A high-position beam falling construction method suitable for high-speed railway prefabricated box girder erection

Abstract

The application provides a high-position beam falling construction method suitable for high-speed railway prefabricated box girder erection, comprising the following steps: pouring pile foundation and concrete enlarged foundation construction; erecting steel pipe support on the enlarged foundation; side pier top reinforced concrete temporary support and steel pipe temporary support construction; prefabricated box girder erection; bridge erecting machine retreat and removal, side pier top reinforced concrete temporary support removal; pouring continuous beam side span straight section and closure section; prefabricated box girder overall jacking, including gradually jacking the prefabricated box girder to a certain height through cushion beam and multiple jacks; side pier top steel pipe temporary support removal; side span closure section prestress tensioning and grouting; side pier approach bridge side high end pier cap and cushion stone concrete pouring, side pier approach bridge side permanent support installation, approach bridge pier permanent support installation; beam falling in place, beam falling equipment and steel pipe support removal. The application solves the prefabricated box girder temporary storage problem, the bridge erecting machine can retreat and be removed in advance, and the rental cost of the bridge erecting machine in the construction process can be reduced.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of precast box girder construction, and particularly relates to a high-position beam falling construction method suitable for precast box girder erection of high-speed railway. BACKGROUND

[0002] The combination of continuous beam and precast beam is a common way of bridge span arrangement in bridge engineering. Since the design of the side span of the continuous beam adopts the tensioning mode at both ends, the precast box girder adjacent to the continuous beam requires to be erected after the longitudinal prestress tensioning of the closure section of the continuous beam side span is completed. When the construction time of the two is quite different, if the bridge erecting machine is not timely removed, the rental cost of the bridge erecting machine will be greatly increased. Therefore, in the actual construction process, it is necessary to consider removing the bridge erecting machine in advance to reduce the rental cost of the bridge erecting machine. SUMMARY

[0003] In order to solve the problems of the prior art, the present application provides a high-position beam falling construction method suitable for precast box girder erection of high-speed railway, which solves the problem of temporary storage of the precast box girder by erecting steel pipe supports and temporary steel pipe piers, and the bridge erecting machine can be retreated and removed in advance, so that the rental cost of the bridge erecting machine in the construction process can be reduced.

[0004] To achieve the above object, the technical scheme of the present application is as follows:

[0005] A high-position beam falling construction method suitable for precast box girder erection of high-speed railway, comprising the following construction steps:

[0006] S1, pouring pile foundation and concrete enlarged foundation construction;

[0007] S2, erecting steel pipe supports on the enlarged foundation and installing longitudinal beams, transverse beams and steel pad blocks on the top of the steel pipe supports;

[0008] S3, side pier top steel pipe temporary pier construction and side pier top reinforced concrete temporary pier construction;

[0009] S4, precast box girder erection, including in-situ beam falling of the bridge erecting machine and the beam hoisting trolley to make one end of the precast box girder support on the steel pad pillow laid on the approach bridge pier support cushion stone and the other end support on the side pier top steel pipe temporary pier;

[0010] S5, retreat and remove the bridge erecting machine and remove the side pier top reinforced concrete temporary pier;

[0011] S6, pouring the straight section and closure section of the continuous beam side span;

[0012] S7, precast box girder overall jacking, including gradually jacking the precast box girder to a certain height by the cushion beam and multiple jacks;

[0013] S8, remove the edge pier top steel pipe temporary support;

[0014] S9, prestressed tension and grouting of the edge span closure section;

[0015] S10, pouring of the edge pier approach bridge side high end pier cap and cushion stone, installation of the edge pier approach bridge side permanent support, and installation of the approach bridge pier permanent support;

[0016] S11, installation of the fallen beam, and removal of the fallen beam equipment and steel pipe support.

[0017] Further, step S1 specifically comprises:

[0018] S11, drilling into a hole by using impact drilling and rotary drilling methods;

[0019] S12, installation of the pile foundation steel reinforcement cage;

[0020] S13, pouring of the underwater concrete of the pile foundation, and completion of the pile foundation construction;

[0021] S14, installation of the expanded foundation steel reinforcement;

[0022] S15, installation of the expanded foundation top surface embedded steel plate, with the center (support column steel pipe pile) of the embedded steel plate corresponding to the center of the bored pile;

[0023] S16, installation of the expanded foundation formwork;

[0024] S17, pouring of the expanded foundation concrete;

[0025] Further, step S2 specifically comprises:

[0026] S21, vertical steel pipe column installation of the steel pipe support by manual cooperation with a crane, with welding connection between the bottom of the steel pipe column and the embedded steel plate on the top surface of the expanded foundation;

[0027] S22, welding of scissors between the double-row steel pipe columns to form a stable lattice structure of the double-row steel pipe pile, with multiple groups of the vertically arranged scissors;

[0028] S23, installation of the steel pipe support top end longitudinal beam, with welding connection between the longitudinal beam and the steel pipe support column;

[0029] S24, installation of the cross beam on the top of the longitudinal beam, with welding connection between the cross beam and the longitudinal beam;

[0030] S25, installation of the profiled steel cushion block on the top of the cross beam.

[0031] Further, 3 steel pipe supports are arranged outside the side pier cap, with a center distance of 2.0 m and a distance of 0.85 m from the edge of the cap. Steel pipe pile expanded foundations are arranged on the top surface of the side pier cap and the top surface of the bored pile, with a thickness of 60 cm. The top surface of the two is kept consistent, and C25 reinforced concrete is used.

[0032] Further, step S3 specifically includes:

[0033] S31, a pre-buried steel plate is installed on the top of the side pier cap, and the pre-buried steel plate is anchored in the cap concrete;

[0034] S32, a temporary support steel pipe column is installed on the top of the side pier, and the bottom of the steel pipe column is welded with the pre-buried steel plate, and the top surface of the column is supported on the bottom surface of the pre-buried steel plate of the bottom of the precast box girder;

[0035] S33, a reinforced concrete temporary support steel bar is installed, and the steel bar is welded and connected with the cap steel bar;

[0036] S34, a reinforced concrete temporary support formwork is installed;

[0037] S35, reinforced concrete temporary support concrete is poured.

[0038] Further, the total of two steel pipe temporary supports on the left and right is Φ820x16mm; the height of the reinforced concrete temporary support is 3.5m, and the total of two on the left and right is 2.

[0039] Further, step S4 specifically includes:

[0040] S41, the bridge erecting machine is in place, the front support leg is supported on the two reinforced concrete temporary supports on the top of the side pier, the rear support leg is supported on the precast box girder in the erected hole, and the front end of the guide beam is suspended by a crane;

[0041] S42, the precast box girder is moved forward to the design position of the hole to be erected by using a beam hoist;

[0042] S43, the beam is in place in situ, one end is supported on a steel cushion pillow laid on the approach bridge pier support cushion stone, and the other end is supported on the steel pipe temporary support on the top of the side pier.

[0043] Further, step S7 specifically includes:

[0044] S71, a cushion beam and a jacking jack are installed;

[0045] S72, the jacking jack and the cushion beam are constructed alternately, and a synchronous control method is used to control multiple jacks to gradually jack up the precast box girder by 1.5m.

[0046] Further, step S10 specifically includes:

[0047] S101, the top surface of the side pier approach bridge side cap is chiseled.

[0048] S102, the high end pier cap steel bar of the side pier approach bridge side is installed;

[0049] S103, the high end pier cap formwork of the side pier approach bridge side is installed;

[0050] S104, the high end pier cap concrete of the side pier approach bridge side is poured;

[0051] S105, the side pier approach bridge side support pad stone steel bar is installed;

[0052] S106, the side pier approach bridge side support pad stone formwork is installed;

[0053] S107, the side pier approach bridge side support pad stone concrete is poured;

[0054] S108, the side pier approach bridge side permanent support is hoisted in place, and the approach bridge pier permanent support is hoisted in place;

[0055] S109, the formwork around the permanent support is installed;

[0056] S110, the side pier approach bridge side permanent support anchor bolt hole grouting and the approach bridge pier permanent support anchor bolt hole grouting are carried out.

[0057] Further, step S11 specifically comprises:

[0058] S111, the jack lifting and the cushion beam are alternately constructed, and the type steel cushion block is removed layer by layer;

[0059] S112, the jack is lowered, and the precast box girder is lowered to the position;

[0060] S113, the side pier approach bridge side permanent support and the approach bridge pier permanent support anchor bolt are installed;

[0061] S114, the beam falling equipment is removed;

[0062] S115, the steel pipe support is removed.

[0063] The beneficial effects of the present application are:

[0064] 1, the present application solves the problem of temporary storage of precast box girder by erecting steel pipe support and steel pipe temporary support pier, the bridge erecting machine can be retreated and removed in advance, so as to reduce the rental cost of the bridge erecting machine in the construction process.

[0065] 2, in the present application, the high end pier cap and the pad stone concrete of the side pier approach bridge side are constructed, which solves the problem of the conflict between the steel strand tensioning of the lower half part of the continuous beam and the position of the high end pier cap of the side pier.

[0066] 3, in the present application, the precast box girder is lifted by 1.5m, which solves the problem of the conflict between the steel strand tensioning of the upper half part of the continuous beam and the position of the precast box girder.

[0067] 4. In this invention, the steel pipe pile support outside the side pier cap adopts a bored cast-in-place pile foundation, with a total of 3 piles in one row, a center-to-center spacing of 2.0m, and a distance of 0.85cm from the edge of the cap. The rock embedment depth of the pile bottom meets the specification requirements, ensuring that the foundation bearing capacity meets the requirements; both the top surface of the side pier cap and the top surface of the bored cast-in-place piles are equipped with expanded foundations of steel pipe pile columns for beam support, avoiding uneven settlement problems in the double-row steel pipe pile support.

[0068] 5. In this invention, two temporary steel pipe supports are set on the top of the side piers, one on each side, using Φ820×16mm steel pipes. This solves the problem of ensuring that the temporary support points are located in the permanent support positions when the precast box girder is stored for a long time, making the stress on the precast box girder more reasonable during long-term storage. Two reinforced concrete temporary supports are set on the top of the side piers, with a height of 3.5m, one on each side. This solves the problem of supporting the bridge erecting machine's front guide beam during the erection of the precast box girder when the construction of the high-end pier cap and pad stone concrete on the side approach bridge is delayed.

[0069] 6. In this invention, a multi-layered steel support beam is set up, which works in conjunction with the jack to gradually lower and lift the beam, thus solving the problem of limited single lifting stroke of the jack. Attached Figure Description

[0070] Appendix Figure 1 This is a schematic diagram of the construction process of the present invention.

[0071] Appendix Figure 2 This is a front view of the temporary support structure during the box girder erection stage of the present invention.

[0072] Appendix Figure 3 This is a side view of the temporary support structure during the box girder erection stage of the present invention.

[0073] Appendix Figure 4 This is a front view of the temporary support structure during the box girder lowering stage of the present invention.

[0074] Appendix Figure 5 This is a side view of the temporary support structure during the box girder lowering stage of the present invention. Detailed Implementation

[0075] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0076] This invention provides a high-level beam-lowering construction method suitable for the erection of precast box girders in high-speed railways. By erecting steel pipe supports and employing the high-level beam-lowering method, the bridge erecting machine can be dismantled earlier. This construction method not only reduces bridge erecting machine rental costs but also ensures rapid, efficient, and safe construction.

[0077] refer to Figures 2-5 This is a partial structural diagram of the box girder construction process of the present invention.

[0078] The high-level beam lowering construction method of the present invention is mainly implemented by the following construction steps.

[0079] (1) Construction of bored pile foundation

[0080] ① Drilling is carried out using methods such as impact drilling and rotary drilling;

[0081] ②Install the pile foundation reinforcement cage;

[0082] ③ Pour underwater concrete into the pile foundation to complete the pile foundation construction.

[0083] like Figure 2 , 3 As shown, the diameter of the bored pile 8 is D=1.0m.

[0084] (2) Construction of concrete spread foundation

[0085] ① Install the reinforcement bars for the enlarged foundation;

[0086] ② Install the pre-embedded steel plate on the top surface of the enlarged foundation, with the center of the pre-embedded steel plate (support column steel pipe pile) corresponding to the center of the bored pile 8;

[0087] ③ Install the expanded foundation template;

[0088] ④ Pour the enlarged foundation concrete.

[0089] like Figure 2 , 3 As shown, the enlarged foundation 9 is constructed through the above steps. The top surface of the pier 3 cap and the top surface of the bored piles 8 are both equipped with steel pipe pile enlarged foundations 9 for beam support columns to avoid uneven settlement of the double-row steel pipe pile support. The foundation thickness is 60cm, and the top surface height of both is consistent. C25 reinforced concrete is used.

[0090] (3) Erection of 10 steel pipe supports

[0091] ① The vertical steel pipe columns of the steel pipe support 10 are installed manually with the help of a crane. The bottom of the steel pipe column is welded to the pre-embedded steel plate on the top surface of the enlarged foundation 9.

[0092] The two rows of steel pipe columns are welded with scissors braces to form a stable lattice structure, and the scissors braces are vertically arranged in three groups.

[0093] (4) Installation of the top longitudinal beam 11, the cross beam 12 and the steel pad 13 of the steel pipe support 10

[0094] ① The top longitudinal beam 11 of the steel pipe support 10 is installed, and the longitudinal beam 11 is welded with the column of the steel pipe support 10;

[0095] ② The cross beam 12 is installed on the top of the longitudinal beam 11, and the cross beam 12 is welded with the longitudinal beam 11;

[0096] ③ The steel pad 13 is installed on the top of the cross beam 12.

[0097] As shown in Figure 3 , in the present embodiment, the steel pipe pile support outside the bearing platform of the side pier 3 adopts a bored pile foundation, and a total of 3 piles are arranged in one row with a center distance of 2.0 m and a distance of 0.85 cm from the edge of the bearing platform, and the rock-embedding depth of the pile bottom meets the specification requirements to ensure that the foundation bearing capacity meets the requirements.

[0098] (5) Construction of the steel pipe temporary support 7 on the top of the side pier 3

[0099] ① The embedded steel plate is installed on the pier cap top of the side pier 3, and the embedded steel plate is anchored in the pier cap concrete;

[0100] ② The steel pipe column of the temporary support of the side pier 3 is installed, and the bottom of the steel pipe column is welded with the embedded steel plate, and the top surface of the column is supported on the bottom surface of the embedded steel plate of the bottom of the prefabricated box girder 1.

[0101] As shown in Figure 2 , the steel pipe temporary support 7 is arranged on the top of the side pier 3, and a total of 2 are arranged on the left and right, which are made of Φ820x16mm steel pipes, which solves the problem that when the prefabricated box girder 1 is stored for a long time, the temporary support point can be located at the permanent support position, so that the stress during the long-term storage of the prefabricated box girder 1 is more reasonable.

[0102] (6) Construction of the steel reinforced concrete temporary support 4 on the top of the side pier 3

[0103] ① The steel reinforcement of the steel reinforced concrete temporary support is installed, and the steel reinforcement is welded with the steel reinforcement of the pier cap;

[0104] ② The formwork of the steel reinforced concrete temporary support is installed;

[0105] ③ The concrete of the steel reinforced concrete temporary support is poured.

[0106] As shown in Figure 1As shown, in this embodiment, the steel reinforced concrete temporary support 4 is arranged on the top of the side pier 3, with a height of 3.5 m, and a total of 2 on the left and right sides, which solves the problem of the support of the front girder of the bridge erecting machine 5 during the erection of the precast box girder 1 when the concrete of the high end pier cap and the abutment stone of the side pier 3 of the approach bridge is constructed with a delay.

[0107] (7) In-situ falling of the precast box girder 1 (as shown in Figure 1

[0108] ① The bridge erecting machine 5 is positioned, with the front support legs supported on the two steel reinforced concrete temporary supports 4 and the rear support legs supported on the precast box girder 1 of the hole that has been erected, and the front end of the guide beam is suspended with the assistance of a crane;

[0109] ② The precast box girder 1 is moved forward to the design position of the hole to be erected by using the beam hoist;

[0110] ③ The in-situ falling of the precast box girder 1 is completed, with one end supported on the steel pad pillow laid on the abutment stone of the pier 2 support of the approach bridge and the other end supported on the steel pipe temporary support 7 on the top of the side pier 3, and the steel pipe support system is not stressed at this stage.

[0111] (8) Retreating of the bridge erecting machine 5 and removal thereof

[0112] ① The bridge erecting machine 5 is retreated to the precast girder field and removed;

[0113] ② The steel reinforced concrete temporary support 4 on the top of the side pier 3 is removed.

[0114] (9) Construction of the straight section of the side span of the continuous girder 6

[0115] ① Erection of the support of the straight section of the side span and preloading thereof;

[0116] ② Installation of the permanent support of the main bridge side of the side pier 3;

[0117] ③ Installation of the formwork and reinforcement of the straight section of the side span and pouring of concrete.

[0118] (10) Construction of the closure section of the side span of the continuous girder 6

[0119] ① Installation of the hanging support system of the closure section of the side span;

[0120] ② Installation of the formwork and reinforcement of the closure section of the side span;

[0121] ③ Installation of the rigid framework of the closure section of the side span;

[0122] ④ Pouring of concrete of the closure section of the side span.

[0123] (11) Overall lifting of the precast box girder 1 by 1.5 m

[0124] ① Installation of the cushion beam and the lifting jack 14;

[0125] ​②Jack 14 jacking and cushion beam alternate construction, using intelligent synchronous control system, control 4 sets of 300t jack 14 will be gradually jacking 1.5m prefabricated box girder 1.

[0126] In this embodiment, the multi-layer type steel cushion beam is arranged, which cooperates with the jack to gradually fall and jacking, solves the problem of limited single jacking stroke of the jack, and the intelligent synchronous control system is used for centralized control of the prefabricated box girder jacking, solves the problem of synchronous overall jacking of the four jacks. The overall jacking of the prefabricated box girder is 1.5m, which solves the problem of position conflict between the steel strand tensioning in the upper half region of the continuous beam and the prefabricated box girder.

[0127] (12) Remove the side pier steel pipe temporary support 7

[0128] ①Remove the vertical column steel pipe of the temporary support 7 on the top of the side pier;

[0129] ②Remove the embedded steel plate on the pier cap top.

[0130] (13) Prestressed tensioning and grouting of the side span closure section

[0131] ①Prestressed tensioning of the side span closure section;

[0132] ②Prestressed grouting of the side span closure section.

[0133] (14) Concrete pouring of the high-end pier cap and cushion stone on the approach bridge side of the side pier 3

[0134] ①Chasing on the top surface of the pier cap on the approach bridge side of the side pier 3;

[0135] ②Reinforcement installation of the high-end pier cap on the approach bridge side of the side pier 3;

[0136] ③Formwork installation of the high-end pier cap on the approach bridge side of the side pier 3;

[0137] ④Concrete pouring of the high-end pier cap on the approach bridge side of the side pier 3;

[0138] ⑤Reinforcement installation of the bearing cushion stone on the approach bridge side of the side pier 3;

[0139] ⑥Formwork installation of the bearing cushion stone on the approach bridge side of the side pier 3;

[0140] ⑦Concrete pouring of the bearing cushion stone on the approach bridge side of the side pier.

[0141] In this embodiment, the concrete of the high-end pier cap and cushion stone on the approach bridge side of the side pier is constructed in a lagging manner, which solves the problem of position conflict between the steel strand tensioning in the lower half region of the continuous beam and the high-end pier cap on the approach bridge side of the side pier.

[0142] (15) Installation of the permanent bearing on the approach bridge side of the side pier 3

[0143] ①Hoisting and positioning of the permanent bearing on the approach bridge side of the side pier 3;

[0144] ②Formwork installation around the permanent bearing;

[0145] ③Girder pier 3 approach bridge side permanent support anchor hole grouting.

[0146] (16) Install approach bridge pier 2 permanent support

[0147] ① Approach bridge pier 2 permanent support hoisting in place;

[0148] ② Permanent support around the form installation;

[0149] ③ Approach bridge pier 2 permanent support anchor hole grouting.

[0150] (17) Beam in place

[0151] ① Jack 14 jacking and cushion beam alternate construction, complete the type steel cushion block 13 layer by layer removal;

[0152] ② Jack 14 back down, complete the precast box girder 1 beam in place;

[0153] ③ Pier approach bridge side permanent support and approach bridge pier permanent support anchor bolt installation.

[0154] (18) Remove beam equipment and steel pipe support 10

[0155] ① Remove beam equipment;

[0156] ② Remove steel pipe support 10.

[0157] Through the above construction steps of the embodiment, by erecting steel pipe support 10 and steel pipe temporary support pier 7, the temporary storage problem of the precast box girder 1 is solved, the launching gantry 5 can be retreated and removed in advance, so that the rental cost of the launching gantry 5 in the construction process can be reduced, and the specific construction method provided by the embodiment is safe and reliable in construction and high in efficiency.

Claims

1. A high-position beam dropping construction method suitable for high-speed railway prefabricated box girder erection, characterized in that, The construction steps include: S1, construction of the cast-in-place pile foundation and the concrete enlarged foundation; S2, erecting the steel pipe support on the enlarged foundation and installing the longitudinal beam, the cross beam and the steel pad on the top of the steel pipe support; S3, construction of the temporary support of the steel pipe on the top of the side pier and construction of the temporary support of the reinforced concrete on the top of the side pier; S4, erection of the precast box girder, including in-situ beam placement by the bridge erecting machine and the beam lifting crane, with one end supported on the steel pad pillow laid on the top surface of the pillow stone of the pier abutment of the approach bridge and the other end supported on the temporary support of the steel pipe on the top of the side pier; S5, retreat of the bridge erecting machine and removal of the temporary support of the reinforced concrete on the top of the side pier; S6, pouring of the straight section and the closure section of the side span of the continuous girder; S7, integral jacking of the precast box girder, including gradual jacking of the precast box girder to a certain height by the cushion beam and multiple jacks; S8, removal of the temporary support of the steel pipe on the top of the side pier; S9, prestress tensioning and grouting of the closure section of the side span; S10, pouring of the concrete of the side pier cap and the pillow stone of the side pier of the approach bridge, installation of the permanent support of the side pier of the approach bridge and installation of the permanent support of the pier of the approach bridge; S11, in-situ beam placement and removal of the beam placement equipment and the steel pipe support.

2. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, The step S1 specifically includes: S11, drilling into a hole by the impact drill and the rotary drill; S12, installation of the pile reinforcement cage; S13, underwater pouring of the concrete of the pile foundation, thus completing the construction of the pile foundation; S14, installation of the reinforcement of the enlarged foundation; S15, installation of the embedded steel plate on the top surface of the enlarged foundation, with the center of the embedded steel plate corresponding to the center of the cast-in-place pile; S16, installation of the formwork of the enlarged foundation; S17, pouring of the concrete of the enlarged foundation.

3. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, The step S2 specifically includes: S21, installation of the vertical steel pipe column of the steel pipe support by manual cooperation with the crane, with the bottom of the steel pipe column welded to the embedded steel plate on the top surface of the enlarged foundation; S22, welding of the scissors brace between the double-row steel pipe columns, so that the double-row steel pipe columns form a stable lattice structure, with multiple groups of the scissors brace vertically arranged; S23, installation of the longitudinal beam at the top of the steel pipe support, with the longitudinal beam welded to the column of the steel pipe support; S24, installation of the cross beam on the top of the longitudinal beam, with the cross beam welded to the longitudinal beam; S25, installation of the steel pad on the top of the cross beam.

4. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 3, characterized in that, One row of three steel pipe columns is arranged outside the side pier pile cap, with a center distance of 2.0 m and a distance of 0.85 m from the edge of the pile cap, the top surface of the side pier pile cap and the top surface of the cast-in-place pile are both provided with the beam placement support column steel pipe pile enlarged foundation, the thickness of the foundation is 60 cm, the top surface height of the two is kept consistent, and C25 reinforced concrete is adopted.

5. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, The step S3 specifically includes: S31, installation of the embedded steel plate on the top of the side pier cap, with the embedded steel plate anchored in the concrete of the cap; S32, installation of the steel pipe column of the temporary support on the top of the side pier, with the bottom of the steel pipe column welded to the embedded steel plate and the top surface of the column supported on the bottom surface of the embedded steel plate on the bottom of the precast box girder; S33, installation of the reinforcement of the temporary support of the reinforced concrete, with the reinforcement welded to the reinforcement of the cap; S34, installation of the formwork of the temporary support of the reinforced concrete; S35, pouring of the concrete of the temporary support of the reinforced concrete.

6. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, The steel pipe temporary support is composed of two steel pipes with a diameter of Φ820x16 mm, and the temporary support of the reinforced concrete is composed of two temporary supports with a height of 3.5 m.

7. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, The step S4 specifically includes: S41, the bridge machine is in place, the front support leg is supported on the two reinforced concrete temporary support piers on the pier top, the rear support leg is supported on the prefabricated box girder of the hole, and the front end of the guide beam is suspended by a crane; S42, the prefabricated box girder is moved forward to the design position of the hole to be erected by using the beam hoist; S43, the beam is lowered in place, one end is supported on the steel pad pillow laid on the pier support cushion stone of the approach bridge, and the other end is supported on the steel pipe temporary support pier on the pier top.

8. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, Step S7 specifically includes: S71, install the cushion beam and the jack; S72, jack up and alternate construction with the cushion beam, and use a synchronous control method to control multiple jacks to gradually jack up the prefabricated box girder by 1.5 m.

9. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, Step S10 specifically includes: S101, chisel the top surface of the pier cap on the side pier of the approach bridge; S102, install the steel reinforcement of the high-end pier cap on the side pier of the approach bridge; S103, install the formwork of the high-end pier cap on the side pier of the approach bridge; S104, pour concrete for the high-end pier cap on the side pier of the approach bridge; S105, install the steel reinforcement of the bearing cushion stone on the side pier of the approach bridge; S106, install the formwork of the bearing cushion stone on the side pier of the approach bridge; S107, pour concrete for the bearing cushion stone on the side pier of the approach bridge; S108, hoist and place the permanent support of the side pier of the approach bridge and the permanent support of the pier of the approach bridge; S109, install the formwork around the support; S110, grout the anchor bolt hole of the permanent support on the side pier of the approach bridge and the permanent support of the pier of the approach bridge.

10. The high-position beam dropping construction method suitable for the erection of a prefabricated box girder of a high-speed railway according to claim 1, characterized in that, Step S11 specifically includes: S111, jack up and alternate construction with the cushion beam, and complete the layer-by-layer removal of the steel pad block; S112, jack down, and complete the beam lowering of the prefabricated box girder; S113, install the anchoring bolt of the permanent support on the side pier of the approach bridge and the permanent support of the pier of the approach bridge; S114, remove the beam lowering equipment; S115, remove the steel pipe support.

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