CN111560836A - Construction method of main arch of an arch bridge and construction method of prefabricated arch bridge - Google Patents

Abstract

The invention discloses a method for constructing a main arch of an arch bridge and a method for constructing an assembled arch bridge, which comprise the following steps: a. dividing the main arch into a plurality of main arch sub-bodies with the same shape along the width direction, sequentially dividing the main arch sub-bodies into a front section, a middle section and a rear section along the span direction, wherein the two divided surfaces are planes with the bending moment of 0 on the main arch; b. prefabricating the front section, the middle section and the rear section; c. splicing and hoisting the sections on the abutment of the arch bridge after prefabrication is finished; the main arch is divided into the main arch split body, the main arch split body is divided into the front section, the middle section and the rear section, so that each part can be prefabricated, the transportation and the hoisting are convenient, the water pumping and the blocking of a river are not needed, and in addition, the two splitting surfaces of the main arch are the surfaces with the bending moment of 0 under the condition that the main arch split body is subjected to the uniform load, the load capacity of the main arch can be ensured, and the service life of the main arch is prolonged.

Description

Construction method of main arch of an arch bridge and construction method of prefabricated arch bridge

technical field

The invention relates to the technical field of bridges, in particular to a construction method of a main arch of an arch bridge and a construction method of an assembled arch bridge.

Background technique

The existing arch bridge structure, one is steel structure, the other is reinforced concrete structure. Due to its light weight and high strength, steel structure arch bridges are generally suitable for large-span bridges, but steel structures are subject to corrosion, rust, and high maintenance costs under the action of the atmosphere, so the cost is relatively high, and it is not suitable for small-span arch bridges. For the construction of reinforced concrete arch bridges, if the river is relatively short, it is generally used to drain the river water first and then build the arch bridge. Prepare the construction site for the construction of the arch bridge, then arrange maintenance structures such as supports, scaffolding, and formwork, and then start the processes of tying steel bars and pouring concrete on site. Even if an arch bridge is built in a mountainous area, it is necessary to erect a full hall of brackets and arches, which is a cumbersome process. , the construction is difficult, such as the invention patent titled "a top-loaded open-shoulder arch bridge and its construction method" with the application number "201310065824.2", and the application number "201810529770.3" titled "a construction method of a reinforced concrete arch bridge" The invention patents are all set up with supporting structures such as arches. There are three main disadvantages of the above construction methods: (1) Blocking rivers or pumping and draining water, etc., requires a large amount of engineering, requires a certain amount of time and cost, and is not conducive to environmental protection; (2) The construction of bridges requires the construction of a large number of Scaffolding, formwork and other supporting structures consume manpower and material resources; (3) The construction of the bridge is a field operation, and noise, dust, garbage, etc. affect the surrounding environment.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a construction method for the main arch of an arch bridge and a construction method for a prefabricated arch bridge, so as to solve the problems existing in the above-mentioned prior art, make the construction process simpler, shorten the construction period, save costs, and at the same time ensure the arch bridge load performance.

In order to achieve the above object, the present invention provides the following scheme: the present invention provides a method for constructing the main arch of an arch bridge, comprising the following steps:

a. The main arch is divided into several main arch splits with the same shape along the width direction, and the main arch splits are divided into three parts: front section, middle section and rear section in turn in the span direction, and the two split surfaces are the The plane where the bending moment of the main arch split body is 0 under uniform load;

b. Prefabricating the front section, the middle section and the rear section;

c. After the prefabrication is completed, the front section, the middle section and the rear section are spliced and hoisted on the abutment of the arch bridge.

Preferably, in step c, after the splicing of the front section, the middle section and the rear section is completed, the two ends of the first prestressed tendon are respectively anchored to the ends of the front section and the rear section, and then the The main arch is hoisted and fixed on the bridge abutment separately.

Preferably, in step c, after a plurality of the main arch splits are fixed on the bridge abutment, a second prestressed rib is used to fasten a plurality of the main arch splits in series along the width direction, and the second prestressed Ribs are provided on the front section, the middle section and/or the rear section.

Preferably, in step b, the front section, the middle section, and the rear section are all prefabricated by a 3D printing method, and a through hole for the second prestressing rib to pass through is reserved at the same time of printing.

Preferably, in step c, the front section and the middle section, and the middle section and the rear section are all bonded by mortar.

The present invention also provides a method for constructing a prefabricated arch bridge, wherein the arch bridge comprises two fixed abutments, a main arch arranged between the abutments, a vault side wall and a vault filler, including the following steps:

1) splitting the arch bridge according to the design drawings of the arch bridge, and the split components include the abutment, the main arch, the side walls of the vault and the vault filler;

2) Manufacture the abutment, and prepare the main arch and the side walls of the vault by a 3D printer;

3) Fixing the abutment, then hoisting the main arch and the side wall of the dome in sequence, and finally laying the dome filler to complete the construction of the arch bridge;

Wherein, the above-mentioned construction method of the main arch of the arch bridge is used to construct the main arch.

Preferably, the arch bridge further includes an abdominal arch having the same width as the main arch and overlapping above both ends of the main arch. In step 1), the abdominal arch is divided into several identical abdominal arches along the width direction. The arch split body, and the abdominal arch split body is overlapped on the main arch split body.

Preferably, in step 3), after the installation of the main arch is completed, the web arch split body is hoisted, and the web arch split body and the main arch split body are bonded with magnesium phosphate mortar.

Preferably, in step 1), the side wall of the vault is divided into several side wall parts along the span direction. After the abdominal arch parts are fixed in step 3), the side wall parts are hoisted. Magnesium phosphate mortar is used for bonding between the wall split body, the main arch split body and the abdominal arch split body.

Preferably, in step 2), when preparing the abutment, an anchoring end for fixing the third prestressed tendon is reserved.

The present invention has achieved the following technical effects with respect to the prior art:

1. In the present invention, the main arch is divided into main arch parts, and the main arch part is divided into front section, middle section and rear section, so that each part can be prefabricated, and it is convenient for transportation and hoisting, and the entire construction process of the main arch does not require The river is pumped and blocked, and there is no need to erect supporting structures such as arches, which makes the construction process simpler, shortens the construction period and saves costs;

2. In the present invention, the two split surfaces of the main arch are the surfaces with a bending moment of 0 when the main arch split is subjected to a uniform load. After the front, middle and rear sections are spliced, the main arch split near the seam is subjected to a uniform load. The lower bending moment can ensure the stable connection of the joints and will not affect the overall strength of the main arch, thereby ensuring the load capacity of the main arch and prolonging the life of the main arch;

3. Compared with on-site construction operations, 3D printing is used to prefabricate the front, middle and rear sections. The temperature and humidity of the prefabricated environment can be effectively controlled and adjusted, and the maintenance can be more refined, which is conducive to controlling the molding of concrete structures. quality;

4. The whole arch bridge is prefabricated in blocks and then hoisted for construction. While shortening the construction period and saving costs, it also reduces the impact on the environment and achieves automated, efficient and green bridge construction.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is a block diagram of an arch bridge;

Figure 2 is a schematic diagram of the main arch after anchoring the first prestressing tendon;

Figure 3. The bending moment diagram of the main arch under balanced load condition;

Among them, 1. Main arch split; 2. Bridge abutment; 3. Web arch split; 4. Dome side wall; 5. First prestressing tendon; 6. Second prestressing tendon; 7. Third prestressing tendons;

In Figure 3, L is the main arch split axis; q is the load; F is the horizontal component force of the abutment on the arch foot; M is the bending moment.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a construction method for the main arch of an arch bridge and a construction method for a prefabricated arch bridge, so as to solve the problems existing in the above-mentioned prior art, make the construction process simpler, shorten the construction period and save the cost.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

The present invention provides the following solutions: the present invention provides a method for constructing a main arch of an arch bridge, comprising the following steps:

a. The main arch is divided into several main arch splits 1 with the same shape along the width direction, and the main arch split 1 is divided into three parts in sequence along the span direction: front section, middle section and rear section, and the two split surfaces are main arch splits 1 A plane with a bending moment of 0 under a uniform load;

b. Prefabricate the front, middle and rear sections;

c. After the prefabrication is completed, the front section, the middle section and the rear section are spliced and hoisted on the abutment 2 of the arch bridge.

By dividing the main arch into the main arch split 1, and dividing the main arch split 1 into the front section, the middle section and the rear section, each part can be prefabricated, and it is convenient for transportation and hoisting. It is not necessary to set up supporting auxiliary structures such as arch frames for pumping and blocking, which makes the construction process simpler, shortens the construction period and saves costs; and the two split surfaces of the main arch split 1 are subjected to uniform load conditions for the main arch. On the surface with the lower bending moment of 0, after the front, middle and rear sections are spliced, the bending moment near the joint under the uniform load of the main arch is low, which can ensure the stable connection of the joint and will not affect the main arch. The overall strength can ensure the load capacity of the main arch and prolong the life of the main arch.

Here, the surface of the main arch split body 1 with a bending moment of 0 is described. As shown in Figure 3, the main arch split body 1 is regarded as an arc, and the axis L of the main arch split body 1 is obtained, and the load is uniformly distributed. Under the action of q, the lower side of the axis L of the main arch split 1 is tensioned, resulting in a positive bending moment, and the horizontal component force of the bridge abutment 2 on the arch foot pulls the upper side of the arch structure, resulting in a negative bending moment, and the main arch split 1 The bending moment at each point on the axis L is the superposition of the positive and negative bending moments to obtain the bending moment diagram shown in Figure 3. The point where the positive and negative bending moments are equal is the position where the bending moment is equal to 0, so that the main arch fraction can be obtained. The face of body 1 with bending moment 0.

In step c, after the splicing of the front section, the middle section and the rear section is completed, the two ends of the first prestressing tendon 5 are respectively anchored at the ends of the front section and the rear section, and an inward pre-tightening force is applied, and then the main arch is divided into two parts. 1. It is hoisted and fixed on the abutment 2; the function of the first prestressing rib 5 is to pre-stretch the main arch split 1 to enhance the bearing capacity of the main arch split 1; After the arch split body 1 is hoisted on the abutment 2, the abutment 2 has a clamping effect on the main arch split body 1. After the main arch split body 1 is fixed, if the first prestressing tendon 5 is relatively close to the river water surface, it will block the ships on the water surface. When driving, the first prestressing tendon 5 can be removed.

In order to ensure the stability of the main arch, in step c, after several main arch splits 1 are fixed on the abutment 2, the second prestressed ribs 6 are used to fix the several main arch splits 1 in series along the width direction, so that several main arch splits 1 are fixed in series along the width direction. The split body 1 is connected as a whole, and the second prestressing tendons 6 are arranged on the front section, the middle section and/or the rear section.

In this embodiment, the front section, the middle section, and the rear section are all prefabricated by 3D printing, and through holes for the second prestressing ribs 6 to pass through are reserved during printing; In the front, middle, and back sections of 3D printing, the ambient temperature and humidity can be effectively controlled and adjusted during the prefabrication process, and the maintenance can be made more refined, which is conducive to controlling the molding quality of the concrete structure.

In this embodiment, the front section and the middle section, and the middle section and the rear section are all bonded by concrete mortar, and the strength of the concrete mortar is higher than that of the concrete used in the front section, the middle section, and the rear section. For example, the strength grade of the concrete used for 3D printing For C40, the strength grade of concrete mortar for bonding can be C60 or even C80 to ensure stable bonding. However, those skilled in the art should understand that in the actual construction process, the connection method of the front section, the middle section and the rear section is not limited to bonding. You can also pre-embed steel bars at both ends of the middle section, and reserve steel bars at the corresponding positions of the front section and the rear section. The pre-buried holes and the grouting holes for grouting are then spliced and grouted to ensure a stable connection. Of course, other ways to realize the connection are also feasible.

The present invention also provides a method for constructing a prefabricated arch bridge. The arch bridge comprises two fixed abutments 2, a main arch arranged between the abutments 2, a vault side wall 4 and a vault filler, including the following steps:

1) Split the arch bridge according to the design drawings of the arch bridge, and the split components include the abutment 2, the main arch, the vault side walls 4 and the vault filler;

2) Manufacture the abutment 2, and prepare the main arch and the side walls 4 of the vault by a 3D printer;

3) Fix the abutment 2, then hoist the main arch and the vault side wall 4 in turn, and finally lay the vault filler to complete the construction of the arch bridge;

Wherein, the main arch of the arch bridge is constructed by applying the above-mentioned construction method of the main arch of the arch bridge.

In this embodiment, the arch bridge is prefabricated in blocks, which can save prefabrication time, improve the prefabrication accuracy, and then hoist one by one, which can reduce the impact on the environment and achieve automated, efficient, and green bridge construction.

The dome filler in this implementation can be prefabricated in a 3D manner, and then bonded to the dome, or can be laid on the dome.

The arch bridge also includes an abdominal arch with the same width as the main arch and overlapped above both ends of the main arch. In step 1), the abdominal arch is divided into several identical abdominal arch splits 3 along the width direction, and the abdominal arch splits 3 It is overlapped on the main arch split 1.

In order to improve the load capacity of the main arch and the web arch, in this embodiment, the web arch split body 3 is staggered and overlapped on the main arch split body 1, for example, the width of the main arch and web arch is 20m, and the width of the main arch split body 1 is 4m , the width of the abdominal arch is 5m, to ensure that the joints of the split 3 of the abdominal arch will not overlap with the joints of the split 1 of the main arch.

In step 3), after the main arch is installed, the web arch split body 3 is hoisted, and the web arch split body 3 and the main arch split body 1 are bonded with magnesium phosphate mortar.

In order to facilitate the prefabrication and installation of the dome side wall 4, in step 1), the dome side wall 4 is divided into several side wall parts along the span direction. , Magnesium phosphate mortar is used for bonding between the side wall split, the main arch split 1 and the abdominal arch split 3.

In step 2), when the abutment 2 is prepared, the anchoring end for fixing the third prestressed tendon 7 is reserved. Since the abutment 2 is the foundation of the load-bearing arch bridge, its stability is of great significance to the overall stability of the arch bridge; when the abutment 2 is set in the foundation of relatively soft soil, the third prestressing tendon 7 can be applied at the anchoring end to ensure the bridge The abutment 2 will not move to both sides under the action of the load; when the abutment 2 is set in a hard foundation, such as a natural rock mass, the foundation conditions can ensure that the abutment 2 does not move to both sides, so it is not necessary to apply the third prestress tendons 7.

Railings, pavements, steps, etc. can also be set on the arch bridge, and the railings and steps can also be prefabricated by 3D printing.

Adaptive changes made according to actual needs are all within the protection scope of the present invention.

In the present invention, specific examples are used to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; There will be changes in the specific implementation manner and application scope of the idea of the invention. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. a construction method of main arch of an arch bridge, is characterized in that, comprises the following steps: a. The main arch is divided into several main arch splits with the same shape along the width direction, and the main arch splits are divided into three parts: front section, middle section and rear section in turn in the span direction, and the two split surfaces are the The plane where the bending moment of the main arch split body is 0 under uniform load; b. Prefabricating the front section, the middle section and the rear section; c. After the prefabrication is completed, the front section, the middle section and the rear section are spliced and hoisted on the abutment of the arch bridge. 2. The construction method of the main arch of an arch bridge according to claim 1, wherein in step c, after the splicing of the front section, the middle section and the rear section is completed, the two ends of the first prestressed tendon are respectively It is anchored at the ends of the front section and the rear section, and then the main arch is hoisted and fixed on the bridge abutment separately. 3. The method for constructing a main arch of an arch bridge according to claim 2, wherein in step c, after a plurality of the main arches are separately fixed on the abutment, the second prestressed tendons are used to separate the main arches along the width direction. A plurality of the main arch splits are fixed in series, and the second prestressing tendons are arranged on the front section, the middle section and/or the rear section. 4. The method for constructing the main arch of an arch bridge according to claim 3, wherein in step b, the front section, the middle section, and the rear section are all prefabricated by 3D printing, and are reserved while printing. a through hole for the second prestressing rib to pass through. 5 . The method for constructing the main arch of an arch bridge according to claim 2 , wherein in step c, the front section and the middle section, and the middle section and the rear section are all bonded by mortar. 6 . 6. A construction method of a prefabricated arch bridge, the arch bridge comprising two fixed abutments, a main arch arranged between the abutments, a vault side wall and a vault filler thereof, characterized in that, comprising the following steps : 1) splitting the arch bridge according to the design drawings of the arch bridge, and the split components include the abutment, the main arch, the side walls of the vault and the vault filler; 2) Manufacture the abutment, and prepare the main arch and the side walls of the vault by a 3D printer; 3) Fixing the abutment, then hoisting the main arch and the side wall of the dome in sequence, and finally laying the dome filler to complete the construction of the arch bridge; Wherein, the construction method of the main arch of an arch bridge according to any one of claims 1-5 is used to construct the main arch. 7. The method for constructing a prefabricated arch bridge according to claim 6, wherein the arch bridge further comprises an abdominal arch having the same width as the main arch and overlapping above both ends of the main arch, step 1 ), the abdominal arch is divided into the same several abdominal arch parts along the width direction, and the abdominal arch parts are overlapped on the main arch part. 8. The method for constructing a prefabricated arch bridge according to claim 7, wherein in step 3), after the installation of the main arch is completed, the web arch split body is hoisted, and the web arch split body and the Magnesium phosphate mortar is used for bonding between the main arch parts. 9. The construction method of the prefabricated arch bridge according to claim 7, wherein in step 1), the side wall of the vault is divided into several side wall parts along the span direction, and in step 3), the side wall is divided into several parts. After the arch split body is fixed, the side wall split body is hoisted, and magnesium phosphate mortar is used to bond the side wall split body, the main arch split body and the abdominal arch split body. 10 . The method for constructing a fabricated arch bridge according to claim 6 , wherein in step 2), when preparing the abutment, an anchoring end for fixing the third prestressed tendon is reserved. 11 .

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