of the geotube bag, two ends of each blind pipe extend out of the geotube bag, two ends of each blind pipe are connected with one end of a branch pipeline through blind pipe joints, the branch pipeline is connected with one end of a first main pipeline, a first valve is arranged on the first main pipeline, the other end of the first main pipeline is connected with an air compressor, the branch pipeline is connected with one end of a second main pipeline, a second valve is arranged on the second main pipeline, and the other end of the second main pipeline is connected with a vacuum pump. The invention also discloses a working method of the dewatering and consolidating device for treating the slurry by the geotextile tube bag. The dehydration consolidation device for slurry treatment of the geotextile tube bags and the working method thereof effectively combine the pressurization method and the vacuum pumping method, are applied to proper stages and time nodes in the dehydration consolidation process of slurry treatment of the geotextile tube bags, and can effectively promote the dehydration consolidation speed of the slurry.

Description

Dehydration and consolidation device for slurry treatment of geotechnical pipe bag and working method thereof

Technical Field

The invention relates to a dehydration and consolidation device for treating slurry by a geotextile tube bag and a working method thereof, belonging to the technical field of slurry dehydration and consolidation.

Background

The amount of mud to be treated in China is huge every year, and the mud comprises dredging mud generated by river and lake dredging, construction waste mud generated by underground shield and pile foundation drilling, tailing mud generated by mineral separation, industrial waste residue and the like. The slurry has high water content, high content of sticky particles, huge volume and low bearing capacity and shear strength, is difficult to directly store and utilize, and needs to be dewatered, consolidated and volume-reduced firstly so as to reduce the volume of the slurry and improve the bearing capacity and the shear strength of the slurry.

The conventional slurry dewatering and consolidating treatment method mainly comprises the following steps: natural drying method, mechanical dehydration method and sintering method. The natural drying method is to discharge the slurry to a certain storage yard and remove free water in the slurry by airing, but the method is greatly influenced by weather and needs a large enough field to store and air the slurry; the mechanical dehydration method is to discharge water in the slurry by means of a dehydration machine, but the common dehydration equipment has higher price and lower dehydration efficiency; the sintering method is to dehydrate and consolidate the slurry by drying or high-temperature treatment, but the method requires special equipment, has limited treatment capacity, high energy consumption and high cost. In summary, these conventional methods of dewatering and consolidating slurries do not allow for large-scale, efficient and environmentally friendly treatment of the slurries.

In the last 60 years, the geotextile is made into a filling tube bag for the first time for bank protection and plugging projects, so that the construction cost of the projects is greatly reduced. In recent years, geotextiles are continuously popularized and applied to treatment of slurry, and a mature technology, namely a geotextile tube bag dehydration consolidation method is formed.

In principle, the dehydration and consolidation of slurry carried out by the geotextile tube bag are divided into three stages: (1) and (3) filling stage: and (3) filling the slurry into the geotechnical pipe bag, wherein the slurry is filled for many times in the whole process until the final filling degree reaches more than 80%. (2) And (3) a rapid dehydration stage: after each filling, the water content of the slurry in the soil engineering pipe bag is higher, the slurry in the soil engineering pipe bag bears higher water pressure at this stage, the water in the slurry is easy to separate out through the action of gravity and the tension of the bag wall, but the dehydration rate of the slurry is slower and slower along with the time. (3) And (3) consolidation stage: after the rapid dehydration, the water content of the slurry in the geotechnical pipe bag is reduced, the slurry is slowly converted into an unsaturated state from a saturated state, the pore water pressure is not continuous any more, the tension of the bag wall is very small, and at the moment, the slurry in the pipe bag is continuously solidified only under the self-weight stress, but the solidification rate is slower.

The dehydration and consolidation method for the soil engineering pipe bag has the advantages of simple construction, low cost and the like, and can carry out dehydration and consolidation treatment on the slurry on a large scale. However, the dewatering and consolidation speed of the slurry with high content of sticky particles is slow, which results in overlong treatment period and overhigh time cost of the slurry. Before the present invention, CN111088790A, CN110777773A and CN110451760A all propose a dewatering method for treating slurry by using a vacuuming combination with a geotextile bag, i.e. a drainage plate is arranged in the interior of the geotextile bag in advance or a reversed filter tank hole pipe is inserted into the upper cuff of the geotextile bag, and the geotextile bag is vacuumized by a vacuum pump to quickly dewater and solidify the slurry. The above patent method can actually accelerate the dehydration rate of the slurry and reduce the construction period in principle, but has the main disadvantages: the drainage plate or the anti-filtration slotted hole pipe arranged in the geotechnical pipe bag is made of common drainage materials, and is easy to block during the suction filtration process, so that the effect of promoting the slurry dewatering and solidifying speed by a vacuum method is reduced. In addition, the dehydration of the slurry by the geotextile tube bag involves multiple times of filling, and the dehydration and consolidation principles at the 3 different stages are different. For example, in the rapid dehydration stage, the dehydration principle mainly depends on the water pressure inside the slurry to promote the rapid discharge of the water body, and at the moment, if the vacuum pumping is applied, the water pressure is reduced, so that the dehydration effect is poor. The vacuum pumping method can be adopted only at a proper time point in the implementation process, so that the dehydration and consolidation speed can be effectively improved. None of the methods proposed in the above patents describe at which stage or at which time node in the process a vacuum is applied to accelerate dewatering consolidation. Therefore, the method of the patent can not effectively guide the construction of the on-site geotechnical pipe bag mud dewatering engineering, and can not be really popularized and applied in engineering practice.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a staged accelerated dehydration consolidation device which effectively combines a pressurization method and a vacuum pumping method, is applied to a proper stage and time node in the process of dehydrating and consolidating slurry in a geotextile tube bag treatment process and can effectively promote the dehydration consolidation speed of the slurry and a working method thereof; further, the invention provides a staged accelerated dehydration consolidation device and a working method thereof, which can avoid the problem that a drainage material arranged in a geotechnical pipe bag is easy to be silted up in the suction filtration process and ensure the promotion effect of a vacuumizing method on the dehydration consolidation speed of slurry.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the utility model provides a dehydration consolidation device for soil engineering pipe bag treatment mud, including the soil engineering pipe bag, arrange a plurality of blind pipe in the soil engineering pipe bag on its length direction, the both ends of blind pipe extend the soil engineering pipe bag external, the blind pipe both ends are passed through the blind pipe and are connected with branch road pipeline one end, the other end of a plurality of branch road pipeline passes through the parallelly connected intercommunication of pipe joint, the branch road pipeline that is located soil engineering pipe bag one side is connected with the one end of first trunk line, first valve has been arranged on the first trunk line, the other end of first trunk line is connected with the air compressor machine, the branch road pipeline that is located soil engineering pipe bag opposite side is connected with the one end of second trunk line, the second valve has been arranged on the second trunk line, the other end of second. According to the invention, two ends of a plurality of blind pipes in the geotechnical pipe bag are respectively communicated in parallel through the pipeline joints and are respectively detachably connected with the air compressor and the vacuum pump, so that the geotechnical pipe bag can be pressurized or vacuumized at a proper time, the dehydration and consolidation speed of slurry is effectively promoted, and the construction period of a slurry dehydration project is shortened.

The blind pipe is covered with a layer of anti-clogging composite geotextile, the anti-clogging composite soilThe woven fabric comprises a woven geotextile layer arranged on an inner layer and a non-woven geotextile layer arranged on an outer layer. Effective aperture O of anti-clogging composite geotextile₉₅In the range of 0.08 to 0.15 mm. In the process of slurry dehydration and consolidation, the blind pipe always keeps better water permeability by utilizing the excellent reverse filtration characteristic of the anti-clogging composite geotextile, and the problem that the promotion effect of the vacuumizing acceleration dehydration method on slurry dehydration is reduced due to clogging of the blind pipe is avoided.

The woven geotextile layer and the non-woven geotextile layer are compounded into a whole in a hot sticking or needling or gluing mode, and the combination effect between the woven geotextile layer and the non-woven geotextile layer is better.

The distance between the blind pipes and the bag body of the geotechnical pipe bag is not more than 30cm, and the distance between two adjacent blind pipes is not more than 60 cm. According to the invention, a series of blind pipes are arranged in the geotechnical pipe bag along the length direction, and the distance between adjacent blind pipes is strictly set, so that a dehydration channel of slurry is increased, the drainage distance is effectively reduced, and the simultaneous drainage in multiple directions inside and outside the geotechnical pipe bag is realized, thereby realizing accelerated dehydration.

A working method of a dewatering and consolidating device for processing slurry by using a geotextile tube bag comprises the following steps:

S01, filling the slurry into the geotechnical pipe bag through a slurry pump, adding a flocculating agent into the slurry conveying pipeline in the filling process, and ensuring that the flocculating agent and the slurry can be fully mixed and react;

and S02, after the geotechnical pipe bag is filled with slurry, connecting the air compressor with the first main pipe, unscrewing the first valve, screwing the second valve on the second main pipe, opening the air compressor, and pressurizing the blind pipe through the branch pipe.

And S03, repeating S01 and S02 after the slurry in the geotube bag is dehydrated under the high-pressure condition and the volume of the slurry is reduced to 60-70% of the maximum capacity of the geotube bag. This stage belongs to the quick dehydration stage, and its dehydration principle mainly relies on the inside water pressure of mud to promote the quick discharge of water, increases geotechnological tube bag internal pressure this moment, can promote the quick dehydration effect of mud. In the prior art, it is not clear that the pressurization treatment is performed at this stage.

S04, when the volume of the slurry in the geotube bag is more than 80% of the maximum volume of the geotube bag and no water seeps out of the wall of the geotube bag under the high pressure condition, closing the air compressor and the first valve, connecting the vacuum pump with the second main pipeline, slightly unscrewing the second valve, unscrewing the first valve, opening the vacuum pump, and vacuumizing the blind pipe through the branch pipeline. The stage belongs to a consolidation stage of slurry dehydration, the moisture content of the slurry in the geotechnical pipe bag is reduced at the moment, the slurry is slowly converted into an unsaturated state from a saturated state, the pore water pressure is not continuous any more, the tension of the bag wall is very small, the slurry in the pipe bag is continuously consolidated only under the self-weight stress at the moment, but the consolidation rate is slower. The invention can reduce the pressure in the soil engineering pipe bag, is suitable for dehydration under the slurry unsaturated state, and can accelerate the dehydration process of the slurry.

And S05, when no water flows out of the first main pipeline, the vacuum pump is turned off.

The invention has the beneficial effects that: the invention provides a dehydration and consolidation device for slurry treatment of a geotechnical pipe bag and a working method thereof, wherein the dehydration and consolidation speed of the slurry is effectively promoted by pressurizing and vacuumizing a blind pipe at different stages of dehydration and consolidation of the slurry treatment of the geotechnical pipe bag, and the construction period of a slurry dehydration project is shortened; and the anti-clogging composite geotextile wrapped on the blind pipe can effectively prevent the blind pipe from being clogged, so that the dewatering and consolidation speed and effect of the slurry can be more effectively promoted by pressurization and vacuum pumping.

Drawings

FIG. 1 is a schematic structural view of an accelerated dewatering and consolidating apparatus for geotextile bags used for processing slurry according to the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a cross-sectional view of the blind tube structure of the present invention.

The figures are labeled as follows: 1-a soil engineering pipe bag; 2-blind pipe; 3-filling the mouth; 4-slurry; 5-a blind pipe joint; 6-pipe joint; 7-branch pipeline; 8-a first valve; 9-a first main conduit; 10-a second valve; 11-a second main conduit; 12-a vacuum pump; 13-an air compressor; 14-a drainage layer; 15-ground; 16-a woven geotextile layer; 17-nonwoven geotextile layer.

Detailed Description

The present invention is further described with reference to the accompanying drawings, and the following examples are only for clearly illustrating the technical solutions of the present invention, and should not be taken as limiting the scope of the present invention.

As shown in fig. 1 and 2, the invention provides a dewatering and consolidating device for slurry in a geotextile tube bag, which comprises a geotextile tube bag 1, wherein a plurality of blind pipes 2 are arranged in the geotextile tube bag 1 along the length direction of the geotextile tube bag, and two ends of the blind pipes 2 extend out of the geotextile tube bag 1. The arrangement of the blind pipe 2 should meet the following 2 requirements: a) the distance between the blind pipe 2 and the bag body of the geotube bag 1 is not more than 30 cm; b) the distance between two adjacent blind pipes 2 is not more than 60 cm. According to the invention, a series of blind pipes 2 are arranged in the geotechnical pipe bag 1 along the length direction, and the distance between adjacent blind pipes 2 is strictly set, so that a dehydration channel of slurry is increased, the drainage distance is effectively reduced, and the simultaneous drainage in multiple directions inside and outside the geotechnical pipe bag 1 is realized, thereby realizing accelerated dehydration.

As shown in fig. 3, the blind pipe 2 is covered with a layer of anti-clogging composite geotextile, the anti-clogging composite geotextile is formed by a layer of non-woven geotextile layer 17 and a layer of woven geotextile layer 16 which are compounded into a whole by hot sticking or needling or gluing, the woven geotextile layer 16 is arranged inside, the non-woven geotextile layer 17 is arranged outside, and the effective pore diameter O of the anti-clogging composite geotextile is ₉₅In the range of 0.08-0.15 mm, in the process of slurry dehydration and consolidation, the blind pipe always keeps better water permeability by utilizing the excellent reverse filtration characteristic of the anti-clogging composite geotextile, and the problem that the promotion effect of the vacuumizing acceleration dehydration method on slurry dehydration is reduced due to clogging of the blind pipe is avoided.

As shown in fig. 1, two ends of the blind pipe 2 are connected with one end of a branch pipeline 7 through blind pipe joints 5, and the other ends of a plurality of branch pipelines 7 are communicated in parallel through pipeline joints 6 to collect the branch pipelines 7 together. Branch pipeline 7 that is located geotechnical pipe bag 1 one side is connected with the one end of first trunk line 9, has arranged first valve 8 on the first trunk line 9, and the other end of first trunk line 9 is connected with air compressor machine 13. The branch pipeline 7 on the other side of the geotechnical pipe bag 1 is connected with one end of a second main pipeline 11, a second valve 10 is arranged on the second main pipeline 11, and the other end of the second main pipeline 11 is connected with a vacuum pump 12.

The invention provides a working method of a dehydration consolidation device for processing slurry by a geotextile tube bag, which comprises the following steps:

step one, arranging a drainage layer 14 on a relatively flat ground 15, laying the geotechnical pipe bags 1 with the arranged blind pipes 2 and pipelines on the drainage layer 14, and preparing to start slurry filling.

And step two, connecting a mud pump with the filling opening 3 through a mud conveying pipeline, opening the mud pump to fill the mud into the geotechnical pipe bag 1, and adding a proper amount of flocculating agent into the mud conveying pipeline at a distance from the filling opening 3 in the filling process so as to ensure that the flocculating agent and the mud can be fully mixed and react.

And step three, after the geotechnical pipe bag 1 is filled with the slurry 4, connecting the air compressor 13 with the first main pipeline 9, unscrewing the first valve 8, screwing the second valve 10, opening the air compressor 13, and pressurizing the blind pipe 2 through the pipeline. In the rapid dehydration stage, the air compressor is used for pressurizing the blind pipe, so that the slurry in the geotechnical pipe bag is in a high-pressure state, and the dehydration speed of the slurry in the stage can be effectively promoted.

And step four, after the slurry 4 in the geotechnical pipe bag 1 is dehydrated under the high-pressure condition and the volume of the slurry 4 is reduced to 60-70% of the maximum capacity of the geotechnical pipe bag 1, repeating the step two and the step three.

And step five, when the volume of the slurry 4 in the geotechnical pipe bag 1 is more than 80% of the maximum capacity of the geotechnical pipe bag 1, and under the high-pressure condition, almost no seepage water flows out of the wall of the geotechnical pipe bag 1, the air compressor 13 is closed, the connection between the air compressor 13 and the first main pipeline 9 is disconnected, the vacuum pump 12 is connected with the second main pipeline 11, the second valve 10 is unscrewed, the first valve 8 is slightly unscrewed, air and water can slowly flow into or out of the first main pipeline 9, the vacuum pump 12 is opened, and the blind pipe 2 is vacuumized through the pipeline. When the bag wall of the geotextile tube bag does not drain water any more in the consolidation stage, the blind pipe is vacuumized by the vacuum pump, and the consolidation speed and the consolidation effect of the slurry in the stage can be effectively improved.

And step six, when almost no water flows out of the first main pipeline 9, the vacuum pump 12 is switched off.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. The utility model provides a dehydration consolidation device for geotechnological pipe bag handles mud which characterized in that: comprises a geotube bag (1), a plurality of blind pipes (2) are arranged in the geotube bag (1) along the length direction thereof, the two ends of the blind pipes (2) extend out of the geotube bag (1) bag body, the two ends of the blind pipes (2) are connected with one ends of branch pipelines (7) through blind pipe joints (5), the other ends of the branch pipelines (7) are communicated in parallel through pipeline joints (6), the branch pipeline (7) positioned on one side of the geotube bag (1) is connected with one end of a first main pipeline (9), a first valve (8) is arranged on the first main pipeline (9), the other end of the first main pipeline (9) is detachably connected with an air compressor (13), the branch pipeline (7) positioned on the other side of the geotube bag (1) is connected with one end of a second main pipeline (11), a second valve (10) is arranged on the second main pipeline (11), the other end of the second main pipeline (11) is detachably connected with a vacuum pump (12).

2. The dewatering and consolidating apparatus for geotextile bag process slurry of claim 1, wherein: the blind pipe (2) is externally coated with a layer of anti-clogging composite geotextile, and the anti-clogging composite geotextile comprises a woven geotextile layer (16) arranged on the inner layer and a non-woven geotextile layer (17) arranged on the outer layer.

3. The dewatering and consolidating apparatus for geotextile bag process slurry of claim 2, wherein: effective aperture of the anti-clogging composite geotextileO₉₅In the range of 0.08 to 0.15 mm.

4. The dewatering and consolidating apparatus for geotextile bag process slurry of claim 2, wherein: the woven geotextile layer (16) and the non-woven geotextile layer (17) are compounded into a whole by means of thermal bonding or needling or gluing.

5. The dewatering and consolidating apparatus for geotextile bag process slurry of claim 1, wherein: the distance between the blind pipe (2) and the bag body of the geotechnical pipe bag (1) is not more than 30cm, and the distance between two adjacent blind pipes (2) is not more than 60 cm.

6. A working method of a dehydration and consolidation device for processing slurry by a geotextile tube bag is characterized by comprising the following steps: the method comprises the following steps:

S01, filling the slurry into the geotechnical pipe bag (1) through a slurry pump, adding a flocculating agent into the slurry conveying pipeline in the filling process, and ensuring that the flocculating agent and the slurry can be fully mixed and react;

s02, after the geotechnical pipe bag (1) is filled with mud (4), connecting an air compressor (13) with a first main pipe (9), unscrewing a first valve (8), screwing a second valve (10) on a second main pipe (11), opening the air compressor (13), and pressurizing the blind pipe (2) through a branch pipe (7);

s03, repeating S01 and S02 after the slurry in the geotube bag (1) is quickly dehydrated under the high pressure condition and the volume of the slurry is reduced to 60-70% of the maximum capacity of the geotube bag (1);

s04, when the volume of slurry in the geotube bag (1) is more than 80% of the maximum capacity of the geotube bag (1), and under the condition of high pressure, when no seepage water flows out of the bag wall of the geotube bag (1), closing an air compressor (13) and a first valve (8), disconnecting the air compressor (13) from a first main pipeline (9), connecting a vacuum pump (12) with a second main pipeline (11), unscrewing a second valve (10), slightly unscrewing the first valve (8), opening the vacuum pump (12), and vacuumizing the blind pipe (2) through a branch pipeline (7);

and S05, when no water flows out of the first main pipeline (9), the vacuum pump (12) is turned off.