Wharf cast-in-place pile cap cross beam construction structure and construction method

Abstract

The invention discloses a wharf cast-in-place pile cap cross beam construction structure and method, and particularly relates to the technical field of pile cap cross beam construction.The outer wall of the top of a foundation pile is connected with a steel casing, bracket structures are welded to the two sides of the steel casing correspondingly, and each bracket structure comprises a top plate and a bracket web plate; a bottom die supporting structure is arranged on a top overhanging part of the bracket structure, the bottom die supporting structure comprises an I-shaped steel support, a secondary beam, square timber and a bottom die, the I-shaped steel support is connected with the bracket structure in a welded mode, and the secondary beam is arranged on the top of the I-shaped steel support; before initial setting of the concrete, chiseling treatment is conducted on the concrete on the surfaces of the pile caps and the cross beams, it is ensured that the combination face of new concrete and old concrete is coarse before secondary concrete construction, the box girder mounting laying face is shrunk and compacted, it is ensured that the laying face is flat, and the concrete is subjected to multi-layer pouring, so that the strength of the concrete is improved, cracking in the pouring process is avoided, and the construction quality is improved. The service life of the pile cap cross beam is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of pile cap and crossbeam construction, and more specifically, to a cast-in-situ pile cap and crossbeam construction structure and construction method for a wharf. Background Art

[0002] The construction of cast-in-situ pile caps and beams is an important part of wharf construction, which involves the stability and bearing capacity of the wharf. During the construction process, pile foundation construction is required first, and then pile caps and beams are cast in-situ on the pile foundation; At present, the pouring of pile cap beams during the construction of cast-in-situ pile caps for docks is often carried out in an integral pouring process. The concrete volume of the pile cap beams is large, and if the curing conditions are poor, the integrally poured concrete structure is prone to large-scale cracking, which not only affects the appearance of the structure, but also may reduce the durability and safety of the structure. At the same time, the pile cap beams of docks at this stage often do not have the function of wave dissipation. Therefore, in order to solve the above problems, a wharf cast-in-situ pile cap beam construction structure and construction method are proposed.

[0003] Application Contents In order to overcome the above-mentioned defects of the prior art, the present application provides a wharf cast-in-situ pile cap beam construction structure and a construction method to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a cast-in-place pile cap beam construction structure for a wharf, comprising foundation piles, wherein the top outer wall of the foundation piles is connected to a steel casing, and a corbel structure is welded on both sides of the steel casing, and the corbel structure comprises a top plate and a corbel web, and corbel webs are welded on both sides of the bottom of the top plate, and a T-shaped connection is formed between the corbel web and the steel casing, and a bottom formwork support structure is provided at the top cantilevered part of the corbel structure, and the bottom formwork support structure comprises an I-beam support, a secondary beam, square timber and a bottom formwork, the I-beam support is welded to the corbel structure, a secondary beam is provided on the top of the I-beam support, a square timber is provided on the top of the secondary beam, the top of the square timber is connected to the bottom formwork, and the square timber and the bottom formwork are fixed by nails.

[0005] Preferably, a steel frame is provided on the top of the bottom formwork, and the steel frame includes main bars and stirrups, and the main bars and stirrups are tied with plum blossom points. Pads are arranged on the surface of the steel frame, and the grade of the pads shall not be lower than C45, and the number of the pads shall not be less than 4 / ㎡.

[0006] Preferably, a side form structure is provided at the edge of the bottom form, and the side form structure includes a side form steel form, a steel tie rod, a nut and a rubber stop-slurry strip. The steel bar skeleton is connected to the side form steel form through the steel tie rod, and the steel tie rod is connected to the side form steel form with a nut through the side form steel form. A rubber stop-slurry strip is provided at the joint between the side form steel form and the bottom form.

[0007] Preferably, a longitudinal beam is provided on the top of the steel frame, a surface layer is provided on the top of the longitudinal beam, and a mooring component is connected to one side of the foundation pile, and the mooring component includes a support frame, a rubber fender, a wave-breaking plate and a through hole.

[0008] Preferably, a rubber fender is provided on one side of the support frame, and the bottom end of the support frame is connected to a wave-breaking plate via a movable shaft, and through holes are arranged on the surface of the wave-breaking plate.

[0009] Preferably, the corbel structure is welded into a π shape using Q235 steel plates, the top plate is 400 mm long, 760 mm wide, and 12 mm thick, the corbel web is 760 mm high, 760 mm long, and 12 mm thick, the center distance between the two groups of corbel webs is 200 mm, the steel casing is 1.2 cm thick, and the corbel structure is formed by double-sided welding, with a weld height of 12 mm.

[0010] Preferably, the model of the I-beam support is II56b / II50, the secondary beam adopts I-20b with a spacing of 40 cm, the square wood adopts 100mm×100mm wood square with a length of 4.2m, and the bottom formwork adopts 15mm plywood or plastic formwork.

[0011] Preferably, the main reinforcement weld joints do not exceed 50% of the number of main reinforcements, the staggered spacing is greater than 35d and not less than 500mm, a 1m×1m opening is reserved for the top surface reinforcement, the steel pull rod is made of A16 round steel, and the top is supported by a steel pipe or channel steel inner side.

[0012] Preferably, the construction method comprises the following steps: S1: Elevation measurement, taking the pile cap bottom elevation as the relative 0 point, based on the pile cap design bottom elevation of 0, reversely calculate the bottom elevation of the bottom formwork panel to be -0.015m, the timber to be -0.115m, the I-beam support and secondary beam to be -0.315m, the double-jointed 45b main beam to be -0.765m, and the corbel structure elevation to be -0.765m. Other elevations are similar and calculated according to the drawing; S2: After the bottom formwork support system is laid out and the surveyors mark the elevation of the lower pile cap and the bottom of the beam, the on-site construction personnel determine the elevation of the corbel structure through the cast-in-place piles and use a horizontal pipe to guide it to other piles. The corbel structure is symmetrically arranged on both sides of the cast-in-place pile, with one corbel structure on each side. The corbel structure is formed by double-sided welding, and the weld height is 12mm. The coating should be removed after welding. After the corbel structure is welded, the top elevation of the corbel structure is checked to ensure that the height difference between them does not exceed 3mm. Otherwise, the elevation of the local corbel structure needs to be adjusted. The measures are to level it with cement slurry, mortar or thin steel plate. After the corbel structure is welded or installed and passed the acceptance inspection, the front pile cap II56b / II50 I-beam support is erected, and then the reverse corbel structure is welded. After passing the acceptance inspection, II45b is installed; S4: Pile head removal: After manually marking a circular cut at the pile top elevation, the concrete outside the steel cage is chiseled out to form a gap, exposing the steel bars. The chiseling depth is the thickness of the steel bar protective layer. After the steel bars are exposed, the steel bars are slightly bent outward (no more than 30 degrees). When manually chiseling, the jackhammer is drilled horizontally or slightly upward into the concrete in the middle and upper part of the key construction area, which is the concrete about 10 cm from the pile top as required by the design. The gap is continuously deepened. When the gap depth reaches about 30 cm, the jackhammer is drilled to the top with the drill bit horizontal or slightly upward. After completion, cleaning is carried out. After all cleaning work is completed, two people work together to straighten the steel bars with a steel wrench. S5: Use a total station to measure and locate according to the dimensions of the pile cap and beam. First, roughly lay out the wooden planks according to the dimensions of the pile cap and beam. Then, measure the four corner points of the pile cap and beam and the center axis on the wooden planks. Finally, mark the layout points with a red marker or nails to determine the position of the bottom formwork. S6: Rebar binding. The pile cap and beam reinforcement projects are layered and tied to the top according to the pouring order. The transverse reinforcement of the upper beam is tied after the longitudinal beam is installed. To ensure that the construction joints are roughened during construction, a 1m×1m hole is reserved for the top surface reinforcement to facilitate personnel access. Binding is carried out when the surface layer is constructed. The center and both ends of the reinforcement joints should be tied tightly with wire. Pads should be set on the reinforcement. The pads are purchased as finished products and delivered to the site to ensure that the protective layer meets the requirements. The reinforcement is tied with plum blossom points, and the wire heads must not extend into the concrete protective layer. S7: Install the side formwork structure. Clean the formwork before installation and apply release agent evenly. The formwork installation elevation and position must be strictly in accordance with the drawings. The installation joints, straightness, and flatness must be strictly in accordance with the specifications. The side formwork steel formwork uses tension screws with a horizontal spacing of 80 cm and a vertical spacing of 100 cm. The tie rods are made of A16 round steel, and the top is supported by steel pipes or channel steel inner supports to control the formwork installation dimensions. S8: Concrete pouring. After the acceptance of concealed works is completed, the construction of pile caps and beams shall be organized. Concrete pouring shall be carried out at low tide. When the tide recedes to the bottom of the pile caps or beams, the concrete pouring can be started after cleaning the steel skeleton and debris in the formwork. Before each concrete pouring, a detailed analysis shall be made to ensure the pouring speed and emergency measures shall be taken to ensure that the concrete is not submerged before initial setting. The pouring shall be started from the lowest point first. The height of the single concrete pouring layer shall be controlled at 50cm. The concrete shall be poured in multiple layers and vibrated and compacted layer by layer. The upper layer of concrete must be poured before the initial setting of the lower layer of concrete. Construction cold joints are strictly prohibited. After the concrete pouring is completed, the surface concrete of the pile caps and beams shall be roughened before the initial setting of the concrete to ensure that the interface between the new and old concrete is rough before the secondary concrete construction. The shelf surface of the box beam installation shall be polished and compacted to ensure that the shelf surface is flat. S9: After the formwork is removed and the initial setting is completed, the surface layer must be kept moist. The side formwork structure and bottom formwork can be removed only after the concrete reaches 2.5MPa. When removing the formwork, it can be done in blocks. The main construction process is as follows: a1: It is planned to use four 3t hand hoists to tie to the main reinforcement of the beam, and use steel wire ropes or slings to support the I-beam formwork.

[0013] a2: Carry out the work of cutting the corbel structure. When cutting the corbel structure, arrange one person from each team to observe the sea conditions and the rise and fall of the tide.

[0014] a3: After the corbel structure is cut off, all operators at the pile cap and the bottom of the beam evacuate, and release the hand hoist to lower the steel main beam.

[0015] a4: Start to dismantle the bottom formwork and wooden planks, and transport them out with a floating raft and hoist them ashore. The spot welding positions of the secondary beam and the main beam can be pried open with a crowbar or cut with a gas cutter. After the main and secondary beams are separated, tie a wire rope on the secondary beam and use a ship crane or a crane on the pile cap or the top of the beam to pull them out one by one. Considering the repeated use of the secondary beam in construction, try not to cut it with a gas cutter.

[0016] a5: After all the secondary beams are taken out, the operator ties a wire rope on the main beam and slowly moves the main beam out using a ship crane or a crawler crane on a steel platform. The removal of the pile caps and cross beams is completed.

[0017] The technical effects and advantages of this application are: 1. Compared with the existing technology, the construction structure and construction method of the cast-in-situ pile cap and beam of the wharf are as follows: during the pouring process, the height of the layered construction layer of the concrete is controlled at 50 cm in a single pouring, and the concrete is poured in multiple layers and vibrated and compacted in layers. The upper layer of concrete must be poured before the initial setting of the lower layer of concrete. After the concrete pouring is completed, before the initial setting of the concrete, the surface concrete of the pile cap and the beam is roughened to ensure that the bonding surface of the new and old concrete is rough before the secondary concrete construction. The shelf surface of the box beam is polished and compacted to ensure that the shelf surface is flat. By pouring the concrete in multiple layers, the strength of the concrete is improved, cracking during the pouring process is avoided, and the service life of the pile cap and beam is extended.

[0018] 2. Compared with the existing technology, this kind of cast-in-place pile cap beam construction structure and construction method of the wharf has the following characteristics: when the waves flow through the wave-breaking board, the wave-breaking board will sway left and right with the waves, and the seawater at the junction of the wave-breaking board will pass through the through holes to play a diversion and buffering role. The wave-breaking board can change the flow direction and energy distribution of the waves, thereby reducing the impact of the waves on the structure and protecting the stability and safety of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall support structure of this application.

[0020] Figure 2 This is a schematic diagram of the connection structure between the foundation pile and the steel casing in this application; Figure 3 This is a schematic structural diagram of the bottom mold support structure of this application; Figure 4 This is a schematic diagram of the bracket structure of this application; Figure 5 This is a schematic diagram of the connection structure between the side form steel template and the bottom form of this application; Figure 6 This is a schematic diagram of the steel skeleton structure of this application; Figure 7 This is a schematic diagram of the construction method steps of this application.

[0021] The accompanying drawings are marked as follows: 1. foundation piles; 2. steel casing; 3. corbel structure; 4. top plate; 5. corbel web; 6. bottom formwork support structure; 7. I-beam support; 8. secondary beam; 9. square timber; 10. bottom formwork; 11. steel skeleton; 12. main reinforcement; 13. stirrups; 14. pads; 15. side formwork structure; 16. side formwork steel formwork; 17. steel tie rod; 18. nut; 19. rubber stop slurry strip; 20. longitudinal beam; 21. surface layer; 22. mooring component; 23. support frame; 24. rubber fender; 25. wave-breaking board; 26. through hole. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] Example 1 As attached Figures 1 to 7 The illustrated embodiment shows a cast-in-situ pile cap beam construction structure for a wharf, comprising a foundation pile 1, a steel casing 2 connected to the top outer wall of the foundation pile 1, a corbel structure 3 welded to both sides of the steel casing 2, the corbel structure 3 comprising a top plate 4 and a corbel web 5, corbel webs 5 welded to both sides of the bottom of the top plate 4, a T-shaped connection between the corbel web 5 and the steel casing 2, a bottom formwork support structure 6 provided at the top cantilevered portion of the corbel structure 3, the bottom formwork support structure 6 comprising an I-beam support 7, a secondary beam 8, a square timber 9 and a bottom formwork 10, the I-beam support 7 being welded to the corbel structure 3, a secondary beam 8 provided on the top of the I-beam support 7, a square timber 9 provided on the top of the secondary beam 8, a bottom formwork 10 connected to the top of the square timber 9, and the square timber 9 being fixed to the bottom formwork 10 by nails; Among them, the steel casing 2 serves as a guiding device for the pile foundation, which can ensure that the pile foundation 1 is constructed along the design direction. By controlling the position and verticality of the steel casing 2, the accuracy and verticality of the corbel structure 3 are ensured, and deviations and errors in the construction process are avoided. The corbel structure 3 can improve the force distribution of the structure, reduce stress concentration, and improve the bearing capacity of the structure. The corbel construction adopts a π-type corbel, and the top plate 4 and the corbel web 5 are connected to each other for supporting and fixing. The I-beam support 7 and the secondary beam 8 play a supporting and fixing role, and the square wood 9 plays a role in supporting the bottom mold 10. The bottom mold 10 is the bottom mold of the pile cap and the crossbeam.

[0024] Example 2 Based on Example 1, the solution in Example 1 is further detailed in combination with the following specific working methods. Figures 1 to 7 As shown, see the following description for details: As a preferred embodiment, a steel skeleton 11 is provided on the top of the bottom formwork 10. The steel skeleton 11 includes main bars 12 and stirrups 13. The main bars 12 and stirrups 13 are tied with plum blossom points. Pads 14 are arranged on the surface of the steel skeleton 11. The grade of the pads 14 shall not be lower than C45, and the number of pads 14 shall not be less than 4 / ㎡.

[0025] As a preferred embodiment, the main reinforcement 12 and the stirrups 13 can be connected and fixed to the steel bars on the top of the foundation pile 1, so as to improve its stability when the pile cap beam is poured. The steel skeleton 11 is a three-dimensional structure formed by connecting the main reinforcement 12 and the stirrups 13 by binding and welding. It is manufactured before concrete pouring to enhance the bearing capacity and durability of the concrete.

[0026] A side form structure 15 is provided at the edge of the bottom form 10. The side form structure 15 includes a side form steel form 16, a steel tie rod 17, a nut 18 and a rubber stop-slurry strip 19. The steel frame 11 is connected to the side form steel form 16 through the steel tie rod 17. The steel tie rod 17 passes through the side form steel form 16 and is connected to the nut 18. A rubber stop-slurry strip 19 is provided at the joint between the side form steel form 16 and the bottom form 10.

[0027] As a preferred embodiment, the side form structure 15 and the bottom form 10 are connected to each other to form a mold for the pile cap beam, so as to facilitate its casting and molding. The steel tie rod 17 can be embedded in the concrete and fixedly connected to the side form steel form 16. After casting and molding, the side form steel form 16 can be disassembled by twisting the nut 18. At the same time, the steel tie rod 17 is reserved outside the concrete for standby use to connect other subsequent workpieces.

[0028] A longitudinal beam 20 is provided on the top of the steel frame 11, and a surface layer 21 is provided on the top of the longitudinal beam 20. One side of the foundation pile 1 is connected to a mooring component 22, which includes a support frame 23, a rubber fender 24, a wave-breaking plate 25 and a through hole 26.

[0029] As a preferred embodiment, the longitudinal beam 20 plays a supporting role and cooperates with the cross beam to support the surface layer 21. The surface layer 21 is made of concrete and is cushioned when the ship docks through the mooring member 22. The rubber fender 24 is connected through the support frame 23 to cushion the ship.

[0030] A rubber fender 24 is provided on one side of the support frame 23 , and a wave-breaking plate 25 is connected to the bottom end of the support frame 23 via a movable shaft. Through holes 26 are arranged on the surface of the wave-breaking plate 25 .

[0031] As a preferred embodiment, when waves flow through the wave-breaking plate 25, the wave-breaking plate 25 will sway left and right with the waves. The seawater at the connection point of the wave-breaking plate 25 passes through the through hole 26 to play a diversion and buffering role. The wave-breaking plate 25 can change the flow direction and energy distribution of the waves, thereby reducing the impact force of the waves on the structure and protecting the stability and safety of the structure.

[0032] The corbel structure 3 is welded into a π shape with Q235 steel plates. The top plate 4 is 400 mm long, 760 mm wide and 12 mm thick. The corbel web 5 is 760 mm high, 760 mm long and 12 mm thick. The center distance between the two sets of corbel webs 5 is 200 mm. The thickness of the steel casing 2 is 1.2 cm. The corbel structure 3 is formed by double-sided welding, and the weld height is 12 mm.

[0033] As a preferred embodiment, the corbel structure 3 ensures construction safety by setting specific values, thereby improving the force distribution of the structure, reducing stress concentration, and improving the bearing capacity of the structure.

[0034] The model of the I-beam support 7 is II56b / II50, the secondary beam 8 adopts I-20b with a spacing of 40 cm, the square wood 9 adopts 100mm×100mm wooden square with a length of 4.2m, and the bottom formwork 10 adopts 15mm plywood or plastic formwork.

[0035] As a preferred embodiment, the I-beam support 7 is a long steel strip with an I-shaped cross section, which plays a supporting role, and the square wood 9 plays a role in supporting the bottom mold 10.

[0036] The welded joints of the main reinforcement 12 shall not exceed 50% of the number of the main reinforcement 12, and the staggered spacing shall be greater than 35d and not less than 500mm. A 1m×1m opening shall be reserved for the top reinforcement. The steel tie rod 17 shall be made of A16 round steel, and the top shall be supported by a steel pipe or channel steel inner side.

[0037] As a preferred embodiment, the number of welding joints of the main reinforcement 12 does not exceed 50% of the number of main reinforcements 12. By controlling the number of welding joints, the strength of the main reinforcement 12 is improved, and the bound steel skeleton 11 is sufficiently stable to ensure that the steel bars do not shift in position during the concrete pouring process. A 1m×1m opening is reserved on the top surface of the steel bars for easy entry and exit of personnel.

[0038] The construction method includes the following steps: S1: Elevation measurement, taking the pile cap bottom elevation as the relative 0 point, based on the pile cap design bottom elevation of 0, reversely calculate the bottom elevation of the bottom formwork 10 panel to be -0.015m, the timber 9 to be -0.115m, the I-beam support 7 and secondary beam 8 to be -0.315m, the double-jointed 45b main beam to be -0.765m, and the corbel structure 3 to be -0.765m. Other elevations are similar and calculated according to the drawing; S2: After the bottom formwork support system is laid out and the surveyors have set out the elevations of the lower pile cap and the bottom of the beam, the on-site construction personnel determine the elevation of the corbel structure 3 through the cast-in-place piles and use a horizontal pipe to guide it to other piles. The corbel structures 3 are symmetrically arranged on both sides of the cast-in-place piles, with one corbel structure 3 on each side. The corbel structure 3 is formed by double-sided welding, with a weld height of 12mm. The coating should be removed after welding. After the welding of the corbel structure 3 is completed, the top elevation of the corbel structure 3 is checked to ensure that the height difference between them does not exceed 3mm. Otherwise, the elevation of the local corbel structure 3 needs to be adjusted. The measures are cement slurry, mortar or thin steel plate leveling. After the welding or installation of the corbel structure 3 is completed and passed the acceptance, the front pile cap II56b / II50 I-beam support 7 is erected, and then the reverse corbel structure 3 is welded. After passing the acceptance, II45b is installed; S4: Pile head removal: After manually marking a circular cut at the pile top elevation, the concrete outside the steel cage is chiseled out to form a gap, exposing the steel bars. The chiseling depth is the thickness of the steel bar protective layer. After the steel bars are exposed, the steel bars are slightly bent outwards by no more than 30 degrees. When manually chiseling, the jackhammer is drilled horizontally or slightly upwards into the concrete in the middle and upper part of the key construction area, which is the concrete about 10 cm from the pile top as required by the design. The gap is continuously deepened. When the gap depth reaches about 30 cm, the jackhammer is drilled with the drill bit horizontally or slightly upwards. After completion, cleaning is carried out. After all cleaning work is completed, two people work together to straighten the steel bars with a steel wrench. S5: Use a total station to measure and locate according to the dimensions of the pile cap and beam. First, roughly lay out the wooden square 9 according to the dimensions of the pile cap and beam. Then, measure the four corner points of the pile cap and beam and the center axis on the wooden square 9. Finally, mark the layout points with a red marker or nails to determine the position of the bottom formwork 10. S6: Rebar binding. The pile cap and beam reinforcement projects are layered and tied to the top according to the pouring order. The transverse reinforcement of the upper beam is tied after the longitudinal beam is installed. In order to ensure that the construction joints are roughened during construction, a 1m×1m hole is reserved for the top surface reinforcement to facilitate personnel access. Binding is carried out when the surface layer is 21 hours old. The center and both ends of the reinforcement joints should be tied tightly with wire. Pads 14 should be set on the reinforcement. Pads 14 are purchased as finished products and delivered to the site to ensure that the protective layer meets the requirements. The reinforcement is tied with plum blossom points, and the wire heads must not extend into the concrete protective layer. S7: Install the side formwork structure 15. Clean the formwork before installation and evenly apply the release agent. The formwork installation elevation and position must be strictly in accordance with the drawings. The installation joints, straightness, and flatness must be strictly in accordance with the specifications. The side formwork steel formwork 16 uses tension screws with a horizontal spacing of 80 cm and a vertical spacing of 100 cm. The steel tie rods 17 are made of A16 round steel, and the top is supported by steel pipes or channel steel inside to control the formwork installation dimensions. S8: Concrete pouring. After the acceptance of concealed works is completed, the construction of pile caps and beams is organized. Concrete pouring is carried out at low tide. When the tide recedes to the bottom of the pile caps or beams, the concrete pouring can be started after cleaning the steel skeleton 11 and the debris in the formwork. Before each concrete pouring, a detailed analysis should be made to ensure the pouring speed and emergency measures should be taken to ensure that the concrete is not submerged before initial setting. The pouring should be started from the lowest point first. The height of the single concrete pouring layer should be controlled at 50cm. The concrete should be poured in multiple layers and vibrated and compacted layer by layer. The upper layer of concrete must be poured before the initial setting of the lower layer of concrete. Construction cold joints are strictly prohibited. After the concrete pouring is completed, before the initial setting of the concrete, the surface concrete of the pile caps and beams should be roughened to ensure that the interface between the new and old concrete is rough before the secondary concrete construction. The shelf surface of the box beam installation should be polished and compacted to ensure that the shelf surface is flat. S9: After the formwork is removed and the initial setting is completed, the surface layer 21 must be kept moist. The side formwork structure 15 and the bottom formwork 10 can be removed only after the concrete reaches 2.5MPa. When removing the formwork, it can be done in blocks. The main construction process is as follows: a1: It is planned to use four 3t hand hoists to tie to the main reinforcement 12 of the beam, and use steel wire ropes or slings to support the I-beam formwork.

[0039] a2: Carry out the work of cutting the corbel structure 3. When cutting the corbel structure 3, arrange one person from each team to observe the sea conditions and the rise and fall of the tide.

[0040] a3: After the corbel structure 3 is cut off, all operators at the pile cap and the bottom of the beam evacuate, and release the hand hoist to lower the steel main beam.

[0041] a4: Start to dismantle the bottom formwork 10 and wooden planks 9, and transport them out with a floating raft and hoist them ashore. The spot welding position between the secondary beam 8 and the main beam can be pried open with a crowbar or cut with a gas cutter. After the main and secondary beams are separated, tie a steel wire rope on the secondary beam 8 and use a ship crane or a crane on the pile cap or the top of the beam to pull them out one by one. Considering the repeated use of the secondary beam 8 in construction, try not to cut it with gas cutting.

[0042] a5: After all the secondary beams 8 are taken out, the operator ties a steel wire rope on the main beam and slowly moves the main beam out using a ship crane or a crawler crane on a steel platform. The removal of the pile caps and cross beams is completed.

[0043] The working process of this application is as follows: first, the elevation is measured, and then the bottom formwork support system is laid. After the surveyors have laid out the elevation of the lower pile cap and the bottom of the beam, the on-site construction personnel determine the elevation of the corbel structure 3 through the cast-in-place pile, and use a horizontal pipe to lead it to other piles. The pile head is broken, and the concrete on the outside of the steel cage is chiseled out to form a gap, exposing the steel bars. According to the external dimensions of the pile cap and the beam, a total station is used to measure and locate. First, according to the external dimensions of the pile cap and the beam, the wooden square 9 is roughly laid, and then the pile cap, the four corner points of the beam and the central axis are measured on the wooden square 9. Finally, a red marker or nails are used to mark the layout point to determine the position of the bottom formwork 10 and the steel bars are tied. The pile cap and beam reinforcement projects are tied to the top in layers according to the pouring order. The horizontal reinforcement of the upper beam part is tied after the longitudinal beam is installed, and then the side formwork structure 15 is installed. After the installation is completed, the pouring work is carried out. The height of the layered construction layer of the single concrete pouring is controlled at 50cm. It is poured in multiple layers and vibrated to be dense in layers. The upper concrete must be poured before the lower concrete begins to set. After the concrete is poured, before the concrete begins to set, the surface concrete of the pile cap and beam is roughened to ensure that the interface between the new and old concrete is rough before the secondary concrete construction. The shelf surface of the box beam is installed and compacted to ensure that the shelf surface is flat. Then the formwork is removed to complete the construction.

Claims

1. A cast-in-situ pile cap beam construction structure for a dock, comprising foundation piles (1), characterized in that: The top outer wall of the foundation pile (1) is connected to a steel casing (2), and a corbel structure (3) is welded to both sides of the steel casing (2), and the corbel structure (3) includes a top plate (4) and a corbel web (5). The bottom sides of the top plate (4) are welded to corbel webs (5), and the corbel webs (5) are connected to the steel casing (2) in a T-shaped manner. The top cantilevered portion of the corbel structure (3) is provided with a bottom formwork support structure (6), and the bottom formwork support structure (6) includes an I-beam support (7), a secondary beam (8), a square timber (9) and a bottom formwork (10). The I-beam support (7) is welded to the corbel structure (3), and the top of the I-beam support (7) is provided with a secondary beam (8), and the top of the secondary beam (8) is provided with a square timber (9). The top of the square timber (9) is connected to the bottom formwork (10), and the square timber (9) and the bottom formwork (10) are fixed by nails.

2. The cast-in-situ pile cap beam construction structure for a dock according to claim 1, characterized in that: A steel frame (11) is provided on the top of the bottom formwork (10), the steel frame (11) comprising main bars (12) and stirrups (13), the main bars (12) and stirrups (13) being tied with a plum blossom pattern, and pads (14) are arranged on the surface of the steel frame (11), the pads (14) having a grade not lower than C45, and the number of the pads (14) not less than 4 per m2.

3. The cast-in-situ pile cap and beam construction structure for a wharf according to claim 2, characterized in that: A side form structure (15) is provided at the edge of the bottom form (10), and the side form structure (15) includes a side form steel form (16), a steel tie rod (17), a nut (18) and a rubber stop-slurry strip (19). The steel skeleton (11) is connected to the side form steel form (16) through the steel tie rod (17), and the steel tie rod (17) passes through the side form steel form (16) and is connected to the nut (18). A rubber stop-slurry strip (19) is provided at the joint between the side form steel form (16) and the bottom form (10).

4. The cast-in-situ pile cap beam construction structure for a dock according to claim 3, characterized in that: A longitudinal beam (20) is provided on the top of the steel frame (11), a surface layer (21) is provided on the top of the longitudinal beam (20), and a mooring member (22) is connected to one side of the foundation pile (1), and the mooring member (22) includes a support frame (23), a rubber fender (24), a wave-breaking plate (25) and a through hole (26).

5. The cast-in-situ pile cap and beam construction structure for a dock according to claim 4, characterized in that: A rubber fender (24) is provided on one side of the support frame (23), and a wave-breaking plate (25) is connected to the bottom end of the support frame (23) via a movable shaft. Through holes (26) are arranged on the surface of the wave-breaking plate (25).

6. The cast-in-situ pile cap and beam construction structure for a dock according to claim 1, characterized in that: The corbel structure (3) is welded into a π shape using Q235 steel plates. The top plate (4) is 400 mm long, 760 mm wide, and 12 mm thick. The corbel web (5) is 760 mm high, 760 mm long, and 12 mm thick. The center spacing between two groups of corbel webs (5) is 200 mm. The steel casing (2) is 1.2 cm thick. The corbel structure (3) is formed by double-sided welding, and the weld height is 12 mm.

7. The cast-in-situ pile cap and beam construction structure for a dock according to claim 3, characterized in that: The model of the I-beam support (7) is II56b / II50, the secondary beam (8) adopts I-20b with a spacing of 40 cm, the square wood (9) adopts 100mm×100mm wood square with a length of 4.2m, and the bottom formwork (10) adopts 15mm plywood or plastic formwork.

8. The cast-in-situ pile cap and beam construction structure for a dock according to claim 3, characterized in that: The welded joints of the main reinforcement (12) do not exceed 50% of the number of the main reinforcement (12), and the staggered spacing is greater than 35d and not less than 500mm. A 1m×1m opening is reserved for the top reinforcement. The steel tie rod (17) is made of A16 round steel, and the top is supported by a steel pipe or channel steel inner side.

9. A construction method for a cast-in-situ pile cap and crossbeam construction structure for a wharf, applying the cast-in-situ pile cap and crossbeam construction structure according to any one of claims 1 to 8, characterized in that: The construction method comprises the following steps: S1: Elevation measurement, taking the pile cap bottom elevation as the relative 0 point, based on the pile cap design bottom elevation of 0, the bottom elevation of the bottom formwork (10) panel is calculated to be -0.015m, the wood (9) is -0.115m, the I-beam support (7) and the secondary beam (8) is -0.315m, the double 45b main beam is -0.765m, and the bracket structure (3) elevation is -0.765m. The remaining elevations are similar and calculated according to the drawing; S2: The bottom formwork support system is laid. After the surveyors have marked out the elevation of the lower pile cap and the bottom of the beam, the on-site construction personnel determine the elevation of the corbel structure (3) through the cast-in-place piles and use a horizontal pipe to guide it to other piles. The corbel structure (3) is symmetrically arranged on both sides of the cast-in-place piles, with one corbel structure (3) on each side. The corbel structure (3) is formed by double-sided welding, and the weld height is 12mm. The coating should be removed after welding. After the corbel structure (3) is welded, the top elevation of the corbel structure (3) is checked to ensure that the height difference between them does not exceed 3mm. Otherwise, the elevation of the local corbel structure (3) needs to be adjusted. The measures are cement slurry, mortar or thin steel plate leveling. After the corbel structure (3) is welded or installed and passed the acceptance inspection, the front pile cap II56b / II50 I-beam support (7) is erected, and then the reverse corbel structure (3) is welded. After passing the acceptance inspection, II45b is installed; S4: Pile head removal: After manually marking a circular cut at the pile top elevation, the concrete outside the steel cage is chiseled out to form a gap, exposing the steel bars. The chiseling depth is the thickness of the steel bar protective layer. After the steel bars are exposed, the steel bars are slightly bent outward (no more than 30 degrees). When manually chiseling, the jackhammer is drilled horizontally or slightly upward into the concrete in the middle and upper part of the key construction area, which is the concrete about 10 cm from the pile top as required by the design. The gap is continuously deepened. When the gap depth reaches about 30 cm, the jackhammer is drilled to the top with the drill bit horizontal or slightly upward. After completion, cleaning is carried out. After all cleaning work is completed, two people work together to straighten the steel bars with a steel wrench. S5: Use a total station to measure and locate according to the dimensions of the pile cap and beam. First, roughly lay out the wooden squares (9) according to the dimensions of the pile cap and beam. Then, measure the four corner points of the pile cap and beam and the central axis on the wooden squares (9). Finally, mark the layout points with a red marker or nails to determine the position of the bottom formwork (10). S6: Steel bar binding. The pile cap and beam reinforcement are layered and tied to the top according to the pouring order. The transverse reinforcement of the upper beam is tied after the longitudinal beam is installed. In order to ensure that the construction joints are roughened during construction, a 1m×1m hole is reserved for the top surface reinforcement to facilitate personnel access. Binding is carried out when the surface layer (21) is constructed. The center and both ends of the reinforcement joints are tightened with iron wire. Pads (14) should be set on the reinforcement. The pads (14) are purchased as finished products and delivered to the site to ensure that the protective layer meets the requirements. The reinforcement is tied with plum blossom points, and the wire heads must not extend into the concrete protective layer. S7: Install the side formwork structure (15). Clean the formwork before installation and apply the release agent evenly. The elevation and position of the formwork installation shall be strictly in accordance with the drawings. The installation joints, straightness and flatness shall be strictly in accordance with the specifications. The side formwork steel formwork (16) shall be arranged with steel tie rods (17) with a horizontal spacing of 80 cm and a vertical spacing of 100 cm. The tie rods shall be made of A16 round steel and the top shall be supported by steel pipes or channel steel inner supports to control the formwork installation dimensions. S8: Concrete pouring. After the acceptance of the concealed works is completed, the concrete construction of pile caps and beams is organized. The concrete pouring construction is carried out at low tide. When the tide recedes to the bottom of the pile caps or beams, the concrete pouring construction can be started after the steel skeleton (11) and the debris in the formwork are cleaned. Before each concrete pouring, a detailed analysis should be made to ensure the pouring speed and emergency measures should be taken to ensure that the concrete is not submerged before the initial setting. The pouring should be started from the lowest point. The height of the single concrete pouring layer should be controlled at 50cm. The concrete should be poured in multiple layers and vibrated and compacted layer by layer. The upper layer of concrete must be poured before the initial setting of the lower layer of concrete. Construction cold joints are strictly prohibited. After the concrete pouring is completed, the concrete surface of the pile caps and beams should be roughened before the initial setting of the concrete to ensure that the interface between the new and old concrete is rough before the secondary concrete construction. The shelf surface of the box beam installation should be polished and compacted to ensure that the shelf surface is flat. S9: The formwork is removed. After the pouring is completed and the initial setting is completed, the surface layer (21) must be kept moist. The side formwork structure (15) and the bottom formwork (10) can be removed only after the concrete reaches 2.5MPa. When removing the formwork, it can be done in blocks. The main construction process is as follows: a1: It is planned to use four 3t hand hoists to tie to the main reinforcement (12) of the beam, and use steel wire ropes or slings to support the I-beam formwork; a2: Carry out the work of cutting the corbel structure (3). When cutting the corbel structure (3), arrange one person from each team to observe the sea conditions and the rise and fall of the tide; a3: After the bracket structure (3) is cut off, all operators at the pile cap and the bottom of the beam evacuate, and the hand hoist is released to lower the steel main beam; a4: Start to dismantle the bottom formwork (10) and the wooden square (9), and transport them out with a floating raft and hoist them ashore. The spot welding position between the secondary beam (8) and the main beam can be pried open with a crowbar or cut with a gas cutter. After the main and secondary beams are separated, a steel wire rope is tied to the secondary beam (8). The beams are pulled out one by one using a ship crane or a crane on the pile cap or the top of the crossbeam. The secondary beam (8) is not cut with a gas cutter as much as possible in order to reuse it in construction. a5: After all the secondary beams (8) are taken out, the operator ties a steel wire rope to the main beam and slowly moves the main beam out using a ship crane or a crawler crane on a steel platform. The removal of the pile caps and cross beams is completed.

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