Fiber sleeve reinforcing method suitable for underwater cast-in-place pile bump

Abstract

The invention discloses a fiber sleeve reinforcing method suitable for underwater cast-in-place pile bulge, which comprises the following steps: step S1, carrying out technical condition inspection on a pile foundation needing to be reinforced, and determining the range of the pile foundation needing to be reinforced and the number of reinforcing materials; s2, prefabricating a fiber sleeve and an open semicircular hose in a factory; s3, attachments on the surface of the pile foundation structure are removed, and the contact face of the pile foundation concrete structure is chiseled away to a new aggregate face; s4, the fiber sleeve and the open semicircular hose are installed and fixed; s5, the bottom is sealed, and a bottom sealing grouting material is poured; and S6, grouting materials are poured, and sealant is used for sealing. The open semicircular hoses are arranged at the bumps, jacket-method reinforcement can be completed without cofferdam and bump chiseling, the construction period is shortened, the cost and difficulty are reduced, and the construction safety is improved; prefabricated parts are installed on site, and the assembly degree is improved; the original structure is prevented from being damaged, an integrated structure is formed, and reinforcing quality is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of bridge pile foundation reinforcement, and particularly to a fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles. Background Technique

[0002] During the construction and use of bridges, underwater cast-in-place piles, as important foundation structures of bridges, bear complex loads and harsh environmental effects for a long time. With the increase of service life, due to factors such as environmental erosion (such as chemical corrosion in seawater and sewage), impact of loads such as vehicles, and aging of materials themselves, diseases such as concrete carbonation, corrosion, cracks, and exposed reinforcement are extremely likely to occur in the pile foundation. These diseases will damage the integrity of the pile foundation structure, lead to stress concentration, and further accelerate the corrosion process in the surrounding area, seriously threatening the safety of the overall bridge structure. Currently, for such pile foundation diseases, the commonly used treatment technology is the jacket method. The jacket method mainly uses a fiber-reinforced composite material sleeve to enclose the existing pile foundation, then fills it with grouting material, and uses components such as sealants, elastic sealing strips, and fasteners to achieve the effects of sealing, reinforcement, and anti-corrosion. With its advantages of high efficiency, flexibility, durability, and economy, the jacket method has become one of the most widely used technologies in the field of underwater pile foundation reinforcement. However, during the construction of underwater cast-in-place pile foundation concrete during the bridge construction period, due to reasons such as too fast pipe pulling speed, deviation of the steel sleeve, or improper retaining wall measures, there are generally many bulging phenomena in underwater cast-in-place piles. In response to this situation, traditional reinforcement methods usually require building a cofferdam in the water first, then chiseling off the bulges, and finally using the jacket method for reinforcement. This traditional treatment method has many disadvantages. On the one hand, the processes of underwater cofferdam construction and chiseling off the bulges are complex, and the construction period is long, resulting in a significant increase in project costs; on the other hand, the underwater operation environment is harsh, the construction difficulty is large, and there are relatively high safety risks. Summary of the Invention

[0003] The present invention mainly aims at the above problems existing in the prior art, and provides a fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles. This method can achieve the jacket method reinforcement of underwater cast-in-place piles without performing cofferdam construction and chiseling off the bulges, thereby effectively shortening the construction period, reducing the project cost, while reducing the construction difficulty and improving the construction safety.

[0004] The object of the present invention is mainly achieved through the following solutions: A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles, comprising the following steps: Step S1: Check the technical condition of the pile foundation to be reinforced, including the basic dimensions of the pile foundation, disease types, and bulge dimensions, and determine the scope to be reinforced of the pile foundation and the quantity of reinforcement materials; Step S2: Factory prefabricate fiber sleeves and open semi-circular hoses; Step S3: Remove the attachments on the surface of the pile foundation structure, and chisel the contact surface of the pile foundation concrete structure to expose the fresh aggregate surface; Step S4: Install and fix the fiber sleeves and open semi-circular hoses; Step S5: Seal the bottom and pour the bottom-sealing grout; Step S6: Pour the grout and seal with sealant.

[0005] Preferably, the step S1 includes the following steps: Step S11: Determine the position of the concrete bulge of the pile foundation; determine the height of the fiber sleeve according to the disease type, position and bulge position; determine the diameter of the fiber sleeve according to the diameter of the pile foundation; determine the size of the open semi-circular hose according to the bulge size; Step S12: Determine the material quantities of the grout, sealing strip, sealant and fastening belt according to the sizes of the fiber sleeve and the open semi-circular hose.

[0006] Preferably, in the step S2, the fiber sleeve is selected as a composite material sleeve with a fiber reinforcement effect formed by winding, molding or extrusion of high-strength fibers and a matrix material; the open semi-circular hose is selected as a corrugated semi-circular hose.

[0007] Preferably, in the step S3, the steel bars within the reinforcement range of the pile foundation are derusted and polished until the metal luster is exposed on the surface; the loose concrete where the bulge exists is chiseled and cleaned.

[0008] Preferably, the step S4 includes the following steps: Step S41: Apply sealant evenly in the locking groove of the sleeve before installing the fiber sleeve; Step S42: Install the fiber sleeve below the bulge to form a closed-loop state; Step S43: Install two open semi-circular hoses at the bulge position to form a closed-loop state, connect the two open semi-circular hoses with sealant, and connect the open semi-circular hose and the fiber sleeve with sealant; Step S44: Install the fiber sleeve above the bulge to form a closed-loop state, and connect the fiber sleeve and the open semi-circular hose with sealant; Step S45: Fix the fiber sleeve and the open semi-circular hose with a fastening belt.

[0009] Preferably, in the step S5, for bottom sealing construction, an elastic sealing strip is used for bottom sealing. The thickness of the sealing strip is greater than 1.5 - 2 times the gap between the fiber sleeve and the pile foundation, and the width is 20 - 30 mm; the bottom-sealing grout is poured by the gravity grouting method with a high-position funnel, and the pouring is stopped when the pouring height reaches 100 mm - 150 mm; after the pouring of the bottom-sealing grout is completed, check the bottom sealing condition.

[0010] Preferably, in step S6, a grouting material with good self-leveling characteristics is selected. After the bottom-sealing grouting material is cured, the grouting material is poured at one time until the top; after the grouting material pouring construction is completed, it is sealed with a sealant at a position 45-55 mm from the top, so that the sealant forms a smooth slope surface with the joint surface of the structure reinforced by the pile foundation; the fastening belt is removed after the compressive strength of the grouting material ≥ 2.5 MPa.

[0011] In summary, compared with the prior art, the present invention has the following beneficial technical effects: (1) By arranging an open semi-circular hose at the concrete bulge of the pile foundation, the present invention avoids the complex processes of chiseling the concrete bulge and underwater cofferdam construction in the traditional method, greatly shortens the construction period, significantly reduces the project cost and construction difficulty, and at the same time effectively improves the safety during the construction process and reduces the working time and intensity of construction workers in the underwater dangerous environment; (2) In the present invention, both the fiber sleeve and the open semi-circular hose are prefabricated in the factory. On-site, only installation and fixation operations are required, and then grouting construction can be carried out. This prefabricated and assembled construction mode not only simplifies the construction process, improves the construction efficiency, but also ensures the quality stability and consistency of the prefabricated components, and reduces the uncertainty and quality risks of on-site construction; (3) By avoiding the operation of chiseling the bulge, the present invention greatly reduces the risk of damaging the original pile foundation structure during the construction process. Moreover, after the open semi-circular hose and the fiber sleeve are sealed and connected with a sealant, the grouting material can form a continuous and complete integrated structure on the surface of the pile foundation, significantly improving the durability and bearing capacity of the pile foundation, effectively ensuring the reinforcement quality of the pile foundation, and extending the service life of the bridge pile foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the bulge of the underwater cast-in-place pile in the present invention; Figure 2 is Figure 1 the sectional view at A-A in Figure 3 is the reinforcement effect diagram of the present invention; Figure 4 is the structural schematic diagram of the open semi-circular hose in the present invention; Figure 5 is the installation schematic diagram of the open semi-circular hose in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The technical solutions of the present invention will be further specifically described below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any formal modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0014] As Figure 1 、 2 、shown in Figure 3, the present invention discloses a technical solution, a fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles. By optimizing the fiber sleeve structure and adding an open semi-circular hose, the jacketing method reinforcement of underwater cast-in-place piles can be completed without chiseling the concrete bulge of the pile foundation. Among them, the fiber sleeve and the open semi-circular hose jointly constitute the main enclosure structure of the pile foundation, and the specific steps are as follows: Step S1: Conduct a technical condition inspection on the pile foundation to be reinforced, including the basic dimensions of the pile foundation, the type of disease, and the bulge size, and determine the scope of the pile foundation to be reinforced and the quantity of reinforcement materials; Step S2: Prefabricate the fiber sleeve and the open semi-circular hose in the factory; Step S3: Remove the attachments on the surface of the pile foundation structure, and chisel the contact surface of the pile foundation concrete structure to a new aggregate surface; Step S4: Install and fix the fiber sleeve and the open semi-circular hose; Step S5: Seal the bottom and pour the bottom seal grout; Step S6: Pour the grout and seal it with sealant.

[0015] Specifically, Step S1 includes the following steps: Step S11: Determine the position of the concrete bulge of the pile foundation; determine the height of the fiber sleeve according to the type of disease, position and bulge position; determine the diameter of the fiber sleeve according to the diameter of the pile foundation; determine the size of the open semi-circular hose according to the bulge size; among them, the inner diameter of the fiber sleeve is at least 60 mm larger than the outer diameter of the pile foundation; the open semi-circular hose is composed of two identical parts, and the overlapping length between the two parts of the hose is at least 200 mm, and the overlapping height between the open semi-circular hose and the fiber sleeve is at least 250 mm to prevent grout leakage; the radius of the assembled open semi-circular hose is at least 50 mm larger than the outermost edge of the bulge to prevent blockage of the grout; Step S12: Determine the quantity of materials for grout, sealing strips, sealant and fastening straps according to the sizes of the fiber sleeve and the open semi-circular hose; try to use elastic sealing strips for bottom sealing, and the thickness of the sealing strip should be greater than 1.5 - 2 times the gap between the fiber sleeve and the pile foundation, and the width should be 25 mm to prevent grout leakage.

[0016] Specifically, in Step S2, the fiber sleeve is selected as a composite material sleeve with a fiber reinforcement effect formed by high-strength fibers and matrix materials through winding, molding or extrusion processes; the open semi-circular hose is selected as a corrugated semi-circular hose, such as Figure 4As shown, the open semicircular hose is composed of two identical parts spliced ​​together, and its structure includes a semicircular arc tube and two upper and lower smooth fiber soft boards.

[0017] Specifically, in step S3, the steel bars within the reinforcement range of the pile foundation are derusted and polished until the surface shows a metallic luster; the loose concrete existing in the bulge is chiseled out and cleaned, and the surface of the underwater pile foundation is cleaned with a wire brush to ensure that the surface of the pile foundation is free of aquatic attachments, mud and debris.

[0018] Specifically, step S4 includes the following steps: Step S41: Before installing the fiber sleeve, evenly apply sealant in the locking groove of the sleeve; after the fiber sleeve is transported to the site, first check the size and accept it before use; after applying sealant in the locking groove of the sleeve, install it in water as soon as possible; Step S42: Install the fiber sleeve below the bulge to form a closed loop; the diver goes into the water to unfold the fiber sleeve to wrap the pile body, connect the locking groove with the joint, and then fix the overlapping part of the interface with screws, place the positioner inside the sleeve according to the designed gap, and adjust the distance between the fiberglass casing and the pile body; Step S43: Install two open semicircular hoses at the bulge position to form a closed loop state, connect the two open semicircular hoses with sealant, and connect the open semicircular hose and the fiber sleeve with sealant; the open semicircular hose is composed of two identical parts spliced ​​together, and the overlap length between the two parts of the hose is at least 200mm; before installation and splicing, apply sealant to the overlapped parts of the two hoses and the overlapped parts of the hoses and the installed sleeves, and then splice the open semicircular hoses into a closed ring on the outside of the bulge as soon as possible, and form the ring-shaped open semicircular hose and the sleeve as a whole; Step S44: Install a fiber sleeve above the bulge to form a closed loop, and use sealant to connect the fiber sleeve and the open semicircular hose; before installing the fiber sleeve, first apply sealant to the overlapping part of the annular open semicircular hose and the uninstalled sleeve, and then install and fix the fiber sleeve in place as soon as possible to form an integral enclosure structure with the annular open semicircular hose; Step S45: fix the fiber sleeve and the open semicircular hose with a tightening belt; check and adjust the gap between the enclosure structure and the pile foundation, and tighten the sleeve with a tightening belt after confirming that it meets the design requirements.

[0019] Specifically, in step S5, first install the bottom sealing strip, then pour the bottom sealing grouting material, try to use the high-position funnel gravity grouting method and stop when the pouring height reaches 100mm-150mm; after the bottom sealing grouting material is poured, check the bottom sealing condition.

[0020] Specifically, in step S6, a grouting material with better self-leveling characteristics is preferably selected. The grouting of the grouting material is carried out after the bottom-sealing grouting material is cured, and the grouting material is preferably grouted to the top at one time. After the grouting construction of the grouting material is completed, the position 50 mm from the top is sealed with a sealant, and a smooth slope surface is formed at the connection surface between the sealant and the structure to be reinforced by the pile foundation. The fastening band is removed after the compressive strength of the grouting material ≥ 2.5 MPa.

[0021] The following further illustrates the present application through specific examples: In a reinforcement project of underwater cast-in-place piles of a certain bridge, it is found that some pile foundations have bulging diseases, and the fiber sleeve reinforcement method of the present invention is now used for treatment. First, step S1 is carried out. A comprehensive inspection is carried out on the pile foundation to be reinforced, the basic dimensions such as the diameter and length of the pile foundation are accurately measured, the disease type and the specific position and size of the bulge are determined. According to the inspection results, it is determined that the height of the fiber sleeve should cover a certain range above and below the bulge. The diameter of the fiber sleeve is determined according to the diameter of the pile foundation, and the size of the open semi-circular hose is customized according to the size of the bulge to ensure that it can closely fit the surface of the bulge. At the same time, according to the sizes of the fiber sleeve and the open semi-circular hose, the quantities of materials such as grouting material, sealing strip, sealant and fastening band required are accurately calculated. Then, step S2 is carried out. The fiber sleeve and the open semi-circular hose are prefabricated in the factory according to the design requirements. The fiber sleeve is made of high-strength fiber and matrix material by winding process to ensure its good fiber reinforcement effect; the open semi-circular hose is a corrugated semi-circular hose, which consists of two identical parts for easy on-site splicing and installation. Then, step S3 is carried out. Divers are arranged to clean the surface of the pile foundation structure, remove attachments such as algae and silt on the surface, chisel the contact surface of the pile foundation concrete structure to the new aggregate surface, remove rust and polish the steel bars within the reinforcement range of the pile foundation to make the surface of the steel bars show metallic luster; chisel the loose concrete at the bulge and clean it up to ensure that the surface of the pile foundation meets the requirements of reinforcement construction. Proceed to step S4, install and fix the fiber sleeve and the open semi-circular hose. As Figure 5 shown, first evenly apply sealant in the lock groove of the fiber sleeve. The diver goes into the water to install the fiber sleeve at a position below the bulge, unfolds the fiber sleeve to wrap the pile body, docks the lock groove and the tenon and fixes them with screws, places a locator inside the sleeve to adjust the spacing. At the bulge position, splice the two open semi-circular hoses coated with sealant into a closed-loop state and connect them to the installed fiber sleeve. Finally, install the fiber sleeve at a position above the bulge, also apply sealant and connect it to the open semi-circular hose, and fix it with a fastening band after checking and adjusting the gap. In step S5, install the bottom elastic sealing strip, whose thickness and width meet the design requirements, and then use the high-position funnel gravity grouting method to pour the bottom sealing grouting material. When the pouring height reaches 120mm, stop pouring. After the pouring is completed, check the bottom sealing condition to ensure that there is no leakage. Finally, step S6 is performed. After the bottom sealing grouting material is cured, a grouting material with good self-leveling properties is selected and poured to the top at one time. After the pouring is completed, a sealant is used to seal the top 50mm to form a smooth slope surface. When the compressive strength of the grouting material reaches 2.5MPa, the fastening belt is removed to complete the reinforcement construction of the underwater bored pile bulge. After testing, the reinforced pile foundation structure has good performance and achieves the expected reinforcement effect, which verifies the effectiveness and reliability of the method of the present invention.

[0022] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles, characterized in that It includes the following steps: Step S1: Conduct a technical condition inspection on the pile foundation to be strengthened, including the basic dimensions of the pile foundation, the type of diseases, and the size of the bulge, and determine the scope of the pile foundation to be strengthened and the quantity of the strengthening materials; Step S2: Prefabricate fiber sleeves and open semi-circular hoses in the factory; Step S3: Remove the attachments on the surface of the pile foundation structure, and chisel the contact surface of the pile foundation concrete structure to expose the new aggregate surface; Step S4: Install and fix the fiber sleeves and open semi-circular hoses; Step S5: Seal the bottom and pour the bottom-sealing grout; Step S6: Pour the grout and seal with sealant.

2. The fiber sleeve reinforcement method for the bulge of underwater cast-in-place piles according to claim 1, characterized in that, The said Step S1 includes the following steps: Step S11: Determine the position of the concrete bulge of the pile foundation; determine the height of the fiber sleeve according to the type of disease, position and bulge position; determine the diameter of the fiber sleeve according to the diameter of the pile foundation; determine the size of the open semi-circular hose according to the size of the bulge; Step S12: Determine the quantity of materials for the grout, sealing strip, sealant and fastening belt according to the sizes of the fiber sleeve and the open semi-circular hose.

3. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles according to claim 1, characterized in that, In the said Step S2, the fiber sleeve is selected as a composite material sleeve with a fiber reinforcement effect formed by winding, molding or extrusion of high-strength fibers and matrix materials; the open semi-circular hose is selected as a corrugated semi-circular hose.

4. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles according to claim 1, characterized in that, In the said Step S3, rust removal and grinding are carried out on the steel bars within the strengthening range of the pile foundation until the metal luster is exposed on the surface; chisel and clean the loose concrete where the bulge exists.

5. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles according to claim 1, characterized in that, The said Step S4 includes the following steps: Step S41: Apply sealant evenly in the locking groove of the sleeve before installing the fiber sleeve; Step S42: Install the fiber sleeve at a position below the bulge to form a closed-loop state; Step S43: Install two open semi-circular hoses at the bulge position to form a closed-loop state, connect the two open semi-circular hoses with sealant, and connect the open semi-circular hose and the fiber sleeve with sealant; Step S44: Install the fiber sleeve at a position above the bulge to form a closed-loop state, and connect the fiber sleeve and the open semi-circular hose with sealant; Step S45: Fix the fiber sleeve and the open semi-circular hose with a fastening belt.

6. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles according to claim 1, characterized in that, In the said Step S5, elastic sealing strips are used for bottom sealing during construction, the thickness of the sealing strip is greater than 1.5 - 2 times the gap between the fiber sleeve and the pile foundation, and the width is 20 - 30 mm; the bottom-sealing grout is poured by the high-position funnel gravity grouting method, and the pouring is stopped when the pouring height reaches 100 mm - 150 mm; check the bottom sealing situation after the pouring of the bottom-sealing grout is completed.

7. A fiber sleeve reinforcement method applicable to the bulging of underwater cast-in-place piles according to claim 1, characterized in that, In the said Step S6, a grout with good self-leveling characteristics is selected, and the grout is poured after the bottom-sealing grout is cured, and the grout is poured to the top at one time; after the grout pouring construction is completed, seal at a position 45 - 55 mm from the top with sealant, so that the sealant forms a smooth slope surface with the connection surface of the structure strengthened by the pile foundation; remove the fastening belt after the compressive strength of the grout ≥ 2.5 MPa.

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