Pre-pressing device of bridge zero block support and working method of pre-pressing device

Abstract

The invention discloses a pre-pressing device of a bridge zero block support and a working method of the pre-pressing device, relates to the technical field of support pre-pressing, and solves the technical problems that an existing back-pressing structure is affected by factors such as environment or space in the using process, the cost is high, and the influence on the environment is large. A combined structure of a back pressure longitudinal beam, a jack and a steel strand is arranged on the surface of a bridge zero block support, and the back pressure longitudinal beam and the zero block support are directly fixed, so that force is directly dispersed on the surface of the zero block support, and uniform stress of the zero block support is guaranteed; through the multiple jacks which are tensioned synchronously, it is guaranteed that stress of the zero block support is uniform, meanwhile, pressure can be applied intelligently in the pre-pressing process, and more convenience is achieved; the steel strand can uniformly transmit the pre-pressure to each part of the structure; and therefore, the combined back pressure structure of the back pressure longitudinal beam, the steel strand and the jack is relatively simple to construct, the applied force is more convenient to change in the pre-pressing process, and the whole pre-pressing process is simpler.

Description

Technical Field

[0001] The invention belongs to the field of bridge construction, relates to a support pre-pressing technology, and specifically is a pre-pressing device for a bridge zero block support and a working method thereof. Background Art

[0002] Due to the elastic deformation of the support, the gap in the connection of the components and other factors, in order to prevent cracks in the beam caused by the sinking of the support when pouring the concrete beam and reduce the deformation of the upper structure of the support, after the support is erected and accepted, it is necessary to carry out a pre-stress test on the support to eliminate its inelastic deformation, measure the relationship between its elastic deformation and load, provide reliable data for the reserved height of the bottom formwork of the beam, and at the same time test the strength, rigidity and stability of the support.

[0003] In the construction of large structures such as bridges and buildings, counter-pressure structure is an important measure to ensure structural stability and construction safety. Existing counter-pressure structures are generally pre-loaded by pile load, sandbag pre-load or concrete block pre-load, but push load pre-load, sandbag pre-load and concrete block pre-load all require a large amount of materials for loading. The transportation and storage of materials take up a lot of space, and their purchase requires a lot of money. It is not convenient to quickly adjust the pre-pressure during use. At the same time, safety hazards may occur during the stacking and transportation of sandbags or concrete blocks. Therefore, these methods have low construction efficiency, high cost and great impact on the environment.

[0004] To this end, the present invention proposes a pre-stressing device for a bridge zero block bracket. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a pre-stressing device for a bridge block zero bracket, which solves the problem that the existing counter-pressure structure is affected by environmental or spatial factors during use, has high cost and has a greater impact on the environment.

[0006] To achieve the above-mentioned purpose, according to an embodiment of the first aspect of the present invention, a pre-stressing device for a bridge zero block support is provided, comprising: a plurality of counter-pressure longitudinal beams, a plurality of steel strands and a plurality of jacks;

[0007] The counter-pressure longitudinal beam comprises a first steel section and a second steel section, a plurality of the counter-pressure longitudinal beams are fixedly arranged on the surface of the zero block bracket at intervals, one side of the second steel section is in contact with the zero block bracket, and the other side of the second steel section is close to the surface of the first steel section; any of the first steel section is vertically arranged with any of the second steel section;

[0008] The surfaces of the first steel and the second steel are both provided with a plurality of wire holes; the wire holes are adapted to the steel strands;

[0009] A plurality of the jacks are arranged in a 6*6 array on the surface of the zero block bracket, the jacks are fixedly arranged between the first steel section and the second steel section, and the bottom of the jacks is fixedly arranged with the steel strand.

[0010] Optionally, a plurality of stiffening plates are fixedly connected inside the counter-pressure longitudinal beam, and a plurality of gusset plates are fixedly connected to the surface of the counter-pressure longitudinal beam.

[0011] Optionally, a plurality of steel pipes are fixedly connected to one side of the second steel section close to the pier and close to the first steel section. The specifications of the steel pipes are all 630*8, and the other ends of the steel pipes are fixedly connected to the jacks.

[0012] Optionally, the stiffening plate comprises a first stiffening plate, a second stiffening plate, a third stiffening plate and a fourth stiffening plate, the first stiffening plate and the third stiffening plate are provided with edge bevels on single sides, and the second stiffening plate and the fourth stiffening plate are provided with edge bevels on their edges.

[0013] Optionally, the stiffening plates between the steel strands and the first steel section and the jack and the first steel section are the first stiffening plates and the second stiffening plates, and the stiffening plates between the jack and the second steel section are the third stiffening plates and the fourth stiffening plates.

[0014] Optionally, the No. 0 block bracket is fixedly set on the surface of the bridge, and the bridge includes a pedestal and a pier. The pedestal is fixedly connected to the pier, and a plurality of anchor plates are fixedly set inside the pedestal, and the anchor plates are fixedly connected to the steel strands.

[0015] Optionally, one end of the steel strand away from the cap and away from the counter-pressure longitudinal beam is fixedly connected to a counter-tension pile, and the counter-tension pile is fixedly connected to the cap.

[0016] A working method of a preloading device of a bridge zero block support, the preloading device comprising a counter-pressure longitudinal beam, a plurality of steel strands and a plurality of jacks;

[0017] The working steps are as follows:

[0018] An observation section is set up near the mid-span and support point of the zero-block support, and 5 measuring points are set up in each observation section. The vertical positions of the 5 measuring points correspond to the side of the second steel beam, and observation reflective stickers are arranged at the corresponding positions on the side of the second steel beam;

[0019] Use the jack to apply counter pressure loading at 60% of the construction load to the zero block support. After loading, stop for 1 hour to measure the vertical deformation value and the lateral deformation value, and record them every 6 hours. If the difference between the average values ​​of the two adjacent vertical deformation values ​​and the average value of the lateral deformation value is not greater than 2mm, apply counter pressure loading at 100% of the construction load to the zero block support.

[0020] After loading, stop for 1 hour to measure the vertical deformation and lateral deformation values, and record them every 6 hours; if the difference between the average values ​​of two adjacent vertical deformation values ​​and the average value of lateral deformation values ​​is not greater than 2mm, apply reverse pressure loading at 110% of the construction load on the zero-block support; and observe the vertical deformation and lateral deformation values ​​step by step; measure the elevation values ​​of each measuring point under each load level respectively;

[0021] When the daily settlement of the measured data after loading 110% is less than 2mm compared with the measured data before loading, graded unloading begins, and the back pressure is unloaded from 110% to 100%, and the vertical and lateral deformation values ​​of the No. 0 block bracket are measured and recorded; the back pressure is unloaded from 100% to 60%, and the vertical and lateral deformation values ​​of the No. 0 block bracket are measured and recorded; the back pressure is unloaded from 60% to 0%, and the vertical and lateral deformation values ​​of the No. 0 block bracket are measured and recorded.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: a combined structure of a back-pressure longitudinal beam, a jack and a steel strand is arranged on the surface of the bridge block zero support, and the force is directly dispersed on the surface of the block zero support through direct fixation of the back-pressure longitudinal beam and the block zero support, thereby ensuring uniform force thereon and ensuring that the block zero support will not undergo large deformation during the pre-stressing process; uniform force on the block zero support is ensured through synchronous tensioning of a number of jacks, and pressure can be applied intelligently during the pre-stressing process, which is more convenient; the steel strand can evenly transfer the pre-stressing force to various parts of the structure; and thus the combined back-pressure structure of the back-pressure longitudinal beam, the steel strand and the jack is relatively simple to construct, and it is easier to change the applied force during the pre-stressing process, and the overall pre-stressing process is simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view of the pre-pressing device of the present invention;

[0024] Figure 2 For the present invention Figure 1 Sectional view of aa in the middle;

[0025] Figure 3 For the present invention Figure 1 Cross-section of the middle bb;

[0026] Figure 4 For the present invention Figure 1 Cross-section of the middle cc;

[0027] Figure 5 For the present invention Figure 1 Cross-section of the middle dd;

[0028] Figure 6 For the present invention Figure 1 Cross-section diagram of the middle ee;

[0029] Figure 7 It is a structural front view of a stiffening plate between a steel strand and a first steel section of the present invention;

[0030] Figure 8 For the present invention Figure 7 Cross-section of the middle ff;

[0031] Fig. 9 It is a structural front view of a stiffening plate between a jack and a first steel section of the present invention;

[0032] Fig.10 For the present invention Fig. 9 Cross-section of the middle gg;

[0033] Fig.11 It is a structural front view of the jack and the stiffening plate between the second steel section of the present invention;

[0034] Fig.12 For the present invention Fig.11 Cross-sectional view of hh.

[0035] In the figure: 11, first steel section; 12, second steel section;

[0036] 2. Steel strand; 3. Jack; 4. Block zero bracket; 5. Wire hole;

[0037] 61. The first stiffening plate; 62. The second stiffening plate; 63. The third stiffening plate; 64. The fourth stiffening plate; 65. The tie plate; 66. The steel pipe. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figure 1-12 As shown, a pre-stressing device for a bridge block zero support includes a plurality of counter-pressure longitudinal beams, a plurality of steel strands 2 and a plurality of jacks 3;

[0040] The counter-pressure longitudinal beam mainly has two specifications: a first steel section 11 of 2HN900*300 and a second steel section 12 of 2HN700*300. A plurality of the first steel sections 11 and a plurality of the second steel sections 12 are fixedly arranged on the surface of the zero block bracket 4 at intervals, wherein the distances between the centers of adjacent first steel sections 11 in the longitudinal direction of the bridge are 3900mm, 4820mm, 9330mm, 4820mm and 3900mm respectively, and the distances between the centers of adjacent second steel sections 12 in the transverse direction of the bridge are 2500mm, 3350mm, 3950mm, 3550mm, 2500mm, 2750mm, 2500mm, 3550mm, 3950mm, 3350mm and 2500mm; any of the first steel sections 11 and any of the second steel sections 12 are vertically arranged, the distance between the center point of the first steel section 11 at the edge and the edge of the second steel section 12 is 1975mm, one side of the second steel section 12 is in contact with the zero block bracket 4, and the other side of the second steel section 12 is close to the surface of the first steel section 11, and a plurality of stiffening plates are fixedly connected inside the counter-pressure longitudinal beam, and a plurality of gusset plates 65 are fixedly connected on the surface of the counter-pressure longitudinal beam, and the thickness of the stiffening plates and the gusset plates 65 are both 10mm;

[0041] The first steel section 11 and the second steel section 12 are both provided with wire holes 5 with a diameter of 100 mm for passing the steel strands 2;

[0042] The steel strands 2 are 15 bundles of 1-7*15.2 steel strands 2, which are arranged at intervals inside the cap. The steel strands 2 are anchored into the cap at a depth of 2m within the cap, and are anchored into bored piles 2m outside the cap; the exposed anchor plate of the steel strands 2 embedded in the cap is 15.5cm long, and the exposed anchor plate of the steel strands 2 anchored in the bored pile is 86.7cm; the steel strands 2 are connected by connectors at the top of the cap, and the exposed joints of the steel strands 2 on the top of the cap are wrapped for protection and oil-immersed to prevent rust during the construction of the lower structure;

[0043] Several jacks 3 are arranged at intervals on the support surface, the tops of the jacks 3 are fixedly connected to the back-pressure longitudinal beam, the jacks 3 are fixedly arranged between the first steel section 11 and the second steel section 12, and the bottoms of the jacks 3 are fixedly arranged with the steel strands 2; the maximum weight that the jacks 3 can lift or bear is 300 tons, three rows of back-pressure points are longitudinally arranged on the single-side support, and the jacks 3 are fixedly arranged at the back-pressure point positions, the back-pressure point spacings in a single row are 3.82m and 5.90m, and six back-pressure points are symmetrically arranged transversely, the lateral spacings of the jacks 3 are 2.5m, 3.35m, and 3.95m, and the longitudinal spacings are 3.9m and 4.82m; several jacks 3 are connected in series through an intelligent synchronous controller to ensure that several jacks 3 are tensioned at the same time, thereby ensuring that the applied forces are equal;

[0044] The prestressing device and working method of the bridge zero block support, in actual application, a combined structure of a back-pressure longitudinal beam, a jack 3 and a steel strand 2 is arranged on the surface of the bridge zero block support 4, and the back-pressure longitudinal beam is directly fixed to the zero block support 4, so that the force is directly dispersed on the surface of the zero block support 4, ensuring that it is evenly stressed and that the zero block support 4 will not be greatly deformed during the prestressing process; a number of jacks 3 are tensioned synchronously to ensure that the zero block support 4 is evenly stressed, and pressure can be applied intelligently during the prestressing process, which is more convenient; the steel strand 2 can evenly transfer the prestress to various parts of the structure; and the combined back-pressure structure of the back-pressure longitudinal beam, the steel strand 2 and the jack 3 is relatively simple to construct, and it is more convenient to change the applied force during the prestressing process, and the overall prestressing process is simpler;

[0045] In some specific implementation schemes, the zero block bracket 4 is fixedly arranged on the surface of the bridge, the bridge includes a cap and a pier, the cap is fixedly connected to the pier, a plurality of anchor plates are fixedly arranged inside the cap, and the anchor plates are fixedly connected to the steel strand 2;

[0046] The anchor depth of the steel strand 2 into the cap is 2m, and the distance between the end of the steel strand 2 away from the back pressure longitudinal beam and the anchor plate is 15.5cm;

[0047] The ends of the steel strands 2 away from the cap are fixedly connected with anti-tension piles at their ends away from the back-pressure longitudinal beam, and the anti-tension piles are fixedly connected to the cap;

[0048] The steel strand 2 is anchored into the anti-tension pile for 2 m, and the distance between the end of the steel strand 2 away from the anti-pressure longitudinal beam and the anti-tension pile is 86.7 cm;

[0049] In some specific implementation schemes, a plurality of steel pipes 66 are fixedly connected to one side of the second steel section 12 near the bridge pier and near the first steel section 11. The specifications of the steel pipes 66 are all 630*8, and the other ends of the steel pipes 66 are fixedly connected to the jacks 3. The steel pipes 66 are used to lift the position of the jacks 3, thereby ensuring that the side of the jacks 3 near the bridge pier on the zero block bracket 4 and near the first steel section 11 are located in the same horizontal plane, thereby ensuring that the first steel section 11 at one end of the jacks 3 is parallel.

[0050] In some specific embodiments, the stiffening plate includes a first stiffening plate 61, a second stiffening plate 62, a third stiffening plate 63 and a fourth stiffening plate 64, wherein the first stiffening plate 61 and the third stiffening plate 63 are provided with an edge bevel of 18 on a single side, the length of the first stiffening plate 61 is 844 mm, and the width is 142 mm; the length of the third stiffening plate 63 is 652 mm, and the width is 144 mm; the edges of the second stiffening plate 62 and the fourth stiffening plate 64 are both provided with an edge bevel of 18, wherein the length of the second stiffening plate 62 is 844 mm, and the width is 334 mm; the length of the fourth stiffening plate 64 is 652 mm, and the width is 337 mm;

[0051] In some specific embodiments, the size of the gusset plate 65 is 600*600mm; the distance between adjacent gusset plates 65 is greater than 900mm, and the gusset plates 65 avoid the connection position of the steel strand 2 holes, the jack 3 and the back pressure longitudinal beam;

[0052] In a further embodiment, the stiffening plates between the steel strand 2 and the first steel section 11 and the jack 3 and the first steel section 11 are both first stiffening plates 61 and second stiffening plates 62, the spacing between adjacent first stiffening plates 61 and second stiffening plates 62 away from the wire hole 5 is 250 mm, and the spacing between the second stiffening plates 62 close to the wire hole 5 is 200 mm;

[0053] In a further embodiment, the stiffening plates between the jack 3 and the second steel section 12 are the third stiffening plates 63 and the fourth stiffening plates 64, the spacing between the adjacent third stiffening plates 63 and the fourth stiffening plates 64 away from the wire hole 5 is 250 mm, and the spacing between the fourth stiffening plates 64 close to the wire hole 5 is 200 mm;

[0054] The working method of this device is described below:

[0055] Back pressure observation point arrangement:

[0056] An observation section is set at the middle of the span of the 4th block support and near the support point. Five measuring points are set in each observation section. The vertical positions of the five measuring points correspond to the side of the beam of the second steel section 12. Observation reflective stickers are arranged at the corresponding positions on the side of the beam of the second steel section 12.

[0057] Determination of back pressure load:

[0058] The counter pressure load is 110% of the total construction load. The stress condition of each counter pressure point is obtained by calculating the construction load combination (the load value includes the dead weight of concrete, the dead weight of formwork, the load of construction personnel and equipment, and the vibration load);

[0059] Backpressure loading:

[0060] The counter pressure load is 60% of the construction load. After loading, the vertical deformation value and the lateral deformation value are measured after one hour of static stopping, and the records are recorded every 6 hours. If the difference between the average values ​​of the two adjacent vertical deformation values ​​and the average value of the lateral deformation value is not greater than 2mm, the counter pressure load is 100% of the construction load.

[0061] After the counter pressure loading is applied at 100% of the construction load, the vertical deformation value and the lateral deformation value are measured after one hour of static stopping, and the values ​​are recorded every 6 hours; if the difference between the average values ​​of the two adjacent vertical deformation values ​​and the average value of the lateral deformation value is not greater than 2mm, the counter pressure loading is applied at 110% of the construction load; and the vertical deformation value and the lateral deformation value are observed step by step; the elevation value of each measuring point under each load level is measured respectively;

[0062] After the deformation data analysis and evaluation of the zero block bracket 4 and the bracket inspection and acceptance are qualified, unloading:

[0063] The back pressure unloading of the zero block bracket 4 is carried out in three stages.

[0064] The back pressure is unloaded from 110% to 100%, and the vertical deformation value and the lateral deformation value of the zero block bracket 4 are measured and recorded; the back pressure is unloaded from 100% to 60%, and the vertical deformation value and the lateral deformation value of the zero block bracket 4 are measured and recorded; the back pressure is unloaded from 60% to 0%, and the vertical deformation value and the lateral deformation value of the zero block bracket 4 are measured and recorded;

[0065] When monitoring data exceeds the standard during preloading, analyze the data exceeding the standard, find out the cause and deal with it;

[0066] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A preloading device for a bridge zero block support, characterized in that: include: A plurality of counter-pressure longitudinal beams, a plurality of steel strands (2) and a plurality of jacks (3); The counter-pressure longitudinal beam comprises a first steel section (11) and a second steel section (12); a plurality of the counter-pressure longitudinal beams are fixedly arranged at intervals on the surface of the zero block bracket (4); one side of the second steel section (12) is in contact with the zero block bracket (4), and the other side of the second steel section (12) is close to the surface of the first steel section (11); any one of the first steel section (11) and any one of the second steel section (12) are arranged vertically; A plurality of wire holes (5) are provided on the surfaces of the first steel section (11) and the second steel section (12); the wire holes (5) are adapted to fit the steel strands (2); A plurality of the jacks (3) are arranged in a 6*6 array on the surface of the zero block bracket (4); the jacks (3) are fixedly arranged between the first steel section (11) and the second steel section (12); and the bottom of the jacks (3) is fixedly arranged with the steel strand (2).

2. The preloading device of the bridge zero block support according to claim 1 is characterized in that: A plurality of stiffening plates are fixedly connected inside the counter-pressure longitudinal beam, and a plurality of gusset plates (65) are fixedly connected on the surface of the counter-pressure longitudinal beam.

3. The preloading device of the bridge zero block support according to claim 1 is characterized in that: A plurality of steel pipes (66) are fixedly connected to one side of the second steel section (12) close to the bridge pier and close to the first steel section (11). The specifications of the steel pipes (66) are all 630*8, and the other ends of the steel pipes (66) are fixedly connected to the jacks (3).

4. The preloading device for the bridge zero block support according to claim 2 is characterized in that: The stiffening plates include a first stiffening plate (61), a second stiffening plate (62), a third stiffening plate (63) and a fourth stiffening plate (64); the first stiffening plate (61) and the third stiffening plate (63) are provided with edge bevels on single sides, and the second stiffening plate (62) and the fourth stiffening plate (64) are provided with edge bevels on their edges.

5. The preloading device for the bridge zero block support according to claim 4 is characterized in that: The stiffening plates between the steel strand (2) and the first steel section (11) and the jack (3) and the first steel section (11) are the first stiffening plate (61) and the second stiffening plate (62), and the stiffening plates between the jack (3) and the second steel section (12) are the third stiffening plate (63) and the fourth stiffening plate (64).

6. The preloading device for the bridge zero block support according to claim 1 is characterized in that: The zero block bracket (4) is fixedly arranged on the surface of the bridge, the bridge comprises a cap and a pier, the cap is fixedly connected to the pier, a plurality of anchor plates are fixedly arranged inside the cap, and the anchor plates are all fixedly connected to the steel strands (2).

7. The preloading device for the bridge zero block support according to claim 1 is characterized in that: One end of the steel strand (2) away from the cap is fixedly connected to a back-tension pile, and the back-tension pile is fixedly connected to the cap.

8. A working method of a preloading device for a bridge zero block support according to any one of claims 1 to 7, characterized in that: The working steps are as follows: An observation section is set at the mid-span and near the support point of the zero block support (4), and 5 measuring points are set at each observation section. The vertical positions of the 5 measuring points correspond to the side faces of the cross beam of the second steel section (12), and observation reflective stickers are arranged at corresponding positions on the side faces of the cross beam of the second steel section (12); A jack (3) is used to apply a counter pressure load at 60% of the construction load to the zero block support (4). After loading, the vertical deformation value and the lateral deformation value are measured after standing for 1 hour, and the values ​​are recorded every 6 hours. If the difference between the average values ​​of the two adjacent vertical deformation values ​​and the average value of the lateral deformation value is not greater than 2 mm, a counter pressure load is applied at 100% of the construction load to the zero block support (4); After loading, the vertical deformation value and the lateral deformation value are measured after one hour of static stop, and the values ​​are recorded every six hours; if the difference between the average values ​​of the two adjacent vertical deformation values ​​and the average value of the lateral deformation value is not greater than 2 mm, a counter pressure load of 110% of the construction load is applied to the zero block support (4); and the vertical deformation value and the lateral deformation value are observed step by step; and the elevation value of each measuring point under each load level is measured respectively; When the daily settlement of the measured data after loading 110% is less than 2 mm (excluding measurement error) compared with the measured data before loading, graded unloading begins, the back pressure is unloaded from 110% to 100%, and the vertical deformation value and the lateral deformation value of the zero block bracket (4) are measured and recorded; the back pressure is unloaded from 100% to 60%, and the vertical deformation value and the lateral deformation value of the zero block bracket (4) are measured and recorded; The back pressure is unloaded from 60% to 0%, and the vertical deformation value and the lateral deformation value of the zero block bracket (4) are measured and recorded.

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