CN104452597A - Supporting system for construction of super-long water pier prestressed cap beam - Google Patents

Abstract

The invention discloses a construction supporting system for super-long prestressed cover beams of underwater piers. Four steel pipe columns around each underwater pier; a pin hinge and its support are connected at the bottom of each strut, and the pin hinge support at the bottom of the steel diagonal brace passes through the pre-embedded steel plate II and the corresponding underwater pier The cap is connected; the top of the strut and the top of the steel pipe column are equipped with a horizontal support cover, and a longitudinal support beam is fixed on the horizontal support cover; a sandbox is provided at each end of the longitudinal support beam, and the sandbox supports the horizontal load. Beams, multiple longitudinal distribution beams are fixed on the horizontal load-bearing beams, and all the longitudinal distribution beams form the horizontal support surface of the system. The invention has strong bearing capacity and high stability, and can be applied to the construction of ultra-long underwater pier cap beams with a length of more than 40m, an installation height of more than 8m, and a clear distance between pier bodies of more than 18m.

Description

Construction support system of ultra-long prestressed cover beam for pier in water

technical field

The invention relates to a construction support system of a cover beam, in particular to a construction support system of an ultra-long prestressed cover beam for an underwater pier.

Background technique

At present, domestic large-scale municipal and highway bridges are mostly designed with six or eight lanes in two directions, and three or four lanes in one direction. and the non-stent method. The support method has high requirements on the bearing capacity of the foundation, the cost of foundation treatment is high, and the construction period is limited. A little carelessness in construction can cause the overall support of the support to sink, seriously affecting the construction quality of the cap beam, and it is not suitable for piers in water; no support The common methods of construction are: pre-embedded method, crossing method and hoop method. Although they are suitable for high pier cap beams and underwater cap beams, the three methods have their own advantages and disadvantages, and the advantages of each method cannot ensure the support of the cap beam. The system has overall control requirements for construction progress, quality and cost.

The Wusong River Bridge in the Suzhou Zhonghuan Expressway Industrial Park Section Project is a single-span double-width simply supported steel truss bridge with a total weight of about 4410t, a span of 119m, and a single width of 22.8m. It is the largest single width in China, Suzhou and Jiangsu The longest span in the province, the cover beam: 54.2m in length, 3.6m in width, and 2.5m in height, also the length of the bridge of the same type in China, the total weight of a single cover beam can reach 1300t, between the pier columns under the cover beam The net distance is 20.2m, and the construction is located on the water. There is a muddy soil layer more than 20m deep on the south bank of the Wusong River. Neither the traditional support method nor the non-support method construction is suitable for this project. At the same time, this project has very high requirements on the bearing capacity and stability of the bracket. Moreover, in the construction of the above-mentioned cover beams, in order to avoid cracking of local node concrete caused by concrete shrinkage deformation and creep stress on the pier body, it is necessary to adopt a pre-topping process. Usually, it is necessary to erect temporary supports and carry out foundation treatment and The construction of the support frame is difficult, the construction period is long, and the cost is high.

Contents of the invention

In order to solve the technical problems existing in the known technology, the present invention provides a super-long prestressed cover beam construction support system for piers in water. The support system has strong bearing capacity and high stability. Construction of ultra-long underwater piers and cap beams with a net distance of more than 18m.

The technical solution adopted by the present invention to solve the technical problems existing in the known technology is: a support system for the construction of super-long prestressed cover beams in water piers, the lower part of the cover beams is provided with at least two underwater pier columns, and the support system includes Support, the support includes two steel diagonal braces arranged in a figure-eight shape between two adjacent water piers and four steel pipe columns arranged around each of the water piers; corresponding to each of the water piers The bottom ends of the four steel pipe columns of the above-mentioned water pier columns are fixed on the four corners of the caps of the water pier columns through pre-embedded steel plates I; each of the steel diagonal braces is provided with two struts, each The projections of the two struts of the steel diagonal brace on the horizontal elevation of the bracket coincide, and the longitudinal distance is the same as the distance between the two vertically adjacent steel pipe columns 1, and the two steel diagonal braces of each The struts are connected together through a steel structure, and a pin hinge and its support are connected at the bottom end of each strut, and the pin hinge support at the bottom end of the steel diagonal brace is connected with the corresponding said strut through the embedded steel plate II. The caps of pier columns in water are connected, the pre-embedded steel plate II is located on the outside of the pre-embedded steel plate I close to it; the tops of the two steel braces arranged in a figure-eight shape are connected by transverse connecting beams; each of the The tops of the struts and the tops of each of the steel pipe columns are provided with horizontal support covers of equal elevation, and a longitudinal support beam is fixed on each of the two vertically opposite horizontal support covers; all of the steel pipe columns and all the steel braces are connected together through the horizontal connecting member I;

A sand box is respectively provided at both ends of the plurality of longitudinal support beams, and the sand boxes at the two ends of the longitudinal support beams support two transverse load-bearing beams respectively, and a plurality of vertical load-bearing beams arranged side by side are fixed on the two transverse load-bearing beams. Distribution beams, all of said longitudinal distribution beams form the horizontal support surface of the system.

The pre-jacking mechanism is installed on the bracket, and the pre-jacking mechanism includes the relative pre-jacking steel plate I and the pre-jacking steel plate II, and the pre-jacking steel plate I and the pre-jacking steel plate II are respectively pre-embedded in two adjacent On the outer surface of the pier column in the water, between the pre-jacking steel plate I and the pre-jacking steel plate II, there are pre-jacking steel pipes, jacks and pressure seats connected horizontally in sequence from the pre-jacking steel plate I. The pre-jacking steel pipe is connected to the pre-jacking steel plate I; the pre-jacking steel pipe is supported by a limit clamp, and the limit clamp is fixed on the middle top surface of the longitudinal support beam.

Under the pre-embedded steel plate I and the pre-embedded steel plate II, an inverted U-shaped anchoring steel bar and a horizontal reinforcement mesh are welded, and the horizontal reinforcement mesh is connected to the inverted U-shaped anchoring steel bar.

The sand box is composed of a lower sand barrel fixedly connected with the longitudinal support beam and an upper piston buttress; fine sand bodies are contained in the lower sand barrel; the upper piston buttress is provided with an inverted barrel, The inverted barrel is filled with concrete structures; the inverted barrel is inserted into the lower sand barrel, the upper piston abutment is supported by the fine sand body, and the lower sand barrel is A sand outlet is provided on the side wall of the lower end, and a plugging door is installed on the sand outlet.

The sand discharge port is formed by threaded holes, and the plugging door is formed by bolts.

The inverted barrel is provided with a bottom with an outer edge protruding outside the barrel to form a buttress top support cover; the outer edge of the bottom of the lower sand barrel is stretched out between the barrel of the lower sand barrel Outside, form the bottom supporting pallet of the sand box.

The embedded steel plate II and the embedded steel plate I adjacent to it are a whole steel plate.

The transverse connection beam, the longitudinal support beam, the members of the steel diagonal bracing, the transverse load-bearing beam and the longitudinal distribution beam all adopt double I-shaped steel structure.

The bottoms of the four steel pipe columns corresponding to each of the underwater piers are integrated through the horizontal connecting member II.

The pin-hinge support at the bottom end of the steel diagonal brace is connected to the bottom of the steel pipe column near the pin-hinge support by a horizontal steel plate.

The advantages and positive effects that the present invention has are:

1) The support adopts the cap of the pier column as the focus point, and transfers the load of the structure to the permanent structure, breaking the current domestic municipal and highway bridge field. Pre-embed the steel plate during the construction of the pier column cap in the water. After the construction of the pier column in the water is completed, connect the steel diagonal brace and the steel pipe column to the pre-embedded steel plate, pull out the Larsen pile used for the construction of the pier column and the cap, and place the steel When the diagonal brace is turned to the set inclination angle, the next step of construction can be carried out, which can shorten the installation period of the cover beam support system and save costs. The reason is that the angle of the steel diagonal brace can be adjusted by using the pin-hinge structure. Since the cofferdam Larsen piles used for pier column construction are intersected with the steel diagonal braces of the support, the Larsen piles at the intersection must be pulled out first when the support is installed. If the erection method of direct welding of the steel diagonal brace and the pre-embedded steel plate of the cap is adopted, the construction is difficult, the cap is far away from the river bank, and there are underwater obstacles, so a hinged structure is added at the foot of the steel diagonal brace It is connected with the pre-embedded steel plate of the cap, and the use of this hinged structure can not be affected by the site environmental conditions and the crossing of Larsen piles. After the steel diagonal brace is connected with the pre-embedded steel plate of the cap, a chain hoist is used to hold and pass through the upper part of the steel diagonal brace The steel wire rope of the ear plate is temporarily fixed to the pier column, so that the steel diagonal brace is perpendicular to the cap, and the Larsen pile is pulled out and then installed according to the oblique angle. If there is no pin-hinge rotatable structure, Larsen pile cofferdam needs to be erected as a whole to form a closed whole of all pier caps. The setting of pin-hinge joints can remove some Larsen piles used for platform cap construction in advance, and at the same time reduce the cost and construction period of the overall setting of Larsen piles, shorten the installation time of supports, and save the rental cost of Larsen piles. The present invention utilizes the existing pier caps as the foundation of the structure, reduces the technical links of foundation treatment, and the steel components used in the structure can also be recycled, which can save a lot of cost. Compared with the traditional support method and no support method, the present invention avoids the disadvantages of the need to deal with the foundation or install steel pipe piles in the construction of the support method, and the shortcomings of insufficient bearing capacity and stability, and adopts section steel support, which has high rigidity and strong bearing capacity , compared with the construction of cap beams without support method, it avoids the defects of pre-embedding method, crossing method and hoop method, and has no effect on the quality and appearance of the permanent structure pier body. It is suitable for the construction of ultra-long cover beams for underwater piers with a net distance of more than 18m, and can be applied to the construction of cover beams for non-cylindrical pier columns.

2) The system support provides temporary support for the pre-push device of the pier column, which reduces the process links such as foundation treatment and support frame erection for erecting the temporary support, further shortens the construction period, reduces labor costs and material costs.

3) The sand box is used as the support of the horizontal load-bearing beam, so that the support elevation of the system can be fine-tuned, the installation accuracy is improved, and the formwork removal and construction can be facilitated. The sand box has simple structure, convenient processing and high bearing capacity, which can effectively improve the construction efficiency. Especially when the pier is a high pier, using the sand box as an adjustable support structure can effectively reduce the construction difficulty and improve the safety factor. The main processing materials of the sand box are steel pipe and fine sand. The sand box is small in size, which can save materials and reduce construction costs. After the construction is completed, the box body and fine sand can be used again, and there is no waste left on site. , and can effectively reduce environmental pollution.

To sum up, the present invention has high rigidity, strong bearing capacity, can shorten the construction period, reduce labor costs and material costs, and has high installation precision. It is a recyclable multifunctional support structure system.

Description of drawings

Fig. 1 is the elevation view of the present invention;

Fig. 2 is the top view of Fig. 1;

Figure 3-1 is a sectional view of I-I in Figure 1;

Figure 3-2 is a sectional view of II-II in Figure 1;

Figure 3-3 is a sectional view of III-III in Figure 1;

Fig. 3-4 is A-A sectional view of Fig. 1;

Fig. 4 is the elevation view of the pre-embedded steel plate I and the pre-embedded steel plate II of the present invention;

Fig. 5 is a schematic diagram of the anchoring reinforcement structure of the pre-embedded steel plate I of the cap and the pre-embedded steel plate II of the present invention;

Fig. 6 is the structural schematic diagram of pier column pre-embedded steel plate of the present invention;

Figure 7 is a schematic diagram of the installation of the pre-jacking mechanism of the present invention;

Figure 8 is a top view of Figure 7;

Fig. 9 is a front view of the sand box of the present invention.

In the figure: 1. Steel pipe column; 2. Pier column in water; 3-1. Strut; 3-2. Steel structure; Buried steel plate Ⅰ; 8. Embedded steel plate Ⅱ; 9. Horizontal connecting member Ⅱ; 10. Pin hinge; 11. Pin hinge support; 16. Horizontal reinforcing steel mesh; 17. Inverted U-shaped anchoring steel bar; 18. Pre-jacking steel plate I; 19. Limit clamping plate; 20. Pre-jacking steel pipe; 21. Jack; 22. Pressure seat; 23. Pre-top steel plate II; 24. U-shaped anchoring steel bar; 25. Vertical steel plate for force transmission; 26. Axial limit baffle; 27. Sand box; 27-1. Lower sand barrel; 27-1-1. The bottom supporting plate of the sand box; 27-1-2, fine sand body; 27-1-3, the plugging door; 27-2, the upper piston pier; 27-2-1, the supporting cover plate at the top of the pier; 27-2-2. Concrete structure; 28. Horizontal load-bearing beam; 29. Vertical distribution beam; 30. Cover beam; 31. Guardrail; 32. Bottom form.

Detailed ways

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

Please refer to the accompanying drawings, a super-long prestressed cover beam construction support system for submerged pier, at least two submerged pier columns 2 are arranged at the lower part of the cover beam 30, and the support system includes a bracket and its upper supporting structure.

The support includes two steel diagonal braces arranged in a figure-eight shape between two adjacent water piers 2 and four steel pipe columns 1 arranged around each water piers; corresponding to each of the water piers The bottom ends of the four steel pipe columns 1 of the pier column 2 are fixed to the four corners of the cap 12 of the pier column 2 in the water through the embedded steel plate I7; each of the steel diagonal braces is provided with two struts 3 -1, the projections of the two struts 3-1 of each of the steel diagonal braces on the horizontal elevation of the bracket coincide, and the longitudinal spacing is the same as that of the two vertically adjacent steel pipe columns 1, each The two struts 3-1 of the steel diagonal brace are connected together by a steel structure 3-2, and a pin hinge 10 and its support 11 are connected to the bottom end of each strut 3-1. The pin-hinge support 11 at the bottom of the diagonal brace is connected to the cap 12 of the corresponding underwater pier 2 through the embedded steel plate II8, the embedded steel plate II8 is located on the outside of the embedded steel plate I1 close to it, and the brace The bottom end of the rod 3-1 is connected with the pin hinge support 11 at the bottom end of the steel brace through a pin hinge 10, and an annular groove is arranged at the tail of the pin hinge 10, and an axial shaft is inserted in the annular groove. The limit baffle 26, the axial limit baffle 26 is fixed on the pin-hinge support 11 at the bottom end of the steel brace; Connection; the top of each of the struts 3-1 and the top of each of the steel pipe columns 2 are provided with a horizontal support cover 13 of equal elevation, on each of the two vertically opposite horizontal support covers 13 A longitudinal support beam 5 is fixed; it is used as a platform for placing the pre-jack steel pipe 20 and the sand box 27; all the steel pipe columns 1 and all the steel diagonal braces are connected together through horizontal connecting members I6.

A sand box 27 is respectively provided at two ends of the plurality of longitudinal support beams 5, and the sand boxes 27 at the two ends of the longitudinal support beam 5 support two transverse load-bearing beams 28 respectively, and are fixed on the two transverse load-bearing beams 28. A plurality of longitudinal distribution beams 29 arranged side by side, all of which form the horizontal support surface of the system. Bottom form 32 and guardrail 31 etc. that are used to install cover beam.

The sand box 27 is composed of a lower sand barrel 27-1 fixedly connected with the longitudinal support beam 5 and an upper piston pier 27-2; the lower sand barrel 27-1 is filled with a fine sand body 27-1 -1; the upper piston abutment 27-2 is provided with an inverted barrel, and a concrete structure 27-2-2 is built in the inverted barrel; the inverted barrel is inserted into the lower sand In the barrel 27-1, the upper piston abutment 27-2 is supported by the fine sand body 27-1-1, and a sand outlet is provided on the lower end side wall of the lower sand barrel 27-1. A plugging door is installed on the sand outlet.

In this embodiment, the sand discharge opening is formed by a threaded hole, and the plugging door is formed by bolts 27-1-3. The inverted barrel body is provided with a bottom with an outer edge protruding from the barrel body to form a buttress top supporting cover plate 27-2-1; the bottom outer edge of the lower sand barrel 27-1 extends above the In addition to the barrel body of the following sand barrel, the bottom supporting plate 27-1-2 of the sand box is formed, so as to be connected with the longitudinal support beam 5 by bolts, so that the horizontal position of the sand box 27 can be adjusted, so that the sand box 27 can be multi- repeated recycling.

In this embodiment, the cross-section of the middle pier is elliptical. The 14 cofferdam Larsen piles used for pier column construction are 18m long. If the elevation of the riverbed top is 0.00m, then the water surface elevation is 1.5m, and the elevation of the pier cap top is -2.8m. In order to facilitate construction and save costs, the pre-jacking mechanism is installed on the above-mentioned bracket. The pre-jacking mechanism includes the relative pre-jacking steel plate I18 and the pre-jacking steel plate II23. Buried on the outer surfaces of two adjacent piers 2 in water, between the pre-roofing steel plate I18 and the pre-roofing steel plate II23, there are pre-roofing steel pipes 20 horizontally connected sequentially from the pre-roofing steel plate I18 , a jack 21 and a pressure seat 22, the pre-jack steel pipe 20 is connected to the pre-jack steel plate I18, and the jack 21 and the pressure seat are installed between the other end of the pre-jack steel pipe 20 and the pre-jack steel plate II23 22. The jack 21 is located between the pre-jacked steel pipe 20 and the pressure seat 22. Before implementing the pre-jacking operation, the jack 21 and the pressure seat 22 are suspended from the horizontal support surface of the system. The pre-jacking steel pipe 20 is supported by a limit clamp 19 , and the limit clamp 19 is fixed on the middle top surface of the longitudinal support beam 5 .

If the pre-jacking force is applied to the pier column, if there is direct contact, the contact surface between the jack head and the pier column is small, the force is concentrated, and there is a possibility of local cracking. The reason is that a pre-jacking steel plate I18 is set outside the end of the pre-jacking steel pipe 20 away from the jack 21. The pre-jacking steel plate I18 and the pre-jacking steel plate II23 have the same structure, and both include a piece that is adapted to the outer surface of the pier column 2 in the water. Arc-shaped steel plate, U-shaped anchoring steel bar 24 is welded on the back side of the arc-shaped steel plate, the opening direction of the U-shaped anchoring steel bar 24 is the same as the opening direction of the described arc-shaped steel plate, and the bottom of the U-shaped anchoring steel bar 24 is provided There are two inverted hook-like structures. The function of the hook structure is similar to that of the expanding tube. The pre-roofing steel plate I18 and the pre-roofing steel plate II23 achieve the function of diffusing concentrated stress by welding anchor bars. The pressure bearing seat 22 includes a force-transmitting vertical steel plate 25, and the force-transmitting vertical steel plate 25 is connected to the pre-supporting steel plate II 23 through a steel connection structure II. During the pre-roofing construction, in order to prevent pollution to the piers, geotextiles are used to wrap the surrounding areas of the pre-roofing steel plate I18 and the pre-roofing steel plate II23.

The pre-jacking device uses the bracket of the cover beam support system as a temporary support, and installs the pre-jacking steel pipe and the pressure seat. The pre-jacking steel pipe is fixed by the limit clamp and the bracket, which reduces the foundation treatment and the erection of the supporting frame for temporary support alone. The process link can shorten the construction period, reduce labor costs and material costs.

The steel pipe column 1 is under pressure, the connection between the bottom and the cap 12 is under local pressure, and the connection between the bottom hinge node of the steel diagonal brace and the cap 12 is under pressure and resists shearing. Shaped anchoring steel bars 17 are connected to the permanent structure of the platform cap, and three layers of horizontal reinforcing steel mesh 16 are arranged under the pre-embedded steel plate I7 and pre-embedded steel plate II8. The U-shaped anchoring steel bar 17 is connected with the inner steel bar of the cap respectively. The longitudinal bars and transverse bars of the welded steel mesh form a network structure, which has good bonding and anchoring properties with concrete, and the bearing load is evenly spread and distributed, which can significantly improve the anti-seismic cracking performance of reinforced concrete structures. It can reduce the cracks of concrete and improve the shear capacity and local compressive bearing capacity. The steel brace is located on the outside of the steel pipe column 1 adjacent to it, and the embedded steel plate II8 and the embedded steel plate I7 adjacent to it are a whole steel plate to further facilitate construction. In order to strengthen the stability of the structure, the pin-hinge support at the bottom end of the steel diagonal brace is connected with the bottom of the steel pipe column near the pin-hinge support by a horizontal steel plate. In order to reduce the weight of the structure while satisfying the structural strength and rigidity, the transverse connection beam 4, the longitudinal support beam 5, the members of the steel diagonal brace, the transverse load-bearing beam 28 and the longitudinal distribution beam 29 All adopt double I-beam structure. In order to further enhance the structural rigidity, the bottoms of the four steel pipe columns 1 corresponding to each of the underwater pier columns 2 are integrated through a horizontal connecting member II9. In order to ensure a reliable connection between the steel pipe column 1 and the embedded steel plate I7, a stiffener plate welded to the embedded steel plate I7 is provided at the bottom of the steel pipe column 1 . The two struts 3-1 of each of the steel diagonal braces are connected together through a rice-shaped steel structure, which is convenient for construction and reliable in structure.

In summary, the present invention pre-embeds the steel plate during the construction of the cap, welds the steel pipe column and the steel diagonal bracing hinge joints on the pre-embedded steel plate, pulls out the local Larsen pile used for the construction of the cap, and then rotates the steel diagonal brace to the specified angle , take the structure of welded horizontal connecting beams to fix the steel diagonal braces, strengthen the horizontal support connection by welding the horizontal connecting members, fix the longitudinal connecting beams on the vertically opposite steel pipe columns and steel diagonal braces, and fix the middle parts of multiple longitudinal connecting beams The limit clamping plate of the pre-jacking steel pipe provides temporary support for the pre-jacking device of the pier column; the sand boxes are respectively fixed at the two ends of the multiple longitudinal connecting beams to support the two horizontal load-bearing beams. Fix multiple longitudinal distribution beams to form the horizontal support surface of the system. The invention is a recyclable multifunctional supporting structure system.

This structural system formed by steel pipe columns and steel diagonal braces bears the vertical load transmitted by the self-weight of the cap beam and the construction load, and transmits the force to the foundation of the permanent structural cap, which has little impact on the permanent structure and the structural force Uniform and well supported. Moreover, this structural system can well solve the problem of insufficient foundation stability due to the lengthening of the steel pipe piles caused by the vertical load of the steel pipe piles and the friction with the river bed in other support systems. It is suitable for relatively deep silty soil layers, and meets the requirements of bearing capacity without increasing the support height. In addition, the horizontal support cover plate is welded on the top of the steel pipe column. First, it can be used for hanging around the steel wire rope when lifting at a single point. Pass directly to the steel pipe column.

Pre-jacking steel pipes are arranged on the support, and a pre-jacking force is applied to the pier body through a jack, which can avoid local joint concrete cracking caused by the stress generated by the shrinkage deformation and creep of the ultra-large-volume cap beam concrete on the pier body. After the pre-jacking force is loaded, the steel member is welded between the pre-jacking steel pipe and the pre-jacking steel plate II, the jack and the pressure seat are unloaded, and the pre-jacking force is transferred to the steel member. The pre-jacking force can be transmitted through the pre-jacking steel pipe and acts on the In the range of about 1m below the top of the pier column, the top of the pier body can bear the pre-jacking force, which can offset the tensile stress generated by the shrinkage stress of the super-long cover beam mass concrete on the pier top, so as to avoid cracks and cracks at the joints. The pre-pushed steel pipes cannot be removed until the cover beams are poured and reach the design strength.

The sand box set at the node position is used as the lower fulcrum of the horizontal load-bearing beam, and the elevation can be adjusted, which can effectively avoid errors in the installation process of the bracket. In addition, after the construction of the cover beam is completed, the sand box can be dropped (10-20cm) to complete the horizontal direction. The lowering of the load-bearing beams reserves a space for the removal of the bottom form, which is beneficial to the removal of the formwork.

For the sand box used to adjust the elevation, it is first necessary to select engineering sand with excellent performance and dry it in the sun. The sand box needs to be tested for bearing performance in advance, and preloaded according to the load borne during the construction process. Relevant parameters are obtained through the test to determine the amount of sand and After loading, the height reduction caused by the compaction of the sand itself should be reserved according to this parameter during construction. The working principle of the sand box is mainly to generate extrusion force on the sand under pressure. After the bolt holes are tightened, the sand box is under pressure, the bolts on the bolt holes are removed, and the sand in the sand box is manually pulled out to reduce the elevation.

The height-adjustable sand box acts like a jack. There are a total of 20 supporting systems. In order to ensure that the sand boxes are evenly stressed, the sand box spacing between pier columns (within a single span) is arranged at an average of 6.06m. compression value. Determine the compression value, reserve the compression height, and accurately adjust the elevation of the top of the sand box to achieve the purpose of controlling the height of the bottom mold of the cover beam. When removing the bottom mold, the bolts are removed first, and the sand in the sand box is manually pulled out to achieve the purpose of falling as a whole, thereby leaving a space for the bottom mold to be removed.

The sand box, as an important transmission component of the entire support system and a means of removing the formwork, can be regarded as the support of the transverse load-bearing beam. During construction, a single sand box bears a load of more than 130t, so it is necessary to control the plane deviation and maintain multi-point adjustable sand. When the box is installed, the plane net is accurate to avoid changing the stress system of the bracket and causing the system to be unstable. It is necessary to measure and adjust the wires of the 20 sand boxes after installation to ensure that the elevations are consistent, the center lines are on the same straight line, and the plane deviation does not exceed 1cm. In order to ensure construction safety, before using the sand box, random samples are taken for testing on a 150t press to verify the force of the sand box and the compression value after the sand box is filled with engineering sand (standard sand is about 1cm, and engineering yellow sand can reach 2cm ). According to the compression value determined by the test, the compression height is reserved, and the elevation of the top of the sand box is precisely adjusted to achieve the purpose of controlling the height of the bottom formwork of the cover beam.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, people can also make many forms without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection scope of the present invention.

Claims (10)

1. A super-long prestressed cover beam construction support system for pier in water, the bottom of the cover beam is provided with at least two pier columns in water, it is characterized in that, the support system includes a support, and the support includes two adjacent Two steel diagonal braces arranged in a figure-eight shape between the piers in the water and four steel pipe columns arranged around each of the piers in the water; the four steel pipe columns corresponding to each of the piers in the water The bottom end is fixed on the four corners of the caps of the piers in the water by pre-embedded steel plates I; The projections on the horizontal elevation of the bracket coincide, and the longitudinal distance is the same as the distance between two vertically adjacent steel pipe columns 1, and the two braces of each steel diagonal brace are connected together by a steel structure. The bottom end of each strut is connected with a pin hinge and its support, and the pin hinge support at the bottom end of the steel diagonal brace is connected to the cap of the corresponding underwater pier through the embedded steel plate II. The steel plate II is located on the outside of the pre-embedded steel plate I close to it; the tops of the two steel diagonal braces arranged in a figure-eight shape are connected by a transverse connecting beam; the top of each strut and each steel pipe column Horizontal support covers of the same elevation are provided at the top of each, and a longitudinal support beam is fixed on every two horizontal support covers vertically opposite; all the steel pipe columns and all the steel diagonal braces pass through the horizontal connecting member connected together; A sand box is respectively provided at both ends of the plurality of longitudinal support beams, and the sand boxes at the two ends of the longitudinal support beams support two transverse load-bearing beams respectively, and a plurality of vertical load-bearing beams arranged side by side are fixed on the two transverse load-bearing beams. Distribution beams, all of said longitudinal distribution beams form the horizontal support surface of the system. 2. The super-long prestressed cover beam construction support system for pier in water according to claim 1, characterized in that a pre-jacking mechanism is installed on the support, and the pre-jacking mechanism includes a relative pre-jacking steel plate I and a pre-jacking Steel plate II, the pre-roof steel plate I and the pre-roof steel plate II are respectively pre-embedded on the outer surfaces of two adjacent water piers, and the pre-roof steel plate I and the pre-roof steel plate II are automatically The pre-jacking steel plate I is initially equipped with a pre-jacking steel pipe, a jack and a pressure seat connected horizontally in sequence, and the pre-jacking steel pipe is connected with the pre-jacking steel plate I; the pre-jacking steel pipe is supported by a limit clamp, so The limiting clamping plate is fixed on the middle top surface of the longitudinal support beam. 3. The super-long prestressed cover beam construction support system for pier in water according to claim 1, characterized in that an inverted U-shaped anchoring steel bar and a horizontal Reinforcing reinforcement mesh, the horizontal reinforcement reinforcement mesh is connected with the inverted U-shaped anchoring reinforcement. 4. The super-long prestressed cover beam construction support system of pier in water according to claim 1, wherein the sand box is composed of a lower sand bucket and an upper piston pier affixed to the longitudinal support beam; The lower sand barrel is filled with fine sand; the upper piston abutment is provided with an inverted barrel, and a concrete structure is built in the inverted barrel; the inverted barrel is inserted into the lower In the sand bucket, the upper piston abutment is supported by the fine sand body, and a sand outlet is provided on the side wall of the lower end of the lower sand bucket, and a plugging door is installed on the sand outlet. 5. The super-long prestressed cover beam construction support system for submerged pier according to claim 4, characterized in that, the sand outlet is formed by threaded holes, and the plugging door is formed by bolts. 6. The super-long prestressed cover beam construction support system for pier in water according to claim 4, characterized in that, the inverted barrel is provided with a bottom with an outer edge protruding from the barrel to form the top of the buttress The supporting cover plate; the outer edge of the bottom of the lower sand bucket protrudes outside the body of the lower sand bucket to form the bottom supporting plate of the sand box. 7. The super-long prestressed cover beam construction support system for underwater pier according to claim 1, characterized in that the embedded steel plate II and the embedded steel plate I adjacent to it are a whole steel plate. 8. The super-long prestressed cover beam construction support system for pier in water according to claim 1, characterized in that, the transverse connecting beam, the longitudinal support beam, the member of the steel diagonal brace, and the transverse load-bearing beam Both the longitudinal distribution beam and the longitudinal distribution beam adopt a double-span I-beam structure. 9. The super-long prestressed cover beam construction support system for underwater pier according to claim 1, characterized in that the bottoms of the four steel pipe columns corresponding to each of the underwater pier columns are integrated through horizontal connecting members II . 10. The super-long prestressed cover beam construction support system for pier in water according to claim 1, characterized in that, the pin-hinge support at the bottom end of the steel diagonal brace and the bottom of the steel pipe column near the pin-hinge support Connected by horizontal steel plates.