Arch-beam combined bridge arch-doweling combined hanging basket cantilever casting combined construction method

Abstract

The present application relates to the field of arch beam combined bridge, and discloses a combined construction method of arch beam combined bridge arch buckling and hanging basket suspension pouring, which comprises the following steps: step one, completing bridge pier construction, pouring 0# segment of upper chord beam on the top of the bridge pier, and installing an upper chord hanging basket on the 0# segment of the upper chord beam; step two, after the lower chord hanging basket is lowered, pouring 1# segment of the lower chord arch, erecting a lower chord hanging basket on the 1# segment of the lower chord arch, and pouring the upper chord beam and the lower chord arch by using the hanging basket in sections; meanwhile, installing a lower buckling cable on each segment of the lower chord arch, and passing the middle part of the lower buckling cable through the bridge pier; meanwhile, the upper chord beam lags behind the lower chord arch by two segments in construction; meanwhile, erecting a support on the lower chord arch to support the bottom of the upper chord beam, and the support lags behind the upper chord beam by one segment in construction; and step three, removing the hanging basket on the lower chord arch, and pouring the closing segment by using the hanging basket on the upper chord beam. The operation space of the support and the hanging basket of the lower chord arch is prevented from partially overlapping.

Description

Technical Field

[0001] This invention relates to the field of arch-beam composite bridges, specifically to a construction method for arch-beam composite bridges that combines arch fastening with hanging baskets and cantilever casting. Background Technology

[0002] In the long-span bridge 1, the arch-beam composite bridge adopts a combination of upper chord beam and lower chord arch. The lower chord arch provides support for the upper chord beam, resulting in less mid-span deflection, a larger maximum span, and reduced self-weight, thus achieving higher economic efficiency.

[0003] For the construction of arch-beam composite bridges, our company has developed several construction schemes. The initial scheme is as follows: prioritize the construction of the lower chord arch, install the tie cables on the lower chord arch, erect scaffolding on the lower chord arch, and then complete the construction of the upper chord beam on the scaffolding. To ensure the balance between the tie cable tension and the upper chord beam load, the upper chord beam and the lower chord arch are usually constructed in segments, with the upper chord beam being constructed two stages behind the lower chord arch. To ensure the progress of the upper chord beam, the progress of the scaffolding erected on the lower chord arch cannot be too slow. Therefore, the working space of the scaffolding and the hanging basket of the lower chord arch inevitably overlaps to some extent. Cross-operation is not convenient for construction, inspection and maintenance, which increases the construction difficulty and reduces the construction efficiency. Summary of the Invention

[0004] The present invention aims to provide a construction method for arch-beam composite bridges that combines arch fastening with hanging baskets and cantilever casting, thereby avoiding partial overlap of the working space of the support frame and the hanging basket of the lower chord arch.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a combined arch-beam bridge construction method using a hanging basket and cantilever construction method. The arch-beam bridge includes an upper chord beam and a lower chord arch. Both the upper chord beam and the lower chord arch are constructed using a hanging basket, which includes an upper chord hanging basket and a lower chord hanging basket. The construction is carried out cantilevered from the central axis of the pier to both sides of the pier. One end of the upper chord beam and the arch foot of the lower chord arch are connected to the pier, and the other end of the upper chord beam is joined to the arch top of the lower chord arch. Both the upper chord beam and the lower chord arch are divided into several segments for casting. Includes the following steps: Step 1: Complete the pier construction, pour the upper chord beam section 0# on the top of the pier, and install the upper chord hanging basket on the upper chord beam section 0#. Step 2: After the upper chord formwork is lowered, the lower chord arch segment 1 is poured. The lower chord formwork is erected on the lower chord arch segment 1. Both the upper chord beam and the lower chord arch are poured in segments using the formwork. At the same time, the lower tie cable is installed on each segment of the lower chord arch, with the middle of the lower tie cable passing through the pier. Meanwhile, the upper chord beam is constructed two segments behind the lower chord arch. At the same time, a support frame is erected on the lower chord arch to support the bottom of the upper chord beam, and the support frame is constructed one segment behind the upper chord beam. Step 3: Remove the hanging basket on the lower chord arch and use the hanging basket on the upper chord beam to pour the closure section.

[0006] The beneficial effects of this plan are: 1. The construction of the upper chord beam lags behind the lower chord arch by two segments, and the scaffolding lags behind the upper chord beam by one segment, meaning the scaffolding lags behind the lower chord arch by three segments. Compared to directly erecting the upper chord beam formwork on the scaffolding, this scheme involves erecting and pouring the upper chord beam formwork on the upper chord hanging basket. The scaffolding only needs to support the remaining poured upper chord beam segments, thus delaying the scaffolding erection progress. This allows for sufficient space between the scaffolding and the lower chord hanging basket, preventing partial overlap of the working space between the scaffolding and the lower chord arch hanging basket. This facilitates construction, inspection, and maintenance, reduces construction difficulty, and improves construction efficiency.

[0007] 2. Since there is a lack of space to erect the lower chord hanging basket before the pouring of the lower chord arch section 1#, this plan requires prioritizing the erection of the upper chord hanging basket on the upper chord beam section #, so as to pour the lower chord arch section 1#. After the lower chord hanging basket is erected, the upper chord hanging basket can be discontinued and the upper chord beam can continue to be poured without dismantling. At the same time, a support is erected on the lower chord arch to prevent the cantilever end of the upper hanging basket from downward disturbance. Downward disturbance refers to downward deformation, and the degree of downward disturbance is called disturbance. The upper chord beam is poured using the upper chord hanging basket until the closure section construction is completed.

[0008] Furthermore, both the upper chord hanging basket and the lower chord hanging basket include a traveling system, a main truss system, a suspension system, and a bottom basket system. The traveling system is installed on the upper surface of the upper chord beam or the lower chord arch. The main truss system is installed on the traveling system and extends towards the cantilever end. The upper end of the suspension system is detachably connected to the main truss system, and the lower end of the suspension system is connected to the bottom basket system. The bottom basket system serves as a support platform to bear the construction load. In step two, the method of using a hanging basket to cast the upper chord beam and lower chord arch in segments is as follows: Step 2.1 Use the upper chord hanging basket to pour the upper chord beam section 1#. Install a lifting system on the main truss system of the upper chord hanging basket. The lifting system can drive the bottom basket system to move downward. Remove the connection between the upper end of the suspension system and the main truss system. Step 2.2: The lifting system moves the bottom basket system downward to the arch foot of the lower chord arch, extending the upper end of the suspension system to connect the upper end of the suspension system with the upper chord hanging basket main truss system. The lower chord arch section 1 is then poured with the bottom basket system as support. Step 2.3: The traveling system of the upper chord hanging basket drives the main truss system, lifting system, suspension system and bottom basket system to move forward together, and the bottom basket system is used as support to pour the lower chord arch section 2. Step 2.4: Install the travel system and main truss system of the lower chord hanging basket on the lower chord arch segments 1 and 2, connect the upper end of the main truss system of the lower chord hanging basket and the suspension system of the upper chord hanging basket, and convert the suspension system and bottom basket system of the upper chord hanging basket into the suspension system and bottom basket system of the lower chord hanging basket. Step 2.5: Use the lower chord hanging basket to pour the lower chord arch section 3, reinstall the suspension system and bottom basket system of the upper chord hanging basket, and use the upper chord hanging basket to pour the upper chord beam section 2. Step 2.6: Pour the remaining segments of the upper chord beam and lower chord arch until the segment above the closing segment of the lower chord arch is completed.

[0009] Furthermore, the lifting system includes several electric hoists; In step one, during the construction of the bridge pier, the lower chord arch section 0# is reserved for horizontal installation. The upper ends of the electric hoists are all connected to the main truss system of the upper chord hanging basket, and the lower ends of the electric hoists are all hung on the bottom basket system. In step 2.2, during the process of the electric hoist driving the bottom basket system to move downward, the upper end of the suspension system is temporarily fixed to the steel cable of the electric hoist; after the electric hoist drives the bottom basket system to move downward, the template of the lower chord arch section 1 is erected on the bottom basket system. The template of the bottom basket system and the template of the lower chord arch section 1 are detachably connected, and the template of the lower chord arch section 1 is connected to the lower chord arch section 0.

[0010] Furthermore, the suspension system of the upper chord hanging basket includes several suspension units, each of which includes a hanger and an extension rod. The upper and lower ends of the hanger are respectively provided with an upper connector and a lower connector. The upper end of the hanger passes through the main truss system of the upper chord hanging basket and is threadedly connected to the upper connector. The upper connector is supported on the main truss system. In step 2.2, the upper connecting piece is removed, and the hoist's cable is temporarily fixed with wire. The electric hoist drives the bottom basket system to move downward. The upper end of the extension rod passes through the main truss system of the upper chord hanging basket and is threadedly connected to the upper connecting piece. The upper connecting piece is supported on the main truss system. The extension connecting piece is threadedly connected to the lower end of the extension rod. The lower end of the extension connecting piece is threadedly connected to the upper end of the hoist. The wire on the hoist's cable and the electric hoist's cable is removed.

[0011] Furthermore, the threads of the hanger and the extension rod are in the same direction, and the lower end of the extension connector is welded with a conversion pad, through which the upper end of the hanger can pass; the main truss system of both the upper and lower chord hanging baskets includes a main truss, on which a front crossbeam and a rear crossbeam are provided. Each front or rear crossbeam is composed of two parallel I-beams, and the distance between the two I-beams is less than the width of the conversion pad; the bottom basket system of the upper chord hanging basket includes a front cantilever beam and a rear cantilever beam, with several longitudinal beams between the front and rear cantilever beams; one end of each longitudinal beam is hinged to the front cantilever beam, and several horizontally arranged support tubes are provided on the rear cantilever beam, with the other end of each longitudinal beam supported on the support tube, and the other end of each longitudinal beam can slide on the support tube; In step 2.4, the method for converting the suspension system and bottom basket system of the upper-curved basket into the suspension system and bottom basket system of the lower-curved basket is as follows: Step 2.4.1 During the installation of the main truss system of the lower chord hanging basket, make the hoisting rod of the upper chord hanging basket pass through the front or rear crossbeam of the lower chord hanging basket, and hang the upper end of the electric hoist on the front or rear crossbeam, and hang the lower end of the electric hoist on the front or rear cantilever beam. Step 2.4.2: Rotate the extension connector so that the conversion pad at the lower end of the extension connector is supported on the main truss system of the lower chord hanging basket. Remove the upper connector at the upper end of the extension rod. Rotate the extension rod so that the lower end of the extension rod is separated from the extension connector. Remove the extension rod and the electric hoist.

[0012] Furthermore, in step 2.4.2, after the conversion pad is supported on the front or rear crossbeam of the main truss system of the lower chord hanging basket, two limiting blocks are welded to the bottom of the conversion pad. The two limiting blocks are attached to both sides of the front or rear crossbeam, thereby limiting the spacing between the two I-beams that make up the front or rear crossbeam.

[0013] Furthermore, in step 2.1, longitudinal temporary prestress is applied to the upper side of segment 1 of the upper chord beam; In step 2.5, after the scaffold is erected, the temporary prestress applied to the upper chord beam segment 1 is removed.

[0014] 1. In this scheme, the forward direction of the upper chord hanging basket is the cantilever end of the upper chord beam. The upper chord hanging basket is erected on the 0# segment of the upper chord beam, and then the bottom basket of the upper chord hanging basket is lowered to the arch foot of the lower chord arch through the lifting system, providing a platform for the pouring of the 1# segment of the lower chord arch. Compared with directly erecting a platform at the arch foot of the lower chord arch, this scheme erects the upper chord hanging basket on the 0# segment of the upper chord beam, which provides sufficient operating space and footholds, eliminating the worry of falling off the platform and making the operation safer, so as to construct the 1# segment of the lower chord arch more safely.

[0015] 2. The top of the pier can provide sufficient support for the upper chord hanging basket. Compared with the existing technology, there is no need to build a cantilever platform, making the construction process safer and faster, so as to efficiently construct the lower chord arch section 1.

[0016] 3. After pouring the No. 2 section of the lower chord arch, the lower chord hanging basket is erected. The main truss system of the lower chord hanging basket provides support for the bottom basket system, thereby transferring the bottom basket system of the upper chord hanging basket to the lower chord hanging basket. This eliminates the cumbersome step of reinstalling the bottom basket system on the lower chord hanging basket and improves the construction efficiency of the lower chord arch.

[0017] 4. To facilitate the hoisting of materials for the lower chord arch and ensure sufficient construction space, the construction progress of the lower chord arch usually needs to precede that of the upper chord beam by several segments. The construction progress of the lower chord arch determines the overall construction progress. Therefore, in this scheme, the bottom basket system of the upper chord hanging basket is directly transferred to the lower chord hanging basket, allowing the lower chord arch to begin construction ahead of schedule. Meanwhile, the upper chord beam takes the opportunity to reinstall its suspension system and bottom basket system. After installation, the upper chord beam lags behind the lower chord arch by just a few segments. Subsequently, the upper chord beam and the lower chord arch are constructed simultaneously towards the cantilever end, which ensures both the construction progress and the construction space for the lower chord arch.

[0018] 5. During the construction of the bridge piers, a horizontally positioned lower chord arch section 0# is reserved to provide a connection point for the formwork of lower chord arch section 1#.

[0019] 6. Compared to using jacks to move the boom downwards, this solution uses an electric hoist to move the basket system downwards, which is faster and more efficient; Furthermore, during construction on high bridge piers, the wind load is significant, and the lower end of the gantry is in a free state, resulting in severe swaying. As the basket system moves downward, the wind load on the gantry gradually increases, causing even more severe swaying and making it prone to deformation and damage. In this design, the electric hoist's steel cable is more flexible than the gantry, and it can recover even if deformed under wind load. The upper end of the gantry is no longer fixed, and the gantry sways along with the steel cable, thus reducing its deformation. When the basket system reaches the arch foot of the lower chord and is connected to the template and the lower chord arch segment 0, the basket system tends to stabilize under the support of the lower chord arch segment 0. At this point, the swaying of the lower end of the gantry under wind load decreases, and the gantry can be extended using a lengthening rod, making it less prone to deformation.

[0020] 7. In step 2.4, since the boom is the main load-bearing component, if the connection between the boom and the extension rod is suddenly disconnected, the electric hoist's steel cable becomes the main load-bearing component. The steel cable will be under increased stress and become longer, making the electric hoist susceptible to impact and damage. If the main truss system of the boom and the lower chord hanging basket needs to be fixed first, the connection between the boom and the extension rod still needs to be disconnected first so that the upper connector can be connected to the upper end of the boom. In this solution, without disconnecting the hanging rod and the extension rod, the bottom basket system of the upper chord hanging basket is transferred to the lower chord hanging basket. This function is achieved through a specially designed extension connector, which can connect the hanging rod and the extension rod, and also serve as a nut and a pad to support the lower chord hanging basket.

[0021] Specifically, in this solution, since both the front and rear crossbeams are composed of two I-beams, when welding the front crossbeam, the lifting rod is positioned between the two I-beams, allowing it to pass through the front or rear crossbeam without disconnecting the lifting rod and the extension rod. Then, by rotating the extension connector, it is moved downwards until the conversion pad at the lower end of the extension connector supports the front or rear crossbeam of the lower chord hanging basket. At this point, the lifting rod and the extension rod remain connected through the extension connector, achieving the conversion of the load-bearing parts in advance. Disconnecting the lifting rod and the extension rod at this point will prevent significant impact on the electric hoist or other load-bearing parts due to the conversion of the load-bearing parts.

[0022] The extension connector in this design is not simply a combination of a nut and a washer. It needs to be long enough to connect both the boom and the extension rod simultaneously, and also to move downwards to allow the conversion washer to contact the front or rear cantilever beam while maintaining its connection to the extension rod. Finally, by rotating the extension rod, the lower end of the extension rod is disengaged from the extension connector.

[0023] 8. In step 2.1, mark the connection position between the upper end of the boom and the front or rear crossbeam of the upper chord hanging basket; In step 2.2, the connection position between the extension rod and the front or rear crossbeam of the upper chord hanging basket is also at the positioning mark. When installing the extension rod, a tower crane is used to fix the upper end of the extension rod. At this time, the extension rod remains vertical under the action of gravity. Only when there is no wind will the hoist also remain vertical, and the lower end of the extension rod can be aligned and connected with the upper end of the hoist. Then, check whether the hoist and the extension rod are on the same straight line and adjust them in time. Since the connection position between the lower end of the hoist and the front or rear cantilever beam of the bottom basket system remains unchanged, it is ensured that the extension rod and the hoist always remain vertical in the windless state. The direction of force in the windless state is always the axial direction of the rod, without eccentric force, thereby ensuring the load-bearing capacity of the extension rod and the hoist.

[0024] The higher the pier, the greater the wind load. Since the length of the suspenders plus the extension rods is relatively large, they are more affected by the wind load. The verticality mentioned in this plan can only guarantee verticality in the windless state. It is impossible to be vertical at all times. Therefore, it is not possible to wait until the wind stops to check the verticality. We can only ensure that the upper end of the suspenders is always in a fixed state, so that the verticality remains unchanged.

[0025] In step 2.4 of this scheme, before fixing the upper end of the hanger and the front crossbeam of the lower hanging basket, the hanger and the extended hanger are always connected to prevent the upper end of the hanger from changing its verticality due to loss of connection. This ensures that the central axis of the upper chord hanging basket and the lower chord hanging basket are vertically aligned, thereby ensuring that the central axis of the cast upper chord beam and the lower chord arch are vertically aligned, and preventing the load of the upper chord beam from generating eccentric force on the lower chord arch.

[0026] 9. The upper chord beam is constructed in parallel with the lower chord arch, with the two segments being constructed in sync. This is to allow sufficient working space for the lower chord arch, prevent interference between the support frame and the lower chord hanging basket, and prevent collisions between the upper chord beam and the materials being hoisted into the lower chord arch; at the same time, it ensures the stability of the structure.

[0027] 10. In step 2.2, when the lifting system moves the bottom railing system downwards, due to the inclination of the bottom of the lower chord arch, the longitudinal beams in the bottom railing system also need to be inclination, so that the formwork of the lower chord arch is supported on the longitudinal beams. If the two connection points of the longitudinal beam, the front cantilever beam, and the rear cantilever beam are fixed, then after the longitudinal beam tilts, the horizontal distance between the front and rear cantilever beams decreases. This leads to a decrease in the distance between the lower ends of the hangers connected to the front and rear cantilever beams, causing the hangers to tilt. No matter what adjustments the operator makes, it is impossible to keep all the hangers vertical at the same time, which will result in the following adverse effects: a. At this time, the operator cannot judge whether there is wind by whether the boom is vertical, so he cannot adjust the construction progress of the formwork of the lower chord arch on the bottom railing system in a timely manner according to whether there is wind, thus reducing the construction accuracy of the lower chord arch formwork.

[0028] b. In step 2.4, when installing the main truss of the lower chord hanging basket, the two I-beams on the front and rear crossbeams of the main truss clamp the hanger rod to prevent it from swaying. However, when the hanger rod is no longer vertical, the clamping of the hanger rod by the two I-beams will bring the upper end of the hanger rod back to a vertical state, while the lower end of the hanger rod remains tilted, which causes the hanger rod to deform and has a large internal force, thereby reducing the durability of the hanger rod.

[0029] In this design, one end of the longitudinal beam is hinged to the front cantilever beam, and the other end is slidably connected to the rear cantilever beam (sliding can be ensured by applying lubricating oil to the contact surface), so that the longitudinal beam will not change the horizontal distance between the front and rear cantilever beams when tilted, and the suspension rod can still remain vertical under the action of gravity. Regarding adverse effect a, it allows operators to judge whether there is wind by whether the hanger is vertical, thus ensuring the construction accuracy of the lower chord arch formwork; regarding adverse effect b, it can prevent the hanger from generating internal forces, thus ensuring the durability of the hanger.

[0030] 11. Regarding effect 10, during the adjustment of the longitudinal beam inclination, if insufficient lubrication on the contact surface between the longitudinal beam and the rear cantilever beam leads to increased friction and abnormal sliding, or if rust occurs at the hinge point between the longitudinal beam and the front cantilever beam, leading to increased friction and abnormal rotation, or if concrete falls onto the connection point between the longitudinal beam and the front or rear cantilever beam during previous concrete pouring, the hanger may not be able to maintain verticality. In this case, clamping the hanger with the two I-beams that make up the front or rear cantilever beam provides a reaction force for the longitudinal beam to overcome friction. When the hanger connection point is near the end of the I-beam, the end of the I-beam is prone to deformation due to the cantilever effect. When the hanger is tilted, it is easy to widen the gap between the two I-beams, making it impossible for the I-beams to clamp the hanger, thus preventing the hanger from maintaining verticality. This solution uses a limiting block to restrict the gap between the two I-beams, thereby ensuring that the two I-beams can clamp the hanger while minimizing the widening of the gap. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the hanging basket construction in Example 1; Figure 2 This is a schematic diagram of a single-side structure of the arch-beam composite bridge in Example 1; Figure 3 This is a three-dimensional isometric view of the upper-curved hanging basket of Example 1; Figure 4 This is a structural diagram of step 2.1 of Example 1; Figure 5 This is a structural diagram of step 2.2 in Example 1; Figure 6 This is a structural diagram of step 2.3 in Example 1; Figure 7 This is a structural diagram of step 2.4 in Example 1; Figure 8 This is a structural diagram of step 2.5 in Example 1; Figure 9 This is a structural diagram of step 2.2 in Example 2; Figure 10 This is a structural diagram of step 2.3 in Example 2; Figure 11 This is a structural diagram of step 2.4 in Example 2; Figure 12 This is a schematic diagram of the extension connector in Example 2; Figure 13 This is a three-dimensional isometric view of the suspension system and bottom basket system of the upper chord hanging basket in Example 3 when they are transferred to the lower chord hanging basket. Figure 14 for Figure 13 Enlarged view of point A in the image; Figure 15 This is a schematic diagram of point P in Example 3. Detailed Implementation

[0032] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: pier 1, upper chord beam 2, upper chord beam segment 0# 20, upper chord beam segment 1# 21, closing segment 22, lower chord arch 3, lower chord arch segment 0# 30, lower chord arch segment 1# 31, lower chord arch segment 2# 32, lower chord arch segment 3# 33, upper chord hanging basket 41, lower chord hanging basket 42, walking system 50, main truss 51, front crossbeam 52, rear crossbeam 53, front cantilever beam 61, rear cantilever beam 62, longitudinal beam 63, connecting block 64, pin 65, electric hoist 7, upper connector 81, upper nut 811, upper pad 812, extension connector 82, conversion pad 83, limit block 831, suspender rod 84, extension rod 85, bracket 9, lower cable 10.

[0033] Example 1 Construction method of arch-beam composite bridge using arch-fixture hanging and cantilever casting combined with formwork. Applicable to arch-beam composite bridges, such as... Figure 1 , Figure 2 As shown, with the centerline of pier 1 as the axis of symmetry, the two sides of pier 1 are constructed symmetrically and synchronously. Taking the segment on the right side of pier 1 as an example: the segment includes the upper chord beam 2 and the lower chord arch 3. The left end of the upper chord beam 2 and the left arch foot of the lower chord arch 3 are both connected to pier 1. The right end of the upper chord beam 2 and the arch crown of the lower chord arch 3 are joined together, as shown. Figure 1 As shown, both the upper chord beam 2 and the lower chord arch 3 are cast in 13 segments. The thirteenth segment is the closure segment 22 of the upper chord beam 2 and the lower chord arch 3. The section above pier 1 is the upper chord beam 0# segment 20. From the nearest point to the upper chord beam 0# segment 20, the sections are upper chord beam 1# segment 21, upper chord beam 2# segment, and so on. The lower chord arch 0# segment 30 is cast together with pier 1 on both sides of pier 1. From the nearest point to the lower chord arch 0# segment 30, the sections are lower chord arch 1# segment 31, lower chord arch 2# segment 32, and so on. The purpose of casting the lower chord arch 0# segment 30 together with pier 1 is to reserve space in advance for connection with the lower chord arch 1# segment 31. Several lower cable 10s are installed on pier 1. All lower cable 10s pass through pier 1, and both ends of the lower cable 10s are anchored in the lower chord arch 3 on both sides of pier 1. Starting from the lower chord arch 2# segment 32, one lower cable 10 is installed for each segment being cast. The upper chord beam 2 and the lower chord arch 3 are constructed using formwork, with cantilever construction extending from the top of pier 1 to both sides. The formwork includes an upper chord formwork 41 and a lower chord formwork 42. Both the upper chord formwork 41 and the lower chord formwork 42 include a traveling system 50, a main truss system, a suspension system, and a bottom formwork system. The traveling system 50 is installed on the upper surface of the upper chord beam 2 or the lower chord arch 3. The main truss system is installed on the traveling system 50 and extends towards the cantilever end. The upper end of the suspension system is detachably connected to the main truss system, and the lower end of the suspension system is connected to the bottom formwork system. The bottom formwork system serves as a support platform to bear the construction load. In this scheme, the traveling system 50 and the main truss system of the formwork with lifting function are the same as those in the prior art. The key point of this embodiment is that the upper chord formwork 41 is given a lifting function through the lifting system, so that the bottom formwork system can move downward, so that the upper chord formwork 41 and the lower chord formwork 42 can alternately use the suspension system and the bottom formwork system. like Figure 3 As shown, the main truss systems of the upper chord hanging basket 41 and the lower chord hanging basket 42 both include a prismatic main truss 51. A front crossbeam 52 is welded to the front end of the main truss 51, and a rear crossbeam 53 is welded to the middle of the main truss 51. Both the front crossbeam 52 and the rear crossbeam 53 are formed by combining two parallel I-beams, with a gap between the two parallel I-beams. The difference between the main truss systems of the upper chord hanging basket 41 and the lower chord hanging basket 42 is that the slope of the bottom of the main truss 51 is different, so as to adapt to the movement on the upper chord beam 2 and the lower chord arch 3 respectively.

[0034] The bottom basket system of the upper chord hanging basket 41 includes a front cantilever beam 61 and a rear cantilever beam 62. The front cantilever beam 61 is located directly below the front crossbeam 52, and the rear cantilever beam 62 is located directly below the rear crossbeam 53. Two longitudinal beams 63 are provided between the front cantilever beam 61 and the rear cantilever beam 62. The longitudinal beams 63 can provide support for the formwork of the lower chord arch 3. Both the front cantilever beam 61 and the rear cantilever beam 62 are formed by combining two parallel I-beams with a gap between them. The front cantilever beam 61 is provided with two hinge units, each of which includes two connecting blocks 64. Both connecting blocks 64 are welded to the front crossbeam 52. The left end of the longitudinal beams 63 is slidably supported on the rear cantilever beam 62. The right end of the longitudinal beam 63 is provided with a pin 65, which passes through the right end of the longitudinal beam 63 and the two connecting blocks 64 and is rotatably connected to all three. The right end of the longitudinal beam 63 is located between the two connecting blocks 64.

[0035] The lifting system includes four lifting devices (not shown in the figure). The lifting devices are winches or electric hoists 7. In this embodiment, the lifting device is an electric hoist 7. The upper ends of the electric hoists 7 are all bolted to the main truss system of the upper chord hanging basket 41, specifically located at both ends of the front crossbeam 52 and the rear crossbeam 53. The lower ends of the steel cables of the electric hoists 7 are respectively hung at both ends of the front cantilever beam 61 and the rear cantilever beam 62. The suspension system of the upper chord hanging basket 41 includes four suspension units, each corresponding to an electric hoist 7. Each suspension unit includes a rod 84, with an upper connector 81 and a lower connector at both ends. The upper end of the rod 84 passes through the front crossbeam 52 or rear crossbeam 53 of the main truss system of the upper chord hanging basket 41. The upper connector 81 includes an upper nut 811 and an upper pad 812. The upper pad 812 is supported on the front crossbeam 52 or rear crossbeam 53 and allows the rod 84 to pass through. The upper nut 811 is threaded onto the hoist... At the upper end of rod 84, tighten the upper nut 811. The upper nut 811, together with the front crossbeam 52 or the rear crossbeam 53, clamps the upper pad 812. Similarly, the composition of the lower connector is the same as that of the upper nut 811. The lower connector includes a lower nut and a lower pad. The lower pad is set on the lower side of the front cantilever beam 61 or the rear cantilever beam 62 and allows the lower end of the rod 84 to pass through. The lower nut is threaded to the lower end of the rod 84. Tighten the lower nut. The lower nut, together with the front cantilever beam 61 or the rear cantilever beam 62, clamps the lower pad, thereby providing support for the front cantilever beam 61 or the rear cantilever beam 62.

[0036] The arch-beam composite bridge construction method combines arch fastening with hanging basket cantilever casting, such as... Figures 4-8 As shown, it includes the following steps: Step 1: Complete the construction of pier 1. During the construction of pier 1, reserve the lower chord arch section 0# 30 horizontally on both sides of pier 1, pour the upper chord beam section 20# on the top of pier 1, and install the upper chord hanging basket 41 on the upper chord beam section 20#. Step 2: After the upper chord hanging basket 41 is lowered, the lower chord arch segment 31# is poured. The lower chord hanging basket 42 is erected on the lower chord arch segment 31#. Both the upper chord beam 2 and the lower chord arch 3 are poured in segments using hanging baskets. At the same time, the lower tie cable 10 is installed on each segment of the lower chord arch 3, with the middle of the lower tie cable 10 passing through the pier 1. Meanwhile, the upper chord beam 2 is constructed two segments behind the lower chord arch 3. At the same time, the support frame 9 is erected on the lower chord arch 3 to support the bottom of the upper chord beam 2, and the support frame 9 is constructed one segment behind the upper chord beam 2. The method for using a hanging basket to cast the upper chord beam 2 and lower chord arch 3 in segments is as follows: Step 2.1, as follows Figure 4 As shown, the upper chord beam segment 21 (section 1#) is cast using the upper chord formwork 41. Temporary longitudinal prestressing is applied to the upper side of segment 21. The method for applying temporary prestressing is as follows: longitudinal steel strands are embedded in the upper part of the upper chord beam 2, and jacks are used along... Figure 6 The longitudinal steel strands are tensioned in the direction of the middle arrow and the ends of the longitudinal steel strands are anchored with anchors, thereby generating pre-stress on the upper part of the upper chord beam 2 to prevent the ends of the upper chord beam 2 from sinking; a lifting system is installed on the main truss system of the upper chord hanging basket 41. The lifting system can drive the bottom basket system to move downward and remove the connection between the upper end of the suspension system and the main truss system. Step 2.2: Remove the lifting rod 84. The four electric hoists 7 work together to move the bottom basket system downward. The lower end of the electric hoist on the rear crossbeam 53 descends at a greater speed than the lower end of the electric hoist 7 on the front crossbeam 52. The right end of the longitudinal beam 63 rotates around the pin 65 on the front crossbeam 52, so that the slope of the longitudinal beam 63 of the bottom basket system is the same as the slope of the bottom of the lower chord arch 1# section 31. The main truss system, suspension system and bottom basket system are moved backward by the traveling mechanism of the upper chord hanging basket 41, and the bottom basket system is moved to the arch foot position of the lower chord arch 3. The template of the lower chord arch 1# section 31 is erected on the bottom basket system. The bottom basket system and the template of the lower chord arch 1# section 31 are detachably connected by fasteners or other connectors. The template of the lower chord arch 1# section 31 is connected to the lower chord arch 0# section 30. like Figure 5 As shown, replace the longer hanger 84, pass the upper end of the hanger 84 through the main truss system of the upper chord hanging basket 41 and thread it to the upper connector 81. The upper connector 81 is supported on the main truss system. Similarly, connect the lower end of the hanger 84 to the front cantilever beam 61 or the rear cantilever beam 62, and pour the lower chord arch section 1 31 with the bottom basket system as support. Step 2.3, as follows Figure 6 As shown, the walking system 50 of the upper chord basket 41 drives the main truss system, lifting system, suspension system and bottom basket system to move forward together, and the four electric hoists 7 jointly drive the bottom basket system to move upward, while replacing the shorter hoist 84. Step 2.4, as follows Figure 7As shown, a lower chord hanging basket 42 is erected on the lower chord arch section 1# 31, and the lower chord arch section 2# 32 is poured with the lower chord hanging basket 42 as support; the two ends of a lower cable 10 are respectively anchored in the lower chord arch section 2# 32 on both sides of the pier 1. Step 2.5, as follows Figure 8 As shown, the upper chord beam 2 is constructed two segments behind the lower chord arch 3; at the same time, a support 9 is erected on the lower chord arch 3 to support the bottom of the upper chord beam 2, and the support 9 is constructed one segment behind the upper chord beam 2; until the lower chord arch 3 is constructed to the segment before the closing section 22; Step 3: Remove the hanging basket on the lower chord arch 3, and use the hanging basket on the upper chord beam 2 to pour the closure section 22.

[0037] Example 2 The difference between Example 2 and Example 1 is as follows: Figure 12 As shown, each suspension unit also includes an extension rod 85. The suspension rod 84 and the extension rod 85 can be connected by an extension connector 82. The extension connector 82 is a sleeve with internal threads. The lower end of the extension connector 82 is threadedly connected to the upper end of the suspension rod 84. The threads on the suspension rod 84 and the extension rod 85 are in the same direction. A conversion pad 83 is welded to the lower end of the extension connector 82. The upper end of the suspension rod 84 can pass through the conversion pad 83.

[0038] The difference between the cast-in-place construction method for arch-beam composite bridge segments based on the hanging basket with attached lifting function and Example 1 is as follows: In step 2.2, the upper connector 81 at the upper end of the boom 84 is removed, and the boom 84 and the steel cable of the electric hoist are temporarily tied and fixed with wire. The four electric hoists 7 jointly drive the bottom basket system to move downward. The descent speed of the lower end of the electric hoist on the rear crossbeam 53 is greater than that of the lower end of the electric hoist 7 on the front crossbeam 52. The right end of the longitudinal beam 63 rotates around the pin 65 on the front crossbeam 52, so that the slope of the longitudinal beam 63 of the bottom basket system is the same as the slope of the bottom of the lower chord arch 1# section 31. The main truss system, the suspension system and the bottom basket system are driven to move backward through the traveling mechanism of the upper chord hanging basket 41, and the bottom basket system is moved to the arch foot position of the lower chord arch 3. The template of the lower chord arch 1# section 31 is erected on the bottom basket system. The bottom basket system and the template of the lower chord arch 1# section 31 are detachably connected by fasteners or other connectors. The template of the lower chord arch 1# section 31 is connected to the lower chord arch 0# section 30. like Figure 9 As shown, the upper end of the suspension system is extended to connect the upper end of the suspension system with the main truss system of the upper chord hanging basket 41: the upper end of the extension rod 85 passes through the main truss system of the upper chord hanging basket 41 and is threadedly connected to the upper connector 81. The upper connector 81 is supported on the main truss system. The extension connector 82 is threadedly connected to the lower end of the extension rod 85. The wires on the hoist cable and the suspension rod 84 are removed. The lower chord arch section 1# 31 is poured with the bottom basket system as support. In step 2.3, as Figure 10As shown, the traveling system 50 of the upper chord hanging basket 41 drives the main truss system, lifting system, suspension system and bottom basket system to move forward together, and the bottom basket system is used as support to cast the lower chord arch section 2# 32; the two ends of a lower cable 10 are respectively anchored in the lower chord arch section 2# 32 on both sides of the pier 1. In step 2.4, as Figure 11 As shown, the travel system 50 and main truss system of the lower chord hanging basket 42 are installed on the lower chord arch segments 1# 31 and 2#. The main truss system of the lower chord hanging basket 42 and the upper suspension system of the upper chord hanging basket 41 are connected at the upper end. The suspension system and bottom basket system of the upper chord hanging basket 41 are converted into the suspension system and bottom basket system of the lower chord hanging basket 42. The method for converting the suspension system and bottom basket system of the upper-curved hanging basket 41 into the suspension system and bottom basket system of the lower-curved hanging basket 42 is as follows: Step 2.4.1 During the installation of the main truss system of the lower chord hanging basket 42, the hanger rod 84 of the upper chord hanging basket 41 passes through the front crossbeam 52 or the rear crossbeam 53 of the lower chord hanging basket 42. Since the front crossbeam 52 or the rear crossbeam 53 is composed of two I-beams, when welding the front crossbeam 52, the hanger rod 84 is positioned between the two I-beams, which achieves the effect of the hanger rod 84 passing through the front crossbeam 52 or the rear crossbeam 53 without having to disconnect the hanger rod 84 and the extension rod 85. The upper end of the electric hoist 7 is bolted to the end of the front crossbeam 52 or the rear crossbeam 53 of the lower chord hanging basket 42, and the lower end of the electric hoist 7 is hung on the end of the front cantilever beam 61 or the rear cantilever beam 62 of the upper line hanging basket. Step 2.4.2, as follows Figure 11 and Figure 12 As shown, rotate the extension connector 82 to move it downwards, so that the conversion pad 83 at the lower end of the extension connector 82 is supported on the main truss system of the lower chord hanging basket 42. Remove the upper connector 81 at the upper end of the extension rod 85, rotate the extension rod 85 to separate the lower end of the extension rod 85 from the extension connector 82, and remove the extension rod 85 and the electric hoist 7.

[0039] Example 3 Example 3 is based on Example 2: In step 2.4.2, as follows Figure 13 , Figure 14 As shown, after the conversion pad 83 is supported on the front crossbeam 52 or rear crossbeam 53 of the main truss system of the lower chord hanging basket 42, two limiting blocks 831 are welded to the bottom of the conversion pad 83. The two limiting blocks 831 are attached to both sides of the front crossbeam 52 or rear crossbeam 53, thereby limiting the spacing between the two I-beams that make up the front crossbeam 52 or rear crossbeam 53.

[0040] The effect of Example 3 is as follows Figure 15As shown: The weight of the formwork, concrete, and various components of the lower chord arch 3 will all be transferred to the longitudinal beam 63. Since the longitudinal beam 63 and the cantilever beam 61 are hinged, most of the load of the longitudinal beam 63 is transferred to the cantilever beam 61 through the pin 65. If only the pin 65 is considered to bear most of the load, the strength of the pin 65 is often insufficient to withstand it. In this embodiment, the direct contact point P between the longitudinal beam 63 and the cantilever beam 61 also needs to be considered. When the longitudinal beam 63 rotates to a certain angle, the load of the longitudinal beam 63 is transmitted to the longitudinal beam 63 through point P. However, at this time, the longitudinal beam 63 exerts pressure on the cantilever beam 61 perpendicular to the length direction of the longitudinal beam 63 (arrow direction in the figure). This causes the lower end of the hanger 84 to move to the right through the cantilever beam 61, thereby causing the hanger 84 to tilt. The greater the pressure change, the greater the back-and-forth swaying. In this solution, by setting a limiting block 832, the upper end of the hanger 84 is clamped by the front crossbeam 52 of the lower chord hanging basket 42, which restricts the tilting of the hanger 84, reduces this swaying, and ensures construction safety.

[0041] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A construction method for arch-beam composite bridges using a combination of arch buckle hanging and cantilever casting with formwork, characterized by: The arch-beam composite bridge consists of an upper chord beam and a lower chord arch. Both the upper chord beam and the lower chord arch are constructed using hanging baskets, which include upper chord hanging baskets and lower chord hanging baskets. The construction is carried out cantilevered from the central axis of the pier to both sides of the pier. One end of the upper chord beam and the arch foot of the lower chord arch are connected to the pier, and the other end of the upper chord beam is joined to the arch crown of the lower chord arch. Both the upper chord beam and the lower chord arch are divided into several segments for casting. Includes the following steps: Step 1: Complete the pier construction, pour the upper chord beam section 0# on the top of the pier, and install the upper chord hanging basket on the upper chord beam section 0#. Step 2: After the upper chord formwork is lowered, the lower chord arch segment 1 is poured. The lower chord formwork is erected on the lower chord arch segment 1. Both the upper chord beam and the lower chord arch are poured in segments using the formwork. At the same time, the lower tie cable is installed on each segment of the lower chord arch, with the middle of the lower tie cable passing through the pier. Meanwhile, the upper chord beam is constructed two segments behind the lower chord arch. At the same time, a support frame is erected on the lower chord arch to support the bottom of the upper chord beam, and the support frame is constructed one segment behind the upper chord beam. Step 3: Remove the hanging basket on the lower chord arch and use the hanging basket on the upper chord beam to pour the closure section; Both the upper chord hanging basket and the lower chord hanging basket include a traveling system, a main truss system, a suspension system, and a bottom basket system. The traveling system is installed on the upper surface of the upper chord beam or the lower chord arch. The main truss system is installed on the traveling system and extends towards the cantilever end. The upper end of the suspension system is detachably connected to the main truss system, and the lower end of the suspension system is connected to the bottom basket system. The bottom basket system serves as a support platform to bear the construction load. In step two, the method of using a hanging basket to cast the upper chord beam and lower chord arch in segments is as follows: Step 2.1 Use the upper chord hanging basket to pour the upper chord beam section 1. Install a lifting system on the main truss system of the upper chord hanging basket. The lifting system can drive the bottom basket system to move downward. Remove the connection between the upper end of the suspension system and the main truss system. Step 2.2: The lifting system moves the bottom basket system downward to the arch foot of the lower chord arch, extending the upper end of the suspension system to connect the upper end of the suspension system with the upper chord hanging basket main truss system. The lower chord arch section 1 is then poured with the bottom basket system as support. Step 2.3: The traveling system of the upper chord hanging basket drives the main truss system, lifting system, suspension system and bottom basket system to move forward together, and the bottom basket system is used as support to pour the lower chord arch section 2. Step 2.4: Install the travel system and main truss system of the lower chord hanging basket on the lower chord arch segments 1 and 2, connect the upper end of the main truss system of the lower chord hanging basket and the suspension system of the upper chord hanging basket, and convert the suspension system and bottom basket system of the upper chord hanging basket into the suspension system and bottom basket system of the lower chord hanging basket. Step 2.5: Use the lower chord hanging basket to pour the lower chord arch section 3, reinstall the suspension system and bottom basket system of the upper chord hanging basket, and use the upper chord hanging basket to pour the upper chord beam section 2. Step 2.6: Pour the remaining segments of the upper chord beam and lower chord arch until the segment above the closing segment of the lower chord arch is completed; The lifting system includes several electric hoists; In step one, during the construction of the bridge pier, the lower chord arch section 0# is reserved for horizontal installation. The upper ends of the electric hoists are all connected to the main truss system of the upper chord hanging basket, and the lower ends of the electric hoists are all hung on the bottom basket system. In step 2.2, during the process of the electric hoist driving the bottom basket system to move downward, the upper end of the suspension system is temporarily fixed to the steel cable of the electric hoist; after the electric hoist drives the bottom basket system to move downward, the template of the lower chord arch section 1 is erected on the bottom basket system. The template of the bottom basket system and the template of the lower chord arch section 1 are detachably connected, and the template of the lower chord arch section 1 is connected to the lower chord arch section 0. The suspension system of the upper chord hanging basket includes several suspension units, each of which includes a hanger and an extension rod. The upper and lower ends of the hanger are respectively provided with an upper connector and a lower connector. The upper end of the hanger passes through the main truss system of the upper chord hanging basket and is threadedly connected to the upper connector. The upper connector is supported on the main truss system. In step 2.2, the upper connecting piece is removed, and the hoist's cable is temporarily fixed with wire. The electric hoist drives the bottom basket system to move downward. The upper end of the extension rod passes through the main truss system of the upper chord hanging basket and is threadedly connected to the upper connecting piece. The upper connecting piece is supported on the main truss system. The extension connecting piece is threadedly connected to the lower end of the extension rod. The lower end of the extension connecting piece is threadedly connected to the upper end of the hoist. The wire on the hoist's cable and the electric hoist's cable is removed.

2. The arch-beam composite bridge arch-buckle hanging and cantilever construction method according to claim 1, characterized in that: The threads of the hanger and the extension rod are in the same direction. The lower end of the extension connector is welded with a conversion pad, and the upper end of the hanger can pass through the conversion pad. The main truss system of both the upper chord hanging basket and the lower chord hanging basket includes a main truss. The main truss is equipped with a front crossbeam and a rear crossbeam. The front crossbeam or the rear crossbeam is composed of two parallel I-beams. The distance between the two I-beams is less than the width of the conversion pad. The bottom basket system of the upper chord hanging basket includes a front cantilever beam and a rear cantilever beam. Several longitudinal beams are provided between the front cantilever beam and the rear cantilever beam. One end of each longitudinal beam is hinged to the front cantilever beam. Several horizontally arranged support tubes are provided on the rear cantilever beam. The other end of each longitudinal beam is supported on the support tube and can slide on the support tube. In step 2.4, the method for converting the suspension system and bottom basket system of the upper-curved basket into the suspension system and bottom basket system of the lower-curved basket is as follows: Step 2.4.1 During the installation of the main truss system of the lower chord hanging basket, make the hoisting rod of the upper chord hanging basket pass through the front or rear crossbeam of the lower chord hanging basket, and hang the upper end of the electric hoist on the front or rear crossbeam, and hang the lower end of the electric hoist on the front or rear cantilever beam. Step 2.4.2: Rotate the extension connector so that the conversion pad at the lower end of the extension connector is supported on the main truss system of the lower chord hanging basket. Remove the upper connector at the upper end of the extension rod. Rotate the extension rod so that the lower end of the extension rod is separated from the extension connector. Remove the extension rod and the electric hoist.

3. The arch-beam composite bridge arch-buckle hanging and cantilever construction method according to claim 2, characterized in that: In step 2.4.2, after the transfer pad is supported on the front or rear crossbeam of the main truss system of the lower chord hanging basket, two limiting blocks are welded to the bottom of the transfer pad. The two limiting blocks are attached to both sides of the front or rear crossbeam, thereby limiting the spacing between the two I-beams that make up the front or rear crossbeam.

4. The arch-beam composite bridge arch-buckle hanging and cantilever construction method according to claim 2, characterized in that: In step 2.1, longitudinal temporary prestress is applied to the upper side of segment 1 of the upper chord beam; In step 2.5, after the scaffold is erected, the temporary prestress applied to segment 1 of the upper chord beam is removed.

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