Pipe jacking friction reducing slurry and its injection device and method

Abstract

The invention discloses a pipe jacking anti-friction mud and a pouring device and a pouring method thereof. The anti-friction mud is composed of bentonite, water, caviar-shaped particles, soda ash and a thickener. Counted by weight, the bentonite accounts for 240-260 parts, the water accounts for 800 parts, the caviar-shaped particles account for 200-220 parts, the soda ash accounts for 6 parts, and the thickener accounts for 2.5 parts. The viscosity of the anti-friction mud is 60-61 parts. The caviar-shaped particles include hard plastic, stone powder and cement. The hard plastic, stone powder and cement are used as the raw materials. The ratio of powder to cement is 2.5-3:1:1. The diameter of the roe-shaped particles is 2-3 mm, the density is 1.15 g / cm³, and the roe-shaped particles account for 18-22% of the total weight of the friction-reducing mud. The jacking pipe friction-reducing mud and its grouting device and grouting method can reduce jacking pipe friction, increase the travel speed of the pipe section, and improve construction efficiency when used. The cement slurry replaces the friction-reducing mud, thereby increasing the overall strength and preventing soil deformation, and is suitable for promotion and use.

Description

TECHNICAL FIELD

[0001] The present application relates to pipe jacking construction technology field, especially to a pipe jacking friction reducing mud and its pouring device and pouring method. BACKGROUND

[0002] In the process of municipal engineering construction, in order to cross the river, road, pipeline, pipe gallery and other existing buildings, reduce the influence of open excavation on the surrounding, often use pipe jacking construction method. The most effective method to reduce the jacking resistance in pipe jacking construction is to pour friction reducing mud outside the pipe wall.

[0003] The traditional friction reducing mud has poor friction reducing effect, and cannot convert sliding friction in pipe jacking process into rolling friction, thus directly affecting the pipe jacking speed and construction efficiency; in addition, after the pipe jacking hole is passed, the internal friction reducing mud needs to be replaced by cement slurry in order to increase the strength.

[0004] The Chinese invention patent with publication number CN104265325B discloses a non-replacement construction method for reinforcing pipe jacking friction reducing mud, which comprises: after the tunnel is passed, solidified mud is injected into the grouting hole on the pipe joint, so that the solidified mud is mixed with the friction reducing mud outside the pipe joint to form a solidifiable mixed slurry; the solidified mud comprises cement, lime and water; the technical problems of ground subsidence and soil layer easy disturbance are solved.

[0005] However, when replacing the friction reducing mud, the cement slurry will directly flush on the tunnel soil, increasing the flushing and disturbance of the slurry on the surrounding soil; in addition, the method is to inject the solidified mud into the pipe joint outside the pipe joint and mix with the friction reducing mud, not to completely replace the friction reducing mud, so the performance of the mixed friction reducing mud is relatively weak, the surrounding soil has poor anti-deformation ability, and the use is not convenient. SUMMARY

[0006] The purpose of the present application is to solve the above problems and provide a pipe jacking friction reducing mud, which can reduce the pipe jacking friction, increase the pipe joint advancing speed, improve the construction efficiency, replace the friction reducing mud with cement slurry, increase the overall strength, and prevent the soil from deforming.

[0007] To achieve the above purpose, the technical scheme of the present application is: a pipe jacking friction reducing mud, the friction reducing mud is composed of bentonite, water, fish roe shaped particles, soda ash and thickening agent, wherein the bentonite accounts for 240-260 parts, the water accounts for 800 parts, the fish roe shaped particles accounts for 200-220 parts, the soda ash accounts for 6 parts, and the thickening agent accounts for 2.5 parts, and the viscosity of the friction reducing mud is 60-61.

[0008] Preferably, the fish roe shaped particles comprise hard plastic, stone powder and cement, and the ratio between the hard plastic, stone powder and cement is 2.5-3:1:1.

[0009] Preferably, the caviar-like particles have a diameter of 2-3 mm and a density of 1.15 g / cm3, and the caviar-like particles account for 18-22% of the total weight of the friction-reducing slurry.

[0010] A pipe jacking friction-reducing slurry pouring device comprises a pipe section, the pipe section is provided with a friction-reducing slurry pouring port, a cement slurry pouring port and a friction-reducing slurry replacement port, the friction-reducing slurry pouring port is provided on the outer wall of the pipe section in multiple and uniformly, the cement slurry pouring port and the friction-reducing slurry replacement port are both communicated with the outside of the pipe section, and the friction-reducing slurry pouring port and the cement slurry pouring port are both provided with a one-way valve.

[0011] Preferably, the one-way valve comprises a pre-buried steel pipe, a sleeve and a blocking plate, the pre-buried steel pipe is arranged in the friction-reducing slurry pouring port and the cement slurry pouring port, the sleeve is arranged in the pre-buried steel pipe, the end of the sleeve is provided with a support, the blocking plate is fixed on the support, the sleeve, the support and the blocking plate form a pouring port, and a pull-back mechanism is arranged between the blocking plate and the pre-buried steel pipe, the pull-back mechanism drives the blocking plate to block the pre-buried steel pipe.

[0012] Preferably, the pull-back device comprises multiple springs, the multiple springs are arranged along the axis of the pre-buried steel pipe, one end of the spring is fixed on the blocking plate, and the other end is fixed in the side wall of the pre-buried steel pipe.

[0013] Preferably, the pull-back device comprises a telescopic shaft and two strong magnets that are attracted to each other, one end of the telescopic shaft is fixed on the blocking plate, and the other end is fixed in the side wall of the pre-buried steel pipe, one of the strong magnets is arranged at the circumference of the port of the pre-buried steel pipe, and the other strong magnet is arranged on the blocking plate, and when the two strong magnets are attracted to each other, the telescopic shaft is retracted into the side wall of the pre-buried steel pipe.

[0014] Preferably, a rubber gasket is further arranged around the end of the pre-buried steel pipe, and the blocking plate extrudes the rubber gasket when blocking the pre-buried steel pipe.

[0015] Preferably, the sleeve is always not separated from the pre-buried steel pipe.

[0016] A grouting method for a jacking friction-reducing mud grouting device comprises the following steps: (1) preparing friction-reducing mud using a mud mixer; soda ash and a thickener should be dissolved in advance, and then bentonite is added and stirred for 20 minutes to be evenly mixed, and then roe-like particles are added according to 20% of the weight of the mud, and stirred again for 5-8 minutes to ensure that the roe-like particles are evenly suspended in the mud. After the mud has expanded for 24 hours, the friction-reducing mud is prepared; (2) grouting the pipe segment with slurry; after the slurry preparation is completed, the friction-reducing mud is extracted from the slurry pool through a grouting pump and a grouting pipe, and after being extracted, the friction-reducing mud is injected through a one-way valve at the friction-reducing mud pouring port; (3) replacing the friction-reducing mud; after the friction-reducing mud stops injecting, the pull-back device in the one-way valve pulls the plug back to seal the embedded steel pipe, and then injects cement slurry into the cement slurry pouring port. At this time, the friction-reducing mud between the pipe segment and the tunnel will be replaced and discharged from the friction-reducing mud replacement port; (4) Treatment of friction-reducing mud: The displaced friction-reducing mud is filtered through a screen to collect the roe-like particles for use. The filtered mud is discharged through a mud-water separation device, and after passing the three-level sedimentation, it is discharged into the municipal sewage network, and the mud is transported to a designated location for treatment.

[0017] Compared with the prior art, the present invention discloses a friction-reducing mud for pipe jacking and its grouting device and grouting method, which have the following beneficial effects: (1) A kind of fish roe-shaped particles that can be evenly suspended in the mud are added to the mud, so that the mud not only has the effect of sliding friction during jacking, but also has the effect of local rolling friction, thereby increasing the travel speed of the pipe section and improving construction efficiency. (2) The friction force and jacking force during jacking construction are reduced, thereby saving energy consumption and reducing cost expenditure. (3) The addition of fish roe-shaped particles reduces the amount of bentonite used, and the fish roe-shaped particle material is stable and can be recycled and reused. The purpose of reducing material input and reducing construction material costs is achieved. (4) Construction quality is guaranteed: by grouting the mud through a one-way valve, the pressure mud can be prevented from directly scouring the soil during jacking construction, thereby preventing the stability of the soil outside the pipe section of the pipe jacking. (5) Cement slurry replaces the friction-reducing mud, which can fill the gap between the soil and the pipe section densely, increasing the overall strength while preventing the soil from deforming. After the cement slurry is poured, the area around the friction-reducing mud pouring port is sealed to prevent water seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the arrangement of multiple pipe segments in the present invention.

[0019] Figure 2 It is a structural schematic diagram of the pipe segment in the present invention.

[0020] Figure 3 The structure of the one-way valve in the present invention is shown in FIG. Figure 1 .

[0021] Figure 4 The structure of the one-way valve in the present invention is shown as follows Figure 2.

[0022] Figure 5 The structure diagram of the one-way valve closing in the application.

[0023] Figure 6 The flow chart of the pipe jacking mud perfusion in the application.

[0024] Figure 7 The on-site construction picture of the application.

[0025] In the figure: 1, working well; 2, slurry pool; 3, slurry pump; 4, grouting pipe; 5, flow switch; 6, pipe joint; 61, friction-reducing mud pouring port; 62, cement slurry pouring port; 63, friction-reducing mud replacement port; 64, one-way valve; 641, embedded steel pipe; 642, rubber gasket; 643, spring; 644, sleeve; 645, support; 646, blocking plate; 647, slurry outlet; 648, telescopic shaft; 649, strong magnet; 7, pipe jacking machine. DETAILED DESCRIPTION

[0026] The application will now be described in further detail with reference to the drawings. The drawings are simplified schematic views which only show the basic structure of the application in a schematic manner, and therefore only show the components which are relevant to the application.

[0027] Please refer to Figures 1-6 A pipe jacking friction-reducing mud, which is composed of bentonite, water, caviar-shaped particles, soda ash and thickening agent, wherein the bentonite accounts for 240-260 parts by weight, the water accounts for 800 parts by weight, the caviar-shaped particles accounts for 200-220 parts by weight, the soda ash accounts for 6 parts by weight, and the thickening agent accounts for 2.5 parts by weight, preferably, the bentonite accounts for 251 parts by weight, and the caviar-shaped particles accounts for 211.7 parts by weight, and the viscosity of the friction-reducing mud is 60.5.

[0028] The caviar-shaped particles include hard plastic, stone powder and cement, the ratio of the hard plastic, the stone powder and the cement is 2.5-3:1:1, the diameter of the caviar-shaped particles is 2-3 mm, the density of the caviar-shaped particles is 1.15 g / cm³, and the caviar-shaped particles account for 18-22% of the total weight of the friction-reducing mud, preferably 20%.

[0029] The above friction-reducing mud has the characteristics of strong stability, no water loss / absorption, water insolubility, moisture resistance, pressure resistance and non-deformation, and can be recycled and reused; due to the presence of the thickening agent and the caviar-shaped particles in the mud, the mud has good fluidity and certain consistency, the density of the caviar-shaped particles is consistent with the specific gravity of the mud, and the caviar-shaped particles can be uniformly suspended in the slurry without sedimentation or floating.

[0030] In the application, the friction-reducing mud is filled between the pipe section and the tunnel, the pipe section is jacked into the tunnel by the pipe jacking machine 7 and the foundation, the outer wall of the pipe section is in contact with the friction-reducing mud during the jacking movement, at this time, the friction-reducing mud forms a lubricating mud sleeve on the outer wall of the pipe section, and the sliding friction is changed into local rolling friction during the pipe jacking, so that the friction coefficient between the pipe jacking machine and the soil is further reduced, and the pipe section advancing speed is improved; that is to say, the sliding friction between the tunnel soil and the pipe section is changed into local rolling friction due to the existence of the friction-reducing mud, the friction resistance is reduced, and the advancing speed and the construction efficiency are improved.

[0031] The friction-reducing effect of the friction-reducing mud is due to the existence of the caviar-shaped particles, after the caviar-shaped particles are mixed into the bentonite, the caviar-shaped particles can be suspended in the inside, reduce the friction, and the caviar-shaped (spherical) particles can also facilitate the rolling of the pipe section and improve the advancing speed.

[0032] The comparison data of the traditional mud and the friction-reducing mud of the application are as follows:

[0033]

[0034] From the above data, it can be seen that when the traditional mud and the friction-reducing mud are used in pipe sections of the same size and weight and are subjected to the same traction, the advancing speed of the pipe section filled with the friction-reducing mud is greater than that of the pipe section filled with the traditional mud.

[0035] The 3# and 4# entrances of Shaoguang Station of Changsha Metro Line 6 are located on the north side of Renmin East Road, in order to avoid the excavation of the baby love road vehicle driving, therefore, the pipe jacking method is used for construction, and the friction-reducing mud of the application is filled during the pipe jacking, so that the pipe section advancing speed is greatly improved, and the construction efficiency is improved.

[0036] The application further discloses a pipe jacking friction-reducing mud filling device, which comprises a pipe section 6, the pipe section 6 is provided with a friction-reducing mud pouring port 61, a cement mud pouring port 62 and a friction-reducing mud replacement port 63, the friction-reducing mud pouring port 61 is provided on the outer wall of the pipe section 6 in a plurality of and annular uniform manners, the cement mud pouring port 62 and the friction-reducing mud replacement port 63 are both communicated with the outside of the pipe section 6, and the friction-reducing mud pouring port 61 and the cement mud pouring port 62 are provided with one-way valves 64; when the friction-reducing mud is filled, the mud is filled between the soil and the pipe section through the one-way valves.

[0037] Specifically, the one-way valve 64 comprises a pre-embedded steel pipe 641, a sleeve pipe 644 and a blocking plate 646. The pre-embedded steel pipe 641 is arranged in the friction-reducing mud pouring port 61 and the cement slurry pouring port 62. The sleeve pipe 644 is arranged in the pre-embedded steel pipe 641. The end of the sleeve pipe 644 is provided with a support 645. The blocking plate 646 is fixed on the support 645. At this time, the sleeve pipe 644, the support 645 and the blocking plate 646 form a slurry outlet 647. After the friction-reducing mud is injected into the pre-embedded steel pipe 641, the mud is poured around through the plurality of slurry outlets 647. In the pouring process, the mud is blocked by the blocking plate 646, so as to avoid direct washing of the soil by the mud and reduce the disturbance of the mud pouring to the soil. The blocking plate 646 and the pre-embedded steel pipe 641 are provided with a pulling-back mechanism. The pulling-back mechanism drives the blocking plate 646 to block the pre-embedded steel pipe 641. In use, the pressurized mud is injected into the pre-embedded steel pipe 641. At this time, the blocking plate 646 moves outward and extends to start the mud injection and pouring. After the pouring is completed, the blocking plate is automatically blocked by the pulling-back mechanism, so as to avoid slurry leakage of the pre-embedded steel pipe 641.

[0038] The pulling-back device comprises a plurality of springs 643. The plurality of springs 643 are arranged along the axis of the pre-embedded steel pipe 641. One end of the spring 643 is fixed on the blocking plate 646, and the other end is fixed in the side wall of the pre-embedded steel pipe 641. When the pressurized friction-reducing mud is poured, the spring is stretched and the blocking plate is pushed outward at the same time. At this time, the mud flows out from the plurality of slurry outlets 647. After the pouring is stopped, the spring 643 is contracted to pull back the blocking plate. At the same time, the sleeve pipe 644 enters the pre-embedded steel pipe 641. The blocking plate after being pulled back blocks the port of the pre-embedded steel pipe 641 to avoid slurry leakage. The friction-reducing mud pouring port 61 is closed.

[0039] Based on the above embodiment, the pulling-back device comprises a telescopic shaft 648 and two strong magnets 649 which are attracted to each other. One end of the telescopic shaft 648 is fixed on the blocking plate 646, and the other end is fixed in the side wall of the pre-embedded steel pipe 641. One of the strong magnets is arranged at the port circumference of the pre-embedded steel pipe 641, and the other strong magnet is arranged on the blocking plate 646. When the two strong magnets are attracted to each other, the telescopic shaft 648 is retracted into the side wall of the pre-embedded steel pipe. When the pressurized friction-reducing mud is poured, the telescopic shaft 648 is stretched and the blocking plate is pushed outward at the same time. At this time, the mud flows out from the plurality of slurry outlets 647. After the pouring is stopped, the two strong magnets are attracted to each other. The telescopic shaft 648 is contracted into the pre-embedded steel pipe 641 and pulls back the blocking plate at the same time. The sleeve pipe 644 enters the pre-embedded steel pipe 641. The blocking plate after being pulled back blocks the port of the pre-embedded steel pipe 641 to avoid slurry leakage. The friction-reducing mud pouring port 61 is closed.

[0040] In addition, the end of the pre-embedded steel pipe 641 is further provided with a rubber gasket 642. The blocking plate 646 extrudes the rubber gasket 642 when blocking the pre-embedded steel pipe 641, so as to improve the blocking and sealing performance of the friction-reducing mud pouring port 61. The sleeve pipe 633 is always not separated from the pre-embedded steel pipe 641, so as to ensure that the whole opening and closing and blocking are realized by the pulling-back device.

[0041] In the application, the establishment of the one-way valve 64 can meet the mud pouring requirement, and can reduce the erosion and disturbance of the soil by the mud during pouring, and can timely block the friction-reducing mud pouring port 61, facilitating the subsequent replacement of the internal friction-reducing mud.

[0042] The application further discloses a pouring method of the pipe jacking friction-reducing mud pouring device, which comprises the following steps: (1) preparing the friction-reducing mud by using a mud mixer; the soda ash and thickening agent are pre-opened, then the bentonite is added and stirred for 20 minutes until uniform, then the fish roe-shaped particles are added according to 20% of the weight of the mud, and the fish roe-shaped particles are stirred for 5-8 minutes again to ensure that the fish roe-shaped particles are uniformly suspended in the mud, and the friction-reducing mud is prepared after the mud is swelled for 24 hours; (2) jacking the pipe section to pour the mud; after the mud preparation is completed, the friction-reducing mud is pumped out from the mud pool 2 by the mud pump 3 and the mud injection pipe 4, wherein the flow switch 5 is arranged on the mud injection pipe 4, and the friction-reducing mud is poured at the friction-reducing mud pouring port 61 through the one-way valve 64 after being pumped out;

[0043] The pipe jacking friction-reducing mud pouring method specifically refers to Figure 6 : that is, mud preparation→ starting the mud pump→ opening the mud feeding valve→ mud feeding (jacking starts) → pipe section valve closing (jacking stops) → main pipe valve closing→ well inner quick connector dismounting→ pipe section lowering→ main pipe lengthening→ cyclically repeating until jacking is completed. When the lubricating mud is pressed and injected, the principle of "pressing first, jacking and pressing simultaneously, and timely mud supplementing" must be adhered to, wherein the mud pump and the output pressure are controlled at 2-3 MPa; (3) friction-reducing mud replacement; after the friction-reducing mud stops pouring, the pull-back device in the one-way valve pulls back the blocking plate to block the embedded steel pipe, thereby playing a role of closing the friction-reducing mud pouring port 61, then the cement mud is poured into the cement mud pouring port 62, all the friction-reducing mud pouring ports 61 are closed during the cement mud pouring, and the friction-reducing mud between the soil and the pipe section is discharged from the friction-reducing mud replacement port 63 after the cement mud is poured, which indicates that the internal friction-reducing mud replacement is completed; the cement mud is filled and compacted in the gap between the soil and the pipe section, thereby increasing the overall strength and preventing the soil from deforming, the friction-reducing mud pouring port 61 around the cement mud pouring port 62 is closed after the cement mud is poured, and water seepage is avoided.

[0044] Before the friction-reducing mud is poured, the cement mud pouring port 62 and the friction-reducing mud replacement port 63 are blocked in advance; the friction-reducing mud pouring port 61 is automatically blocked by the pull-back mechanism after the friction-reducing mud is poured, at this time, the cement mud pouring port 62 and the friction-reducing mud replacement port 63 are opened, the cement mud is poured into the cement mud pouring port 62, and the friction-reducing mud is replaced.

[0045] Obviously, the above-mentioned embodiments are only examples for clearly illustrating the present application, but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the embodiments. The changes or variations derived from the above are still within the protection scope of the present application.

Claims

1. A pipe jacking friction reducing slurry, characterized in that: The friction-reducing mud is composed of bentonite, water, roe-shaped particles, soda ash and a thickener, wherein, by weight, the bentonite accounts for 240-260 parts, the water accounts for 800 parts, the roe-shaped particles account for 200-220 parts, the soda ash accounts for 6 parts, and the thickener accounts for 2.5 parts. The viscosity of the friction-reducing mud is 60-61; The roe-shaped particles include hard plastic, stone powder and cement, and the ratio of the hard plastic, stone powder and cement is 2.5-3:1:1; The diameter of the roe-shaped particles is 2-3 mm, the density is 1.15 g / cm³, and the roe-shaped particles account for 18-22% of the total weight of the friction-reducing mud.

2. A jacking pipe friction reduction slurry injection device, comprising a pipe joint, characterized in that: The pipe segment is provided with a friction-reducing mud pouring port, a cement slurry pouring port and a friction-reducing mud replacement port. The friction-reducing mud pouring port is provided in multiple and evenly arranged in an annular shape on the outer wall of the pipe segment. The cement slurry pouring port and the friction-reducing mud replacement port are both connected to the outside of the pipe segment. One-way valves are provided in the friction-reducing mud pouring port and the cement slurry pouring port. The one-way valve includes a pre-buried steel pipe, a sleeve and a plugging plate. The pre-buried steel pipe is arranged in the friction-reducing mud pouring port and the cement slurry pouring port. The sleeve is arranged in the pre-buried steel pipe. A bracket is provided at the end of the sleeve. The plugging plate is fixed on the bracket. The sleeve, the bracket and the plugging plate form a slurry outlet. A pull-back device is provided between the plugging plate and the pre-buried steel pipe. The pull-back device drives the plugging plate to seal the pre-buried steel pipe.

3. The jacking pipe friction reducing slurry injection device according to claim 2, characterized in that: The pull-back device includes a plurality of springs arranged in an array along the axis of the embedded steel pipe. One end of the spring is fixed on the blocking plate, and the other end is fixed in the side wall of the embedded steel pipe.

4. The jacking pipe friction reducing slurry injection device according to claim 3, characterized in that: The pullback device includes a telescopic shaft and two strong magnets that attract each other. One end of the telescopic shaft is fixed on the blocking plate, and the other end is fixed in the side wall of the embedded steel pipe. One of the strong magnets is arranged at the port circumference of the embedded steel pipe, and the other strong magnet is arranged on the blocking plate. When the two strong magnets attract each other, the telescopic shaft retracts into the side wall of the embedded steel pipe.

5. The jacking pipe friction reducing slurry injection device according to any one of claims 2 to 4, characterized in that: A rubber gasket is also provided around the end of the embedded steel pipe, and the blocking plate squeezes the rubber gasket when blocking the embedded steel pipe.

6. The jacking pipe friction reducing slurry injection device according to claim 2, characterized in that: The sleeve never leaves the embedded steel pipe.

7. A method for pouring a slurry pouring device for reducing friction of a pipe jacking, characterized in that: The friction-reducing mud for pipe jacking according to claim 1 is used, comprising the following steps: (1) preparing the friction-reducing mud by using a mud mixer; soda ash and thickener should be dissolved in advance, and then bentonite is added and stirred for 20 minutes to be evenly mixed, and then roe-like particles are added according to 20% of the weight of the mud, and stirred again for 5-8 minutes to ensure that the roe-like particles are evenly suspended in the mud. After the mud has expanded for 24 hours, the friction-reducing mud is prepared; (2) grouting the pipe segment; after the slurry preparation is completed, the friction-reducing mud is extracted from the slurry pool by a grouting pump and a grouting pipe, and after being extracted, the friction-reducing mud is poured through a one-way valve at the friction-reducing mud pouring port; (3) replacing the friction-reducing mud; after the friction-reducing mud stops being poured, the pull-back device in the one-way valve pulls the plug back to seal the embedded steel pipe, and then pours cement slurry into the cement slurry pouring port. At this time, the friction-reducing mud between the pipe segment and the tunnel will be replaced and discharged from the friction-reducing mud replacement port; (4) Treatment of friction-reducing mud: The displaced friction-reducing mud is filtered through a screen to collect the roe-like particles for use. The filtered mud is discharged through a mud-water separation device, and after passing the three-level sedimentation, it is discharged into the municipal sewage network, and the mud is transported to a designated location for treatment.

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