Method for reinforcing bridge pier through steel sleeve

Abstract

The invention discloses a method for reinforcing a bridge pier by adopting a steel sleeve, and relates to the technical field of bridge reinforcement, in particular to a filling layer filled between an original bridge pier and a steel pipe sleeve by utilizing the ultrahigh mechanical property of self-compacting micro-expansion concrete. The reinforcing method comprises the steps that the surface of an original bridge pier is treated, the steel pipe sleeve is arranged outside the reinforced bridge pier in a sleeving mode, and finally a filling layer between the original bridge pier and the steel pipe sleeve is poured through self-compacting micro-expansion concrete, so that the steel pipe sleeve and the original bridge pier are better bonded to form a whole. The self-compacting filling concrete has the mechanical property of micro-expansion, so that the possibility of void of the filling layer is reduced. Under the effective restraining effect of the steel pipes, the concrete in the pier is in a three-way pressed state, the compressive strength of the pier and the limit strain of the whole structure after reinforcement are remarkably improved, the stress performance of the pier after reinforcement is effectively improved, the construction efficiency is high, and consumables are few.

Description

Technical Field

[0001] The invention relates to the technical field of building structure reinforcement, in particular to a method for quickly reinforcing a bridge pier, and in particular to a method for reinforcing a bridge pier by using a steel pipe sleeve. Background Art

[0002] The pier is one of the main load-bearing components of the bridge, directly supporting the superstructure of the bridge and transferring the load of the superstructure to the foundation. The stability and strength of the pier directly affect the overall safety and service life of the bridge. At present, the pier suffers from durability problems, impact damage, natural disasters and other hazards, resulting in insufficient bearing capacity, so it is necessary to repair and reinforce it. Traditional pier reinforcement methods include increasing the cross-section reinforcement method, outsourcing fiber reinforced composite reinforcement method and bonding steel sheet reinforcement method. However, the above-mentioned pier reinforcement methods have many defects and inadaptability. The reinforcement method of increasing the cross-sectional area will greatly reduce the passage space under the bridge and consume a large amount of concrete pouring formwork; the outsourcing fiber reinforced composite reinforcement method also has shortcomings. After reinforcement, it is limited by the brittleness of the fiber reinforced composite material, and the overall ductility of the reinforced composite structure is poor; the bonding steel sheet reinforcement method has the problem of aging and failure of the adhesive layer, that is, the bonding effectiveness of the steel sheet and the original pier is difficult to guarantee. By comparing the reinforcement methods of traditional structures, the present invention proposes a reinforcement method that can better solve the above problems.

[0003] With the acceleration of urbanization, the current construction industry has problems such as waste of resources and environmental pollution. Seeking a resource-saving and environmentally friendly construction method is in line with the development trend of the construction industry. A method of reinforcing bridge piers with steel pipe sleeves can save a lot of concrete pouring formwork, save building materials while ensuring the quality of the building, reduce environmental pollution and simplify the construction.

[0004] Self-compacting micro-expansive concrete is a kind of concrete that fully combines the working performance of self-compacting concrete and expansive concrete, and has excellent properties of high flowability, vibration-free and micro-expansion. Compared with ordinary concrete, it has obvious shrinkage characteristics and weak fluidity. SMC can increase the bond strength between steel pipes and concrete and reduce the possibility of voiding of the filling layer. Summary of the invention

[0005] In view of the above shortcomings of the prior art, the present invention provides a method for reinforcing bridge piers using steel pipe sleeves. The purpose of the present invention is firstly achieved through the following technical solutions: A method for reinforcing a bridge pier using a steel pipe sleeve specifically comprises the following steps: Furthermore, the surface of the original bridge pier is processed, and the concrete of the cracked protective layer on the surface of the damaged column is roughened and leveled. The thickness of the roughened and leveled concrete is determined according to the most severely damaged part.

[0006] Furthermore, anchor holes are drilled in the original bridge piers after roughening. The anchor holes are located at a certain distance from the upper and lower ends of the original bridge piers, and a non-reinforced area is reserved. The anchor holes of the bridge piers are located corresponding to the anchor holes reserved above and below the steel pipe sleeves.

[0007] Furthermore, a steel cage is arranged in the filling layer between the original bridge pier and the steel pipe sleeve, which further improves the hooping effect on the bridge pier.

[0008] Furthermore, the steel pipe sleeve and the bridge pier need to form a complete load-bearing body after reinforcement, and the anchor bolts need to provide reliable connection performance. The diameter and strength of the anchor bolts should meet the relevant specifications and structural requirements.

[0009] Furthermore, the semicircular steel pipe sleeves on the left and right sides are overlapped and welded, and the welding quality should meet the corresponding specifications and structural requirements. The function of the steel pipe sleeve is to increase the ultimate bearing capacity of the pier and increase the ductility range. Since the steel pipe sleeve participates in the force calculation, the design of the steel pipe sleeve affects the bearing capacity and deformation capacity of the reinforced pier.

[0010] Furthermore, self-compacting micro-expansive concrete is poured into the filling layer between the original bridge pier and the newly added steel pipe. The self-compacting micro-expansive concrete is required to increase the bonding performance between the steel pipe sleeve and the concrete.

[0011] A method for reinforcing bridge piers with steel pipe sleeves is designed to solve the problem of durability, impact damage, and insufficient bearing capacity of bridge piers caused by natural disasters. The method uses steel pipe sleeves to reinforce columns and pours self-compacting micro-expansive concrete to increase the bonding strength between the steel pipe and concrete and reduce the possibility of the filling layer becoming empty.

[0012] Compared with traditional bridge pier reinforcement methods, this technology has high durability, significantly improved compressive strength and overall ductility, and this method has a wide range of usage scenarios and can be applied to the reinforcement of various bridge piers.

[0013] Compared with traditional bridge pier reinforcement methods, the components required for construction can be completed in the factory and assembled and welded after being transported to the site, thus ensuring the quality of the reinforcement construction while reducing construction time.

[0014] Compared with the traditional steel pipe sleeve reinforcement method, this technology reserves a certain unreinforced area at the upper and lower ends of the original pier, that is, retaining the interface properties between the original pier and the cap beam and abutment, facilitating the pouring of filling concrete while reducing the impact on the internal stress distribution at the interface of the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the steel pipe sleeve structure used to reinforce the original bridge pier.

[0016] Figure 2 This is a schematic diagram of the internal structure of the original pier-steel pipe sleeve filling layer.

[0017] Figure 3 This is a schematic diagram of a structure using steel pipe sleeves to reinforce bridge piers.

[0018] In the figure: 1-original bridge pier; 2-anchor bolt; 3-reserved hole for anchor bolt; 4-reinforcement cage; 5-steel pipe sleeve; 6-self-compacting micro-expanding filling concrete. Specific implementation methods

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Example 1

[0020] The present invention proposes a method for reinforcing a bridge pier using a steel pipe sleeve. First, the concrete of the cracked protective layer on the surface of the original bridge pier is chiseled off. The thickness of the chiseled and leveled concrete is determined according to the most severely damaged part. Anchor bolt pre-holes 3 are drilled for the chiseled bridge pier, and a steel pipe sleeve 5 with a thickness of 2.5 mm is used. Anchor bolt pre-holes 3 are drilled at the corresponding positions of the steel pipe sleeve 5. Figure 1 As shown. A steel cage 4 is arranged in the filling layer between the steel pipe sleeve 5 and the original bridge pier. Figure 2 As shown. The steel pipe sleeve 5 is fixed to the original bridge pier 1 by anchor bolts 2, and the left and right halves of the round steel pipe sleeve 5 are welded. After the welding of the steel pipe sleeve is completed, the excellent micro-expansion performance of the self-compacting micro-expansion concrete 6 is used for pouring to form the original bridge pier-self-compacting micro-expansion concrete-steel pipe sleeve as a whole. Figure 3 It is a bridge pier reinforced with a steel pipe sleeve.

[0021] The self-compacting slightly expansive concrete used in this embodiment is recorded by weight as 471 parts of P.II.52.5R cement, 68 parts of fly ash, 34 parts of silica fume, 57 parts of AUA expansive agent, 88 parts of S95 mineral powder, 700 parts of sand, 657 parts of stone, 213 parts of water, and 20 parts of Sika water reducer. Example 2

[0022] The present invention proposes a method for reinforcing a bridge pier using a steel pipe sleeve. First, the concrete of the cracked protective layer on the surface of the original bridge pier is chiseled off, and the thickness of the chiseled and leveled concrete is determined according to the most severely damaged part. Anchor bolt reserved holes 3 are drilled for the chiseled bridge pier, and a steel pipe sleeve 5 with a thickness of 3.75 mm is used, and anchor bolt reserved holes 3 are drilled at corresponding positions of the steel pipe sleeve 5. Figure 1 As shown. A steel cage 4 is arranged in the filling layer between the steel pipe sleeve 5 and the original bridge pier. Figure 2 As shown. The steel pipe sleeve 5 is fixed to the original bridge pier 1 by anchor bolts 2, and the left and right halves of the round steel pipe sleeve 5 are welded. After the welding of the steel pipe sleeve is completed, the excellent micro-expansion performance of the self-compacting micro-expansion concrete 6 is used for pouring to form the original bridge pier-self-compacting micro-expansion concrete-steel pipe sleeve as a whole. Figure 3 It is a bridge pier reinforced with a steel pipe sleeve.

[0023] The self-compacting slightly expansive concrete used in this embodiment is recorded in parts by mass as 450 parts of P.II.52.5R cement, 71 parts of fly ash, 26 parts of silica fume, 32 parts of AUA expansive agent, 64 parts of S95 mineral powder, 632 parts of sand, 590 parts of stone, 166 parts of water, and 15 parts of Sika water reducer. Example 3

[0024] The present invention proposes a method for reinforcing a bridge pier using a steel pipe sleeve. First, the concrete of the cracked protective layer on the surface of the original bridge pier is chiseled off, and the thickness of the chiseled and leveled concrete is determined according to the most severely damaged part. Anchor bolt reserved holes 3 are drilled for the chiseled bridge pier, and a steel pipe sleeve 5 with a thickness of 5.75 mm is used, and anchor bolt reserved holes 3 are drilled at corresponding positions of the steel pipe sleeve 5. Figure 1 As shown. A steel cage 4 is arranged in the filling layer between the steel pipe sleeve 5 and the original bridge pier. Figure 2 As shown. The steel pipe sleeve 5 is fixed to the original bridge pier 1 by anchor bolts 2, and the left and right halves of the round steel pipe sleeve 5 are welded. After the welding of the steel pipe sleeve is completed, the excellent micro-expansion performance of the self-compacting micro-expansion concrete 6 is used for pouring to form the original bridge pier-self-compacting micro-expansion concrete-steel pipe sleeve as a whole. Figure 3 It is a bridge pier reinforced with a steel pipe sleeve.

[0025] The self-compacting slightly expansive concrete used in this embodiment is recorded in parts by mass as 490 parts of P.II.52.5R cement, 87 parts of fly ash, 58 parts of silica fume, 72 parts of AUA expansive agent, 94 parts of S95 mineral powder, 720 parts of sand, 775 parts of stone, 186 parts of water, and 29 parts of Sika water reducer. Example 4

[0026] The present invention proposes a method for reinforcing a bridge pier by using a steel pipe sleeve. First, the concrete of the cracked protective layer on the surface of the original bridge pier is chiseled off. The thickness of the chiseled and leveled concrete is determined according to the most severely damaged part. Anchor bolt reserved holes 3 are drilled for the chiseled bridge pier, and a steel pipe sleeve 5 with a thickness of 7 mm is used. Anchor bolt reserved holes 3 are drilled at corresponding positions of the steel pipe sleeve 5. Figure 1 As shown. A steel cage 4 is arranged in the filling layer between the steel pipe sleeve 5 and the original bridge pier. Figure 2 As shown. The steel pipe sleeve 5 is fixed to the original bridge pier 1 by anchor bolts 2, and the left and right halves of the round steel pipe sleeve 5 are welded. After the welding of the steel pipe sleeve is completed, the excellent micro-expansion performance of the self-compacting micro-expansion concrete 6 is used for pouring to form the original bridge pier-self-compacting micro-expansion concrete-steel pipe sleeve as a whole. Figure 3 It is a bridge pier reinforced with a steel pipe sleeve.

[0027] The self-compacting slightly expansive concrete used in this embodiment is recorded in parts by mass as 479 parts of P.II.52.5R cement, 74 parts of fly ash, 36 parts of silica fume, 64 parts of AUA expansive agent, 93 parts of S95 mineral powder, 731 parts of sand, 667 parts of stone, 231 parts of water, and 26 parts of Sika water reducer.

Claims

1. A method for reinforcing bridge piers using steel pipe sleeves, characterized in that: Specifically include the following steps: Treat the surface of the original bridge pier; The steel pipe is sleeved on the outside of the original pier; Pour self-compacting micro-expansive concrete into the filling layer between the original pier and the newly added steel pipe.

2. The method for reinforcing bridge piers using steel casing according to claim 1, characterized in that: The processing of the original bridge pier surface in step (1) is characterized by comprising the following steps: The concrete of the cracked protective layer on the surface of the damaged pier is roughened and leveled, and the thickness of the roughened and leveled concrete is determined based on the most severely damaged part.

3. The method for reinforcing bridge piers using steel pipe sleeves according to claim 1, characterized in that: The steel pipe sleeve described in step (2) is connected to the outside of the original bridge pier, characterized in that it includes the following steps: Anchor holes are drilled on the original bridge piers after roughening, and the positions of the anchor holes should maintain a certain distance from the upper and lower ends of the original bridge piers, leaving unreinforced areas, and the positions of the pier anchor holes should correspond to the anchor bolt holes reserved on the steel pipe sleeves.

4. For the bridge piers that have been roughened, a steel cage is arranged in the filling layer between the original bridge pier and the steel pipe sleeve.

5. The steel pipe sleeve is installed on the surface treated bridge pier by using anchor bolts in the anchor bolt holes reserved in the steel pipe sleeve. The diameter and strength of the anchor bolts shall meet the relevant specifications and construction requirements.

6. After fixing the steel pipe sleeve on the bridge pier, overlap the semicircular steel pipes on the left and right sides and weld them. The welding quality should meet the relevant specifications and structural requirements.

7. The method for reinforcing bridge piers using steel pipe sleeves according to claim 1, characterized in that: The self-compacting slightly expansive concrete is poured into the filling layer between the original bridge pier and the newly added steel pipe in step (3), wherein the self-compacting slightly expansive concrete is characterized in that the raw materials for preparation include, by weight: P.II.52.5R cement 450~500 parts, fly ash 70~90 parts, silica fume 20~60 parts, AUA expansion agent 30~80 parts, S95 mineral powder 60~100 parts, sand 600~800 parts, stone 550~800 parts, water 120~240 parts, Sika water reducer 10~60 parts.

Images