Long cantilever concrete beam truss type hanging bracket and construction technology thereof

Abstract

The invention relates to a long cantilever concrete beam truss type hanging bracket and a construction technology thereof. The long cantilever concrete beam truss type hanging bracket comprises a bridge girder constructed section erected on a pier, a main longitudinal beam module, a bottom longitudinal beam module, a formwork assembly and a hanging mechanism for connecting the bottom longitudinal beam module and the main longitudinal beam module, and the hanging bracket is installed on the side, close to a to-be-constructed section of a next bridge girder, of the bridge girder constructed section. The main longitudinal beam module is erected at the top end of a constructed section of a bridge girder and used for bearing main stress of the cantilever hanging bracket. The bottom longitudinal beam module is installed at the bottom end of the constructed section of a bridge girder and used for bearing the main load of the cantilever hanging bracket, and the formwork assembly is installed on the bottom longitudinal beam module. The main longitudinal beam module and the bottom longitudinal beam module are arranged at the upper end and the lower end of the bridge main beam respectively, the rear anchor assembly and the hanging mechanism are arranged between the main longitudinal beam module and the bottom longitudinal beam module, a stable truss type hanging bracket can be built in the air, and large-span beams can be conveniently subjected to suspended pouring.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete beam construction, and particularly to a truss-type hanger for long cantilever concrete beams and its construction technology. Background Technique

[0002] The truss-type hanger for long cantilever concrete beams is a structure used to support and fix the casting construction of the main long cantilever concrete beam, and is used for the cantilever casting construction of bridges. Its core function is to bear the load of the concrete beam during the casting process to ensure the stable and safe force during the casting construction.

[0003] Long-span concrete cable-stayed bridges are usually designed for large-segment cable-stayed hanging basket cantilever casting construction. Due to the large length of the hanging basket, in order to meet the requirements of the installation space of the cable-stayed hanging basket, it is usually necessary to cast the 0#, 1#, and 2# blocks of the main concrete beam on-site (the length of the cast-in-place section is determined according to the length of the cable-stayed hanging basket). For the 0# block of the main beam, the formwork can be erected on the pier crossbeam position, and a bracket is supplemented for casting construction. However, for the 1# and 2# blocks, due to the large cantilever length, it is impossible to directly erect the formwork on the existing structure of the pier, and it is difficult to meet the large-segment load-bearing requirements when using the bracket as the force-bearing structure. Existing solutions: When the pier height is relatively low, a floor bracket can be erected as the force-bearing structure, and a bracket is set on the pier as an auxiliary structure. When the pier is relatively high, such as more than 40m, it involves high-altitude construction. The installation of the floor bracket is difficult and its stability is difficult to guarantee, and the safety risk is high.

[0004] Therefore, for the construction of the 1# block of the main concrete beam of the high-tower large-segment cable-stayed bridge, it is necessary to provide a new truss-type hanger for long cantilever concrete beams to solve the above technical problems. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a truss-type hanger for long cantilever concrete beams and its construction technology. The hanger has a robust structure, is convenient for the suspended casting of large-span cantilever beams, and the installation and positioning of the hanger are accurate, which can improve the quality of the later-stage bridge casting.

[0006] To achieve the above technical purpose, the present invention provides a truss-type hanger for long cantilever concrete beams, including a bracket erected on the pier and the constructed section of the bridge main beam. The hanger is installed on one side of the constructed section of the bridge main beam adjacent to the next section of the bridge main beam to be constructed, and supports the construction of the next section of the bridge main beam to be constructed. The hanger includes a main longitudinal beam module, a bottom longitudinal beam module, a formwork assembly, and a hanging mechanism connecting the main longitudinal beam module and the bottom longitudinal beam module;

[0007] The main longitudinal beam module is erected on the top of the constructed section of the bridge main beam, and a part of it extends to the outside of the construction end of the constructed section of the bridge main beam to form a cantilever section. The main longitudinal beam module is used to bear the main force of the cantilever hanger;

[0008] The bottom longitudinal beam module is installed in parallel on the bottom surface of the constructed section of the bridge main beam, with a part of it extending to the outside of the construction end of the constructed section of the bridge main beam, and the extension length of the bottom longitudinal beam module is greater than that of the main longitudinal beam module. The bottom longitudinal beam module is used to bear the main load of the hanging scaffold; the formwork assembly is installed on the bottom longitudinal beam module;

[0009] The hanging mechanism is located at the cantilever section of the main longitudinal beam module and includes an upper cross beam, a lower cross beam, and reinforcing suspension rods. The upper cross beam is fixedly installed on the top of the main longitudinal beam module, the lower cross beam is fixed to the bottom of the bottom longitudinal beam module, and there are two groups of reinforcing suspension rods, which are respectively arranged on both sides of the upper cross beam, and the upper ends of the reinforcing suspension rods are fixedly connected to the upper cross beam, and the lower ends are fixedly connected to the lower cross beam.

[0010] A further technical solution of the present invention: The main longitudinal beam module includes a leveling cross beam and an upper Bailey beam group. There are multiple leveling cross beams, and the multiple leveling cross beams are installed on the top of the constructed section of the bridge main beam. The upper Bailey beam group is installed on the multiple leveling cross beams and partially extends to the outside of the construction end of the constructed section of the bridge main beam to form a cantilever frame. There are multiple rear anchor assemblies on the rear side of the upper Bailey beam group away from the cantilever end; the hanging mechanism is installed on the cantilever section of the upper Bailey beam group.

[0011] A further technical solution of the present invention: The bottom longitudinal beam module includes a lower Bailey beam group and multiple suspension beams. The lower Bailey beam group is arranged in parallel at the bottom of the constructed section of the bridge main beam and is integrated with the construction underframe of the constructed section of the bridge main beam. A part of the lower Bailey beam group extends to the outside of the construction end of the constructed section of the bridge main beam, and the extended part of the lower Bailey beam group is located above the lower cross beam and is fixedly connected to the lower cross beam by bolts; one end of the suspension beam is fixedly connected to one side of the bracket near the construction end, and the other end is connected to the bottom of the lower Bailey beam group. The formwork assembly is installed on the lower Bailey beam group.

[0012] A preferred technical solution of the present invention: The rear anchor assembly includes an anchoring suspension rod, and the anchoring suspension rod is fixedly connected to a reserved part reserved on the constructed section of the bridge main beam through a nut. The top end of the anchoring suspension rod passes through a balance beam installed on the upper Bailey beam group.

[0013] Preferred technical solution of the present invention: The leveling cross beam includes a bottom plate beam, which is fixedly installed at the top of the constructed section of the bridge main beam, and the gap between the bottom plate beam and the constructed section of the bridge main beam is filled with concrete grout; a T-shaped groove is formed on the bottom plate beam, and a support seat is fixedly installed at one end of the T-shaped groove on the bottom plate beam. A cushion beam is hinged at the top of the support seat, a lead screw is rotatably installed on the support seat, a T-shaped sliding seat is threadedly installed on the lead screw, an adjusting plate is hinged on the T-shaped sliding seat, and the end of the adjusting plate away from the T-shaped sliding seat is hinged to the cushion beam. The T-shaped sliding seat is slidably matched with the T-shaped groove, and one end of the lead screw passes through the T-shaped groove and is fixedly installed with a hand wheel.

[0014] Preferred technical solution of the present invention: The formwork assembly includes a bottom formwork, which is composed of combined steel plates and is fixedly installed on the lower Bailey beam group, and side formworks are installed on the bottom formwork. The formwork assembly also includes an inner formwork, which is inserted into the holes of the constructed section of the bridge main beam, and a protection assembly is installed on the bottom formwork.

[0015] Preferred technical solution of the present invention: Prestressed backing plates and double nuts for locking are provided on the lifting beam.

[0016] Preferred technical solution of the present invention: The protection assembly includes a guardrail, an upper cross beam protection platform, a lower cross beam protection platform, a bottom basket protection platform and upper and lower ladders, and the guardrail is arranged on the outer edge of the bottom formwork.

[0017] The present invention also provides a construction technology for a long-cantilever concrete beam truss-type hanging bracket, which specifically includes the following steps:

[0018] S1. Installation of the bottom longitudinal beam module: The bottom longitudinal beam module includes a lower Bailey beam group and multiple suspension beams. One end of each suspension beam is anchored on one side of the adjacent construction end of the bracket, and the lower Bailey beam group is installed at the bottom of the constructed section of the bridge main beam. The lower Bailey beam group is docked with the original construction bottom frame at the bottom of the constructed section of the bridge main beam, and a part of the lower Bailey beam group extends to the outside of the construction end of the constructed section of the bridge main beam to form a lower cantilever frame, and the other ends of multiple suspension beams are fixedly connected to the cantilever section of the lower Bailey beam group;

[0019] S2. Installation of the main longitudinal beam module: First, level the leveling cross beam and then fill the bottom densely with concrete or grout, leaving holes for the installation of the rear anchor and the suspender during filling; install the upper Bailey beam group on the leveled leveling cross beam and use channel steel as a limit. A part of the upper Bailey beam group extends to the outside of the construction end of the constructed section of the bridge main beam to form an upper cantilever frame, and the area of the upper Bailey beam group away from the cantilever end is anchored to the top of the constructed section of the bridge main beam through the rear anchor assembly;

[0020] S3. Installation of the hanging mechanism: Install the upper crossbeam on the upper Bailey beam group, then install the strengthening suspension rods at both ends of the upper crossbeam. The bottom end of each strengthening suspension rod extends below the lower Bailey beam group. Then install the lower crossbeam on the strengthening suspension rods, and install double nuts at both ends of the strengthening suspension rods for locking.

[0021] S4. Installation of the formwork assembly: After the hanging mechanism is installed, install the formwork assembly on the lower Bailey beam group.

[0022] S5. Preloading of the hanging bracket: After completing step S4, conduct preloading according to the pouring range and construction load combination, and use preloading blocks + water bags for preloading.

[0023] A preferred technical solution of the present invention: In step S4, the formwork assembly includes a bottom formwork, side formworks, and inner formworks. The bottom formwork is installed on the lower Bailey beam group, the side formworks and inner formworks are both installed on the bottom formwork, and a protective component is installed on the hanging bracket. The protective component includes a guardrail, an upper crossbeam protective platform, a lower crossbeam protective platform, a bottom basket protective platform, and upper and lower ladders.

[0024] Compared with the related technologies, a truss-type hanging bracket for a long cantilever concrete beam provided by the present invention has the following beneficial effects:

[0025] (1) For the truss-type hanging bracket for a long cantilever concrete beam provided by the present invention, by respectively arranging a main longitudinal beam module and a bottom longitudinal beam module at the upper and lower ends of the casting block of the 0-block of the bridge main beam, and arranging a rear anchor component and a hanging mechanism between the main longitudinal beam module and the bottom longitudinal beam module, a stable truss-type hanging bracket can be built in the air, which is convenient for the suspended casting of long-span beams.

[0026] (2) When the main longitudinal beam module of the present invention is installed, by using the cooperation of the bottom beam plate, support seat, cushion beam, lead screw, T-shaped sliding seat, adjusting plate, handwheel, and T-shaped groove of the leveling crossbeam, it is convenient to level when installing the upper Bailey beam group, ensuring accurate installation and positioning of the overall hanging bracket, which helps to improve the forming quality of the later bridge casting. Brief Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a preferred embodiment of the present invention;

[0028] Figure 2 It is Figure 1 a schematic structural diagram of the hanging bracket from another perspective in

[0029] Figure 3 It is a schematic structural diagram of the leveling crossbeam installed on the bridge main beam of the present invention;

[0030] Figure 4 It is a schematic structural diagram of the extended Bailey beam group installed on the bridge main beam of the present invention;

[0031] Figure 5 Schematic structural diagram of the leveling cross beam provided by the present invention;

[0032] Figure 6 Flow chart of the construction technology of the long cantilever concrete beam truss type hanger in the present invention.

[0033] Reference numerals in the figure: 1, constructed section of the bridge main beam; 2, main longitudinal beam module; 21, leveling cross beam; 211, bottom plate beam; 212, support seat; 213, cushion beam; 214, lead screw; 215, T-shaped sliding seat; 216, adjusting plate; 217, hand wheel; 218, bubble level; 201, T-shaped groove; 22, upper Bailey beam group; 3, bottom longitudinal beam module; 31, suspension beam; 32, lower Bailey beam group; 4, rear anchor assembly; 41, anchoring suspension rod; 42, cross beam; 43, prestressed backing plate; 5, hanging mechanism; 51, upper cross beam; 52, strengthening suspension rod; 53, lower cross beam; 6, formwork assembly; 61, bottom formwork; 62, side formwork; 63, inner formwork; 7, protection assembly; 8, bridge pier; 9, bracket; 10, construction chassis. Specific embodiments

[0034] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] The following describes in detail the specific implementation of the present invention with reference to specific embodiments.

[0036] A long cantilever concrete beam truss type hanger provided in Embodiment 1 is used for the construction of the starting section of the cable-stayed bridge main beam, and includes the 0# block bridge main beam section at the starting end of the cable-stayed bridge. The 0# block bridge main beam section is erected above the bridge pier 8 and is formed in advance by driving a bracket 9 above the bridge pier 8, erecting a cross beam support and a formwork and then pouring concrete. The hanger is mainly used as a support structure during the construction of the long cantilever section of the 0# block bridge main beam section or the 1# block main beam section adjacent to the 0# block bridge main beam section. The hanger is installed at the end of the constructed 0# block bridge main beam section; as Figures 1 to 5 shown, the hanger includes a main longitudinal beam module 2 erected on the top of the constructed section 1 of the bridge main beam, a bottom longitudinal beam module 3 installed at the bottom of the constructed section 1 of the bridge main beam, and a formwork assembly 6 installed on the bottom longitudinal beam module 3. The main longitudinal beam module 2 is used to bear the main force of the cantilever hanger, and the bottom longitudinal beam module 3 is used to bear the main load of the cantilever hanger. A hanging mechanism 5 is provided between the bottom longitudinal beam module 3 and the main longitudinal beam module 2.

[0037] When in use, first fix the bottom longitudinal beam module 3 at the bottom of the constructed section 1 of the bridge main beam, then install the main longitudinal beam module 2 at the top of the constructed section 1 of the bridge main beam, and use the hanging mechanism 5 to fix the bottom longitudinal beam module 3 and the main longitudinal beam module 2 to build a truss-type hanger body, and then install the formwork assembly 6 on the truss-type hanger body, and then the bridge can be cast-in-place constructed. The entire truss-type hanger body does not need to build a complex beam-column support frame, which is easy to build and convenient for cast-in-place construction of large-span suspended beams.

[0038] In embodiment 1 of the present invention, please refer to Figures 1 to 3 As shown, the main longitudinal beam module 2 includes a leveling beam 21 and an upper Bailey beam group 22. There are multiple leveling beams 21, and multiple leveling beams 21 are equidistantly installed on the top surface of the constructed section 1 of the bridge main beam. The upper Bailey beam group 22 includes multiple Bailey beam frames, one end of each Bailey beam frame is located above the constructed section 1 of the bridge main beam that has been completed, and the other end extends horizontally out of the constructed section 1 of the bridge main beam to form a cantilever structure, and the upper Bailey beam group 22 is installed on multiple leveling beams 21; the hanging mechanism 5 is installed on the cantilever section of the upper Bailey beam group 22, and the hanging mechanism 5 includes an upper beam 51, and the upper beam 51 is fixedly installed on the top of the upper Bailey beam group 22 by bolts, and reinforcing hangers 52 are installed on both sides of the upper beam 51, and a lower beam 53 is suspended at the bottom end of the reinforcing hanger 52, and the lower beam 53 is fixedly connected to the bottom longitudinal beam module 3. Figure 5 As shown, the leveling beam 21 includes a bottom beam plate 211, which is fixedly installed on the top surface of the constructed section 1 of the bridge main beam, and a T-slot 201 is opened on the bottom beam plate 211, a support seat 212 is fixedly installed on one end of the T-slot 201 on the bottom beam plate 211, a cushion beam 213 is hinged on the top of the support seat 212, a lead screw 214 is rotatably installed on the support seat 212, a T-slide 215 is threadedly installed on the lead screw 214, an adjustment plate 216 is hinged on the T-slide 215, and the end of the adjustment plate 216 away from the T-slide 215 is hinged to the cushion beam 213, the T-slide 215 is slidably matched with the T-slot 201, and one end of the lead screw 214 passes through the T-slot 201 and is fixedly installed with a handwheel 217.

[0039] In Example 1, Figures 1 to 3 As shown, the upper Bailey beam group 22 is provided with a plurality of rear anchor assemblies 4 at the rear end thereof located above the constructed section 1 of the bridge main beam. The rear anchor assembly 4 includes an anchoring hanger 41. The anchoring hanger 41 is fixedly connected to a reserved part reserved on the constructed section 1 of the bridge main beam by a nut. A shoulder beam 42 is installed on the top end of the anchoring hanger 41 through the upper Bailey beam group 22. A prestressed pad 43 and a double nut for locking are provided on the shoulder beam 42.

[0040] It should be noted that when the main longitudinal beam module 2 is erected, first place the bottom plate 211 of the leveling cross beam 21 on the constructed section 1 of the bridge main beam. After placement, rotate the lead screw 214 by turning the handwheel 217. When the lead screw 214 rotates, it drives the T-shaped sliding seat 215 to slide along the T-shaped groove 201. During the sliding process, adjust the support angle of the cushion beam 213 through the adjusting plate 216 until it is leveled. After leveling, install the upper Bailey beam group 22 on the cushion beams 213 of several leveling cross beams 21 to complete the installation of the main longitudinal beam module 2. Among them, the upper Bailey beam group 22 consists of 7 Bailey beams, which are hoisted, assembled and positioned according to the design position and connected horizontally into a group. After installation, it is anchored by the rear anchor assembly 4. Specifically, 21 φ32 PSB930 high-strength rolled steel bars are used as the anchoring suspension rods 41 for the single-sided rear anchor, which are anchored on the web or top plate of the beam. The anchored high-strength rolled steel bars on the web are embedded in the web of the beam during the construction of the 0# block, and the embedding depth is not less than 1m, and the exposed length is not less than 20cm for installing the connector to extend. A prestressed backing plate 43 and a single nut are arranged at the bottom of the anchoring position. For the high-strength rolled steel bars anchored on the top plate, φ48 steel pipes are pre-embedded in advance to facilitate the installation and removal construction of the high-strength rolled steel bars. After the installation of the high-strength rolled steel bars is completed, pre-tension is applied. The designed tension of each high-strength rolled steel bar is 30t. Except for the high-strength rolled steel bars embedded in the beam body, which use single gaskets and nuts, the rest of the high-strength rolled steel bars use double nuts.

[0041] In this Embodiment 1, a bubble level 218 is embedded on the outer side wall of the cushion beam 213 for observation during leveling to ensure that it can be adjusted to a horizontal support. The gap between the bottom plate 211 and the constructed section 1 of the bridge main beam is filled with concrete grout, so as to level first, which is convenient for quick leveling support in the later stage.

[0042] In Embodiment 1 of the present invention, please refer to Figures 1 to 5, the bottom longitudinal beam module 3 includes a lower Bailey beam group 32 and a plurality of suspension beams 31. The plurality of suspension beams 31 are evenly distributed at the bottom of the lower Bailey beam group 32. One end of each suspension beam 31 is fixedly connected to the end face of the bracket 9, and the other end is fixedly connected to the bottom of the lower Bailey beam group 32. The lower Bailey beam group 32 includes a plurality of lower Bailey beam frames. The lower Bailey beam group 32 is parallel to the upper Bailey beam group 22, and the cantilever length is greater than that of the upper Bailey beam group 22. The lower Bailey beam group 32 is arranged above the lower cross beam 53 and is integrally connected with the construction bottom frame 10 at the bottom of the constructed section 1 of the bridge main beam. The construction bottom frame 10 is an original structure, and it can adopt the same structure as the lower Bailey beam group 32 or other support frame structures. The lower Bailey beam group 32 is fixedly connected to the lower cross beam 53 by bolts. The formwork assembly 6 is installed on the lower Bailey beam group 32. The formwork assembly 6 includes a bottom formwork 61, which is composed of composite steel plates and is fixedly installed on the lower Bailey beam group 32. A side formwork 62 is installed on the bottom formwork 61. The formwork assembly 6 further includes an inner formwork 63, which is inserted into the hole of the constructed section 1 of the bridge main beam. A protection assembly 7 is installed on the bottom formwork 61; in this embodiment, the protection assembly 7 includes a guardrail, an upper cross beam protection platform, a lower cross beam protection platform, a bottom basket protection platform and upper and lower ladders. The guardrail is arranged at the outer edge of the bottom formwork 61. In this way, it is convenient to use the guardrail, upper cross beam protection platform, lower cross beam protection platform, bottom basket protection platform and upper and lower ladders of the protection assembly 7 to carry out safety protection on the truss type hanging frame, which is convenient to improve the safety of standing construction.

[0043] In Embodiment 1, when installing the bottom longitudinal beam module 3, a plurality of suspension beams 31 are fixed to one side of the constructed section 1 of the bridge main beam one by one, and then the lower Bailey beam group 32 composed of multiple groups of Bailey beams spliced together is fixed to the suspension beams 31 one by one to complete the installation of the bottom longitudinal beam module 3. Then, the bottom formwork 61 of the formwork assembly 6 is installed on the lower Bailey beam group 32, and the side formwork 62 and the inner formwork 63 are installed on the bottom formwork 61 one by one. After the formwork installation is completed, the steel reinforcement cage can be placed for pouring.

[0044] In Example 2, the long-cantilever concrete beam truss type hanger in Example 1 is used to construct the starting section of the bridge main girder of the Hanjiang River Extra-large Bridge. To meet the installation space requirements of the cable-stayed hanging basket and smoothly realize the cantilever construction of the cable-stayed hanging basket for the subsequent sections of the cable-stayed bridge, it is necessary to carry out in-situ casting construction for Block 0 and Block 1 of the Hanjiang River Extra-large Bridge. The height of the main girder Block 0 of the Hanjiang River Extra-large Bridge is 3 m, the length of the beam section is 22 m, the single-side cantilever of the main girder is 6.75 m, the length of Section 1 is 5 m, and Block 0 is located at an altitude of 66 m. The structural dimensions of Blocks 0 and 1 of the Hanjiang River Extra-large Bridge are large, the construction height is high, and the cantilever length is large. Conventional brackets cannot meet the on-site construction requirements. If beam-column type supports are used, the amount of support work will be greatly increased, and for the subsequent cable-stayed hanging basket assembly construction, a cable-stayed hanging basket assembly platform still needs to be fabricated, greatly increasing the construction difficulty and cost. The single-side cantilever length of the main girder Block 0 is 6.75 m. Limited by the height limit of the lower crossbeam, the conventional bracket design cannot realize the in-situ casting construction of the cantilever section of Block 0 and Block 1.

[0045] In Example 2, the part of the main girder section of Block 0 of the bridge is erected on the pier 8. This part is formed by directly erecting a bracket 9 on the pier 8, erecting a bottom longitudinal beam on the top of the bracket 9, and then placing a formwork above the bottom longitudinal beam to pour concrete. After the construction of this part is completed and the concrete strength reaches the design requirements, a hanger is installed for the construction of the cantilever section. The construction process flow of the long-cantilever concrete beam truss type hanger is as Figure 6 shown, and specifically includes the following steps:

[0046] S1. Installation of the bottom longitudinal beam module: Anchor the suspension beam 31 on one end face of the bracket 9 adjacent to the cantilever section, install the lower Bailey beam group 32 at the bottom of the constructed section 1 of the bridge main girder, and part of the lower Bailey beam group 32 extends to the outside of the construction end of the constructed section 1 of the bridge main girder to form a lower cantilever frame. Connect multiple lower Bailey beam sheets of the lower Bailey beam group 32 to the original bottom longitudinal beam, and fix the cantilever section of the lower Bailey beam group 32 on the suspension beam 31; Limit and fix the Bailey beam bottom longitudinal beam and the front and rear crossbeams with angle steel.

[0047] S2. Installation of the main longitudinal beam module: First, level the leveling crossbeam 21 and then fill the bottom densely with concrete or grout. Pay attention to reserving holes for the rear anchor and the suspender during filling. Then, install the upper Bailey beam group 22 on the leveled leveling crossbeam 21 and use channel steel as a limit. A part of the upper Bailey beam group 22 extends to the outside of the construction end of the constructed section 1 of the bridge main beam, forming an upper cantilever frame, and the length of the upper cantilever frame is less than that of the lower cantilever frame. Anchor the area of the upper Bailey beam group 22 far from the cantilever end to the constructed section 1 of the constructed bridge main beam through the rear anchor assembly to enhance the structural stability. The upper Bailey beam group 22 is strengthened by setting reinforcing chord bars at the top and bottom with standard 321-type Bailey beam plates. There are a total of 3 groups of upper Bailey beam plates. The distance between the left and right Bailey beam groups is 22.5 + 90 + 22.5 + 60 + 3×45 cm, and the middle Bailey beam group is 3×22.5 + 45 + 3×22.5 cm. Each group corresponds to the position of the main beam web. The Bailey beams are installed on the crossbeam after leveling and channel steel is used as a limit.

[0048] S3. Installation of the hanging mechanism: Install the upper crossbeam 51 on the upper Bailey beam group 22, then install the reinforcing suspender 52 on the upper crossbeam 51 and make its bottom end extend below the lower Bailey beam group 32. Then install the lower crossbeam 53 on the reinforcing suspender 52, and install double nuts at both ends of the reinforcing suspender 52 for locking. The upper crossbeam 51 and the lower crossbeam 53 are made of 2HM588×300 / 3I56a steel, and the reinforcing suspender 52 is made of PSB930 Φ32mm precision rolled threaded steel. A crossbeam is set at the anchoring position, and prestressed backing plates and double nuts are equipped.

[0049] S4. Installation of the formwork assembly: After the hanging mechanism 5 is installed, install the bottom formwork 61, the side formwork 62, and the inner formwork 63 on the lower Bailey beam group 32 one by one. The bottom formwork 61 is made of composite steel formwork, the side formwork 62 is made of customized steel formwork, and the inner formwork 63 is reinforced with disk locks + steel trusses.

[0050] S5. Installation of the protection assembly: The protection assembly 7 includes a guardrail, an upper crossbeam protection platform, a lower crossbeam protection platform, a bottom basket protection platform, and upper and lower ladders. The guardrail is set at the outer edge of the bottom formwork 61. In this way, it is convenient to use the guardrail, the upper crossbeam protection platform, the lower crossbeam protection platform, the bottom basket protection platform, and the upper and lower ladders of the protection assembly 7 to carry out safety protection for the truss-type hanging scaffold, which is convenient to improve the safety of standing construction.

[0051] S6. Preloading of the hanging bracket: After completing step S4, preloading is carried out according to the pouring range and construction load combination, and precast concrete blocks + water bags are used for preloading; the preloading is carried out according to the pouring range and construction load combination. The construction loads mainly include: self-weight of the beam body, formwork and support loads, personnel and equipment loads, and concrete pouring and vibration loads; the formwork load is 4 KN / ㎡, the personnel and equipment load is 2.5 KN / ㎡, the concrete vibration load is 2 KN / ㎡, and the concrete pouring load is 2 KN / ㎡; precast concrete blocks with a size of 1×1×1 m and a weight of 2.4 t per block are used for preloading; the preloading is carried out by staged loading, as shown in Table 1 specifically:

[0052] Table 1 Quantity Table of Staged Loading and Preloading

[0053] After preloading, the maximum deformation of the hanging bracket is 24 mm, meeting the specification requirements. The settlement results are basically consistent with the calculations, and subsequent concrete pouring construction is carried out with good construction effects.

[0054] The above are only the embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A long cantilever concrete beam truss hanger, comprising a bracket (9) erected on a bridge pier (8) and a constructed section of a bridge main beam (1), characterized in that: The hanger is installed on a side of a constructed section of a bridge main beam (1) adjacent to a section of a next bridge main beam to be constructed, and supports the construction of the section of the next bridge main beam to be constructed. The hanger comprises a main longitudinal beam module (2), a bottom longitudinal beam module (3), a template assembly (6), and a hanging mechanism (5) connecting the main longitudinal beam module (2) and the bottom longitudinal beam module (3); The main longitudinal beam module (2) is erected on the top of the constructed section (1) of the bridge main beam, and part of it extends to the outside of the construction end of the constructed section (1) of the bridge main beam to form a cantilever section. The main longitudinal beam module (2) is used to bear the main force of the cantilever hanger; The bottom longitudinal beam module (3) is installed in parallel to the bottom surface of the constructed section (1) of the bridge main beam, and a portion of the bottom longitudinal beam module (3) extends to the outside of the construction end of the constructed section (1) of the bridge main beam, and the extension length of the bottom longitudinal beam module (3) is greater than that of the main longitudinal beam module (2), and the bottom longitudinal beam module (3) is used to bear the main load of the hanger; the template assembly (6) is installed on the bottom longitudinal beam module (3); The hanging mechanism (5) is located at the cantilever section of the main longitudinal beam module (2), and comprises an upper crossbeam (51), a lower crossbeam (53) and a reinforcing suspension rod (52); the upper crossbeam (51) is fixedly mounted on the top of the main longitudinal beam module (2); the lower crossbeam (53) is fixedly mounted on the bottom of the bottom longitudinal beam module (3); two groups of the reinforcing suspension rod (52) are respectively arranged on both sides of the upper crossbeam (51); the upper end of the reinforcing suspension rod (52) is fixedly connected to the upper crossbeam (51), and the lower end is fixedly connected to the lower crossbeam (53).

2. The long cantilever concrete beam truss hanger according to claim 1, characterized in that: The main longitudinal beam module (2) comprises a leveling beam (21) and an upper Bailey beam group (22), wherein a plurality of the leveling beams (21) are provided, wherein the plurality of leveling beams (21) are installed at the top of the constructed section (1) of the bridge main beam, and the upper Bailey beam group (22) is installed on the plurality of leveling beams (21) and partially extends to the outside of the construction end of the constructed section (1) of the bridge main beam to form a cantilever frame, and a plurality of rear anchor assemblies (4) are provided on the rear side of the upper Bailey beam group (22) away from the cantilever end; and the hanging mechanism (5) is installed on the cantilever section of the upper Bailey beam group (22).

3. A long cantilever concrete beam truss hanger according to claim 1 or 2, characterized in that: The bottom longitudinal beam module (3) comprises a lower Bailey beam group (32) and a plurality of cantilever beams (31); the lower Bailey beam group (32) is arranged in parallel at the bottom of the constructed section (1) of the bridge main beam and is connected to the construction base frame (10) of the constructed section (1) of the bridge main beam; a portion of the lower Bailey beam group (32) extends to the outside of the construction end of the constructed section (1) of the bridge main beam, and the extended portion of the lower Bailey beam group (32) is located above the lower cross beam (53) and is fixedly connected to the lower cross beam (53) by bolts; one end of the cantilever beam (31) is fixedly connected to a side of the bracket (9) adjacent to the construction end, and the other end is connected to the bottom of the lower Bailey beam group (32); the template assembly (6) is installed on the lower Bailey beam group (32).

4. The long cantilever concrete beam truss hanger according to claim 2, characterized in that: The rear anchor assembly (4) comprises an anchoring hanger (41), the anchoring hanger (41) being fixedly connected to a reserved part reserved on the constructed section (1) of the bridge main beam via a nut, and the top end of the anchoring hanger (41) passes through the upper Bailey beam group (22) and is provided with a shoulder pole beam (42).

5. The long cantilever concrete beam truss hanger according to claim 2, characterized in that: The leveling crossbeam (21) comprises a bottom beam plate (211), the bottom beam plate (211) being fixedly mounted on the top of the constructed section (1) of the bridge main beam, and the gap between the bottom beam plate (211) and the constructed section (1) of the bridge main beam is filled with concrete grout; a T-shaped groove (201) is provided on the bottom beam plate (211), a support seat (212) is fixedly mounted on one end of the bottom beam plate (211) at the T-shaped groove (201), and a cushion beam (213) is hingedly connected to the top of the support seat (212). ), a lead screw (214) is rotatably mounted on the support seat (212), a T-shaped slide (215) is threadedly mounted on the lead screw (214), an adjustment plate (216) is hingedly connected to the T-shaped slide (215), one end of the adjustment plate (216) away from the T-shaped slide (215) is hingedly connected to the cushion beam (213), the T-shaped slide (215) is slidably matched with the T-shaped slot (201), and one end of the lead screw (214) passes through the T-shaped slot (201) and is fixedly mounted with a hand wheel (217).

6. The long cantilever concrete beam truss hanger according to claim 3, characterized in that: The formwork assembly (6) comprises a bottom formwork (61), the bottom formwork (61) being composed of a composite steel plate and fixedly mounted on a lower Bailey beam assembly (32), and a side formwork (62) being mounted on the bottom formwork (61). The formwork assembly (6) further comprises an inner formwork (63), the inner formwork (63) being inserted into a hole of a constructed section (1) of a bridge main beam, and a protective assembly (7) being mounted on the bottom formwork (61).

7. The long cantilever concrete beam truss hanger according to claim 4, characterized in that: The shoulder beam (42) is provided with a prestressed pad (43) and double nuts for locking.

8. The long cantilever concrete beam truss hanger according to claim 6, characterized in that: The protection assembly (7) comprises a guardrail, an upper beam protection platform, a lower beam protection platform, a bottom basket protection platform and an up-and-down ladder, and the guardrail is arranged on the outer edge of the bottom template (61).

9. A construction process for a long cantilever concrete beam truss hanger according to any one of claims 2 to 8, characterized in that: The specific steps include: S1. Installation of bottom longitudinal beam module: The bottom longitudinal beam module includes a lower Bailey beam group and a plurality of cantilever beams. One end of each cantilever beam is anchored on the side of the bracket close to the construction end. The lower Bailey beam group is installed at the bottom of the constructed section of the bridge main beam. The lower Bailey beam group is butted with the original construction bottom frame at the bottom of the constructed section of the bridge main beam, and a portion of the lower Bailey beam group is extended to the outside of the construction end of the constructed section of the bridge main beam to form a lower cantilever frame, and the other ends of the plurality of cantilever beams are fixedly connected to the cantilever section of the lower Bailey beam group. S2. Installation of the main longitudinal beam module: First, fill the bottom of the leveling beam with concrete or grouting material, and reserve holes for rear anchors and hanger installation during filling; install the upper Bailey beam assembly on the leveling beam after leveling, and use channel steel as a limiter. Part of the upper Bailey beam assembly extends to the outside of the construction end of the constructed section of the bridge main beam to form an upper cantilever frame, and the area of ​​the upper Bailey beam assembly away from the cantilever end is anchored to the top of the constructed section of the bridge main beam through the rear anchor assembly; S3. Installation of the hanging mechanism: install the upper crossbeam on the upper Bailey beam group, then install the reinforcing suspension rods on both ends of the upper crossbeam, the bottom end of each reinforcing suspension rod extends below the lower Bailey beam group, then install the lower crossbeam on the reinforcing suspension rod, and install double nuts at both ends of the reinforcing suspension rod for locking; S4. Installation of formwork assembly: After the installation of the hanging mechanism is completed, the formwork assembly is installed on the lower Bailey beam group; S5. Preloading of the hanger: After completing step S4, preloading is performed according to the pouring range and construction load combination, using preloading blocks + water bags for preloading.

10. The construction process of a long cantilever concrete beam truss hanger according to claim 9, characterized in that: In the S4 step, the formwork assembly includes a bottom formwork, a side formwork and an inner formwork, the bottom formwork is installed on the lower Bailey beam group, the side formwork and the inner formwork are both installed on the bottom formwork, and a protection assembly is installed on the hanger, the protection assembly includes a guardrail, an upper beam protection platform, a lower beam protection platform, a bottom basket protection platform and up and down ladders.

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