CN108253223B - Annular prestressing force repair reinforcing system in pipe - Google Patents

Abstract

The invention relates to a repairing and reinforcing system for annular prestress in a pipe, which comprises a mounting disc, a loading disc, a penetrating jack, a wedge-shaped loading body connected with the jack and an equipment platform. The system for repairing and reinforcing the prestress in the pipe can effectively improve or strengthen the capacity of bearing internal water pressure, air pressure and external negative pressure of a common concrete pipe, a prestress steel cylinder concrete pipe (PCCP pipe), a circumferential tubular structure (masonry and composite material body) and a polygonal cavity structure, improves the functions of structural integrity, durability and the like, fully utilizes the tensile mechanical properties of high-strength materials such as carbon fibers and the like, initiates a method for prestress in the pipe, realizes the application of the method, increases the application range of the combination of all accessories, and improves the economical efficiency, the technical efficiency and the high efficiency.

Description

An in-pipe circumferential prestressed repair and reinforcement system

Technical field

The invention relates to an in-pipe circumferential prestressed repair and reinforcement system, which belongs to the technical field of circumferential prestressing, such as ordinary concrete pipe in-pipe reinforcement, PCCP pipe in-pipe reinforcement, steel pipe in-pipe reinforcement, glass fiber reinforced plastic pipe in-pipe reinforcement, indoor annular buildings, annular The inner walls of pools, etc. are currently reinforced inside PCCP pipes, which can better utilize the performance of high-strength materials and high-strength structural adhesives and solve the problem of trenchless pipe reinforcement.

Background technique

PCCP is the abbreviation of Prestressed Concrete Cylinder Pipe. It refers to a pipe core composed of a steel cylinder with socket steel rings at both ends and concrete layers on both sides of the steel cylinder, and is wrapped around the outer wall of the pipe core. A composite pipe made of prestressed high-strength steel wire and a protective layer of cement mortar.

Water transmission projects are the main arteries of urban life and play an important role in the development of the national economy. Once a pipe burst accident occurs in a PCCP water transmission pipeline, it often causes serious economic losses and bad social impact. my country's official application of PCCP pipes in engineering began in the 1990s. In December 2005, the Beijing section of the South-to-North Water Diversion Project kicked off the application of large-diameter PCCP in my country. PCCP pipes are widely used in large-scale domestic water transmission projects because of their excellent characteristics. It is more and more widely used in water engineering. However, with the gradual promotion of PCCP, many PCCP pipelines have begun to approach or reach the age of destruction. Tests in recent years have also shown that a large number of domestic PCCP pipelines have experienced steel wire breakage, and the number of broken wires has been increasing year by year. The occurrence of wire breakage has a greater impact on the normal service limit state, and the probability of bursting and water outage accidents greatly increases. Especially when the scope of wire breakage is large, under the combined effects of prestress, pipe body weight, earth pressure and fluid weight, etc. , it loses its bearing capacity and cannot continue to bear the designed internal water pressure. Under the action of internal water pressure, pipe burst accidents are extremely likely to occur. Therefore, how to effectively repair and strengthen PCCP pipelines is a very important and urgent issue currently faced.

The existing repair methods mainly include external reinforcement method, pipe replacement method, conventional reinforcement method inside the pipe, etc.

The disadvantage of the external reinforcement method is that it requires excavation of a large amount of earth. Although pasting carbon fiber cloth on the outside of the pipe can effectively provide circumferential restraint and accurately reinforce the location of broken wires, the cost is high and the engineering volume is large. It is suitable for large-scale promotion in engineering practice.

The pipe replacement method is to find the location of the damaged pipe through flaw detection, then dig out the upper soil layer, then remove the damaged pipe and replace it with a new PCCP pipe. This method has a greater impact, and construction can only be carried out when water delivery is stopped. It is also difficult to remove the pipeline. The treatment of joints is also a construction problem that needs to be solved urgently. Therefore, this method cannot be a universally applicable method.

In-pipe reinforcement methods usually use non-prestressed reinforcement methods. This method usually uses carbon fiber cloth to be directly pasted for reinforcement. Since the elastic modulus of carbon fiber materials is similar to that of steel bars, the tensile strength is about 7 to 10 times that of steel. It has high strength. It requires large deformation to perform, and it is difficult for the inner sticker to fully utilize the high strength characteristics of carbon fiber materials. This method is a non-active force, that is, it can only play a role under external loads and cannot actively exert the role of carbon fiber materials, which to a certain extent results in a waste of carbon fiber material performance.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a repair and reinforcement system that can actively load prestressing force in the pipe.

In order to solve the above technical problems, the technical solution proposed by the present invention is: an in-pipe prestressed repair and reinforcement system, which is used to apply circumferential prestress to high-strength materials such as carbon fiber plates and stick them to the inner wall of the pipe to improve the structure's ability to withstand the air pressure and water in the pipe. pressure or negative pressure outside the pipe, while enhancing structural integrity and durability. It is characterized in that it includes: a prestressed loading device, a through-type jack and an equipment platform; the through-type jack is installed on the equipment platform, and the The end of the through-core jack extending along the direction of the central axis of the pipe is provided with a loading cone; the prestressed loading device includes a mounting plate, a loading plate and a loading cone connected to the jack, the three of which form an internal force balance system; the mounting plate Fixedly connected to the equipment platform, it functions to fix and adjust the spatial geometric position of the loading device; the mounting plate and the loading plate are coaxial lines, and the loading plate uses the mounting plate as the mounting frame, guide frame and loading reaction frame. The diameter of the disk is smaller than that of the loading disk, and the outer cover of the loading disk is provided with a rubber sleeve or other low elastic modulus and high strength materials; the loading disk is made of several sector-shaped disks and is made into a circle with a void formed around its center; Both sides of the arc-shaped end of the sector-shaped disk have teeth that can be inserted into each other, so that the circumference remains closed after the prestressed load is satisfied; the installation disk has a number of limit blocks, and the sector-shaped disk has teeth extending radially along its sector surface. The bar-shaped holes correspond to each other, that is, the limiting block passes through the bar-shaped hole to fix the sector-shaped disk and the installation disk in the axial direction and limit the position in the radial direction; the loading cone has a Each sector-shaped disc of the loading disc has a one-to-one corresponding cone surface, the loading cone has a tenon on the conical surface, and the sector-shaped disc has a tenon groove that matches the tenon; the loading cone passes through the tenon and the tenon groove. The cooperation is connected with each sector of the loading plate. In use, when the through-type jack drives the loading cone and each sector of the loading plate is squeezed to produce axial slippage, at the same time the loading cone pushes the sector The disk moves outward from the center of the circle in the radial direction until it exerts radial pressure on the circumferential high-strength material to generate an internal force (tensile stress) on the circumferential material; when the circumferential material is stressed and closely adheres to the inner wall of the pipe , the structural glue applied on the surface of the high-strength material and the inner wall of the pipe is cured in advance, and after curing, it serves the purpose of applying circumferential prestress to the inner wall of the pipe; when the through-core jack drives the loading cone to reduce the extrusion force and unloads, the The sector-shaped disk moves inward from the center of the circle along the radial direction and resets, and the circumferential high-strength material is adhered to the inner wall of the pipe. The radial pressure originally borne by the loading disk is instead borne by the structural glue between the high-strength material and the inner wall of the pipe, and finally the ring of the inner wall of the pipe is achieved. applied to prestress.

A further improvement of the above solution is: an in-pipe circumferential prestressed repair and reinforcement system when the slope is moderate, which is characterized in that: the bottom of the equipment platform also has running wheels; a circumferential prestressed repair and reinforcement system in the pipe when the slope is large or close to vertical , its special feature is that the equipment platform can be replaced by a suspension system.

A further improvement of the above solution is that the limiting block is installed on the installation plate through bolts.

A further improvement of the above solution is that: in order to adapt to pipes of different diameters, the loading plate is set as a basic loading plate and a number of detachable fan-shaped frames; the detachable fan-shaped frames are assembled into an annular shape, and the detachable frames are installed on all locations through bolts. The above-mentioned basic loading disk is placed on the sector disk; rubber sleeves or other low elastic modulus and high strength materials are installed on the outer periphery of the outermost sector frame.

A further improvement of the above solution is that the sector plate and the detachable frame have a number of hollow holes.

A further improvement of the above solution is that the sector disk and the detachable frame are hollow frame structures.

A further improvement of the above solution is that the two ends of the detachable frame have bolt holes; the fastening bolts installed through the bolt holes can fix the shape of the ring formed by the detachable frame, and are used to ring high-strength materials and pipes. The structural glue between the walls is strong, and the basic loading plate can stop working.

A further improvement of the above scheme is that the outer ring of the loading plate is made of rubber sleeve or low elastic modulus and high strength material with sufficient thickness and compression deformation to reduce the prestress loss caused by the withdrawal of the foundation loading plate in step 7.

A further improvement of the above scheme is that after the prestressed reinforcement of high-strength materials, such as carbon fiber plates and tubes, is completed, wear-resistant protective materials are pasted on the outside of the high-strength materials to improve the durability and safety of the reinforcement system.

A further improvement of the above solution is that the outermost ring of the loading plate is a polygon with chamfers, which is suitable for the working condition where the inner wall section of the pipe is a polygonal shape with chamfers, or is suitable for the working condition where the inner wall section of the pipe is a polygonal shape with chamfering.

The in-pipe circumferential prestressed repair and reinforcement system provided by the present invention uses high-strength materials such as carbon fiber plates to replace traditional metal materials; and applies prestress to high-strength materials such as carbon fiber plates through hydraulic expansion to achieve the purpose of active reinforcement, such as The purpose of preventing concrete cracking, balancing water pressure, and repairing damaged PCCP pipes; compared with various existing construction methods, the present invention can more effectively restore the bearing capacity of the PCCP structure, reduce the amount of material used, reduce the construction workload, and reduce construction time and improve the output-to-input ratio.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 is a schematic structural diagram of a preferred embodiment 1 of the present invention.

Figure 2 is a schematic structural diagram of the loading disk in Figure 1.

Figure 3 is a schematic diagram of the loading cone structure in Figure 1.

Figure 4 is a schematic structural diagram of the loading tray in a preferred embodiment 2 of the present invention.

Figure 5 is a schematic diagram of the partial structure of the loading disk in Figure 4 after expansion.

Implementation

Example

The in-pipe circumferential prestressed repair and reinforcement system of this embodiment, as shown in Figure 1, includes: a mounting plate 4, a loading plate 5, a through-type jack 3 and an equipment platform 2; the fixed shell setting plate of the through-type jack 3 is installed on the on the equipment platform 2; the bottom of the equipment platform 2 also has running wheels. The end of the through-core jack 3 extending in the horizontal direction is provided with a loading cone 6 .

As shown in Figure 2, the diameter of the installation plate 4 is smaller than that of the loading plate 5; the loading plate 5 is composed of 6 sector-shaped discs formed into a round cake, with an empty portion in the center of the circle; both sides of the arc-shaped end of the sector-shaped disc have teeth that can be inserted into each other; installation A number of limit blocks 9 are installed on the plate 4 through bolts, and the sector plate has strip holes extending in the radial direction; the limit blocks 9 pass through the strip holes and fix the sector plate axially on the installation plate 4; there are no gaps. A loading cone 6 is provided at the bottom.

As shown in Figure 3, the loading cone 6 has six cone surfaces (3 or more) corresponding to the six sector disks; there is a dovetail tenon 10 on the cone surface, and there is a dovetail tenon 10 on one end of the sector disk toward the center of the circle. The matching groove, in this way, by the loading cone 6 moving forward and backward along the axial direction of the loading plate 5, the loading cone 6 can enter and leave the vacant part, the cone surface is used to generate a radial component force, and the cooperation between the dovetail tenon 10 and the groove is It can generate radial components in opposite directions when entering and leaving the vacant part; when the loading cone 6 enters the vacant part, the loading cone 6 can push the sector disk to move outward in the radial direction; when leaving the vacant part, Then the sector disk is pulled to move inward along the radial direction. In this embodiment, a dovetail is used, but other shapes such as T-shape can also achieve this function.

The installation plate 4 and the through-type jack 3 are fixedly connected by bolts; in order to buffer the stress concentration at the toothed connection between the sectors during the loading process and make the loading force more uniform, the outer cover of the loading plate 5 is provided with a rubber sleeve 7 . Since the required expansion size of the carbon fiber plate 8 is smaller, the length of the strip holes is also shorter.

During construction, the above-mentioned parts, materials, tools, etc. are first transported to the construction PCCP1 and assembled; the carbon fiber plate 8 is in the shape of a cylinder (ring), and the initial diameter D ₀ is slightly smaller than the inner diameter D of the PCCP 1. Its specific value is based on the carbon dimension. The target hoop prestress σ of the plate is obtained. The elongation of carbon fiber plate is , the target circumferential prestress of the carbon fiber plate is σ= Eε = E /> , where E is the elastic modulus of the carbon fiber plate, then the initial diameter of the carbon fiber plate is D ₀ = D-σD/ E . The determination of the target circumferential prestress of the carbon fiber plate is related to the radial internal water pressure of the PCCP that needs to be shared and the strength of the adhesive. Polish the bonding part of PCCP1 according to the design requirements until the concrete surface is exposed; mix the bonding glue according to the proportion and stir evenly; apply base glue on the bonding part of the polished inner wall of the prestressed steel cylinder concrete pipe; put the carbon fiber Put the plate 8 outside the rubber sleeve 7, wipe the surface of the carbon fiber plate 8 clean, and apply adhesive immediately. The adhesive layer will be convex and the average thickness should be greater than 2mm.

Then start the through-type jack 3 and pull the loading cone 6; the loading cone 6 pushes the sector plate to move outward, causing the loading plate 5 to expand, and press the carbon fiber plate 8 coated with adhesive glue onto the polished concrete surface, and make The adhesive glue is extruded from both sides to ensure that the interior is dense and void-free; remove excess adhesive glue on both sides. If multiple carbon fiber plates are pasted in parallel, the gap between the two strips should not be less than 5mm.

In this way, the carbon fiber plate 8 can be elongated to generate a circumferential tensile force; the tangential force along the bonding interface is transmitted through the adhesive force to achieve pre-stressing of the concrete pipe; as the adhesive solidifies, the carbon fiber plate 8 is fixed on the inner surface of PCCP1 to complete the prestressed loading; then the repair and reinforcement system of the stress steel cylinder concrete pipe of this embodiment can be dismantled.

Example

This embodiment is improved on the basis of Embodiment 1, and most of it is the same as Embodiment 1. The different parts are as shown in Figure 4: there are several fan-shaped detachable frames 11 between the fan-shaped disk and the rubber sleeve; The detachable frame 11 is assembled into a ring shape, and the detachable frame 11 is installed on the sector disk through bolts. In order to reduce the weight of the loading tray 5, the detachable frame 11 has a number of hollow weight-reduction holes; the sector-shaped tray can be designed with hollow weight-reduction holes or a hollow frame structure while ensuring the required stiffness.

The two ends of the detachable frame 11 are provided with bolt holes; the fastening bolts installed through the bolt holes can fix the shape of the ring formed by the detachable frame 11 .

The construction process is mostly the same as that in Embodiment 1, and the different parts are as follows:

Start the through-core jack 3 and pull the loading cone 6; the loading cone 6 pushes the sector plate to move outward, causing the loading plate 5 to expand; then, as shown in Figure 5, use bolts 12 to fix the detachable frames 11 to each other to ensure that the detachable frames The ring formed by 11 can maintain its own shape, so that it can continue to exert expansion force on the carbon fiber plate 8 without the thrust exerted by the loading cone 6; in this way, the loading cone 6 can be released, and the sector-shaped disk can be loaded with the cone and dovetail. reset under action, and then remove the remaining components, leaving only the detachable frame 11, thereby avoiding blocking the PCCP1 and facilitating the movement of personnel, equipment and materials in the tube. At the same time, the remaining components can be moved to the next position through another The detachable frame 11 can be set and re-operated, which can save operating time, improve operating efficiency, and reduce equipment costs.

The present invention is not limited to the specific technical solutions described in the above embodiments. In addition to the above embodiments, the present invention can also have other implementation modes. All technical solutions formed by using equivalent substitutions fall within the protection scope required by the present invention.

Claims (8)

1. An in-pipe circumferential prestressed repair and reinforcement system, used to apply circumferential prestress to the carbon fiber plate adhered to the inner wall of the pipe, which is characterized in that it includes: a prestressed loading device, a through-hole jack and an equipment platform; The radial jack is installed on the equipment platform; the prestressed loading device includes a mounting plate, a loading plate and a loading cone, and the loading cone is provided with the end of the through-center jack extending along the direction of the central axis of the pipe; The installation disk is fixedly connected to the equipment platform, the installation disk and the loading disk are coaxial, the diameter of the installation disk is smaller than the loading disk, and the loading disk is provided with a rubber sleeve; the loading disk is composed of several sector disks. It is circular and has a vacant portion formed around its center; the two ends of the arc surface of the sector-shaped disk have teeth that can be inserted into each other, the installation disk has a number of limiting blocks, and the sector-shaped disk has teeth along its A strip hole extends radially from the sector surface, and the limiting block passes through the strip hole to fix the sector disc and the installation disc in the axial direction; the loading cone has a sector disc corresponding to the loading disc. One-to-one corresponding cone surfaces, the loading cone cone surface has a tenon, and the sector-shaped disk has a tenon groove that matches the tenon; the loading cone is in use through the cooperation of the tenon and the tenon groove. When the through-core jack drives the loading cone to slide axially to one side, the loading cone pushes the sector-shaped disk to move outward from the center of the circle in the radial direction. When the loading cone slides axially to the other side, the sector-shaped disk moves inward from the center of the circle along the radial direction. 2. The in-pipe circumferential prestressed repair and reinforcement system according to claim 1, characterized in that: the bottom of the equipment platform also has running wheels or a suspension system. 3. The in-pipe circumferential prestressed repair and reinforcement system according to claim 1, characterized in that: the limit block is installed on the installation plate through bolts. 4. The in-pipe circumferential prestressed repair and reinforcement system according to claim 1, characterized in that: an annular or chamfered polygonal outer frame is installed between the loading plate and the rubber sleeve; The frame is composed of several detachable frames; the detachable frames are installed on the loading plate through bolts. 5. The in-pipe circumferential prestressed repair and reinforcement system according to claim 4, characterized in that the sector disk and the detachable frame have a number of hollow holes. 6. The in-pipe circumferential prestressed repair and reinforcement system according to claim 4, characterized in that: the sector disk and the detachable frame are hollow frame structures. 7. The pipe circumferential prestressed repair and reinforcement system according to claim 4, characterized in that: the two ends of the detachable frame have bolt holes; the fastening bolts installed through the bolt holes can fix the detachable frame. The shape of the assembled ring is used to equalize the strength of the structural adhesive between the high-strength material and the inner wall of the pipe, during which the basic loading plate can exit the work. 8. The pipe circumferential prestressed repair and reinforcement system according to claim 4, characterized in that the rubber sleeve is made of low elastic modulus and high strength material.