Midspan beam section segmental beam rapid assembly structure and construction method

Abstract

The invention discloses a midspan beam section segmental beam rapid assembly structure and a construction method, and particularly relates to the technical field of on-site assembly of segmental girders.The midspan beam section segmental beam rapid assembly structure comprises segmental beams with multiple sets of pre-stressed pipelines reserved, notches are reserved in one ends of the segmental beams, anchor bearing plates are pre-buried in the notches, pre-stressed pipeline holes and built-in slurry holes are reserved in the anchor bearing plates, and the pre-stressed pipeline holes and the built-in slurry holes are formed in the anchor bearing plates; a through-wall hole is reserved in the inner side wall of the notch; during grouting, hoisting and splicing of the next section of beam are not affected, the construction sections are connected end to end, and an anchor head does not need to be blocked during grouting; in addition, an external slurry hole can be reserved in the side wall of the notch at one end, the internal slurry hole penetrates out of the through-wall hole, hoisting and splicing of the next section of beam are not affected during slurry jacking, and slurry jacking can be conducted on the prestressed pipeline hole and the notch space in a staged mode. The construction method provided by the invention is convenient, the construction quality is more reliable, the sequential construction of section-by-section installation and section-by-section mud jacking is adjusted into a parallel construction method of section-by-section installation and section-by-section mud jacking, the construction efficiency is greatly improved, and the construction period is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of on-site assembly construction of bridge segment beams, and specifically to a structure and construction method for rapid assembly of mid-span beam segments of segment beams. Background Technique

[0002] The precast segment assembly method is a construction method in which bridge segments are precast in a precast factory and then transported to the site one by one, hoisted to a predetermined position in a cantilever, span-by-span or progressive manner, and then prestressed to connect the segments into a whole. Finally, the pier top or mid-span wet joint is cast in-situ by means of a suspended formwork to complete the construction of the bridge. The main construction methods include the cantilever assembly method and the span-by-span assembly method.

[0003] The mid-span beam segment installation is constructed by adopting the balanced "T" structure symmetric cantilever assembly method, including the steps of: inspection, cleaning and installation preparation of the beam segment precast yard; shipment of the beam segment; simultaneous hoisting of the first pair of beam segments to the predetermined position by two hoisting trolleys of the bridge girder erection machine; trial assembly of the beam segment; application of an epoxy resin adhesive layer; precise positioning of the first pair of beam segments; tensioning of temporary prestress; curing of the adhesive layer until solidification; tensioning of permanent internal prestressed tendons; vacuum grouting of the prestressed duct; sealing of the anchor; longitudinal prestress end sealing; unhooking of the hoisting trolley and preparation for hoisting the next pair of beam segments. Among them, the application of the epoxy resin adhesive layer includes: cleaning the splicing surface → trial assembly and adjustment of the segment → preparation of epoxy resin → application → splicing of the segment beam → scraping and cleaning of the glue.

[0004] After the strength of the epoxy resin reaches the design requirements, the cantilever erection prestressed tendons are tensioned. The prestress construction process: preparation work - inspection of steel strands, anchorages and wedges - cutting of steel strands → threading → installation of jacks → intelligent tensioning.

[0005] Among them, the main procedure of vacuum grouting of the prestressed duct is: after tensioning, cut the redundant steel strands with a grinding wheel cutting machine, and the remaining length of the steel strands is 3 - 5 cm. After the steel strands are cut off, the anchor heads to be grouted are blocked with cement mortar in time to ensure dense sealing of the anchor. Grouting is carried out within 48 hours after tensioning. The vacuum grouting technology is adopted. After the vacuum grouting of the prestressed duct is completed, longitudinal prestress end sealing is carried out.

[0006] The deep-buried anchor design is adopted, and the longitudinal prestress tensioning notch is relatively large. After grouting is completed, end sealing treatment should be carried out in time. The existing end sealing process: installation of end sealing formwork; pouring of concrete. The end sealing concrete uses C50 compensated shrinkage concrete, and is vibrated densely with a vibrating rod during pouring, flush with the beam end face, and the offset of the end sealing concrete from the beam body concrete at each place does not exceed 5 mm. The end sealing concrete should be cured in time after pouring.

[0007] The longitudinal prestressed tension notch is located between the assembly surfaces of two segment beams. At present, the two processes of vacuum grouting of prestressed ducts and sealing the end of the longitudinal prestressed tension notch seriously affect the progress of segment beam assembly work. In particular, the curing after the casting of the end sealing concrete also seriously affects the construction period. The commonly used method for segment beam assembly at present is the sequential operation method of tensioning, grouting, and installing one by one. All three processes are on the critical path. The end sealing concrete uses C50 shrinkage-compensating concrete, and there are also difficulties in casting, small usage per time, difficult mixing, and uneven end sealing surface, which affect the matching installation between segment beams. Summary of the Invention

[0008] In order to solve the problems in the construction process of existing segment beams, the present invention provides: a structure for rapid assembly of segment beams in the mid-span beam segment, including segment beams with multiple groups of prestressed ducts reserved. At one end of each segment beam, a notch is reserved. An anchor backing plate is embedded inside the notch, and prestressed duct holes and internal slurry holes are reserved on the anchor backing plate. Through holes are reserved on the inner side wall of the notch; A circumferential small groove is arranged on the outer side of the notch opening. A ring-shaped aluminum alloy sheet is buried at the corresponding position of the groove on the matching segment beam. The depth of the small groove is 3 - 4 cm, and the aluminum alloy sheet protrudes 2 cm from the plane of the segment beam.

[0009] Based on this structure, the present invention provides a construction method for rapid assembly of segment beams in the mid-span beam segment, including the following steps: S1. Use a bridge erection machine to hoist multiple segment beams, where the multiple segment beams include the Nth pier top segment block; S2. Adopt the symmetric cantilever assembly method to symmetrically hoist the N + 1th and N - 1th segment beams to both ends of the Nth segment; S3. Perform glue bonding treatment on the hoisted segment beams; after completion, carry out steel strand threading and prestressed tensioning; S4. Continue to hoist the symmetric outer segment beams and glue-bond them with the inner segment. After the glue bonding is completed, connect the grouting machine to the through hole at one end of the inner segment that has completed step S3, and connect the other through hole to the vacuum pump, and start the grouting operation; S5. Repeat steps S3 - S4. It should be noted that multiple groups of prestressed ducts are reserved inside the segment beams, and the steel strands are correspondingly threaded between different segment beams in the construction section to complete the construction of this construction section.

[0010] On the basis of the above structure, a plastic pipe for the slurry hole can also be built-in and extended, passed through the wall-piercing hole, and a valve is installed at the outer end of the plastic pipe; an external slurry hole is reserved on the side wall of the notch. The external slurry hole includes a first slurry hole and a second slurry hole. The first slurry hole is arranged at the bottom inside the notch, and the second slurry hole is arranged at the top inside the notch. Both the first slurry hole and the second slurry hole are connected with transparent steel wire pipes, and valves are installed at the outer ends of the transparent steel wire pipes. On the basis of this structure, the present invention also provides a construction method for rapid assembly of segmental beams in the mid-span beam segment, including the following specific steps: S1. Use a bridge erecting machine to hoist multiple segmental beams, where the multiple segmental beams include the Nth pier top segment block; S2. Adopt the symmetric cantilever assembly method to symmetrically hoist the N + 1th and N - 1th segmental beams to both ends of the Nth segment; S3. Carry out glue splicing treatment on the hoisted segmental beams; after completion, carry out steel strand threading and prestress tensioning; S4. Use cement mortar to seal the anchor heads that need to be grouted, and use epoxy resin glue to seal the gap between the wall-piercing hole and the plastic pipe. After sealing, the built-in slurry holes, plastic pipes, prestressed pipe holes, and prestressed pipes at both ends of the construction section form a fully enclosed space. Hoist the symmetrically arranged outer segmental beams and carry out glue splicing with the inner segmental beams. After glue splicing is completed, a closed space is formed at the notch of the inner construction section; Connect the grouting machine to the plastic pipe passing through the wall-piercing hole at one end of the inner segment that has completed step S3, and connect the plastic pipe passing through the wall-piercing hole at the other end to the vacuum pump, and start the grouting operation; S5. Repeat steps S3 - S4 until the segment splicing and grouting operation of the prestressed pipes within the construction section are completed; S6. Carry out grouting operation on the closed space formed at the notch. Specifically, connect the transparent steel wire pipe of the first slurry hole at one end of the notch at the head of the segment that needs to be grouted to the grouting machine, connect the second slurry hole in the middle end to end with the first slurry hole of the next segment, and connect the second slurry hole at the tail of the segment to the vacuum pump, and start the grouting operation to finally complete the construction of the construction section.

[0011] Further, the glue splicing treatment is specifically as follows: Clean the joint surface, paste the sealing ring, mix the glue, and apply the glue in sequence on the joint surface; during installation, fill epoxy resin in the groove, and the groove fits tightly with the aluminum alloy sheet.

[0012] Further, the specific steps of the above-mentioned grouting operation are as follows: Step 1. Start the vacuum pump to make the vacuum degree of the channel reach -0.08~-0.1MPa and keep it stable; Step 2. Start the grouting machine, control the grouting pressure at 0.5~0.7Mpa, and carry out the grouting operation. During the grouting process, the vacuum pump keeps working continuously; Step 3: When there is slurry passing through the air filter of the vacuum pump, close the valve at the front end of the air filter, and then open the exhaust valve. When the cement slurry flows out smoothly from the exhaust valve and its consistency is the same as that of the injected slurry, close all the valves at the vacuum extraction end and perform pressure stabilization. The pressure stabilization pressure shall not be less than 0.5 Mpa, and the pressure stabilization time shall be 3 - 5 minutes. If the pressure of the slurry does not drop during pressure stabilization, then close the grouting machine and the valves at the grouting end to complete the grouting. Step 4: Before the cement slurry loses its fluidity, disassemble the external pipelines and accessories and clean them thoroughly.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: Regarding the first construction method of the present invention, the through-wall holes are arranged on the side wall of the notch. During the grouting operation, it does not affect the assembly construction of the next segment beam. The sequential construction method of installing and grouting section by section is adjusted to a parallel construction method of installing section by section and grouting every other section, which shortens the construction period. After the front and rear segment beams are first installed and matched, the end sealing material is injected, solving the problem that the end concrete surface of the previous segment beam does not match the corresponding surface of the next segment beam. At the same time, there is no need to block the anchor head at the notch. The spaces at the notch are directly combined together, forming a closed space between the head and tail of the construction segment. The end sealing is carried out by the grouting method, canceling the formwork erection process for the end sealing concrete, solving the problems of small-volume concrete mixing and pouring, and replacing the end sealing concrete with the grouting material, improving the density of the end sealing material.

[0014] Regarding the second construction method of the present invention, the through-wall holes, the first grouting holes, and the second grouting holes are all arranged on the side wall of the notch. During the grouting operation, it does not affect the assembly construction of the next segment beam. The sequential construction method of installing and grouting section by section is adjusted to a parallel construction method of installing section by section and grouting every other section, which shortens the construction period. And the grouting is carried out in two steps. The prestressed duct holes and the internal grouting holes form a closed space. First, the anchor heads are blocked and grouted, and finally, all the spaces corresponding to the notches within the construction segment are grouted together, which also solves the problems of small-volume concrete mixing and pouring. The material requirements in the prestressed duct holes are higher than those at the notch. The two-step grouting method can reduce costs.

[0015] 3. Adopting the technology of pouring epoxy resin glue into the groove and inserting the embedded aluminum alloy sheets realizes the improvement of the airtightness of the integral closed space, achieving double airtightness of the plane and the vertical surface, and solving the potential problem of slurry leakage at the splicing surface. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is a schematic diagram of the symmetric cantilever erection construction method of the present invention; Figure 2 is a front projection view of a single segment beam of the present invention; Figure 3 is a schematic diagram of a setting method of the notch of the present invention; Figure 4 is a schematic diagram of the connection relationship between the built-in grouting hole and the prestressed duct hole of the present invention; Figure 5 is a schematic diagram of another setting method at the notch of the present invention; Figure 6 is a side sectional view of the notch of the present invention; Figure 7 is a schematic diagram of the connection method of each hole under a construction method of the present invention; Figure 8 is a schematic diagram of the connection method of each hole when grouting the closed space of the notch of the present invention; Figure 9 is a flow chart of a construction method of the present invention; Figure 10 is a flow chart of another construction method of the present invention.

[0018] Among them, 1, notch; 11, anchor backing plate; 12, prestressed duct hole; 13, built-in grouting hole; 14, through-wall hole; 2, groove; 3, aluminum alloy sheet; 4, external grouting hole; 41, first grouting hole; 42, second grouting hole. Detailed implementation manners

[0019] To make the application purpose, features, and advantages of the present application more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the embodiments described below are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0020] Reference Figure 1-4 and Figure 6, A structure for rapid assembly of segmental beams in the mid-span beam segment, including segmental beams with multiple groups of prestressed ducts reserved. At one end of each segmental beam, a notch 1 is reserved. An anchor plate 11 is embedded inside the notch 1. Prestressed duct holes 12 and internal grouting holes 13 are reserved on the anchor plate 11. A through-wall hole 14 is reserved on the inner side wall of the notch 1; A circumferential small groove 2 is arranged on the outer side of the mouth of the notch 1. A ring-shaped aluminum alloy sheet 3 is buried at the corresponding position of the segmental beam matching the groove 2. The depth of the small groove 2 is 3 cm, and the aluminum alloy sheet 3 protrudes 2 cm from the plane of the segmental beam.

[0021] Reference Figure 7 , Figure 9 , On the basis of this structure, the present invention provides a construction method for rapid assembly of segmental beams in the mid-span beam segment, including the following steps: S1. Use a bridge erection machine to hoist multiple segmental beams, where the multiple segmental beams include the Nth pier top segment block, and no notch 1 is provided on the segment block, only prestressed ducts are reserved; S2. Adopt the symmetric cantilever assembly method to symmetrically hoist the N + 1th and N - 1th segmental beams to both ends of the Nth segment; S3. Perform glue splicing treatment on the hoisted segmental beams; after completion, perform steel strand threading. Here, the steel strands are directly threaded from the notch 1 at one end of the construction section to the corresponding notch 1 at the other end, passing through all the segmental beams inside, and then perform prestress tensioning; S4. Continue to hoist the symmetric outer segmental beams and perform glue splicing with the inner segmental beams. After the glue splicing is completed, connect the grouting machine to the through-wall hole 14 at one end of the inner segment that has completed step S3, and connect the through-wall hole 14 at the other end to the vacuum pump, and start the grouting operation; S5. Repeat steps S3 - S4. It should be noted that multiple groups of prestressed ducts are reserved inside the segmental beams, and the steel strands are threaded correspondingly between different segmental beams within the construction section to complete the construction of this construction section.

[0022] Reference Figure 1 , Figure 2 , Figures 4-6 , On the basis of the above structure, the internal grouting hole 13 can also be extended with a plastic pipe and passed out through the through-wall hole 14. A valve is installed outside the plastic pipe; an external grouting hole 4 is also reserved on the side wall of one end notch 1. The external grouting hole 4 includes a first grouting hole 41 and a second grouting hole 42. The first grouting hole 41 is arranged at the bottom inside the notch 1, and the second grouting hole 42 is arranged at the top inside the notch 1. Both the first grouting hole 41 and the second grouting hole 42 are connected with transparent steel wires, and valves are installed outside the transparent steel wires. Reference Figure 8 , Figure 10 , On the basis of this structure, the present invention also provides a construction method for rapid assembly of segmental beams in the mid-span beam segment, including the following specific steps: S1. Use a bridge erection machine to hoist multiple segmental beams, where the multiple segmental beams include the Nth segmental beam; S2. Adopt the symmetric cantilever erection method to symmetrically splice the (N + 1)th and (N - 1)th segmental beams to both ends of the Nth segment; S3. For the assembled segmental beams, conduct strand threading, glue splicing treatment, and prestress tensioning; S4. Use cement mortar to block the anchor heads of the slots 1 that need to be grouted. After the blocking is completed, the internal grouting holes 13, hoses, and prestressed duct holes 12 at both ends form a fully enclosed space. Connect one end of the hose that passes through the wall hole 14 to the grouting machine, and connect the other end hose to the vacuum pump, and start the grouting operation; at the same time, hoist the symmetrically arranged outer segmental beams and complete the splicing with the inner segmental beams. When the splicing is completed, a fully enclosed space is formed at the corresponding slots 1; S5. Repeat steps S3 - S4 until the segment splicing and grouting operation of the prestressed ducts within this construction section are completed; S6. Conduct grouting operation on the fully enclosed space formed at the corresponding slots 1. Specifically, connect the transparent steel wire hose of the first grouting hole 41 at one end of the slot 1 at the head of the segment that needs to be grouted to the grouting machine, connect the second grouting hole 42 in the middle end-to-end with the first grouting hole 41 of the next segment, connect the second grouting hole 42 at the tail of the segment to the vacuum pump, start the grouting operation, and finally complete the construction of this construction section.

[0023] Specifically, the glue splicing treatment is as follows: Clean the joint surface, paste the sealing ring, mix the glue, and apply the glue in sequence on the joint surface; during installation, fill the epoxy resin in the annular groove 2, and the annular groove 2 fits tightly with the aluminum alloy sheet 3, so that the slot 1 is completely closed.

[0024] Specifically, the specific steps of the aforementioned grouting operation are as follows: Step 1. Start the vacuum pump to make the channel vacuum degree reach -0.1 MPa and keep it stable; Step 2. Start the grouting machine, control the grouting pressure at 0.7 Mpa, and conduct the grouting operation. During the grouting process, the vacuum pump keeps working continuously; Step 3. When there is grout passing through the air filter of the vacuum pump, close the valve at the front end of the air filter, and then open the exhaust valve. When the cement grout flows out smoothly from the exhaust valve and the consistency is the same as that of the grout being pressed in, close all the valves at the vacuum end, conduct pressure stabilization, the pressure stabilization is not less than 0.5 Mpa, and the pressure stabilization time is 5 minutes. If the grout pressure does not drop during pressure stabilization, then close the grouting machine and the valves at the grouting end to complete the grouting; Step 4. Before the cement grout loses fluidity, disassemble the external pipelines and accessories and clean them thoroughly.

[0025] It should be noted that: Due to the wall-piercing holes 14, the first grouting holes 41, and the second grouting holes 42 are all provided on the side wall of the notch 1. During actual construction, the prestressed ducts and the space of the notch 1 within the construction section can be selectively grouted.

[0026] To avoid misunderstanding, specific examples are given here for the hoisting and splicing and grouting processes: First, hoist the Nth segment block, then hoist the (N + 1)th and (N - 1)th segment beams and splice them to the Nth segment block. After completion, the steel strands are inserted from the left notch 1 of the (N - 1)th segment, pass through the Nth segment, and exit from the corresponding notch 1 at the right end of the (N + 1)th segment, and then prestress tensioning is carried out; Next, hoist the (N + 2)th and (N - 2)th segment beams to the outside of the construction section and splice them with the inner segment beams (that is, the (N + 2)th segment is on the right side of the (N + 1)th segment and is spliced with the (N + 1)th segment, and the (N - 2)th segment is on the left side of the (N - 1)th segment and is spliced with the (N - 1)th segment). After completion, the (N - 1)th, Nth, and (N + 1)th segment beams are wrapped between the (N - 2)th and (N + 2)th segments, and the prestressed ducts, notch 1, etc. between them are all closed, leaving only the inlets and outlets at the wall-piercing holes 14 that penetrate through the side walls at both ends. At this time, grouting operations can be carried out on the already closed space of the (N - 1)th, Nth, and (N + 1)th segments, and the grouting operations do not affect the hoisting and splicing work of the (N + 2)th and (N - 2)th segments and even more outer segments. And so on, the construction can be accelerated. Similarly, for the second construction method of separately grouting the notch 1 space and the prestressed ducts, the process is similar to the above. The difference is that the rigid pipes penetrating through the wall-piercing holes 14 only grout the prestressed ducts, and the space of the notch 1 is grouted by connecting the first grouting holes 41 and the second grouting holes 42 end to end, solving the problems of small-volume concrete mixing and pouring. The material requirements in the prestressed ducts are higher than those at the notch 1. This two-step grouting method can reduce costs and is also more flexible in the construction process.

[0027] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent replacements or changes, and should be covered by the protection scope of the present invention.

Claims

1. A structure for rapid assembly of mid-span beam segments, comprising segmental beams with multiple groups of prestressed pipes reserved, characterized in that: A notch is reserved at one end of each segment beam, an anchor plate is embedded in the notch, prestressed pipe holes and built-in mortar holes are reserved on the anchor plate, and a through-wall hole is reserved on the inner wall of the notch; A circumferential small groove is arranged outside the mouth of the notch, and an annular aluminum alloy sheet is buried at a position corresponding to the groove on the matching segment beam. The depth of the small groove is 3-4 cm, and the aluminum alloy sheet protrudes 2 cm from the plane of the segment beam.

2. The structure for rapid assembly of mid-span beam segments according to claim 1, characterized in that: The built-in slurry hole is extended with a plastic pipe and passes through the wall hole. A valve is installed at the outer end of the plastic pipe. An external slurry hole is also reserved on the side wall of the slot. The external slurry hole includes a first slurry hole and a second slurry hole. The first slurry hole is arranged at the bottom of the inner side of the slot, and the second slurry hole is arranged at the top of the inner side of the slot. The first slurry hole and the second slurry hole are both connected to a transparent steel wire tube, and a valve is installed at the outer end of the transparent steel wire tube.

3. A construction method for rapid assembly of mid-span beam segments, comprising a structure for rapid assembly of mid-span beam segments as claimed in claim 1, characterized in that: The specific steps include: S1. hoisting a multi-segment beam by a bridge erecting machine, wherein the multi-segment beam includes an Nth pier top segment block; S2. Use the symmetrical cantilever assembly method to symmetrically hoist the N+1 and N-1 segment beams to the two ends of the Nth segment; S3. Glue the segmental beams that have been hoisted into place. After completion, thread the steel strands and tension the prestressed steel strands. S4, continue to hoist the mutually symmetrical outer segment beams and glue them with the inner segment. After the gluing is completed, connect the grouting machine to the through-wall hole at one end of the inner segment that has completed step S3, and connect the through-wall hole at the other end to the vacuum machine to start the grouting operation; S5. Repeat steps S3-S4 until the construction of the construction section is completed.

4. A construction method for rapid assembly of mid-span beam segments, comprising a structure for rapid assembly of mid-span beam segments as claimed in claim 2, characterized in that: The specific steps include: S1. hoisting a multi-segment beam by a bridge erecting machine, wherein the multi-segment beam includes an Nth pier top segment block; S2. Use the symmetrical cantilever assembly method to symmetrically hoist the N+1 and N-1 segment beams to the two ends of the Nth segment; S3. Glue the segmental beams that have been hoisted into place. After completion, thread the steel strands and tension the prestressed steel strands. S4, use cement mortar to seal the anchor head that needs grouting, and use epoxy resin glue to seal the gap between the wall hole and the plastic pipe. After the sealing is completed, the built-in grouting holes, plastic pipes and prestressed pipe holes and prestressed pipes at both ends of the construction section form a fully enclosed space, hoist the mutually symmetrical outer segment beams and glue them with the inner segment beams. After the gluing is completed, a closed space is formed at the notch of the inner construction section; connect the grouting machine to the plastic pipe passing through the wall hole at one end of the inner segment that has completed step S3, and connect the plastic pipe passing through the wall hole at the other end to the vacuum machine to start the grouting operation; S5, repeating steps S3-S4 until the segment splicing and prestressed pipe grouting operations in the construction section are completed; S6. Carry out grouting operation on the closed space formed at the notch. Specifically, connect the transparent steel wire tube of the first grouting hole at one end of the notch at the head of the segment to be grouted with the grouting machine, connect the second grouting hole in the middle with the first grouting hole of the next segment end to end, connect the second grouting hole at the tail of the segment with the vacuum machine, start the grouting operation, and finally complete the construction of the construction section.

5. A construction method for rapid assembly of mid-span beam segments according to claim 3 or 4, characterized in that: The glue splicing process specifically includes: cleaning the joint surface, pasting the sealing ring, mixing the glue and applying the glue in sequence on the joint surface; during installation, the groove is filled with epoxy resin, and the groove is tightly fitted with the aluminum alloy sheet.

6. A construction method for rapid assembly of mid-span beam segments according to claim 3 or 4, characterized in that: The specific steps of the grouting operation are: Step 1: Start the vacuum pump to make the channel vacuum degree reach -0.08~-0.1MPa and keep it stable; Step 2: Start the grouting machine, control the grouting pressure at 0.5~0.7Mpa, and perform the grouting operation. During the grouting process, the vacuum machine keeps working continuously; Step 3: When slurry passes through the air filter of the vacuum machine, close the valve at the front end of the air filter, and then open the exhaust valve. When the cement slurry flows out of the exhaust valve smoothly and the consistency is equivalent to the pressed slurry, close all valves at the vacuum end and stabilize the pressure. The stabilization pressure is not less than 0.5Mpa and the stabilization time is 3 to 5 minutes. If the slurry pressure does not drop during the stabilization, close the grouting machine and the valve at the grouting end to complete the grouting. Step 4: Before the cement slurry loses fluidity, remove the external pipes and accessories and clean them.

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