CN114135326B - Construction method and construction device for jacking box culvert - Google Patents

Abstract

The present invention relates to a construction method and a construction device for box culvert jacking, including an adjustable angle bow slope installed at the front end of the box culvert and an adjustable pulley arranged between the top of the box culvert and the head-up beam of the original line. The jack of the adjustable angle bow slope, the steel bow slope, and the front end of the box culvert form a triangular structure. The bottom surface of the installed steel bow slope is tilted upward to form an inclination angle with the horizontal plane. The hydraulic synchronous control system controls the jack to push out or retract to change the inclination angle of the steel bow slope. The adjustable pulley includes a vertical jack and a pulley fixed on the top. The pulley pulley contacts the horizontal head-up beam. The hydraulic synchronous control system changes the height of the adjustable pulley by controlling the action of the vertical jack. The present invention can not only automatically adjust the slope of the bow slope to prevent the head from being stuck or head-up when the box culvert is jacked, but also protect the top of the box culvert from damaging the original line, and has dual effects and functions.

Description

Construction method and construction device for box culvert jacking

Technical Field

The invention relates to the technical field of box culvert jacking construction, and in particular to a box culvert jacking construction method and a construction device.

Background Art

During municipal construction, when a new road must pass under the existing railway or roadbed, after taking necessary reinforcement measures for the original line, the box culvert jacking construction technology can be used to build the new line.

A box culvert is a three-dimensional box-shaped structure with a rectangular cross section made of reinforced concrete. The internal culvert provides space for forward excavation. The box culvert jacking construction method is a construction method that uses power equipment to push the prefabricated box culvert under the original line. The box culvert jacking method is widely used because it can reduce interference with the original line traffic.

As shown in Figure 1, when the box culvert is jacked, a working pit is first excavated on one side of the original line and the working pit is well protected; then a slide is cast in the working pit; and a reinforced concrete box culvert is cast on site on the slide; when the concrete strength of the box culvert is maintained to meet the design requirements, the box culvert is gradually jacked forward in the length direction using jacking power equipment, force transmission devices, and back reaction walls. Each time a section of earth is excavated from the inside of the box culvert manually or mechanically, the box culvert is pushed forward one step, and the cycle is repeated until the box culvert is jacked into place; according to the width of the original line, multiple box culverts can be connected and jacked to form an underground passage.

During the jacking process of the box culvert, the head-down phenomenon usually occurs due to the foundation, the force of the soil in front, or the weight of the bottom plate of the box culvert itself, commonly known as "head-down", which affects the quality of the project. In order to prevent the head-down phenomenon of the box culvert, a certain upward slope is often reserved under the bottom plate at the front end of the box culvert, generally called the bow slope, or a steel bow slope is made of steel and installed under the bottom plate at the front end of the box culvert. However, the inclination angle in front of the bow slope of the above two methods is fixed and cannot be adjusted. During the jacking process of the box culvert, the on-site conditions are relatively complex and changeable. For example, if the inclination angle of the bow slope is too small on the route with relatively soft strata, the head-down phenomenon will still occur; for example, the accuracy is not enough during the production or installation of the steel bow slope, and the angle error is too large, and it needs to be adjusted to meet the design requirements; for example, after each step of the box culvert jacking is completed, the posture of the box culvert is different, and the inclination angle of the steel bow slope needs to be adjusted again according to the actual situation. Therefore, it can be seen that the steel bow slope with adjustable angle can better meet the construction needs.

The Chinese patent with application number CN201810137973.8 discloses an adjustable angle "bow slope". The steel truss and steel bottom plate of this steel bow slope are welded together. The fixed hinge is a fixed node below the steel "bow slope". The vertically arranged jack is installed on the bottom plate of the box culvert, and the force transmission jack is located between the jack and the steel truss. During the jacking process of the box culvert, the fixed hinge bolts are locked, and the jack is locked with the steel truss through the force transmission jack. The reaction force of the soil on the steel bottom plate is transmitted to the front edge of the box culvert bottom plate through the steel truss and the force transmission jack, generating a lifting torque to prevent the box culvert from "heading" and "lifting". When the inclination angle of the steel "bow slope" needs to be adjusted, the bolts of the fixed hinge are loosened, and the spatial posture of the welded steel frame is controlled by controlling the lifting or falling of the jack to achieve the purpose of adjusting the angle. From the description and drawings of the above patent, when adjusting the bow slope angle, after loosening the bolts of the fixed hinge, the steel truss and the steel bottom plate are loosened as a whole, and the jack and the force transmission push rod have no supporting and controlling effect on the steel truss and the steel bottom plate during the non-jacking process (Figure 1). It is necessary to support the truss manually or by other means and adjust it to the required angle, and then tighten the bolts of the fixed hinge. During the jacking process of the box culvert, the jack is supported on the steel truss through the force transmission push rod (Figure 2). In the above angle adjustment process, manpower or other facilities are required to assist in supporting and rotating the steel truss and the steel bottom plate, and the bolts of the fixed hinge must be screwed at the same time. Moreover, the loosening and tightening operations are performed twice, which requires many processes and manual labor, and auxiliary support is also required. It is time-consuming and labor-intensive, and the operation is difficult. Secondly, it is also difficult to accurately locate the position of the steel truss and the steel bottom plate in such an adjustment method, and it is difficult to ensure the accuracy of the adjusted angle. In addition, the adjustable angle "bow slope" is installed under the box culvert bottom plate, which occupies a certain space, and will inevitably make the front end thickness of the box culvert bottom plate thinner, which is not conducive to the box culvert to withstand the large jacking force. Moreover, after the box culvert is jacked into place, the adjustable angle device must be removed and the bottom plate must be repaired, which increases the construction workload.

Summary of the invention

In view of the above-mentioned shortcomings or deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a box culvert jacking construction method and a construction device, which can automatically adjust the angle of the steel bow slope, is simple to operate, saves time and effort, and has high adjustment accuracy.

In order to solve the above technical problems, the present invention has the following structure:

A construction method for box culvert jacking comprises the following steps:

S1: Install multiple sets of connectors of the adjustable angle bow slope, install multiple sets of connectors at intervals in the width direction of the cross section of the box culvert, each set of connectors includes a connector fixed at the front end of the box culvert and a connector fixed at the front end of the box culvert bottom plate directly below;

S2: A steel bow slope with an adjustable angle and multiple jacks are installed at the front end of the box culvert. The number of jacks is equal to the number of connector groups. The width of the steel bow slope is determined according to the width of the cross section of the box culvert. In the jacking direction, the root of the steel bow slope is rotatably connected to the lower connector of each connector group, the front end of the steel bow slope is rotatably connected to the lower end of the jack, the jacks are arranged obliquely, and the upper end of the jack is rotatably connected to the upper connector of each connector group. The jacks, the steel bow slope, and the front end of the box culvert form a triangular structure. The bottom surface of the steel bow slope installed on the box culvert is tilted upward to form an inclination angle with the horizontal plane.

S3: Connecting the jacks to the hydraulic synchronous control system, connecting the multiple jacks of the adjustable angle bow slope to the hydraulic synchronous control system;

S4: Automatically adjust the inclination angle of the adjustable angle bow slope. The hydraulic synchronous control system calculates the change in the length of the jack rod according to the size of the foundation reaction force, controls the jack rod to push out or retract, and the jack pulls up or lowers the front end of the steel bow slope, so that the front end of the steel bow slope rotates around the connecting piece at the root, and accurately controls the inclination angle of the bottom of the steel bow slope to reach the target angle.

The construction method for box culvert jacking also includes the following steps: S5: installing an adjustable pulley, installing a plurality of vertical jacks of the adjustable pulley on the top surface of the box culvert, installing the pulley on the vertical jack, the pulley of the pulley faces the upper horizontal lifting beam, the spacing and number of the vertical jacks are determined according to the length of the pulley, and installing a stopper on the top of the box culvert, the height of the stopper is greater than the pulley, and the stopper is located in front of the pulley in the jacking direction of the box culvert to prevent the pulley from moving forward;

S6: Connect the vertical jack and the hydraulic synchronous control system. The vertical jack of the adjustable pulley is connected to the hydraulic synchronous control system. The hydraulic synchronous control system controls the push-out and retraction of the vertical jack jack rod to adjust the height of the adjustable pulley.

In step S2, the rotatable connection is achieved by opening a hole in the connected part itself or in the structure to which the connected part is welded, and the rotating shaft passes through the hole of the connected part and is axially fixed, so as to realize the hinge between the connected parts.

The steel bow slope includes a steel structure support and a steel plate fixed under the support. The steel plate is longer than the steel structure support in the forward direction and extends to under the box culvert bottom plate to cover the gap between the box culvert bottom plate and the steel structure support.

A construction device for jacking a box culvert comprises an adjustable angle bow slope, the adjustable angle bow slope is installed at the front end of the box culvert, comprises a steel bow slope, a plurality of jacks and a plurality of groups of connecting parts connecting the steel bow slope and the box culvert, the number of the jacks is the same as the number of groups of connecting parts, a plurality of groups of connecting parts are installed at intervals in the width direction of the cross section of the box culvert, each group of connecting parts comprises a connecting part fixed at the front end of the box culvert and a connecting part fixed at the front end of the bottom plate of the box culvert directly below, the width of the steel bow slope is determined according to the width dimension of the cross section of the box culvert, in the jacking direction, the root of the steel bow slope is rotatably connected to the lower connecting part of each group of connecting parts, the front end of the steel bow slope is rotatably connected to the lower end of the jack, the jack is arranged obliquely, the upper end of the jack is rotatably connected to the upper connecting part of each group of connecting parts, the jack, the steel bow slope and the front end of the box culvert form a triangular structure, the bottom surface of the steel bow slope installed on the box culvert is inclined upward, and forms an inclination angle with the horizontal plane;

The jack is a hydraulic jack and is connected to a hydraulic synchronous control system of a control box culvert jacking system. The hydraulic synchronous control system automatically adjusts the inclination angle of the steel bow slope according to the magnitude of the foundation reaction force during the jacking process.

The construction device for box culvert jacking also includes an adjustable pulley arranged between the top of the box culvert and the horizontal lifting beam of the original line. Several vertical jacks of the adjustable pulley are vertically installed on the top surface of the box culvert. The pulley is installed on the vertical jack, and the pulley of the pulley faces the horizontal lifting beam above. The spacing and number of the vertical jacks are determined according to the length of the pulley. The block is installed on the top of the box culvert and is located in front of the pulley in the jacking direction of the box culvert. The height of the block is greater than that of the pulley to prevent the pulley from moving forward. The vertical jack of the adjustable pulley is a hydraulic jack, which is connected to the hydraulic synchronous control system. The hydraulic synchronous control system controls the push-out and retraction of the vertical jack push rod to adjust the height of the adjustable pulley.

Rotatable connection, a hole is opened on the connected part body or on the structure welded on the connected part, the rotating shaft passes through the hole of the connected part and is axially fixed to achieve the hinge between the connected parts.

The connector is installed on the box culvert by pre-embedded or chemical anchor bolts.

The steel bow slope consists of a steel structure support and a steel plate fixed under the support. The steel plate is longer than the steel structure support in the forward direction and extends to under the box culvert bottom plate to cover the gap between the box culvert bottom plate and the steel structure support.

The steel structure bracket is made of H-shaped steel welded together.

Compared with the prior art, the advantages of the present invention are:

The box culvert jacking construction method and construction device of the present invention can timely and automatically adjust the slope of the bow slope according to the actual situation on site; no manual work is required, saving time and labor; and the adjustment accuracy of the inclination angle of the steel bow slope is relatively high.

Secondly, the scheme of the present invention can automatically adjust the slope of the bow slope to prevent the box culvert from getting stuck or rising when it is pushed forward, and at the same time it can protect the box culvert from getting stuck or rising without damaging the horizontal lifting beam of the upper original line, so it has dual effects and functions.

Furthermore, the steel bow slope with adjustable angle of the present invention is installed on the front side of the box culvert bottom plate, which does not affect the structure and strength of the box culvert body. After the box culvert is moved into place, it can be directly dismantled without increasing the subsequent workload; the adjustable pulley also has the same advantage.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1: Schematic diagram of box culvert jacking construction technology;

FIG2 is a front view of an embodiment of the present invention;

FIG. 3 : A top view of an embodiment of the present invention.

DETAILED DESCRIPTION

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

The construction device for box culvert jacking of the present invention, as shown in FIG. 2 , comprises an adjustable angle bow slope 100 .

The adjustable angle bow slope 100 is installed at the front end of the culvert, and includes a steel bow slope 110, a plurality of jacks 120, and a plurality of connecting members 130 connecting the steel bow slope 110 and the culvert.

Each set of connectors 130 includes a connector 130 fixed to the front vertical plate of the box culvert and a connector 130 fixed to the front end of the box culvert bottom plate directly below. The connectors 130 are preferably installed by pre-embedded or chemical anchor bolts.

See Figure 2. In the jacking direction, the root of the steel bow slope 110 is rotatably connected to the lower connecting piece 130 of each group of connecting pieces 130, the front end of the steel bow slope 110 is rotatably connected to the lower end of the jack 120, the jack 120 is arranged tilted, the upper end of the jack 120 is rotatably connected to the upper connecting piece 130 of each group of connecting pieces 130, and the jack 120, the steel bow slope 110, and the front end of the box culvert form a triangular structure. The triangular structure makes the steel bow slope 110 more resistant to the reaction force of the foundation, making the structure of the entire adjustable angle bow slope 100 more stable. The bottom surface of the steel bow slope 110 installed on the box culvert is tilted upward, forming an inclination angle a with the horizontal plane.

As shown in FIG3 , the width of the steel bow slope 110 is determined according to the width dimension of the cross section of the culvert. Multiple groups of connectors 130 and the same number of jacks 120 are installed at intervals in the width direction of the cross section of the culvert. The embodiment shown in FIG3 is installed with three groups of connectors 130 and three jacks 120.

The rotatable connection between the steel bow slope 110, the jack 120, and the connecting member 130 is preferably achieved by opening a hole on the connected member body or a structure welded on the connected member, and the rotating shaft passes through the hole of the connected member and is axially fixed to realize the hinge between the connected members. As other embodiments, other hinge structures can also be used as long as the connected members can rotate relative to each other.

The steel bow slope 110 is composed of a steel structure support 111 and a steel plate 112 fixed under the support. The steel plate 112 is longer than the steel structure support 111 in the forward direction. The steel plate 112 extends to the bottom of the box culvert to cover the gap between the box culvert bottom plate and the steel structure support 111 to prevent the soil from entering the gap when the box culvert is pushed forward.

FIG. 2 and FIG. 3 show the same embodiment, in which the steel structure support 111 is preferably formed by welding H-shaped steels to each other. Specifically, three short steels are arranged in parallel, and the short steels are connected by two rows of long steels, and a plurality of reinforcing ribs are arranged between the two rows of long steels. The steels are welded to form the steel structure support 111, and a steel plate 112 is fixed below the steel structure support 111.

The jack 120 of the angle-adjustable bow slope 100 is preferably a hydraulic jack and is connected to a hydraulic synchronous control system. The hydraulic synchronous control system is also connected to a jacking system for jacking construction.

During the jacking process of the box culvert, the bottom surface of the adjustable angle bow slope 100 exerts a thrust on the foundation, and is also subjected to the reaction force of the foundation. The inclination angle a of the steel bow slope 110 is automatically adjusted by the hydraulic synchronous control system according to the magnitude of the foundation reaction force. Specifically, the hydraulic synchronous control system controls the jack 120 push rod of the adjustable angle bow slope 100 to push out or retract, and the jack 120 thereby pulls up or lowers the front end of the steel bow slope 110, so that the front end of the steel bow slope 110 rotates around the connecting piece 130 at the root to change the inclination angle a of the steel bow slope 110, thereby preventing the box culvert from being stuck or lifted. Moreover, the hydraulic synchronous control system can calculate and control the change in the length of the jack 120 push rod according to the size of each part of the adjustable angle bow slope 100, so as to accurately reach the target angle to be adjusted for the steel bow slope 110.

As can be seen from the above, the inclination angle a of the adjustable angle bow slope 100 is automatically adjusted according to the size of the foundation reaction force, can respond in time according to the actual situation of the soil layer, and the adjustment action is also very simple. At the same time, it can ensure accurate control of the inclination angle a of the steel bow slope 110.

The construction device for box culvert jacking also includes an adjustable pulley 200 arranged between the top of the box culvert and the horizontal lifting beam of the original line. Several vertical jacks 210 of the adjustable pulley 200 are vertically installed on the top surface of the box culvert. The pulley 220 is installed on the vertical jack 210. The pulley of the pulley 220 faces the horizontal lifting beam above. The spacing and number of the vertical jacks 210 are determined according to the length of the pulley 220. The block 230 is installed on the top of the box culvert and is located in front of the pulley 220 in the jacking direction of the box culvert. The height of the block 230 is greater than that of the pulley 220 to prevent the pulley 220 from moving forward.

The vertical jack 210 of the adjustable pulley 200 is preferably a hydraulic jack and is connected to a hydraulic synchronous control system. The hydraulic synchronous control system controls the push-out and retraction of the top rod of the vertical jack 210 to adjust the height of the adjustable pulley 200 to adapt it to on-site needs.

As shown in the embodiment of FIG. 2 , two vertical jacks 210 are preferably used below the pulley 220 .

The adjustable pulley 200 can avoid the adverse effect of the change of the upper surface position of the box culvert on the original upper line when the box culvert is stuck or lifted.

The construction method of box culvert jacking of the present invention is realized by the following steps:

S1: Install multiple groups of connectors 130 of the adjustable angle bow slope 100. Multiple groups of connectors 130 are installed at intervals in the width direction of the cross section of the culvert, and each group of connectors 130 includes a connector 130 fixed on the vertical plate at the front end of the culvert and a connector 130 fixed at the front end of the bottom plate of the culvert directly below.

S2: A steel bow slope 110 with an adjustable angle bow slope 100 and a plurality of jacks 120 are installed at the front end of the box culvert. The number of jacks 120 is equal to the number of groups of connectors 130. The width of the steel bow slope 110 is determined according to the width dimension of the cross section of the box culvert. In the jacking direction, the root of the steel bow slope 110 is rotatably connected to the lower connector 130 of each group of connectors 130. The front end of the steel bow slope 110 is rotatably connected to the lower end of the jack 120. The jack 120 is arranged obliquely. The upper end of the jack 120 is rotatably connected to the upper connector 130 of each group of connectors 130. The jack 120, the steel bow slope 110, and the front end of the box culvert form a triangular structure. The bottom surface of the steel bow slope 110 installed on the box culvert is tilted upward, forming an inclination angle a with the horizontal plane.

S3: Connecting the multiple jacks 120 of the adjustable angle bow slope 100 to the hydraulic synchronous control system. Connecting each jack 120 to the hydraulic synchronous control system, the hydraulic synchronous control system simultaneously controls the jacking system of the box culvert jacking construction.

S4: Automatically adjust the inclination angle a of the steel bow slope 110. The hydraulic synchronous control system calculates the change in the length of the jack 120 push rod according to the magnitude of the foundation reaction force and the size of each part of the adjustable angle bow slope 100, controls the jack 120 push rod to push out or retract, and the jack 120 pulls up or puts down the front end of the steel bow slope 110, so that the front end of the steel bow slope 110 rotates around the connecting piece 130 at the root, and accurately controls the inclination angle a of the bottom of the steel bow slope 110 to reach the target angle.

The construction method of box culvert jacking of the present invention also includes the following steps:

S5: Install the adjustable pulley 200. A plurality of vertical jacks 210 of the adjustable pulley 200 are installed on the top surface of the box culvert, and the pulley 220 is installed on the vertical jacks 210, the pulley of the pulley 220 faces the upper horizontal lifting beam, the spacing and number of the vertical jacks 210 are determined according to the length of the pulley 220, and a stopper 230 is installed on the top of the box culvert, the stopper 230 is located in front of the pulley 220 in the jacking direction of the box culvert, and the height of the stopper 230 is greater than the pulley 220 to prevent the pulley 220 from moving forward.

S6: Connect the adjustable pulley 200 and the hydraulic synchronous control system. The vertical jack 210 of the adjustable pulley 200 is connected to the hydraulic synchronous control system, and the hydraulic synchronous control system controls the push-out and retraction of the vertical jack 210 to adjust the height of the adjustable pulley 200 to meet the needs of the site.

Specifically, in S1 , the connector 130 may be installed by pre-embedding or chemical anchoring.

The rotatable connection described in S2 is preferably achieved by opening a hole in the connected part itself or in a structure to which the connected part is welded, and the rotating shaft passes through the hole of the connected part and is axially fixed, thereby realizing the hinge between the connected parts.

In S2, the steel bow slope 110 includes a steel structure support 111 and a steel plate 112 fixed under the support. The steel plate 112 is longer than the steel structure support 111 in the forward direction. The steel plate 112 extends to the bottom of the box culvert to cover the gap between the box culvert bottom plate and the steel structure support 111 to prevent the soil from entering the gap when the box culvert is pushed forward.

The steel structure support 111 described in the steps of the above method is preferably made of H-shaped steels welded together. Specifically, a plurality of short steels are arranged in parallel, the short steels are connected by a plurality of rows of long steels, and a plurality of reinforcing ribs are arranged between the rows of long steels. The steels are welded to form the steel structure support 111, and a steel plate 112 is fixed under the steel structure support 111.

The box culvert jacking construction method and construction device of the present invention have the following advantages compared with the adjustable angle steel bow slope in the prior art: the slope of the bow slope can be adjusted timely and automatically according to the actual situation on site; no manual labor is required, saving time and labor; and the adjustment accuracy of the inclination angle of the steel bow slope is relatively high.

In addition, the method and device of the present invention can automatically adjust the slope of the bow slope to prevent the box culvert from getting stuck or rising when it is pushed forward, and at the same time protect the box culvert from getting stuck or rising without damaging the horizontal lifting beam of the original upper line, thus having dual effects and functions.

Furthermore, the steel bow slope with adjustable angle of the present invention is installed on the front side of the box culvert bottom plate, which does not affect the structure and strength of the box culvert body. After the box culvert is moved into place, it can be directly dismantled without increasing the subsequent workload; the adjustable pulley also has the same advantage.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims (2)

1. A construction method for box culvert jacking, characterized in that it comprises the following steps: S1: installing a plurality of groups of connecting members (130) of an adjustable angle bow slope (100); installing a plurality of groups of the connecting members (130) at intervals in the width direction of the cross section of the culvert, each group of the connecting members (130) comprising a connecting member (130) fixed at the front end of the culvert and a connecting member (130) fixed at the front end of the culvert bottom plate directly below; S2: A steel bow slope (110) of the adjustable angle bow slope (100) and a plurality of jacks (120) are installed at the front end of the culvert; the number of the jacks (120) is equal to the number of the connecting members (130); the width of the steel bow slope (110) is determined according to the width of the cross section of the culvert; in the jacking direction, the root of the steel bow slope (110) is rotatably connected to the connecting members (130) below each group of the connecting members (130); The front end of the steel bow ramp (110) is rotatably connected to the lower end of the jack (120), the jack (120) is arranged tilted, the upper end of the jack (120) is rotatably connected to the upper connecting piece (130) of each group of connecting pieces (130), the jack (120), the steel bow ramp (110), and the front end of the culvert form a triangular structure, and the bottom surface of the steel bow ramp (110) installed on the culvert is tilted upward to form an inclination angle (a) with the horizontal plane; S3: connecting the jack (120) to a hydraulic synchronous control system; connecting each of the plurality of jacks (120) of the adjustable angle bow slope (100) to the hydraulic synchronous control system; S4: automatically adjusting the inclination angle (a) of the adjustable angle bow slope (100); the hydraulic synchronous control system calculates the change in the length of the top rod of the jack (120) according to the magnitude of the foundation reaction force, controls the top rod of the jack (120) to be pushed out or retracted, and the jack (120) pulls up or lowers the front end of the steel bow slope (110), so that the front end of the steel bow slope (110) rotates around the connecting piece (130) at the root, and accurately controls the inclination angle (a) of the bottom of the steel bow slope (110) to reach a target angle; The above method is used in conjunction with the following devices: A construction device for jacking a box culvert comprises an adjustable angle bow slope (100), wherein the adjustable angle bow slope (100) is installed at the front end of the box culvert and comprises a steel bow slope (110), a plurality of jacks (120) and a plurality of groups of connectors (130) connecting the steel bow slope (110) and the box culvert, wherein the number of the jacks (120) is the same as the number of groups of the connectors (130), and the plurality of groups of the connectors (130) are installed at intervals in the width direction of the cross section of the box culvert, wherein each group of the connectors (130) comprises a connector (130) fixed at the front end of the box culvert and a connector (130) fixed at the front end of the box culvert bottom plate directly below, and the width of the steel bow slope (110) is adjusted according to the width of the box culvert. The width dimension of the cross section of the culvert is determined; in the jacking direction, the root of the steel bow slope (110) is rotatably connected to the lower connecting piece (130) of each group of connecting pieces (130); the front end of the steel bow slope (110) is rotatably connected to the lower end of the jack (120); the jack (120) is arranged obliquely; the upper end of the jack (120) is rotatably connected to the upper connecting piece (130) of each group of connecting pieces (130); the jack (120), the steel bow slope (110), and the front end of the culvert form a triangular structure; the bottom surface of the steel bow slope (110) installed on the culvert is inclined upward, forming an inclination angle (a) with the horizontal plane; The jack (120) is a hydraulic jack and is connected to a hydraulic synchronous control system for controlling a culvert jacking system, wherein the hydraulic synchronous control system automatically adjusts the inclination angle (a) of the steel bow slope (110) according to the magnitude of the foundation reaction force during the jacking process; It also includes an adjustable pulley (200) arranged between the top of the box culvert and the horizontal lifting beam of the original line. A plurality of vertical jacks (210) of the adjustable pulley (200) are vertically installed on the top surface of the box culvert. A pulley (220) is installed on the vertical jack (210). The pulley of the pulley (220) faces the horizontal lifting beam above. The spacing and number of the vertical jacks (210) are determined according to the length of the pulley (220). A stopper (230) is installed on the box culvert. The top is located in front of the pulley (220) in the jacking direction of the box culvert, the stopper (230) is higher than the pulley (220) and blocks the pulley (220) from moving forward, the vertical jack (210) of the adjustable pulley (200) is a hydraulic jack, and is connected to the hydraulic synchronous control system, and the hydraulic synchronous control system controls the push-out and retraction of the push rod of the vertical jack (210) to adjust the height of the adjustable pulley (200); The rotatable connection is to open a hole on the body of the connected part or on a structure welded on the connected part, and the rotating shaft passes through the hole of the connected part and is axially fixed to realize the hinge between the connected parts; The connecting piece (130) is installed on the box culvert by means of pre-embedded or chemical anchor bolts; The steel bow slope (110) is composed of a steel structure support (111) and a steel plate (112) fixed below the support, wherein the steel plate (112) is longer than the steel structure support (111) in the forward direction, and the steel plate (112) extends to below the bottom plate of the culvert to cover the gap between the bottom plate of the culvert and the steel structure support (111); The steel structure support (111) is formed by welding H-shaped steels together. 2. The box culvert jacking construction method according to claim 1, characterized in that it also includes the following steps: S5: installing an adjustable pulley (200), installing a plurality of vertical jacks (210) of the adjustable pulley (200) on the top surface of the box culvert, installing a pulley (220) on the vertical jack (210), the pulley of the pulley (220) facing the upper horizontal lifting beam, the spacing and number of the vertical jacks (210) determined according to the length of the pulley (220), installing a stopper (230) on the top of the box culvert, the stopper (230) being higher than the pulley (220), and the stopper (230) being located in front of the pulley (220) in the jacking direction of the box culvert to block the pulley (220) from moving forward; S6: Connecting the vertical jack (210) to the hydraulic synchronous control system, wherein the vertical jack (210) of the adjustable pulley (200) is connected to the hydraulic synchronous control system, and the hydraulic synchronous control system controls the push-out and retraction of the top rod of the vertical jack (210) to adjust the height of the adjustable pulley (200).