[0035] The principles and features of the present invention will be described below with reference to the embodiments. The examples cited are only used to explain the present invention and not to limit the scope of the present invention.
[0036] The invention discloses a cantilever assembling construction process of a continuous beam bridge with double U box type composite variable cross-section segments assembling, including the following steps:
[0037] S1) Construction preparation: Consolidation of cast-in-place 0# beam piers; assembling and debugging the suspension assembly hoisting machine; section beam section factory acceptance;
[0038] S11) Consolidation of cast-in-place 0# beam piers: The 0# beam piers are consolidated by a combination of temporary buttresses and temporary supports; each temporary buttress consists of 6 C30 reinforced concrete buttresses with a radius of 600mm It is composed of pre-embedded steel bars on the top of the pier and connected to the beam body as a whole; the temporary support is a reinforced concrete structure, which is poured together with the 0# beam pier;
[0039] S12) Assembling and debugging of suspension hoisting machine: use a car crane to move the components of the suspension hoisting machine to the bridge deck and assemble; after assembly, a comprehensive inspection should be carried out;
[0040] S13) Ex-factory acceptance of beam section: Check and accept the beam number corresponding to the span of the erected beam, the quality certification data of the finished beam, the appearance and the position of the embedded parts.
[0041] S2) Cantilever balance assembly of section beams: assemble the cantilever symmetrically from the consolidated 0# section beam piers to both sides to realize the rapid adjustment of the three-dimensional airborne direction of the special-shaped eccentric beam section;
[0042] S21) Girder feeding: the beam is fed in-situ by the under-bridge projection by the suspension assembly hoist; and the beam section is transported directly under the spreader by the beam truck or transport ship;
[0043] S22) Lifting beam: When the beam truck or ship transports the beam section directly under the suspension assembly hoist, the hoist lowers the spreader vertically through the hoist, and penetrates four 32mm diameter fine-rolled rebars to connect the spreader and the joint. The beam section should be firmly anchored. Lift the concrete beam by 190~210mm to separate the beam section from the beam transport vehicle. Use the hydraulic system to adjust the vertical and horizontal shifting cylinders on the spreader distribution beam to adjust the center of gravity of the beam section to a balanced state; adjust rotation The hook group rotates the beam section in place and installs anti-rotation bolts for fixed positioning. It is lifted at the rated lifting speed to close to the design height, and then the height of the beam section is adjusted by the low speed gear; the vertical and horizontal directions on the crane are adjusted by the hydraulic system Move the oil cylinder to accurately correspond to the vertical and horizontal positions of the segment beams;
[0044] S23) Wet knot assembly: Wet knot assembly is used between the 1# pier and the 0# pier;
[0045] S24) Gluing assembly: Before gluing, clean up the matching surface of the beam end, and paste a 5-10mm thick sponge washer on the pre-stressed orifice; both ends of the matching surface need to be coated with glue, the coating thickness is 2.8-3.2mm, and use Shovel leveling; after the glue is applied, the translation beam is moved closer to the matching surface, and the temporary prestressing system is stretched immediately after the beam section is in place; after the glue is cured, the permanent prestressing beam of the beam is stretched and vacuumed within 24 hours after stretching Pipeline pressure drop;
[0046] S25) Suspension assembly hoisting through hole: The suspension assembly hoisting machine moves forward and uses the longitudinal propulsion cylinder of the front leg of the walking system to push it from one section to the next; each advancement stroke is 0.5m; suspension assembly hoisting After the machine is in place, anchor the suspension assembly hoist.
[0047] S3) Semi-cantilever assembly of side-span beams: use bracket method to assemble side-span beams with semi-cantilever;
[0048] S31) Foundation treatment: Set two concrete strip foundations on the original hardened ground, and pre-embed M24 anchor bolts on the top surface of the strip foundation; the strip foundation is 3000mm long, 1000mm wide, and 300mm high.
[0049] S32) Installation of steel pipe buttress piers: the steel pipe buttress piers are connected by [12 steel at 45 degrees, and the steel pipe buttress pier and the bridge pier are connected by I-shape steel flat connection; Two sets of H-shaped steel are arranged along the bridge direction. Jack slides and hydraulic jacks are arranged on the bottom of the support side beams and the H-shaped steel, and a sandbox is set next to the jack; There are 4 rows in total, the horizontal spacing of steel pipes is 5m, and the vertical center spacing is set according to the length of the section.
[0050] S33) Segment beam hoisting: Measure the laying-out line to mark the segment in-place line on the bracket, and adjust the top elevation of the jack to the installation elevation of the segment beam; then use a 400t car to lift the segment beam to the marked position and repeat the measurement The plane position and elevation of the beam are adjusted in place through the three-dimensional adjustment system at the bottom of the beam according to the measurement data; the adjustment range of the three-dimensional adjustment system: elevation ±45mm; along the bridge ±300mm; transverse bridge ±60mm.
[0051] The next section is pre-connected and aligned by the suspension assembly hoist, and then glued and assembled; after the end, the beam is removed and moved 20cm outwards. After the glue is applied, the chain hoist is used to pull it back into place, and then temporarily Prestressed tension.
[0052] S4) Construction of the closing section: With the aid of the rigid framework, the dragons are closed, the side spans first, then the middle spans, and finally the continuous girder bridge system conversion is completed through the permanent prestressed beams of the span joints.
[0053] In order to better realize the above-mentioned technical solution, in S23), when the 1# pier and the 0# pier are spliced, the vertical and horizontal lines of the 1# pier should be adjusted to make the 1# pier and the 0# pier longitudinal The extension lines of the axis coincide, then adjust the horizontal axis of the outer edge to be parallel to the horizontal axis of the line, and finally make accurate adjustments according to the elevation;
[0054] Temporary locking is set on the top surface of the top plate and the top surface of the bottom plate of the girder section. The temporary locking is formed by welding the bridge deck pre-embedded steel plate and I32 steel across the seam, with 6 cross sections arranged;
[0055] Connect the prestressed pipe, install the wet joint steel formwork, and pour the wet concrete; the concrete slump is 18±2cm; the pouring is carried out symmetrically, the order is bottom plate-web-top plate; the section of the box girder is wetted before pouring; concrete pouring After the completion, after the curing reaches the design required strength, the permanent pre-stressed beams of the beam body are stretched and grouted.
[0056] In order to better realize the above technical solution, in S24), pre-assembly is also included before the gluing assembly. The specific steps are: first hoist the assembled beam section to the same height as the matching surface, then slowly move closer to the matching surface, and place the wooden wedges on the Cushion the joints of the beam ends to avoid collision of the beam sections; after the beam section is stable, take out the wooden wedge, and adjust the posture of the lifting beam section by the suspension assembly machine to observe whether the upper and lower joints are tight and whether there is a misalignment; After the anastomosis, measure and check the beam section elevation and axis, and check the alignment of the prestressed duct joints.
[0057] After the pre-assembly is completed, remove the beam and move it 20cm outwards and drop it 1.4m for gluing. Before gluing, clean up the matching surface of the beam end and paste a 5-10mm thick sponge washer on the prestressed orifice.
[0058] In order to better realize the above technical solutions, in S24), the temporary prestressing system includes 6 φ32 finishing rolled steel bars arranged on the top plate and 4 φ32 finishing rolling screw bars arranged on the bottom plate; a single φ32 finishing rolling screw The tension of the steel bar is not less than 40t; the tension of the temporary prestressing system is carried out through at least 4 sets of 60t through-core roofs, and is carried out in the order of left and right symmetry, up and down at the same time from inside to outside.
[0059] In order to better realize the above technical solution, the steel pipe buttress includes 4 steel pipes arranged in a matrix, the lateral spacing of the steel pipes is 5m, and the longitudinal center spacing is set according to the segment length.
[0060] The components of the suspension assembly hoist include a frame structure, a traveling system, a hoist, a crane system, a rotating hook group, a spreader distribution beam, an electrical system, and a hydraulic system.
[0061] The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.
