A method for in-situ in-vitro intelligent winding self-prestressed reinforcement of in-service PCCP

Abstract

The present invention discloses an in-situ in vitro intelligent winding self-prestressing reinforcement method for in-service PCCP, which belongs to the field of PCCP repair technology and solves the technical problem of large engineering workload of existing PCCP reinforcement methods. The reinforcement method is as follows: winding memory alloy bars on the outer wall of the part to be reinforced of the PCCP pipeline, the memory alloy bars are close to the PCCP pipeline, and the two ends are anchored to the PCCP pipeline, the memory alloy bars are heated to activate their shape memory effect, and after the temperature of the memory alloy bars is restored, self-prestressing is formed under the action of the recovery stress, thereby achieving reinforcement of the PCCP pipeline. The memory alloy bars are pulled by a drilling robot and wound around the outer wall of the part to be reinforced. A protective tube is provided on the periphery of the memory alloy bars. During the winding process of the memory alloy bars, a quick-setting mortar protective layer is poured into the gap between the memory alloy bars and the protective tube. After the quick-setting mortar protective layer is finally set, the memory alloy bars are heated by electrical excitation. This can solve the problem of large-scale excavation required for existing PCCP reinforcement, and the reinforcement process is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of PCCP repair, and more particularly to an in-situ in vitro intelligent winding self-prestressed reinforcement method and a construction method for an in-service PCCP. Background Art

[0002] PCCP is a composite pipe structure composed of steel plates, concrete, high-strength prestressed steel wire, and cement mortar. Combining the unique properties of steel and concrete, it boasts a wide range of applications, a long economic lifespan, excellent seismic resistance, easy installation, low operating costs, and virtually no leakage. It is commonly used in large-scale water supply projects and urban underground water supply projects. However, due to the highly corrosive environment in which it operates or overloads during operation, the high-strength prestressed steel wires in PCCP often break. Accumulating these wire breaks can lead to PCCP bursts, resulting in engineering accidents. Reinforcing broken PCCP is complex due to its large size and often requires extensive excavation of the surrounding soil and support of the base, significantly impacting nearby traffic and unsuitable for the rapid repair of urban lifeline projects. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art. One purpose of the present invention is to provide an in-situ in-vitro intelligent winding self-prestressed reinforcement method for in-service PCCP that can reduce engineering workload and avoid excavation.

[0004] The second object of the present invention is to provide a construction method for in-situ in-vitro intelligent winding self-prestressed reinforcement of in-service PCCP, which can reduce the amount of engineering work and avoid excavation.

[0005] In order to achieve the above-mentioned first objective, the present invention provides an in-situ in vitro intelligent winding self-prestressed reinforcement method for an in-service PCCP pipeline, wherein a memory alloy bar is wound around the outer wall of the portion to be reinforced of the PCCP pipeline, and both ends of the memory alloy bar are anchored to the PCCP pipeline so that the memory alloy bar is in close contact with the PCCP pipeline. The memory alloy bar is heated to activate its shape memory effect, and after the temperature of the memory alloy bar recovers, self-prestress is formed under the action of the recovery stress, thereby reinforcing the PCCP pipeline.

[0006] As a further improvement, the memory alloy rib is made of any one of NiTi-based shape memory alloy, copper-based shape memory alloy, iron-based shape memory alloy, and gold-cadmium alloy.

[0007] Furthermore, the memory alloy rib is pulled by a ground-boring robot and wound around the outer wall of the portion to be reinforced.

[0008] Furthermore, a first flange is provided at the tail end of the earth-boring robot, and a second flange is provided at one end of the memory alloy rib for traction connection with the first flange.

[0009] Furthermore, it is characterized in that a protective tube is provided around the periphery of the memory alloy rib.

[0010] Furthermore, in the process of wrapping the memory alloy ribs around the outer wall of the part to be reinforced, a quick-setting mortar protective layer is poured into the gap between the memory alloy ribs and the protective tube, and the memory alloy ribs are fully wrapped by the quick-setting mortar protective layer to prevent the memory alloy ribs from sticking to one side of the protective tube.

[0011] Furthermore, the second flange is welded to one end of the protective tube, and a third flange is welded to the other end of the protective tube. The two ends of the memory alloy rib pass through the second flange and the third flange respectively. The surface of the PCCP pipe is provided with anchor grooves corresponding to the second flange and the third flange respectively. After the second flange and the third flange are respectively installed in the anchor grooves, anchor ends are formed by pouring quick-setting mortar for anchoring. The two ends of the memory alloy rib extend out of the anchor ends. After the quick-setting mortar protective layer and the anchor end are finally solidified, the memory alloy rib is heated by electrical excitation. After the heating is completed, the protruding ends of the memory alloy rib are protected against corrosion.

[0012] Furthermore, before winding the memory alloy rib, the memory alloy rib is temporarily fixed at one end of the protection tube by epoxy resin glue.

[0013] Furthermore, the memory alloy rib is spirally wound around the outer wall of the portion to be reinforced, and the helical angle of the memory alloy rib pulled by the drilling robot satisfies the following formula:

[0014]

[0015]

[0016] Where θ is the helix angle, r is the radius of the PCCP pipe, and d is the pitch.

[0017] In order to achieve the above-mentioned second objective, the present invention provides a construction method for external reinforcement of PCCP pipelines, and the reinforcement steps are as follows:

[0018] Step S1. Drilling deep holes in the overburden above the location of the PCCP pipeline to be reinforced. The deep holes extend to the top of the PCCP pipeline. The number of deep holes and the distance between two adjacent deep holes depend on the power of the drilling robot or the power of the power excitation device for the memory alloy reinforcement.

[0019] Step S2. The control terminal of the drilling robot and the energized excitation device of the memory alloy rib are transported to the side of the deep hole for use;

[0020] Step S3. The PCCP pipe between two adjacent deep holes is reinforced using the above-mentioned in-situ in vitro intelligent winding self-prestressed reinforcement method for the in-service PCCP; if there are more than two deep holes, the end point of the previous segment of the memory alloy rib is the starting point of the next segment of the memory alloy rib;

[0021] Step S4: After the PCCP pipes between all deep holes are reinforced, all deep holes are filled to complete the entire reinforcement work.

[0022] Beneficial effects

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The memory alloy self-prestressing technology adopted in the present invention does not require the use of large-scale mechanical equipment for tensioning required by traditional PCCP reinforcement technology. It only needs to use high-power excitation equipment to heat the memory alloy to generate recovery stress. After it cools down, the reinforcement is completed under the action of the recovery stress, which can save construction costs.

[0025] 2. The drilling robot drilling and winding technology adopted in the present invention does not require covering excavation or supporting PCCP, which greatly shortens the time of covering excavation and backfilling before and after reinforcement work.

[0026] 3. The memory alloy bars used in the present invention to reinforce PCCP can be prefabricated in the factory according to the required specifications, shortening the on-site operation time.

[0027] 4. The present invention provides a protective tube around the memory alloy rib. During the process of winding the memory alloy rib, a quick-setting mortar protective layer is poured into the gap between the memory alloy rib and the protective tube, which can protect the memory alloy rib from corrosion in the underground humid environment while improving the efficiency of the reinforcement work.

[0028] 5. The protective tube used in the present invention is connected by a flange, and the memory alloy passes through the flange. The winding and subsequent prestressing excitation are simple to operate, and the reinforcement work will hardly affect the traffic and the normal operation of the PCCP. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the present invention using a ground-drilling robot to pull and wind a memory alloy rib;

[0030] Figure 2 This is a construction scene diagram of the present invention;

[0031] Figure 3This is a side view of the earth-drilling robot used in the present invention;

[0032] Figure 4 This is a diagram showing the connection between the drilling robot and the memory alloy rib of the present invention.

[0033] Figure 5 This is a cross-sectional view of the memory alloy rib, protective tube, and quick-setting mortar protective layer of the present invention;

[0034] Figure 6 is a schematic diagram of the anchoring end of the present invention;

[0035] Figure 7 Schematic diagram of the helical angle of the memory alloy rib in the present invention.

[0036] Among them: 1-PCCP pipeline, 2-memory alloy reinforcement, 3-drilling robot, 4-first flange, 5-second flange, 6-protective pipe, 7-quick-setting mortar protective layer, 8-third flange, 9-anchor end, 10-epoxy resin glue, 11-covering layer, 12-deep hole, 13-powered excitation equipment, 14-control end, 15-drill bit, 16-ball hinge, 17-robot body, 18-tracked wheels, 19-bolts, 20-nuts. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0038] See Figures 1 to 7 , a method for in-situ in vitro intelligent winding self-prestressed reinforcement of an in-service PCCP, wherein a memory alloy rib 2 is wound on the outer wall of the portion to be reinforced of the PCCP pipe 1. The memory alloy can be a memory alloy with a one-way memory effect, a two-way memory effect, or a full-way memory effect, specifically a spirally wound structure. The two ends of the memory alloy rib 2 are anchored to the PCCP pipe 1 so that the memory alloy rib 2 is close to the PCCP pipe 1. The memory alloy rib 2 is heated to activate its shape memory effect, such as heating the memory alloy rib 2 to a predetermined temperature to generate a recovery stress. The heating method can be electric excitation heating or high-frequency induction coil heating. After the memory alloy rib 2 cools naturally, it forms self-prestress under the action of the recovery stress, thereby achieving reinforcement of the PCCP pipe, that is, completing the reinforcement of the specific portion (the portion to be reinforced). In the presence of a covering layer 11, the memory alloy rib 2 is spirally wound by drilling into the ground.

[0039] The memory alloy rib 2 is made of any one of NiTi-based shape memory alloy, copper-based shape memory alloy, iron-based shape memory alloy, and gold-cadmium alloy. Preferably, the memory alloy rib 2 is a stranded wire structure, that is, the memory alloy rib 2 is made of several thin memory alloy wires twisted together.

[0040] Preferably, the memory alloy bar 2 is pulled by a drilling robot 3 and wrapped around the outer wall of the portion to be reinforced. The drilling robot 3 can be an existing mature drilling robot. The drilling robot 3 includes a robot body 17, a drill bit 15 mounted on the front end of the robot body 17 via a ball joint 16, and crawler wheels 18 at the bottom of the robot body 17 that can be attached to the outer surface of the PCCP pipe 1 for walking.

[0041] A first flange 4 is provided at the tail end of the drilling robot 3, and a second flange 5 is provided at one end of the memory alloy rib 2 for traction connection with the first flange 4. The first flange 4 and the second flange 5 are locked by bolts 19 and nuts 20. The drilling robot 3 pulls the memory alloy rib 2 through the first flange 4 and the second flange 5.

[0042] Preferably, a protective tube 6 is provided around the outer periphery of the memory alloy rib 2. During the process of wrapping the memory alloy rib 2 around the outer wall of the portion to be reinforced, a quick-setting mortar protective layer 7 is poured into the gap between the memory alloy rib 2 and the protective tube 6. The quick-setting mortar protective layer 7 ensures that the memory alloy rib 2 is fully wrapped by the memory alloy rib 2 to prevent the memory alloy rib 2 from sticking to one side of the protective tube 6. For example, hollow support rings are placed at appropriate intervals on the surface of the memory alloy rib 2, or a support frame is provided inside the protective tube to prevent the quick-setting mortar protective layer 7 from losing its protective function due to the memory alloy rib 2 sticking to the inner surface of the protective tube 6. The protective tube 6 is made of a corrosion-resistant material, such as a PE tube or other plastic tube.

[0043] The second flange 5 is welded to one end of the protective tube 6, and the third flange 8 is welded to the other end of the protective tube 6. The ends of the memory alloy rib 2 pass through the second flange 5 and the third flange 8, respectively. The second flange 5 and the third flange 8 are injection-molded flanges, while the first flange 4 is a stainless steel flange or an injection-molded flange. The first flange 4 is provided with a receiving hole to accommodate the protruding end of the memory alloy rib 2, which prevents interference when the first flange 4 and the second flange 5 are connected. The surface of the PCCP pipe 1 is provided with anchor grooves corresponding to the second flange 5 and the third flange 8. After the second flange 5 and the third flange 8 are respectively installed in the anchor grooves, the protective tube 6 is placed against the outer surface of the PCCP pipe 1 and anchored by pouring quick-setting mortar to form an anchor end 9. The ends of the memory alloy rib 2 extend from the anchor end 9. After the quick-setting mortar protective layer 7 and the anchor end 9 have completely set, the memory alloy rib 2 is heated by electrical excitation. Specifically, a high-power energized excitation device 13 is used to clamp the two ends of the memory alloy rib 2, and energize the rib to heat up to a set temperature, thereby generating a target recovery stress in the rib 2. After the energized excitation is completed, the protruding ends of the memory alloy rib 2 are protected from corrosion, such as by coating them with anti-corrosion paint or securing them with protective covers.

[0044] Before winding the memory alloy rib 2, the memory alloy rib 2 is fixed at one end of the protective tube 6 by epoxy resin glue 10, that is, the memory alloy rib 2 is fixed at one end of the protective tube 6 connected to the second flange 5 by epoxy resin glue 10 to prevent the protective tube 6 from being detached from the memory alloy rib 2 during the winding process. It can be prefabricated in the factory, or an appropriate amount of epoxy resin glue 10 can be poured on site for temporary fixation.

[0045] The memory alloy rib 2 is spirally wound around the outer wall of the portion to be reinforced. The helical angle of the memory alloy rib 2 pulled by the drilling robot 3 satisfies the following formula:

[0046]

[0047]

[0048] Where θ is the helix angle, r is the radius of the PCCP pipe, and d is the pitch. This helix angle ensures that after the memory alloy rib 2 is helically wound, the stress on the entire PCCP pipe is uniform and the length of the memory alloy rib 2 used is shorter.

[0049] A construction method for external reinforcement of PCCP pipelines, the reinforcement steps are as follows:

[0050] Step S1. Drill deep holes 12 in the overburden 11 above the location of the PCCP pipe 1 to be reinforced. Deep holes 12 extend to the top of the PCCP pipe 1. The number of deep holes 12 and the distance between adjacent deep holes 12 depend on the power of the drilling robot 3 or the power of the energized excitation device 13 of the shape memory alloy ribs 2. The size of the deep holes 12 should be large enough for one worker to work.

[0051] Step S2: The control terminal 14 of the drilling robot 3 and the energizing device 13 for the memory alloy rib 2 are transported to the vicinity of the deep hole 12 for use. Simultaneously, the staff connects the first flange 4 at the rear of the drilling robot 3 to the second flange 5 at the end of the protective tube 6. The memory alloy rib 2 has been pre-installed in the protective tube 6. The drilling robot 3 is then placed on top of the PCCP pipe 1. The helical angle at which the drilling robot 3 pulls the memory alloy rib 2 is set.

[0052] Step S3: The PCCP pipe 1 between two adjacent deep holes 12 is reinforced using the above-mentioned in-service PCCP in-situ in vitro intelligent winding self-prestressing reinforcement method; if there are more than two deep holes 12, the end point of the previous section of memory alloy ribs 2 is the starting point of the next section of memory alloy ribs 2. The details are as follows:

[0053] A worker activates the drilling robot 3 at the control terminal 14, causing it to adhere to the outer surface of the PCCP pipe 1 and spirally wind around it. Simultaneously, another worker pours a quick-setting mortar protective layer 7 into the protective tube 6, ensuring that the memory alloy ribs 2 are fully encased in the quick-setting mortar protective layer 7. This prevents the memory alloy ribs 2 from clinging to one side of the protective tube 6, which would otherwise lose its protective function.

[0054] After the drilling robot 3 pulls the memory alloy bar 2 to the next deep hole 12, the worker removes the drilling robot 3 and connects it to the second flange 5 at the end of the next protective tube 6 (the memory alloy bar 2 has been pre-installed in the protective tube 6) to continue the drilling and winding process. The starting point of the winding process is the end point of the previous winding process.

[0055] Anchor grooves are opened on the PCCP pipe 1 at the positions of the second flange 5 and the third flange 8 at both ends of the previously wound protective pipe 6. After the second flange 5 and the third flange 8 are respectively installed in the anchor grooves, the protective pipe 6 is made to adhere to the outer surface of the PCCP pipe 1, and the anchor ends 9 are formed by pouring quick-setting mortar for anchoring, and the two ends of the memory alloy ribs 2 are extended from the anchor ends 9.

[0056] After the quick-setting mortar protective layer 7 and the anchoring end 9 have completely set, the chucks attached to the high-powered energizing device 13 are used to clamp the two protruding ends of the memory alloy bar 2. This energizing process heats the memory alloy bar 2 to a set temperature, generating a target recovery stress. After cooling, the bar 2 is reinforced under the action of this recovery stress. After the energizing process is completed, the protruding ends of the memory alloy bar 2 are protected against corrosion.

[0057] Step S4: After the PCCP pipes 1 between all the deep holes 12 are reinforced, all the deep holes 12 are filled to complete the entire reinforcement work.

[0058] When prestressing is required later (for example, after years of reinforcement using the memory alloy bar 2, the memory alloy bar 2 has become loose), the following steps can be followed:

[0059] Step S11. Determine the position to be supplemented with prestress, and dig a deep hole at the anchor end 9 of the protective pipe 6 closest to the position to be supplemented. The volume of the deep hole opening can allow one worker to work.

[0060] Step S12. The staff goes down the deep hole, finds the protruding end of the memory alloy rib 2 that has been protected against corrosion during reinforcement, cleans its surface, and clamps the two protruding ends of the memory alloy rib 2 with the chuck of the high-power electric excitation device 13 to perform electric excitation work, and heats the memory alloy rib 2 to the corresponding temperature according to the target prestress that needs to be supplemented.

[0061] Step S13: After the power-on excitation work is completed, the extended end of the memory alloy rib 2 is again subjected to anti-corrosion protection, and the deep hole is filled to complete the prestressing work.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP, characterized in that: A memory alloy rib (2) is wound around the outer wall of the portion to be reinforced of the PCCP pipeline (1), and both ends of the memory alloy rib (2) are anchored to the PCCP pipeline (1) so that the memory alloy rib (2) is closely attached to the PCCP pipeline (1). The memory alloy rib (2) is heated to activate its shape memory effect, and after the temperature of the memory alloy rib (2) is restored, self-prestressing is formed under the action of the recovery stress, thereby achieving reinforcement of the PCCP pipeline; The ground-drilling robot (3) is used to pull the memory alloy rib (2) to spirally wrap around the outer wall of the portion to be reinforced while drilling the ground; The spiral winding process is as follows: placing a drilling robot (3) on the top of the PCCP pipe (1), setting the spiral angle of the drilling robot (3) pulling the memory alloy rib (2); starting the drilling robot (3) so that it adheres to the outer surface of the PCCP pipe (1) and performs spiral winding while drilling according to the spiral angle.

2. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 1 is characterized in that: The memory alloy rib (2) is made of any one of a NiTi-based shape memory alloy, a copper-based shape memory alloy, an iron-based shape memory alloy, and a gold-cadmium alloy.

3. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 1 is characterized in that: The tail end of the drilling robot (3) is provided with a first flange (4), and one end of the memory alloy rib (2) is provided with a second flange (5) for traction connection with the first flange (4).

4. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 3 is characterized in that: A protective tube (6) is provided on the periphery of the memory alloy rib (2).

5. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 4 is characterized in that: During the process of winding the memory alloy rib (2) around the outer wall of the portion to be reinforced, a quick-setting mortar protective layer (7) is poured into the gap between the memory alloy rib (2) and the protective tube (6), and it is ensured that the memory alloy rib (2) is fully wrapped by the quick-setting mortar protective layer (7) to prevent the memory alloy rib (2) from sticking to one side of the protective tube (6).

6. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 5 is characterized in that: The second flange (5) is welded to one end of the protective tube (6), and the other end of the protective tube (6) is welded to a third flange (8). The two ends of the memory alloy rib (2) pass through the second flange (5) and the third flange (8) respectively. The surface of the PCCP pipe (1) is provided with anchoring grooves corresponding to the second flange (5) and the third flange (8). After the second flange (5) and the third flange (8) are respectively installed in the anchoring grooves, anchoring ends (9) are formed by pouring quick-setting mortar for anchoring. The two ends of the memory alloy rib (2) extend out of the anchoring ends (9). After the quick-setting mortar protective layer (7) and the anchoring ends (9) are finally solidified, the memory alloy rib (2) is heated by electrical excitation. After the heating is completed, the extended ends of the memory alloy rib (2) are subjected to anti-corrosion protection.

7. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of an in-service PCCP according to claim 4 is characterized in that: Before winding the memory alloy rib (2), the memory alloy rib (2) is temporarily fixed at one end of the protective tube (6) by epoxy resin glue (10).

8. The method for in-situ in vitro intelligent winding self-prestressing reinforcement of in-service PCCP according to claim 1 is characterized in that: The helical angle of the memory alloy rib (2) pulled by the drilling robot (3) satisfies the following formula: in, is the helix angle, is the radius of the PCCP pipe, is the thread pitch.

9. A construction method for external reinforcement of PCCP pipeline, characterized in that: The reinforcement steps are as follows: Step S1. Drilling deep holes (12) in the overburden layer (11) above the location of the to-be-reinforced portion of the PCCP pipe (1), wherein the deep holes (12) extend to the top of the PCCP pipe (1), and the number of deep holes (12) and the distance between two adjacent deep holes (12) depend on the power of the drilling robot (3) or the power of the power excitation device (13) of the memory alloy rib (2); Step S2. transporting the control terminal (14) of the drilling robot (3) and the energized excitation device (13) of the memory alloy rib (2) to the side of the deep hole (12) for use; Step S3. The PCCP pipeline (1) between two adjacent deep holes (12) is reinforced by using the in-service PCCP in-situ in vitro intelligent winding self-prestressed reinforcement method as described in any one of claims 1 to 7; if there are more than two deep holes (12), the end point of the previous section of the memory alloy rib (2) is the starting point of the next section of the memory alloy rib (2); Step S4: After the reinforcement of the PCCP pipes (1) between all the deep holes (12) is completed, all the deep holes (12) are filled to complete the entire reinforcement work.

Images