Water burst prevention pipe cutting hole sealing method

Abstract

The invention discloses an anti-water-bursting pipe cutting and hole sealing method which comprises the following steps: firstly, filling a rubber bag into a pipeline needing pipe cutting and hole sealing, enabling the periphery of the rubber bag to be in sealing fit with the inner wall of the pipeline, then respectively mounting a liquid supply pipe and an exhaust pipe on a thermal insulation partition plate, and inserting the thermal insulation partition plate into a pipe orifice of the pipeline, the end of the liquid supply pipe and the end of the exhaust pipe are inserted into the pipeline, a pipe opening of the liquid supply pipe is connected with the nitrogen storage tank, the nitrogen storage tank is opened, liquid nitrogen is supplied into a pipe cavity between the rubber bag and the heat preservation partition plate through the liquid supply pipe, the liquid nitrogen is vaporized to absorb heat of a surrounding soil layer to form freezing, and finally pipe cutting operation is conducted. The freezing system is simple and has the technical advantages of being short in freezing time, low in freezing temperature and high in frozen soil strength, the problem of sudden water burst during pipe cutting and hole sealing construction is effectively solved, the major risk of pipe cutting and hole sealing construction is reduced, the safety of pipe cutting and hole sealing construction is ensured, operation is easy, and construction is convenient, fast and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of pipe cutting in freezing construction, and more particularly to a method for sealing a pipe cutting hole to prevent water gushing. Background Art

[0002] The principle of the freezing method is to bury freezing pipes in the stratum to be treated and input refrigerant into the freezing pipes to cool the freezing pipes and form frozen soil columns around the freezing pipes. As the frozen soil columns expand, adjacent frozen soil columns are connected together to form a frozen soil curtain. The strength and stability of the soil layer are enhanced, and the groundwater can be isolated from the underground structure. It has the characteristics of good water-proofing, strong adaptability and little impact on the environment.

[0003] After the permanent support structure is completed, the freezing can be stopped, the frozen pipes can be cut off, and the frozen pipes can be filled and treated for seepage prevention, and grouting can be carried out in time. However, when faced with the following working conditions, how to prevent water gushing when cutting the pipes is a problem that has not yet been properly solved:

[0004] Working condition 1: Some unfrozen through-holes constructed inside the communication channel are used for threading. At present, the melting and grouting time of the freezing method is too long. Forced thawing will reduce the time of melting and grouting, but there will be risks in cutting and sealing the through-hole pipes in the through-hole under forced thawing conditions.

[0005] Working condition 2: When constructing communication passages or other underground projects, the refrigeration station is usually arranged in the tunnel. If the cooling tower and clean water pump cannot be arranged in the tunnel or the middle plate of the working well due to site restrictions, the cooling tower and clean water pump can only be arranged on the surface. The low-temperature cooling water is transported to the condenser of the refrigerator by installing the water inlet pipe through the surface drilling hole. After the condenser absorbs heat, the high-temperature cooling water returns to the cooling tower through the return pipe. After the freezing project is completed, the water inlet pipe and the return pipe need to be sealed to ensure safety. The exposed part of the water pipe needs to be cut off before sealing the hole. When cutting the pipe, it is very easy to cause water and sand gushing, which will lead to disasters such as ground subsidence and deformation of tunnel segments.

[0006] Working condition 3: In general, the conventional frozen pipe cutting process is to cut the frozen pipe when the frozen wall has not thawed, that is, the frozen pipe cutting work is arranged within 3 days of freezing, and the frozen pipe cutting and backfilling are completed. If there are a lot of frozen pipes, the pipe cutting work is very large. If the pipe cutting is not completed within 3 days, the annular space between the frozen pipe and the borehole wall is likely to have water gushing due to the decrease in freezing degree, which may cause damage to the tunnel structure at the least and cause the tunnel to be rerouted at the worst. Summary of the invention

[0007] Therefore, the technical problem to be solved by the present invention is to provide a method for sealing the pipe cutting holes to prevent water gushing, which can quickly freeze the space between the pipe and the stratum where the pipe cutting construction is required.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for sealing a pipe cut to prevent water inrush, comprising the following steps:

[0009] Step A: Put a rubber bag into the pipe that needs to be cut and sealed, and the outer periphery of the rubber bag is sealed and fitted with the inner wall of the pipe;

[0010] Step B: Installing a liquid supply pipe and an exhaust pipe through the heat-insulating baffle, inserting the heat-insulating baffle into the pipe opening of the pipe, and inserting the end of the liquid supply pipe and the end of the exhaust pipe into the pipe, with a gap between the liquid supply pipe and the rubber bag;

[0011] Step C: Connect the outlet of the liquid supply pipe to the nitrogen storage tank, open the nitrogen storage tank, and supply liquid nitrogen into the tube cavity between the rubber bag and the insulation partition through the liquid supply pipe. The liquid nitrogen is vaporized in the tube cavity and then discharged from the exhaust pipe. The vaporized liquid nitrogen absorbs the heat of the surrounding soil layer to form freezing.

[0012] Step D: After freezing is completed, pull out the insulation baffle, and pull out the liquid supply pipe and exhaust pipe together, and then cut the pipe;

[0013] Step E: Fill and seal the pipe opening after the pipe cutting is completed.

[0014] In the above-mentioned method for sealing a pipe by cutting a hole to prevent water gushing, in step B, the outer circumferential surface of the thermal insulation baffle is gap-fitted with the inner wall of the freezing pipe, and the thermal insulation baffle is slidingly fitted in the freezing pipe, and the liquid supply pipe and the exhaust pipe are both sealed and fixedly connected to the thermal insulation baffle.

[0015] In the above-mentioned method for sealing a hole by cutting a pipe to prevent water inrush, in step B, the distance between the wall surface on one side of the tunnel segment in contact with the stratum and the rubber bag is greater than 0.

[0016] In the above-mentioned method for sealing a pipe cut to prevent water gushing, the distance between the wall surface on one side of the tunnel segment in contact with the stratum and the rubber bag is 30 cm.

[0017] In the above-mentioned method for sealing a pipe cut to prevent water gushing, the distance between the end of the liquid supply pipe inserted into the freezing chamber and the rubber bag is 10 cm.

[0018] In the above-mentioned method for sealing a pipe cut to prevent water gushing, the distance between the end of the exhaust pipe inserted into the freezing chamber and the rubber bag is greater than the distance between the end of the liquid supply pipe inserted into the freezing chamber and the rubber bag.

[0019] In the above-mentioned method for sealing a hole by cutting a pipe to prevent water gushing, in step B, the axis of the liquid supply pipe coincides with the axis of the thermal insulation baffle, and the liquid supply pipe is coaxially arranged with the freezing pipe.

[0020] In the above-mentioned method for sealing the pipe cutting holes to prevent water gushing, in step E, the pipes left in the stratum are filled, and before filling, the brine in the pipe is blown dry with compressed air, and the pipes in the stratum are filled with cement mortar of M10 or above or concrete of C20 or above; the length of the filling pipe for the pipe with an upper elevation angle shall not be less than 1.5m within the pipe mouth, and the whole section of the pipe with a lower depression angle is filled; for the steel pipe segment, the cut-off part of the pipe orifice is welded and sealed with a 10mm thick steel plate, the weld height is 6mm, and the weld and the steel pipe segment grid are coated with water-expanding waterproofing glue; for the concrete pipe segment, the cut-off part of the pipe is welded and sealed with a 10mm thick steel plate, the weld height is 6mm, and after the weld is coated with water-expanding waterproofing glue, two expansion bolts of M12 or above are constructed on the side wall of the concrete pipe segment in the cut-off area, and the outer side of the expansion bolts protrudes from the concrete pipe segment by a reserved length of not less than 3cm, and is welded to the remaining part of the orifice pipe; then the grid is filled and a 12mm thick steel plate is welded to re-close the grid.

[0021] In the above-mentioned anti-water gushing pipe cutting and sealing method, in step A, a diverter cone and a guide ring are arranged on the wall surface of the rubber bag facing the liquid outlet end of the liquid supply pipe, the diverter cone and the guide ring are arranged coaxially with the rubber bag, the small diameter end of the diverter cone is arranged toward the liquid outlet end of the liquid supply pipe, and the large diameter end face of the diverter cone is fixedly connected to the side wall of the rubber bag; the axial length of the guide ring gradually increases from the side close to the axis to the side away from the axis, and the outer circumferential surface of the guide ring is sealed and fitted with the inner wall of the pipe. By setting the diverter cone and the liquid supply pipe facing the diverter cone, liquid nitrogen can be diverted, so that the liquid nitrogen is evenly dispersed around and under the action of the guide ring, the dispersed liquid nitrogen flows to the inner wall of the pipe, uniformly cools the soil around the pipe, and achieves a uniform freezing effect. At the same time, it can prevent liquid nitrogen from directly impacting the rubber bag, reduce the impact force, and ensure the stability of the rubber bag. The guide ring can also play a role in improving the sealing effect of the rubber bag.

[0022] In the above-mentioned method for sealing a pipe cutting hole to prevent water gushing, in step B, an annular groove is opened on the outer circumferential surface of the thermal insulation baffle, a sealing ring is installed in the annular groove, and the sealing ring is sealed and fitted with the inner wall of the pipe. At least two annular grooves are provided, and the interval between the two annular grooves is greater than zero, thereby improving the sealing effect between the thermal insulation baffle and the pipe, and a sealing ring is installed in each of the annular grooves, and there is a certain interval between the two annular grooves. After the thermal insulation baffle is installed in the pipe, the two layers of sealing rings are sealed and fitted with the inner wall of the pipe respectively. When freezing construction is carried out, water in the pipe or outside water will not enter between the two layers of sealing rings, thereby effectively reducing the possibility of the thermal insulation baffle and the pipe freezing together after the freezing construction, and facilitating the rapid removal of the thermal insulation baffle after the construction is completed.

[0023] The technical solution of the present invention achieves the following beneficial technical effects:

[0024] The traditional brine circulation freezing method has a complex system, requires many equipments and has a long freezing cycle. The freezing system of the present invention is simple, requires few equipments and has the technical advantages of short freezing time, low freezing temperature and high frozen soil strength. It effectively solves the problem of sudden water gushing during the construction of pipe cutting and sealing of communication channel water pipes, through holes or forced thawing frozen pipes, reduces the major risks of pipe cutting and sealing construction, ensures the safety of pipe cutting and sealing construction, and is simple to operate, convenient and efficient in construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the present invention during the construction of anti-water gushing pipe cutting and freezing.

[0026] Figure 2 A schematic cross-sectional structure diagram of the rubber bladder of the present invention;

[0027] Figure 3 A schematic diagram of the cross-sectional structure of the thermal insulation baffle of the present invention.

[0028] The reference numerals in the figure are as follows: 1-tunnel segment; 2-orifice pipe; 3-pipeline; 4-insulation baffle; 41-ring groove; 42-sealing ring; 5-liquid supply pipe; 6-exhaust pipe; 7-rubber bag; 71-diverter cone; 72-guide ring; 8-lumen. DETAILED DESCRIPTION

[0029] A method for sealing a pipe hole to prevent water inrush in this embodiment includes the following steps:

[0030] Step A: inserting a rubber bag 7 into the pipe 3 to be cut and sealed, and the outer periphery of the rubber bag 7 is sealed and fitted with the inner wall of the pipe 3;

[0031] Step B: Install a liquid supply pipe 5 and an exhaust pipe 6 through the heat-insulating baffle 4, respectively. The liquid supply pipe 5 and the exhaust pipe 6 are both sealed and fixedly connected to the heat-insulating baffle 4. Insert the heat-insulating baffle 4 into the pipe opening of the pipe 3. The outer circumferential surface of the heat-insulating baffle 4 is gap-matched with the inner wall of the pipe 3. The heat-insulating baffle 4 is slidably fitted in the pipe 3. The ends of the liquid supply pipe 5 and the exhaust pipe 6 are inserted into the pipe 3. There is a distance between the liquid supply pipe 5 and the rubber bag 7. The distance between the end of the liquid supply pipe 5 inserted into the tube cavity 8 and the rubber bag 7 is 10 cm. Figure 3As shown, an annular groove 41 is provided on the outer circumference of the thermal insulation partition 4, and a sealing ring 42 is installed in the annular groove 41. The sealing ring 42 is sealed and fitted with the inner wall of the pipe 3. There are at least two annular grooves 41, and the interval between the two annular grooves 41 is greater than zero, and a sealing ring 42 is installed in each annular groove 41. There is a certain gap between the thermal insulation partition 4 and the inner wall of the pipe 3 to ensure that the thermal insulation partition 4 can enter the pipe 3, and the sealing ring 42 ensures the sealing effect. After the freezing construction is completed, the thermal insulation partition 4 and the pipe 3 may be frozen together. In order to further improve the convenience of disassembly after the freezing construction of the thermal insulation partition 4 is completed, a rubber tube is put on the outer circumference of the thermal insulation partition 4, and the rubber tube and the sealing ring 42 are integrally formed. The sealing ring 42 protrudes from the rubber tube. When the freezing construction is completed, the rubber tube isolates the thermal insulation partition 4 and the pipe 3, which can prevent the two from freezing into one, and the thermal insulation partition 4 can be smoothly pulled out.

[0032] Step C: Connect the pipe mouth of the liquid supply pipe 5 to the nitrogen storage tank, open the nitrogen storage tank, and supply liquid nitrogen into the tube cavity 8 between the rubber bag 7 and the heat-insulating partition 4 through the liquid supply pipe 5. The liquid nitrogen is vaporized in the tube cavity 8 and then discharged from the exhaust pipe 6. The vaporized liquid nitrogen absorbs the heat of the surrounding soil layer to form freezing;

[0033] Step D: After the freezing is completed, pull out the insulation baffle 4, and pull out the liquid supply pipe 5 and the exhaust pipe 6 together, and then cut the pipe 3. After the insulation baffle 4 is pulled out, the rubber bag 7 remains in the pipe 3. When filling the pipe 3, the rubber bag 7 is pushed forward under the action of the mortar pressure to ensure the filling effect of the filling section in the pipe 3. Especially for the pipe 3 with a small horizontal angle, it can form a complete filling section after filling the pipe 3. When the pipe 3 is conventionally filled, due to the length of the pipe 3, the mortar enters the pipe 3. The flow rate is reduced, which easily leads to uneven mortar. By setting the rubber bag 7 in conjunction with the diverter cone 71 and the guide ring 72, after the mortar contacts the surface of the rubber bag 7, a local fluid stirring effect will be generated, which is beneficial to the discharge of gas, making the mortar filled in the pipeline more uniform, achieving tight filling of the mortar, and achieving that the filled part of the pipeline 3 can be filled with mortar, and the mortar can impact the pipe wall of the pipeline 3 under the action of the diverter cone 71 and the guide ring 72, thereby improving the bonding strength between the mortar and the inner wall of the pipeline 3 and improving the blocking effect on the pipeline 3;

[0034] Step E: Fill and seal the pipe opening of the pipe 3 after the pipe cutting is completed, and fill the pipe 3 left in the stratum. Before filling, use compressed air to blow out the brine in the pipe 3, and use cement mortar above M10 or concrete above C20 to fill the pipe 3 in the stratum; for the pipe 3 with an upward elevation angle, the filling pipe length shall not be less than 1.5m within the pipe opening, and for the pipe 3 with a downward depression angle, the whole section shall be filled; for the steel pipe segment, the cut-off part of the pipe 3 hole shall be welded and sealed with a 10mm thick steel plate, and the welding The seam height is 6mm, and water-expandable waterproofing glue is applied to the weld and the steel pipe segment grid. For the concrete pipe segment, the cut-off part of the pipeline 3 is sealed by welding with a 10mm thick steel plate. The weld height is 6mm. After applying water-expandable waterproofing glue on the weld, two expansion bolts of M12 or above are constructed on the side wall of the concrete pipe segment in the cut-off area. The reserved length of the expansion bolts extending out of the concrete pipe segment on the outside is not less than 3cm, and it is welded to the remaining part of the orifice pipe; then fill the grid and weld a 12mm thick steel plate to re-close the grid.

[0035] In step B, the distance between the side wall of the tunnel segment 1 in contact with the stratum and the rubber bag 7 is greater than 0. In actual construction, the distance between the side wall of the tunnel segment 1 in contact with the stratum and the rubber bag 7 is 30 cm. The distance between the end of the exhaust pipe 6 inserted into the freezing chamber 8 and the rubber bag 7 is greater than the distance between the end of the liquid supply pipe 5 inserted into the pipe chamber 8 and the rubber bag 7, and the axis of the liquid supply pipe 5 coincides with the axis of the thermal insulation baffle 4. The liquid supply pipe 5 is coaxially arranged with the freezing pipe 3 to ensure that the liquid nitrogen can circulate normally and improve the freezing efficiency.

[0036] like Figure 2 As shown, a diverter cone 71 and a guide ring 72 are provided on the wall surface of the rubber bag 7 on one side facing the liquid outlet end of the liquid supply pipe 5. The diverter cone 71 and the guide ring 72 are coaxially arranged with the rubber bag 7. The small diameter end of the diverter cone 71 is arranged toward the liquid outlet end of the liquid supply pipe 5, and the large diameter end surface of the diverter cone 71 is fixedly connected to the side wall of the rubber bag 7; the axial length of the guide ring 72 gradually increases from the side close to the axis to the side away from the axis, and the outer circumferential surface of the guide ring 72 is sealed and fitted with the inner wall of the pipeline 3.

[0037] The present invention can also be applied to frozen pipes in frozen formations after thawing, water pipes in formations, or through-hole pipes that need to be cut under forced thawing conditions, as well as similar working conditions where there is a risk of water gushing out when cutting pipes and sealing holes.

[0038] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A method for sealing a pipe cut to prevent water inrush, characterized in that: The following steps are involved: Step A: inserting a rubber bag (7) into a pipe (3) to be cut and sealed, wherein the outer periphery of the rubber bag (7) is in sealing contact with the inner wall of the pipe (3); Step B: Installing a liquid supply pipe (5) and an exhaust pipe (6) through the heat-insulating baffle (4), inserting the heat-insulating baffle (4) into the pipe opening of the pipe (3), and inserting the end of the liquid supply pipe (5) and the end of the exhaust pipe (6) into the pipe (3), with a gap between the liquid supply pipe (5) and the rubber bag (7); Step C: connecting the pipe mouth of the liquid supply pipe (5) to the nitrogen storage tank, opening the nitrogen storage tank, and supplying liquid nitrogen into the tube cavity (8) between the rubber bag (7) and the heat-insulating baffle (4) through the liquid supply pipe (5); the liquid nitrogen is vaporized in the tube cavity (8) and then discharged from the exhaust pipe (6); the vaporized liquid nitrogen absorbs the heat of the surrounding soil layer to form freezing; Step D: After the freezing is completed, the heat-insulating baffle (4) is pulled out, and the liquid supply pipe (5) and the exhaust pipe (6) are pulled out together, and then the pipe (3) is cut; Step E: Filling and sealing the opening of the pipe (3) after the pipe cutting is completed.

2. A method for sealing a pipe against water inrush according to claim 1, characterized in that: In step B, the outer circumferential surface of the thermal insulation baffle (4) is gap-fitted with the inner wall of the freezing pipe (3), and the thermal insulation baffle (4) is slidably fitted in the freezing pipe (3); the liquid supply pipe (5) and the exhaust pipe (6) are both sealed and fixedly connected to the thermal insulation baffle (4).

3. A method for sealing a pipe against water inrush according to claim 1, characterized in that: In step B, the distance between the wall surface of one side of the tunnel segment (1) in contact with the stratum and the rubber bag (7) is greater than 0.

4. A method for sealing a pipe against water inrush according to claim 3, characterized in that: The distance between the wall surface of one side of the tunnel segment (1) in contact with the ground and the rubber bag (7) is 30 cm.

5. A method for sealing a pipe against water inrush according to claim 4, characterized in that: The distance between the end of the liquid supply tube (5) inserted into the tube cavity (8) and the rubber bag (7) is 10 cm.

6. A method for sealing a pipe against water inrush according to claim 5, characterized in that: The distance between the end of the exhaust pipe (6) inserted into the tube cavity (8) and the rubber bag (7) is greater than the distance between the end of the liquid supply pipe (5) inserted into the tube cavity (8) and the rubber bag (7).

7. A method for sealing a pipe against water inrush according to claim 1, characterized in that: In step B, the axis of the liquid supply pipe (5) coincides with the axis of the heat-insulating baffle (4), and the liquid supply pipe (5) and the freezing pipe (3) are coaxially arranged.

8. A method for sealing a pipe hole against water inrush according to claim 1, characterized in that: In step E, the pipe (3) left in the stratum is filled. Before filling, the brine in the pipe (3) is blown dry with compressed air. The pipe (3) in the stratum is filled with cement mortar of M10 or above or concrete of C20 or above. For the pipe (3) with an upward elevation angle, the length of the filling pipe is not less than 1.5 m inside the pipe mouth. For the pipe (3) with a downward depression angle, the whole section is filled. For the steel pipe segment, the cut-off part of the pipe (3) is welded and sealed with a 10 mm thick steel plate, and the weld height is 6 mm. , apply water-expandable waterproofing glue around the weld and steel pipe segment grid; for the concrete pipe segment, the pipe (3) is cut and sealed with a 10mm thick steel plate, the weld height is 6mm, and after applying water-expandable waterproofing glue on the weld, two expansion bolts of M12 or above are installed on the side wall of the concrete pipe segment in the cut area. The outer side of the expansion bolt protrudes from the concrete pipe segment to a reserved length of not less than 3cm, and is welded to the remaining part of the orifice pipe; then fill the grid and weld a 12mm thick steel plate to re-seal the grid.

9. A method for sealing a pipe cut to prevent water inrush according to claim 1, characterized in that: In step A, a flow dividing cone (71) and a flow guiding ring (72) are arranged on a wall surface of the rubber bag (7) on one side facing the liquid outlet end of the liquid supply pipe (5); the flow dividing cone (71) and the flow guiding ring (72) are arranged coaxially with the rubber bag (7); the small diameter end of the flow dividing cone (71) is arranged toward the liquid outlet end of the liquid supply pipe (5); the large diameter end surface of the flow dividing cone (71) is fixedly connected to the side wall of the rubber bag (7); the axial length of the flow guiding ring (72) gradually increases from the side close to the axis to the side far from the axis; the outer circumferential surface of the flow guiding ring (72) is sealed and fitted with the inner wall of the pipeline (3).

10. A method for sealing a pipe hole against water inrush according to claim 1, characterized in that: In step B, an annular groove (41) is provided on the outer circumferential surface of the heat-insulating baffle (4), a sealing ring (42) is installed in the annular groove (41), and the sealing ring (42) is sealed against the inner wall surface of the pipe (3); at least two annular grooves (41) are provided, the interval between the two annular grooves (41) is greater than zero, and a sealing ring (42) is installed in each annular groove (41).

Images