Cast-in-place box girder construction technology

Abstract

The invention relates to a cast-in-place box girder construction technology, which belongs to the technical field of box girder construction, and comprises the following steps: S1, bracket cushion layer construction; s2, erecting a bracket; s3, pre-pressing the support; s4, side formworks are installed, and top plate concrete is poured; s5, concrete curing; s6, pre-stress construction is conducted; and S7, the formwork and the support are dismantled. The method has the effect of effectively improving the construction efficiency and safety of the cast-in-place box girder.

Description

Technical Field

[0001] The present application relates to the technical field of box girder construction, and in particular to a cast-in-place box girder construction process. Background Art

[0002] As a common bridge construction method, cast-in-place box girders are widely used in infrastructure construction projects such as roads and railways. They form solid piers and bridge deck structures by pouring concrete on site, and have good integrity and durability.

[0003] The present application provides another cast-in-place box girder construction process that can improve construction efficiency and safety, aiming to provide technical personnel in the field with a variety of options for solving problems. Summary of the invention

[0004] In order to effectively improve the construction efficiency and safety of cast-in-place box girders, the present application provides a cast-in-place box girder construction process.

[0005] The present application provides a cast-in-place box girder construction process that adopts the following technical solution: A cast-in-place box girder construction process comprises the following steps: S1: support cushion construction; The foundation is leveled and compacted according to the plan. After the leveling and compaction of the foundation is completed and accepted, concrete pouring construction is carried out to form the support cushion layer; S2: Scaffold erection; S21: Before the support is erected, the base is installed according to the support erection plan; S22: Install the pole; insert the pole into the already placed base and ensure a firm connection between the pole and the base; S23: Install the transverse horizontal bars and the longitudinal horizontal bars; S24: Install the diagonal tie rod; S25: Install the upper vertical poles, transverse horizontal poles, longitudinal horizontal poles and diagonal braces successively; S26: inserting an adjustable top support into the top of the vertical pole located at the uppermost layer, adjusting the adjustable top support to a support height, and making the support heights of all the adjustable top supports be on the same horizontal plane; S27: Install distribution beam; S3: stent preloading; After the support is erected and accepted, the square timber is laid horizontally on the top surface of the distribution beam, and then the bottom formwork is laid on the top surface of the square timber, and a pre-compression test is carried out on the top surface of the bottom formwork; S4: Installation of side formwork and pouring of top slab concrete; S41: Install back ribs and support components; S42: Install a crossbeam on the top surface of the back rib, and install a side formwork on the top surface of the crossbeam; S43: Tie the bottom formwork reinforcement on the top surface of the bottom formwork, tie the side formwork reinforcement on the inner side surface of the side formwork, and install the prestressed pipe; then tie the crossbeam reinforcement and the longitudinal beam reinforcement on the top surface of the bottom formwork reinforcement; S44: Installation and fixation of the bottom web inner mold; S45: pouring of bottom web concrete; S46: Removal of the inner mold of the bottom belly plate; S47: Top plate inner mold installation; S5: Concrete curing; S6: Prestressed construction; S7: Formwork and support removal.

[0006] By adopting the above technical scheme, firstly, the support cushion construction ensures that the foundation is flat and compacted and has sufficient bearing capacity, effectively reducing the safety hazards caused by uneven settlement; secondly, the modular support erection method not only improves the assembly speed, but also enhances the overall stability and reliability of the structure; thirdly, the design of adjusting the top support enables the support height of all support seats to be accurately adjusted to the same horizontal plane, further reducing the quality problems caused by height differences; thus, the cast-in-place box girder construction process can effectively improve construction efficiency and safety.

[0007] Preferably, in S22, the base includes a bottom plate installed on the top surface of the bracket cushion layer and a starting rod vertically fixed on the top surface of the bottom plate, the bottom end of the vertical rod is fixedly connected with an insert block, the top end of the starting rod is provided with a slot that cooperates with the insert block, and the starting rod is penetrated with a threaded pin for locking the insert block in the slot.

[0008] By adopting the above technical solution, the base plate is firmly fixed to the top surface of the bracket cushion layer by expansion bolts, which increases the stability and load-bearing capacity of the entire bracket system; at the same time, the bottom end of the vertical pole is fixedly connected with an insert block, and the top end of the starting pole is provided with a slot matching the insert block, and the insert block is locked in the slot by a threaded pin. This design not only simplifies the installation process, but also effectively reduces the loosening or falling off of the vertical pole during construction, further improving the overall safety and reliability of the bracket.

[0009] Preferably, in S23, the rod ends of the transverse horizontal rods and the rod ends of the longitudinal horizontal rods are fixedly connected with first buckle joints, a connecting disk fixedly sleeved on the circumferential side of the vertical rods and engaged with the first buckle joints, a plurality of evenly distributed sockets are provided on the connecting disk, and a wedge-shaped pin passing through the sockets is vertically penetrated on the first buckle joint.

[0010] By adopting the above technical solution, the snap-on design of the first buckle joint and the connecting plate simplifies the installation process and reduces the time and difficulty of on-site operations; at the same time, the design of the wedge-shaped pin not only ensures the stability of the connection, but also facilitates disassembly and reuse, further improving the construction flexibility and economy; these improvements help to improve the overall performance of the entire cast-in-place box girder construction process and ensure the safety and stability of the structure.

[0011] Preferably, in S24, the rod end of the inclined tie rod is fixedly connected with a second buckle joint that is clamped with the connecting disk, and the second buckle joint is connected to the socket on the connecting disk through a wedge pin.

[0012] By adopting the above technical solution, the second buckle joint is connected to the socket on the connecting plate through a wedge pin, thereby realizing a quick and stable connection between the diagonal rod and the vertical pole; this design not only simplifies the installation process and improves construction efficiency, but also ensures the overall stability and safety of the bracket.

[0013] Preferably, in S26, the adjusting top support includes a vertically arranged screw, a support seat fixedly connected to the top end of the screw, and a threaded sleeve threadedly connected to the circumference of the screw, and the inner wall of the vertical rod is provided with four equally spaced limit grooves, and the interior of the screw is provided with a limit member in the limit groove at the limit end.

[0014] By adopting the above technical solution, the adjustable top support can achieve height adjustment at the top end of the vertical pole, ensuring that the supporting heights of all the adjustable top supports are located on the same horizontal plane.

[0015] Preferably, an accommodating cavity is opened inside the screw, and the limiting member includes an adjusting rod vertically penetrating the inner bottom wall of the support seat and threadedly connected to the screw, an abutment platform fixedly connected to the bottom end of the adjusting rod, a fixed shaft horizontally fixed inside the accommodating cavity, a spring sheet arranged on the fixed shaft, and a limiting block fixed on the spring sheet; when the abutment platform abuts against the opening of the spring sheet, the limiting block extends into the limiting groove corresponding to the position.

[0016] By adopting the above technical solution, it is possible to achieve precise adjustment of the height of the adjustable top support.

[0017] Preferably, when the abutment platform abuts against the spring sheet so that the limiting block extends into the limiting groove, the top end of the adjustment rod is flush with the inner bottom wall of the support seat.

[0018] By adopting the above technical solution, when the abutment platform abuts against the spring sheet, the limit block will extend into the limit groove corresponding to the position to limit the screw rod. At the same time, the top end of the adjusting rod is flush with the inner bottom wall of the support seat to ensure that the adjusting rod will not be exposed to avoid interference with subsequent construction operations. This design not only improves the stability and reliability of the adjustable top support, but also simplifies the construction process and improves work efficiency.

[0019] Preferably, two symmetrically arranged connecting ears are fixedly connected to the circumferential side of the threaded sleeve, and a locking piece is detachably connected to the connecting ear, and the locking end of the locking piece abuts against the vertical rod to achieve locking.

[0020] By adopting the above technical solution, after the top support is adjusted to a suitable height, the threaded sleeve can be effectively locked through the connecting ear and the locking piece, thereby effectively reducing the loosening or sliding of the adjustment top support caused by external factors during the construction process, ensuring the stability and reliability of the support seat, and improving the safety performance of the entire bracket system.

[0021] Preferably, the locking member includes a fixing tube detachably connected to the connecting ear and coaxially arranged with the vertical pole, an abutment sleeve threadedly connected to the fixing tube, and a locking sleeve arranged on the top of the inner wall of the fixing tube. When the abutment sleeve abuts against the locking sleeve, the locking end of the locking sleeve abuts against the peripheral side of the vertical pole, thereby achieving locking.

[0022] By adopting the above technical solution, the locking member can effectively fix the support seat of the adjustable top support at the required height position, effectively reducing the displacement or loosening of the support seat due to external factors during the construction process, thereby ensuring the stability and safety of the bracket system.

[0023] Preferably, the locking member includes a fixing tube detachably connected to the connecting ear and coaxially arranged with the vertical pole, an abutment sleeve threadedly connected to the fixing tube, and a locking sleeve arranged on the top of the inner wall of the fixing tube. When the abutment sleeve abuts against the locking sleeve, the locking end of the locking sleeve abuts against the peripheral side of the vertical pole, thereby achieving locking.

[0024] By adopting the above technical solution, the fixing cylinder is detachably connected to the connecting ear through the clamping block, making the connection between the fixing cylinder and the connecting ear more convenient and quick, while ensuring the stability and reliability of the connection.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. First, the support cushion construction ensures that the foundation is flat and compacted and has sufficient bearing capacity, effectively reducing the safety hazards caused by uneven settlement; second, the modular support erection method not only improves the assembly speed, but also enhances the overall stability and reliability of the structure; third, the design of adjusting the top support enables the support height of all support seats to be accurately adjusted to the same horizontal plane, further reducing the quality problems caused by height differences; thus, this cast-in-place box girder construction process can effectively improve construction efficiency and safety; 2. The snap-on design between the first buckle joint and the connection plate simplifies the installation process and reduces the time and difficulty of on-site operation. At the same time, the wedge-shaped pin design not only ensures the stability of the connection, but also facilitates disassembly and reuse, further improving the flexibility and economy of construction. These improvements help to improve the overall performance of the entire cast-in-place box girder construction process and ensure the safety and stability of the structure. 3. When the abutment platform abuts against the spring sheet, the limit block will extend into the limit groove corresponding to the position to limit the screw. At the same time, the top end of the adjusting rod is flush with the inner bottom wall of the support seat to ensure that the adjusting rod will not be exposed to avoid interference with subsequent construction operations. This design not only improves the stability and reliability of the adjustable top support, but also simplifies the construction process and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of this application.

[0027] Figure 2 It is an exploded view of the vertical poles, transverse horizontal poles, longitudinal horizontal poles and diagonal braces of the present application.

[0028] Figure 3 yes Figure 2 A partial enlarged view of part A.

[0029] Figure 4 It is a structural schematic diagram of the upright pole and the adjustable top support of the present application.

[0030] Figure 5 yes Figure 4 A partial enlarged view of part B.

[0031] Figure 6 It is a cross-sectional view of the upright pole and the adjustable top support of the present application.

[0032] Figure 7 yes Figure 6 A partial enlarged view of part C.

[0033] Figure 8 It is a schematic diagram of the structure of the locking sleeve of the present application.

[0034] Fig. 9 It is a structural schematic diagram of the distribution beam, support assembly and cross beam of the present application.

[0035] Fig.10 It is an overall side view of this application.

[0036] Fig.11 It is a structural schematic diagram of the side formwork, bottom formwork reinforcement, side formwork reinforcement, crossbeam reinforcement and longitudinal beam reinforcement of the present application.

[0037] Fig.12It is a structural schematic diagram of the side formwork, bottom formwork reinforcement, side formwork reinforcement, crossbeam reinforcement, longitudinal beam reinforcement and bottom web inner formwork of the present application.

[0038] Explanation of reference numerals: 1. support cushion; 2. vertical pole; 21. plug block; 211. perforation; 22. horizontal horizontal pole; 221. first buckle joint; 23. vertical horizontal pole; 24. connecting plate; 241. plug hole; 242. wedge-shaped plug pin; 25. inclined rod; 251. second buckle joint; 26. connecting groove; 27. limiting groove; 3. bottom plate; 31. starting rod; 311. slot; 312. threaded pin; 313. locking nut; 4. screw; 41. support seat; 42. threaded sleeve; 421. connecting ring; 422. connecting ear; 423. through hole; 424. mounting groove; 43. accommodating cavity; 44. adjusting rod; 441. multiple side groove; 45, abutment platform; 46, fixed axis; 47, spring piece; 48, limit block; 5, fixed cylinder; 51, abutment sleeve; 511, inclined plane; 52, vertical axis; 53, clamping block; 54, fixing ring; 541, locking strip; 542, notch; 543, abutment part; 6, distribution beam; 61, square wood; 62, bottom template; 63, long back rib; 64, short back rib; 65, support rod; 66, lower connecting seat; 661, make way; 662, fixing bolt; 67, upper connecting seat; 68, crossbeam; 7, side template; 71, bottom template reinforcement; 72, side template reinforcement; 73, crossbeam reinforcement; 74 longitudinal beam reinforcement; 75, bottom web inner mold; DETAILED DESCRIPTION The following is combined with Figure 1-12 This application is described in further detail.

[0039] The present application embodiment discloses a cast-in-place box girder construction process. Figure 1 and Figure 2 , the cast-in-place box girder construction process includes the following steps: S1: Construction of support cushion layer 1.

[0040] The foundation is leveled and compacted according to the plan. After the leveling and compaction of the foundation is completed and accepted, concrete pouring construction is carried out to form the support cushion layer 1; the pouring width of the support cushion layer 1 is 1m outside the support projection line and a longitudinal drainage ditch is set according to the plan.

[0041] The support foundation must have sufficient bearing capacity. After the support cushion layer 1 is processed, it must be pre-pressed to test the bearing capacity of the support cushion layer 1. The pre-pressing load should not be less than 1.2 times the sum of the weight of the upper structure, steel pipe support, and formwork borne by the support cushion layer 1. The purpose of pre-pressing is to test the bearing capacity of the support cushion layer 1, eliminate the inelastic deformation of the support cushion layer 1 under the construction load, and effectively reduce the settlement of the support cushion layer 1, which may cause cracking of the cast-in-place box girder structure; the support can be erected only after the test is qualified.

[0042] S2: Scaffolding erection.

[0043] S21: Before erecting the scaffold, use a total station to measure the span centerline of the box girder, the longitudinal centerline of the box girder and the projected edge line of the box girder on the foundation, and then install the base according to the scaffold erection plan.

[0044] S22: Install the vertical pole 2; insert the vertical pole 2 into the already placed base, and ensure a firm connection between the vertical pole 2 and the base.

[0045] Reference Figure 2 and Figure 3 The base includes a horizontally arranged bottom plate 3 and a starting rod 31 vertically fixed on the top surface of the bottom plate 3. The bottom plate 3 is installed on the top surface of the bracket cushion layer 1 through expansion bolts, and there are four expansion bolts on each bottom plate 3. The four expansion bolts are respectively located at the four corners of the bottom plate 3, so that the bottom plate 3 can be firmly fixed on the top surface of the bracket cushion layer 1.

[0046] In order to facilitate the connection between the vertical pole 2 and the starting pole 31, the bottom end of the vertical pole 2 is fixedly connected with a plug block 21 with a square cross-section, and the top of the starting pole 31 is provided with a slot 311 matching the plug block 21, and a threaded pin 312 is passed through the starting pole 31, and a locking nut 313 is threadedly connected to the threaded pin 312, so that the plug block 21 is connected with the slot 311, and the threaded pin 312 horizontally penetrates the starting pole 31 and the plug block 21, and then the locking nut 313 is threadedly connected to the threaded pin 312, so that the starting pole 31 is limited between the locking nut 313 and the head of the threaded pin 312; then the plug block 21 is locked in the slot 311, and the installation between the starting pole 31 and the vertical pole 2 is completed.

[0047] The insert block 21 is provided with two mutually connected through holes 211 through which the threaded pin 312 can pass. One through hole 211 passes through the insert block 21 longitudinally, and the other through hole 211 passes through the insert block 21 transversely, so that the threaded pin 312 can pass through the corresponding through holes 211. The connection method between two adjacent vertical poles 2 located on the same vertical line is the same as the connection method between the vertical pole 2 and the starting pole 31, so it will not be repeated.

[0048] S23: Install the transverse horizontal rod 22 and the longitudinal horizontal rod 23.

[0049] The rod ends of the transverse horizontal rod 22 and the rod ends of the longitudinal horizontal rod 23 are fixedly connected with the first buckle joint 221, and the peripheral side of the vertical rod 2 is fixedly sleeved with a connecting plate 24 that is clamped with the first buckle joint 221. The connecting plate 24 is provided with a plurality of evenly distributed insertion holes 241 that vertically penetrate the connecting plate 24, and a wedge-shaped plug 242 is vertically penetrated through the first buckle joint 221. The first buckle joint 221 of the rod end of the transverse horizontal rod 22 and the first buckle joint 221 of the rod end of the longitudinal horizontal rod 23 are buckled on the connecting plate 24, and the wedge-shaped plug 242 is passed through the insertion hole 241, so that the transverse horizontal rod 22 and the vertical horizontal rod are buckled on the peripheral side of the vertical rod 2.

[0050] Two connection plates 24 are provided on the same vertical pole 2 , and the two connection plates 24 are respectively located at the top and bottom of the circumference of the vertical pole 2 ; each connection plate 24 is connected to a corresponding transverse horizontal rod 22 and a longitudinal horizontal rod 23 .

[0051] S24: Install the diagonal tie rod 25.

[0052] An inclined brace 25 is added at the corresponding position, and the rod end of the inclined brace 25 is fixedly connected with a second buckle joint 251, which is clamped with the connecting disk 24 and is also connected to the socket 241 on the connecting disk 24 through a wedge pin.

[0053] S25: Install the upper vertical poles 2, the transverse horizontal poles 22, the longitudinal horizontal poles 23 and the diagonal brace rods 25 successively.

[0054] S26: Insert an adjustable top support at the top of the vertical pole 2 located at the uppermost layer, adjust the adjustable top support to a supporting height, and make the supporting heights of all the adjustable top supports be on the same horizontal plane.

[0055] Reference Figure 4 and Figure 5 The adjusting top support includes a vertically arranged screw rod 4, a support seat 41 fixedly connected to the top of the screw rod 4, and a threaded sleeve 42 threadedly connected to the circumference of the screw rod 4; the bottom surface of the threaded sleeve 42 is fixedly connected to a connecting ring 421 coaxially arranged with the threaded sleeve 42, and the top of the vertical rod 2 is provided with a connecting groove 26 corresponding to the position of the connecting ring 421, the connecting groove 26 is annular, and the connecting ring 421 is plugged into the connecting groove 26. The threaded sleeve 42 is threadedly connected to the screw rod 4, and the connecting ring 421 is plugged into the connecting groove 26, so that the bottom end of the screw rod 4 extends to the inside of the vertical rod 2.

[0056] Reference Figure 6 and Figure 7When the threaded sleeve 42 is rotated, in order to limit the screw rod 4 so that the screw rod 4 can move vertically, the purpose of vertically adjusting the height of the support seat 41 is achieved; a limiting member whose limiting end can extend to the outside of the screw rod 4 is arranged inside the screw rod 4, and four limiting grooves 27 distributed at equal intervals are opened on the inner side wall of the vertical rod 2. The length of the limiting groove 27 is arranged vertically, and when the limiting end of the limiting member extends into the limiting groove 27, the limiting end of the limiting member is slidably connected with the limiting groove 27.

[0057] The support seat 41 has a U-shaped cross section and its opening is arranged upward, and a receiving chamber 43 is provided inside the screw rod 4; the limiting member includes an adjusting rod 44 which vertically penetrates the inner bottom wall of the support seat 41 and is threadedly connected to the screw rod 4, an abutting platform 45 which is fixedly connected to the bottom end of the adjusting rod 44, a fixed shaft 46 which is horizontally fixed inside the receiving chamber 43, a spring 47 which is arranged on the fixed shaft 46, and a limiting block 48 which is fixed on the spring 47. The adjusting rod 44 is arranged coaxially with the screw rod 4, and the bottom end of the adjusting rod 44 extends into the receiving chamber 43; the abutting platform 45 is truncated cone-shaped, and the end of the abutting platform 45 with a larger cross-sectional area is arranged upward; the cross section of the spring 47 is V-shaped and its opening is arranged upward, and the inner bottom of the spring 47 is fixedly connected to the peripheral side of the fixed shaft 46, and two limiting blocks 48 are arranged, and the two limiting blocks 48 are symmetrically arranged on the outer side of the spring 47, and the limiting blocks 48 are located at the opening of the spring 47.

[0058] When the adjusting rod 44 is rotated, the adjusting rod 44 drives the abutment platform 45 to move downward until the abutment platform 45 abuts against the opening of the spring sheet 47, so that the spring sheet 47 expands outward, so that the expanded spring sheet 47 drives the limiting block 48 to penetrate the accommodating cavity 43 and extend to the outside of the screw rod 4, so that the end of the limiting block 48 away from the spring sheet 47 extends to the corresponding limiting groove 27 to limit the screw rod 4.

[0059] In the initial state, the top of the adjustment rod 44 is located above the inner bottom wall of the support seat 41. When the abutment platform 45 abuts against the spring sheet 47, so that the limit block 48 extends into the limit groove 27, the top of the adjustment rod 44 is flush with the inner bottom wall of the support seat 41, so that the adjustment rod 44 that is not exposed can not interfere with subsequent construction. In order to facilitate the rotation of the adjustment rod 44, a polygonal groove 441 is opened at the top of the adjustment rod 44. In this embodiment, the polygonal groove 441 is a hexagonal groove.

[0060] In order to facilitate the rotation of the threaded sleeve 42, two symmetrically arranged connecting ears 422 are fixedly connected to the circumferential side of the threaded sleeve 42. In the initial state, the directions of the two connecting ears 422 are consistent with the direction of the limit block 48, so that the construction personnel can preliminarily determine whether the limit block 48 corresponds to the position of the limit groove 27, so that after the adjusting rod 44 is rotated, the limit block 48 can accurately extend to the limit groove 27 at the corresponding position.

[0061] When the limit block 48 extends into the limit groove 27, the threaded sleeve 42 is rotated to allow the screw rod 4 to drive the support seat 41 to move upward. When the limit block 48 abuts against the top of the inner wall of the limit groove 27, the threaded sleeve 42 cannot be rotated further. Therefore, it can be determined that the adjustment top support has been adjusted to the support height. Through this adjustment method, the support heights of all adjustment top supports are located on the same horizontal plane.

[0062] Referring to Figures 5 and Figure 7 In order to lock the adjusted support seat 41, a locking piece is detachably connected to the connecting ear 422, and the locking end of the locking piece abuts against the vertical rod 2 so that the threaded sleeve 42 cannot continue to rotate, thereby achieving the purpose of locking the adjusted support seat 41.

[0063] Reference Figure 5 and Figure 7 The locking member includes a fixing tube 5 detachably connected to the connecting ear 422 and arranged coaxially with the vertical pole 2, an abutting sleeve 51 threadedly connected to the fixing tube 5, and a locking sleeve arranged on the top of the inner wall of the fixing tube 5. The fixing tube 5 is a hollow cylinder with an opening at the bottom, and the vertical pole 2 vertically passes through the fixing tube 5; the abutting sleeve 51 is arranged coaxially with the vertical pole 2, and the abutting sleeve 51 is threadedly connected to the opening of the fixing tube 5. When the abutting sleeve 51 abuts against the locking sleeve, the locking end of the locking sleeve abuts against the peripheral side of the vertical pole 2, thereby achieving locking.

[0064] The top surface of the fixed cylinder 5 is fixedly connected with two symmetrically arranged vertical shafts 52, and the top of each vertical shaft 52 is rotatably connected with a clamping block 53; the two clamping blocks 53 correspond to the positions of the two connecting ears 422 respectively. The connecting ear 422 is provided with a through hole 423 that vertically penetrates the connecting ear 422, and the top surface of the connecting ear 422 is provided with a mounting groove 424 that communicates with the through hole 423. The cross-sections of the clamping block 53, the through hole 423 and the mounting groove 424 are all set to be rectangular, and the through hole 423 and the mounting groove 424 are arranged in a cross-shaped manner. The cross-sectional area of ​​the clamping block 53 is smaller than the cross-sectional area of ​​the through hole 423, so that the clamping block 53 can pass through the connecting ear 422 through the through hole 423; the cross-sectional area of ​​the clamping block 53 is smaller than the cross-sectional area of ​​the mounting groove 424, so that the clamping block 53 can be placed in the mounting groove 424.

[0065] When it is necessary to connect the fixing tube 5 to the connecting ear 422, first put the fixing tube 5 on the peripheral side of the vertical pole 2, rotate the direction of the clamping block 53 so that the direction of the clamping block 53 is consistent with the direction of the through hole 423, pass the clamping block 53 through the through hole 423, and then rotate the clamping block 53 so that the direction of the clamping block 53 corresponds to the direction of the installation groove 424. After the clamping block 53 is placed in the installation groove 424, the connection between the fixing tube 5 and the connecting ear 422 is realized.

[0066] Reference Figure 7 and Figure 8The locking sleeve includes a fixing ring 54 which is coaxially arranged with the vertical rod 2 and fixedly connected to the top of the inner wall of the fixing tube 5, and a plurality of locking strips 541 which are integrally formed on the inner ring side of the fixing ring 54 and located on the bottom surface of the fixing ring 54; the inner ring side of the fixing ring 54 is slidingly connected with the peripheral side of the vertical rod 2, and a plurality of locking strips 541 are evenly spaced and distributed on the inner ring side of the fixing ring 54, and a gap 542 is formed between two adjacent locking strips 541; an obliquely arranged abutting portion 543 is integrally formed on the outer bottom of each locking strip 541, and an inclined surface 511 which matches the abutting portion 543 is arranged on the inner side wall of the abutting sleeve 51 and located at the top end of the abutting sleeve 51.

[0067] When the abutment sleeve 51 is rotated to make the top end of the abutment sleeve 51 move upward, when the inclined surface 511 of the abutment sleeve 51 abuts against the abutment portion 543, the inner sides of the plurality of locking strips 541 abut against the circumferential side of the vertical rod 2, so that the threaded sleeve 42 cannot continue to rotate, thereby achieving the purpose of locking the adjusted support seat 41 by locking the threaded sleeve 42.

[0068] S27: Install the distribution beam 6.

[0069] Reference Fig. 9 After the support heights of all the support seats 41 are adjusted to the same horizontal plane, at this time, the top end of the adjustment rod 44 is flush with the inner bottom wall of the support seat 41, so as not to affect the placement of the distribution beam 6. The distribution beam 6 with an I-shaped cross-section is placed longitudinally on the support seat 41, and multiple support seats 41 located on the same longitudinal straight line jointly support the distribution beam 6.

[0070] S3: Bracket preload.

[0071] After the scaffolding is erected and accepted, the square timber 61 is laid horizontally on the top surface of the distribution beam 6, and then the bottom formwork 62 is laid on the top surface of the square timber 61. Before the scaffolding is pre-loaded, the settlement observation points are set and the original elevation data is collected. The scaffolding pre-load load should be no less than 1.1 times the maximum construction load. Concrete pre-load blocks are used to pre-load the scaffold. The loading should be divided into three levels. The first loading is up to 60% of the total weight, the second loading is 80% of the total weight, and the third loading is to 100% of the total weight.

[0072] One hour after each level of loading is completed, the deformation of the support should be observed. After loading is completed, the deformation value should be observed every 6 hours. After the support loading and preloading is completed, unloading begins, and a crane is used to unload the concrete preloading blocks one by one in a symmetrical, balanced and synchronous manner.

[0073] The bottom template 62 is provided with a clearance gap (not shown in the figure) corresponding to the position of the pad stone on the top surface of the pier, and the clearance gap (not shown in the figure) is used to make way for the pad stone and the support arranged on the top surface of the pad stone.

[0074] S4: Installation of side formwork 7 and pouring of top slab concrete.

[0075] S41: Install back ribs and support components.

[0076] Reference Fig. 9 and Fig.10 Before installing the side template 7, it is necessary to install a support assembly on the distribution beam 6, and install the back ribs through the support assembly, and the support assembly is supported between the distribution beam 6 and the back ribs. In this embodiment, the back ribs are divided into short back ribs 64 and long back ribs 63. There are three groups of support assemblies on the same side of the bottom template 62. The lengths of the three groups of support assemblies are inconsistent. The shorter support assembly is adjacent to the bottom template 62, and the shorter support assembly supports the short back ribs 64. The bottom end of the short back ribs 64 is installed on one side of the top surface of the bottom template 62; the two longer groups of support assemblies jointly support the long back ribs 63. The cross-sections of the long back ribs 63 and the short back ribs 64 are both I-shaped. The long back ribs 63 and the short back ribs 64 are both obliquely arranged, and the inclination of the short back ribs 64 is greater than that of the long back ribs 63; the top of the short back ribs 64 supports the bottom end of the long back ribs 63.

[0077] Reference Fig. 9 and Fig.11 Each group of support components includes a support rod 65, a lower connecting seat 66 fixedly connected to the bottom end of the support rod 65, and an upper connecting seat 67 fixedly connected to the top end of the support rod 65; the cross section of the lower connecting seat 66 is U-shaped and its opening is set downward, the lower connecting seat 66 clamps the distribution beam 6, and both sides of the lower connecting seat 66 and the opening of the lower connecting seat 66 are provided with a clearance opening 661 for making way for the support seat 41. After the lower connecting seat 66 clamps the distribution beam 6, a fixing bolt 662 is transversely penetrated on the side of the lower connecting seat 66, and the fixing bolt 662 passes through the lower connecting seat 66 and the web of the distribution beam 6, and a fixing nut is threadedly connected to the fixing bolt 662; the lower connecting seat 66 is limited between the fixing nut and the head of the fixing bolt 662, so as to realize the connection between the bottom end of the support rod 65 and the distribution beam 6. The upper connecting seat 67 is sleeved on the back rib, and the connection method between the upper connecting seat 67 and the back rib is the same as the connection method between the lower connecting seat 66 and the distribution beam 6, so it will not be repeated.

[0078] S42: Install the crossbeam 68 on the top surface of the back rib, and install the side formwork 7 on the top surface of the crossbeam 68.

[0079] S43: Tie the bottom formwork reinforcement 71 on the top surface of the bottom formwork 62, tie the side formwork reinforcement 72 on the inner side surface of the side formwork 7, and install the prestressed pipe; then tie the crossbeam reinforcement 73 and the longitudinal beam reinforcement 74 on the top surface of the bottom formwork reinforcement 71; the crossbeam reinforcement 73 is located between two adjacent longitudinal beam reinforcements 74, and the opposite ends of the bottom formwork 62 are longitudinal beam reinforcements 74.

[0080] S44: Install and fix the bottom web inner mold 75.

[0081] Reference Fig.12 , install the bottom web inner form 75 on the cross beam reinforcement 73 and the longitudinal beam reinforcement 74.

[0082] S45: Pouring of bottom slab concrete.

[0083] The order of pouring concrete for the bottom slab is: first pour the transverse beam reinforcement 73, then pour the longitudinal beam reinforcement 74; use a pump truck to start from the mid-span of the transverse reinforcement 73, pour horizontally and obliquely in layers toward the longitudinal beam reinforcement 74, and then pour concrete for the longitudinal reinforcement 74.

[0084] S46: The bottom web inner mold 75 is removed.

[0085] S47: Top plate inner mold installation.

[0086] A top plate inner formwork (not shown) is installed on the top surface of the bottom web concrete and between two adjacent cross beam reinforcements 73. Finally, the top plate reinforcements are tied to the top surface of the top plate inner formwork. After acceptance, the top plate concrete is poured.

[0087] S5: Concrete curing.

[0088] After the top slab concrete is poured, it should be covered with geotextile in time after the slurry is set, and water should be sprinkled for maintenance; if necessary, additional insulation measures should be added according to the actual ambient temperature to ensure the temperature and humidity of the structural concrete during the curing period.

[0089] S6: Prestressed construction.

[0090] The bundle is threaded using the traction method. Before threading the bundle, pressurized water should be used to flush out debris in the hole, and the presence of holes should be observed. The moisture in the hole should then be blown dry with an air compressor. When threading the bundle, the front end of the steel strand bundle is tied tightly and wrapped with a special steel sleeve so that it can pass through the pipeline smoothly. After the concrete strength reaches 90% of the design strength and the age is greater than 7 days, the tensioning operation begins. After the tensioning is completed, the prestressed tendons and anchors are sealed with cement mortar. Grouting begins after the compressive strength of the cement slurry reaches 2Mpa, and the sealing anchor concrete construction is carried out immediately after the grouting construction is completed.

[0091] S7: Formwork and support removal.

[0092] The templates and brackets are removed from top to bottom.

[0093] The implementation principle of a cast-in-place box girder construction process in an embodiment of the present application is: adopting a modular design concept, different special components are required in different links in the construction of cast-in-place box girders, each component can independently complete a specific task and is easy to disassemble and assemble; ensuring that all distribution beams 6 can be accurately placed at the center position of the support seat 41 and maintained in the same horizontal plane, effectively reducing the safety hazards caused by uneven settlement, thereby enhancing safety and stability; thereby realizing the modularization and standardization of cast-in-place box girder construction, greatly improving construction efficiency and safety, enhancing project quality, and reducing maintenance costs.

[0094] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cast-in-place box girder construction process, characterized in that: The following steps are involved: S1: Construction of support cushion (1); The foundation is leveled and compacted according to the plan. After the leveling and compaction of the foundation is completed and accepted, concrete pouring construction is carried out to form a support cushion layer (1); S2: Scaffold erection; S21: Before the support is erected, the base is installed according to the support erection plan; S22: Installing the vertical pole (2); inserting the vertical pole (2) into the already placed base, and ensuring a firm connection between the vertical pole (2) and the base; S23: Install the transverse horizontal rod (22) and the longitudinal horizontal rod (23); S24: Install the diagonal tie rod (25); S25: successively installing the upper vertical poles (2), the transverse horizontal poles (22), the longitudinal horizontal poles (23) and the diagonal brace rods (25); S26: inserting an adjustable top support into the top of the vertical pole (2) located at the uppermost layer, adjusting the adjustable top support to a supporting height, and making the supporting heights of all the adjustable top supports be located on the same horizontal plane; S27: Install the distribution beam (6); S3: stent preloading; After the support is erected and accepted, the square timber (61) is laid horizontally on the top surface of the distribution beam (6), and then the bottom template (62) is laid on the top surface of the square timber (61), and a pre-compression test is performed on the top surface of the bottom template (62); S4: Installation of side formwork (7) and pouring of top slab concrete; S41: Install back ribs and support components; S42: Install a crossbeam (68) on the top surface of the back rib, and install a side template (7) on the top surface of the crossbeam (68); S43: tying bottom formwork reinforcement (71) on the top surface of the bottom formwork (62), tying side formwork reinforcement (72) on the inner side surface of the side formwork (7), and installing the prestressed pipe; then tying the crossbeam reinforcement (73) and the longitudinal beam reinforcement (74) on the top surface of the bottom formwork reinforcement (71); S44: installing and fixing the bottom web inner mold (75); S45: pouring of bottom web concrete; S46: the bottom web inner mold (75) is removed; S47: Top plate inner mold installation; S5: Concrete curing; S6: Prestressed construction; S7: Formwork and support removal.

2. A cast-in-place box girder construction process according to claim 1, characterized in that: In S22, the base comprises a bottom plate (3) mounted on the top surface of the support cushion layer (1) and a starting rod (31) vertically fixed on the top surface of the bottom plate (3); the bottom end of the vertical rod (2) is fixedly connected with an insert block (21); the top end of the starting rod (31) is provided with a slot (311) for plugging with the insert block (21); and the starting rod (31) is provided with a threaded pin (312) for locking the insert block (21) in the slot (311).

3. A cast-in-place box girder construction process according to claim 1, characterized in that: In S23, the rod ends of the transverse horizontal rod (22) and the rod ends of the longitudinal horizontal rod (23) are fixedly connected to the first buckle joint (221), and a connecting plate (24) that is snap-fitted to the first buckle joint (221) is fixedly sleeved on the circumferential side of the vertical rod (2), and a plurality of evenly distributed insertion holes (241) are provided on the connecting plate (24), and a wedge-shaped pin (242) that passes through the insertion hole (241) is vertically penetrated on the first buckle joint (221).

4. A cast-in-place box girder construction process according to claim 3, characterized in that: In S24, the rod end of the inclined rod (25) is fixedly connected to a second buckle joint (251) that is clamped to the connecting plate (24), and the second buckle joint (251) is connected to the socket (241) on the connecting plate (24) through a wedge pin.

5. A cast-in-place box girder construction process according to claim 1, characterized in that: In S26, the adjustable top support includes a vertically arranged screw rod (4), a support seat (41) fixedly connected to the top end of the screw rod (4), and a threaded sleeve (42) threadedly connected to the circumference of the screw rod (4). The inner side wall of the vertical rod (2) is provided with four equally spaced limit grooves (27), and the screw rod (4) is provided with a limit end inside which can limit the limit groove (27).

6. A cast-in-place box girder construction process according to claim 5, characterized in that: An accommodating cavity (43) is provided inside the screw rod (4), and the limiting member comprises an adjusting rod (44) vertically penetrating the inner bottom wall of the supporting seat (41) and threadedly connected to the screw rod (4), an abutting platform (45) fixedly connected to the bottom end of the adjusting rod (44), a fixed shaft (46) horizontally fixed inside the accommodating cavity (43), a spring sheet (47) arranged on the fixed shaft (46), and a limiting block (48) fixed on the spring sheet (47); when the abutting platform (45) abuts against the opening of the spring sheet (47), the limiting block (48) extends into the limiting groove (27) corresponding to the position.

7. A cast-in-place box girder construction process according to claim 6, characterized in that: When the abutment platform (45) abuts against the spring sheet (47), so that the limiting block (48) extends into the limiting groove (27), the top end of the adjustment rod (44) is flush with the inner bottom wall of the support seat (41).

8. A cast-in-place box girder construction process according to claim 6, characterized in that: Two symmetrically arranged connecting ears (422) are fixedly connected to the circumferential side of the threaded sleeve (42), and a locking piece is detachably connected to the connecting ear (422), and a locking end of the locking piece abuts against the vertical rod (2), thereby achieving locking.

9. A cast-in-place box girder construction process according to claim 8, characterized in that: The locking member comprises a fixing tube (5) detachably connected to the connecting ear (422) and arranged coaxially with the vertical pole (2), an abutting sleeve (51) threadedly connected to the fixing tube (5), and a locking sleeve arranged on the top of the inner wall of the fixing tube (5); when the abutting sleeve (51) abuts against the locking sleeve, the locking end of the locking sleeve abuts against the peripheral side of the vertical pole (2), thereby achieving locking.

10. A cast-in-place box girder construction process according to claim 9, characterized in that: The top surface of the fixed cylinder (5) is fixedly connected to two symmetrically arranged vertical shafts (52), the top end of each vertical shaft (52) is rotatably connected to a clamping block (53), and the fixed cylinder (5) is detachably connected to the connecting ear (422) via the clamping block (53).

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