Curved bridge differential pushing walking type jack and pushing method

Abstract

The invention discloses a bent bridge differential pushing walking type jack which comprises a first walking type jack body and a second walking type jack body, the first walking type jack body is arranged on the inner side of a bent bridge, and the first walking type jack body comprises a base, a longitudinal sliding box, a transverse sliding box, a vertical jack body and a plate type rubber support; the longitudinal sliding box is placed on a sliding way of the base, the transverse sliding box is placed in the space of the longitudinal sliding box and can only move transversely, and the vertical jack is placed in the space of the transverse sliding box and can rotate freely. The plate-type rubber support is placed on the vertical jack and located below the pushing bridge; and the second walking type jack is arranged on the outer side of the curved bridge. The bent bridge differential pushing walking type jack can adapt to beam body rotation, transverse displacement and longitudinal differential displacement in the differential pushing process, and the bent bridge differential pushing can be achieved by adopting an oil pump control system of a common walking type jack in cooperation with the pushing method.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a curved bridge differential pushing walking jack and a pushing method. Background Art

[0002] The jacking method is widely used in the construction of continuous beam bridges with uniform cross-sections, including single-point jacking and multi-point jacking. In recent years, the multi-point jacking construction method using walking jacks has been widely used. This method does not affect the traffic and navigation under the bridge and can be well applied to the jacking construction of straight bridges. In the jacking construction of curved beam bridges, the traditional jacking process is to first push forward along the tangent direction of the circular curve. When the deviation between the beam body and the designed line reaches the limit, the deviation is corrected by adjusting the horizontal jack. It is necessary to correct the deviation while pushing, which is quite difficult. The differential jacking process was used for the first time for the steel box girder of the Lotus Bridge (curve radius 55m) at Hengqin Port. During the curved jacking process, the differential jacking control system is used to ensure that the inner and outer jacks have the same angular velocity but different linear velocities, resulting in a difference in the jacking strokes of the jacks on both sides during the jacking process. However, differential jacking places high demands on the equipment. For example, it requires multiple independent control circuits to individually control each crawler jack to achieve differential speed, or a central controller to control multiple circuits, which places high performance requirements on the central controller. This makes the jacking equipment relatively expensive and uneconomical. Because the jacking method does not affect traffic under the bridge, it is widely used in the construction of cross-line bridges. For example, newly built interchanges across existing highways are mostly straight bridges, with only the ramps being curved. In actual construction, ordinary crawler jacks are used for jacking construction of straight bridges. For curved bridges, considering their smaller number and the economic efficiency of construction, the jacking setup for straight bridge construction is generally also used. Therefore, how to improve existing equipment so that it can be applied to the jacking construction of both straight and curved bridges and have good economic efficiency is an urgent problem to be solved. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a curved bridge differential pushing walking jack with a simple structure and convenient construction, and provides a pushing method of the curved bridge differential pushing walking jack.

[0004] The technical solution of the present invention to solve the above technical problems is: a differential pushing walking jack for a curved bridge, comprising a first walking jack and a second walking jack, the first walking jack being arranged on the inner side of the curved bridge, the first walking jack comprising a base, a longitudinal slide box, a transverse slide box, a vertical jack and a plate rubber bearing; the longitudinal slide box is placed on the slideway of the base, the transverse slide box is placed in the longitudinal slide box space and can only move transversely, the vertical jack is placed in the transverse slide box space and can rotate freely, adapting to the rotation of the bridge during the differential pushing process; the plate rubber bearing is placed on the vertical jack and is located under the pushing bridge, the plate rubber bearing generates shear deformation when subjected to force, adapts to the lateral displacement during the differential pushing process, and realizes the adjustment of the longitudinal displacement during the differential pushing process; the second walking jack is arranged on the outer side of the curved bridge, compared with the first walking jack, the second walking jack does not include the plate rubber bearing, and the other structures are the same.

[0005] The above-mentioned curved bridge differential pushing walking jack, the base includes a bottom plate, a slide, a limit bar, an end plate, a pushing jack fixing block, and a pushing jack; two limit bars are symmetrically arranged on both sides of the slide, and the space between the two limit bars forms a slide, an end plate is provided on one side of the slide, the end plate is welded to the bottom plate, and a pushing jack fixing block is fixed on the side of the end plate away from the slide, and a hole is opened in the middle of the pushing jack fixing block, and a pushing jack is arranged in the hole.

[0006] The bottom plate of the above-mentioned curved bridge differential pushing walking jack is made of a smooth stainless steel plate or a polytetrafluoroethylene plate.

[0007] The above-mentioned bending bridge differential pushing walking jack, the longitudinal slide box includes a longitudinal slide box frame, a longitudinal slide box space, a longitudinal slide box ear plate, a correction jack fixing block, and a correction jack; the longitudinal slide box frame is a rectangular box structure with an upper opening, and the length of the longitudinal slide box frame is the same as the distance between the two limit bars on the base; the longitudinal slide box frame is fixed with a longitudinal slide box ear plate in the middle position of the long side close to the end plate, and the longitudinal slide box ear plate has two pieces and is arranged in parallel. There is a circular hole in the middle of the longitudinal slide box ear plate, and the longitudinal slide box frame is connected to the pushing jack through the longitudinal slide box ear plate. The internal space of the longitudinal slide box frame is the longitudinal slide box space, and the correction jack fixing block is welded in the middle position of the short side of one side of the longitudinal slide box frame, and the correction jack is arranged in the middle position of the correction jack fixing block.

[0008] The above-mentioned bending bridge differential pushing walking jack, the transverse slide box includes a transverse slide box frame, a transverse slide box space, and a transverse slide box ear plate; the transverse slide box frame is a regular quadrangular prism, the side length of the transverse slide box frame is the same as the short side of the longitudinal slide box space, the cylindrical space formed by the opening on the top of the transverse slide box frame serves as the transverse slide box space, and a transverse slide box ear plate is fixedly provided in the middle position of the transverse slide box frame close to the side of the correction jack. There are two transverse slide box ear plates in total and they are arranged in parallel. There is a hole in the middle of the transverse slide box ear plate, and the transverse slide box frame is connected to the correction jack through the transverse slide box ear plate.

[0009] The above-mentioned curved bridge differential pushing walking jack, the vertical jack includes a vertical jack housing and a vertical jack piston; the vertical jack housing is a cylinder, and the diameter of the vertical jack housing is the same as the inner diameter of the horizontal sliding box space; the vertical jack piston is also a cylinder, and the vertical jack piston is installed in the vertical jack housing to adjust the vertical height of the pushing bridge.

[0010] The above-mentioned curved bridge differential pushing walking jack, the plate rubber bearing includes a rubber block and a steel plate; the rubber block is a solid cylinder, the steel plate is a circular steel plate, the diameter of the steel plate is smaller than the diameter of the rubber block, and multiple steel plates are evenly stacked and arranged in the rubber block to add ribs to the rubber block.

[0011] The above-mentioned bending bridge differential pushing walking jack, the correction jack includes a correction jack housing, a correction jack piston, a correction jack piston connecting rod, and a pin; the correction jack housing and the correction jack piston are both cylindrical, the correction jack piston is installed in the correction jack housing, the correction jack piston connecting rod is located at the end of the correction jack piston, and a small hole is opened at the front end of the correction jack piston connecting rod, the diameter of the small hole is the same as the diameter of the hole of the transverse slide box ear plate, the pin passes through the small hole at the front end of the correction jack piston connecting rod and the hole of the transverse slide box ear plate, and the correction jack is fixedly connected to the transverse slide box through the pin.

[0012] In the above-mentioned curved bridge differential pushing walking jack, the diameter of the middle part of the pin is the same as the diameter of the small hole, and the diameter of the end part of the pin is larger than the diameter of the small hole.

[0013] A method for pushing a curved bridge differential pushing walking jack comprises the following steps:

[0014] Step 1: Design the placement of the walking jacks. Arrange two walking jacks in each group. The first walking jack is placed on the inner side of the curved bridge, and the second walking jack is placed on the outer side of the curved bridge. The slideway is along the secant line of the arc on the outer side of the curved bridge. The first walking jack and the second walking jack are arranged parallel to each other, and multiple groups of walking jacks are arranged longitudinally.

[0015] Step 2: Calculate the differential distance Δ1. The arc radius of the first crawler jack position is R1, the arc radius of the second crawler jack position is R2, and the longitudinal distance of a single push is D. The differential distance is:

[0016]

[0017] Step 3: Calculate the vertical reaction force of the walking jack during the jacking process of the curved bridge, establish a finite element model for the jacking construction of the curved bridge, simulate and analyze the jacking process, obtain the vertical reaction force values of each walking jack during the jacking process, and take the maximum vertical reaction force N of the jack according to its change law. imax ;

[0018] Step 4: According to the differential distance Δ1 and the maximum vertical reaction force N of the jack imax Design of plate rubber bearings:

[0019] 4-1) Maximum vertical reaction force of the jack N imax Design area A of plate rubber bearing;

[0020]

[0021] Where, σ is the actual compressive stress of the plate rubber bearing, [σ] is the maximum allowable compressive stress of the plate rubber bearing;

[0022] 4-2) Design the thickness t of the rubber layer of the plate rubber bearing e ;

[0023] t e ≥2Δ1

[0024] Determine t e Finally, the total thickness of the plate rubber bearing is obtained based on the thickness of the middle single rubber layer of 5mm, the thickness of the top and bottom rubber layers of 2.5mm, and the thickness of the steel plate of 2mm;

[0025] Step 5: Verify the performance of the plate rubber bearing;

[0026] 5-1) Calculate the shear stiffness k of the designed plate rubber bearing G ;

[0027]

[0028] Where G e is the shear elastic modulus of the plate rubber bearing;

[0029] 5-2) Use finite element model simulation to analyze the structural stress of a push stroke, and enable the geometric nonlinearity option during the analysis;

[0030] 5-3) Obtain the calculation results of the finite element model: displacement, stress, and support reaction force. Observe whether the displacement meets the differential distance and whether the stress is excessive. Verify the anti-slip stability of the outer walking jack and the main beam.

[0031] H i <μN i

[0032] Where H i is the horizontal support reaction force calculated by the finite element model, N i is the deadweight vertical support reaction force calculated by the finite element model, μ is the friction coefficient of the contact surface between the walking jack and the main beam;

[0033] If the differential distance, stress, and anti-slip stability do not meet the requirements, increase the thickness of the rubber layer of the plate rubber bearing;

[0034] Step 6: Pre-pushing to check the accuracy of design parameters:

[0035] 6-1) Finite element model calibration and model correction: The measured vertical support reaction force of the jack is compared with the deadweight vertical support reaction force calculated by the finite element model. If the relative error exceeds 10%, the finite element model is corrected to make the vertical support reaction force of the jack calculated by the finite element model close to the measured vertical support reaction force of the jack. The material bulk density and elastic modulus of the structure are selected as correction parameters, and the measured vertical support reaction force of the jack is used as the target value. The two-parameter response surface method is used to correct the model;

[0036] 6-2) Plate rubber bearing design verification must meet the maximum bearing reaction pressure requirements calculated by the modified finite element model and compare the measured bearing shear deformation Δ 1c and differential distance Δ1, if the ratio η=Δ1 / Δ 1c If the difference from 1 exceeds 10%, adjust the thickness of the rubber layer of the plate rubber bearing and take η·t e Redesigned plate rubber bearings;

[0037] Step 7: Formal jacking construction, the first step crawler jack is arranged on the bottom surface of the inner main beam of the curved bridge, and the second step crawler jack is arranged on the bottom surface of the outer main beam of the curved bridge, and it is continuously pushed to the designed position. When the lateral deviation of the bridge exceeds the allowable value during the pushing process, the lateral deviation is corrected. The second step crawler jack on the bottom surface of the outer main beam pushes a stroke D, and the outer main beam moves forward a distance D. The first step crawler jack on the bottom surface of the inner main beam pushes a stroke D, the plate rubber bearing undergoes shear deformation Δ1, and the inner main beam moves forward a distance D1, D1=D-Δ1. The purpose of differential jacking of the curved bridge is achieved through the shear deformation of the plate rubber bearing.

[0038] The beneficial effects of the present invention are as follows: the invented walking jack for differential pushing of a curved bridge can adapt to the rotation, lateral displacement and longitudinal differential displacement of the beam during the differential pushing process. In conjunction with the pushing method of the invention, the oil pump control system of an ordinary walking jack can be used to achieve differential pushing of the curved bridge, achieving an ideal state in which theoretically almost no correction is required. In addition, it is possible to consider increasing the length of the slideway, increasing the longitudinal distance of each pushing, reducing the number of pushing times, and further improving the construction efficiency of the curved bridge pushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the principle of the differential pushing of the curved bridge of the present invention.

[0040] Figure 2 It is a three-dimensional structural diagram of the curved bridge differential pushing walking jack of the present invention.

[0041] Figure 3 It is a top view of the curved bridge differential pushing walking jack of the present invention.

[0042] Figure 4 It is a side view of the curved bridge differential pushing walking jack of the present invention.

[0043] Figure 5 It is a three-dimensional exploded view of the curved bridge differential pushing walking jack of the present invention.

[0044] Figure 6 It is a structural schematic diagram of the base of the present invention.

[0045] Figure 7 It is a structural schematic diagram of the longitudinal sliding box of the present invention.

[0046] Figure 8 It is a structural schematic diagram of the transverse sliding box of the present invention.

[0047] Figure 9 It is a structural schematic diagram of the vertical jack of the present invention.

[0048] Figure 10 It is a structural schematic diagram of the cross section of the plate-type rubber bearing belt of the present invention.

[0049] Figure 11 It is a structural schematic diagram of the deviation-correcting jack of the present invention.

[0050] Figure 12 This is a plan view of the walking jacks for the jacking construction of a curved bridge according to an embodiment of the present invention.

[0051] Figure 13 This is a horizontal layout diagram of the walking jacks for the jacking construction of a curved bridge according to an embodiment of the present invention.

[0052] Figure 14 This is a finite element model diagram of a curved bridge according to an embodiment of the present invention.

[0053] Figure 15 This is a schematic diagram of the jacking working condition of a curved bridge according to an embodiment of the present invention.

[0054] Figure 16 This is the vertical reaction diagram of the support of the finite element model of the curved bridge jacking working condition 1 in an embodiment of the present invention.

[0055] Figure 17 This is a vertical reaction diagram of the inner vertical jack in the jacking working condition of the curved bridge according to an embodiment of the present invention.

[0056] Figure 18 This is a vertical reaction diagram of the outer vertical jack in the jacking working condition of the curved bridge according to an embodiment of the present invention.

[0057] Figure 19 This is a displacement component diagram of the outer walking jack with a stroke of 500mm along the outer arc in the jacking working condition 1 of the curved bridge according to an embodiment of the present invention.

[0058] Figure 20 This is a schematic diagram of the displacement of walking jacks 4# and 8# pushing along the outer arc for a stroke of 500 mm in working condition 1 of the curved bridge pushing according to an embodiment of the present invention. The thin lines in the figure are the structural lines before deformation, and the thick lines are the structural lines after deformation.

[0059] Figure 21 This is a schematic diagram of the local displacement of the walking jacks 4# and 8# pushing along the outer arc for a stroke of 500mm in working condition 1 of the curved bridge pushing according to an embodiment of the present invention.

[0060] Figure 22 This is a schematic diagram of the displacement of walking jacks 1# to 8# pushing along the outer arc for a stroke of 500 mm in working condition 1 of the curved bridge pushing according to an embodiment of the present invention. The thin lines in the figure are the structural lines before deformation, and the thick lines are the structural lines after deformation.

[0061] Figure 23 This is a schematic diagram of the local displacement of walking jacks 1# to 8# pushing along the outer arc for a stroke of 500 mm in working condition 1 of the curved bridge pushing according to an embodiment of the present invention.

[0062] Figure 24 This is a structural stress diagram of the curved bridge pushing working condition 1 of an embodiment of the present invention, where walking jacks 1# to 8# push along the outer arc for a stroke of 500 mm.

[0063] Figure 25 This is a diagram of the reaction force of a support with a stroke of 500 mm, shown in working condition 1 of the curved bridge jacking according to an embodiment of the present invention, where walking jacks 1# to 8# push along the outer arc.

[0064] Figure 26This is a schematic diagram of the displacement of the curved bridge jacking working condition 1 in an embodiment of the present invention, in which the walking jacks 1# to 8# push along the outer arc for a stroke of 500 mm after the plate rubber bearing is added on the inner side. In the figure, the thin line is the structural line before deformation, and the thick line is the structural line after deformation.

[0065] Figure 27 This is a schematic diagram of the first local displacement of the curved bridge in the embodiment of the present invention, in which a plate rubber bearing is added on the inner side and the walking jacks 1# to 8# push along the outer arc with a stroke of 500 mm.

[0066] Figure 28 This is a schematic diagram of the second local displacement of the curved bridge in working condition 1 of the present invention, in which a plate rubber bearing is added on the inner side and the walking jacks 1# to 8# push along the outer arc with a stroke of 500 mm.

[0067] Figure 29 This is a structural stress diagram of the curved bridge jacking working condition 1 according to an embodiment of the present invention, in which a plate rubber bearing is added on the inner side and the walking jacks 1# to 8# push along the outer arc for a stroke of 500 mm.

[0068] Figure 30 This is a diagram of the support reaction force of a curved bridge in working condition 1 in an embodiment of the present invention, in which a plate-type rubber support is added on the inner side and walking jacks 1# to 8# push along the outer arc for a travel of 500mm.

[0069] Figure 31 Schematic diagram of the displacement of the outer beam during the jacking construction of a curved bridge according to an embodiment of the present invention.

[0070] Figure 32 Schematic diagram of the displacement of the inner beam during the jacking construction of a curved bridge according to an embodiment of the present invention. DETAILED DESCRIPTION

[0071] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0072] like Figures 1-9As shown, a bending bridge differential pushing walking jack includes a first walking jack and a second walking jack. The first walking jack is arranged on the inner side of the bending bridge. The first walking jack includes a base 11, a longitudinal slide box 12, a transverse slide box 13, a vertical jack 14 and a plate rubber support 15; the longitudinal slide box 12 is placed on the slideway of the base 11, and the transverse slide box 13 is placed in the longitudinal slide box space 122. The plane of the transverse slide box 13 is a square, and the side length of the transverse slide box 13 is the same as the width of the longitudinal slide box space 122, ensuring that the transverse slide box 13 can only move horizontally. The vertical jack 14 is a cylinder and is placed in the transverse Inside the slide box space 132, the horizontal slide box space 132 is also a cylinder with the same diameter as the vertical jack 14, ensuring that the vertical jack 14 cannot produce translational displacement and can only rotate freely to adapt to the rotation of the bridge during the differential pushing process; the plate rubber bearing 15 is placed on the vertical jack 14 and is located under the pushing bridge. The plate rubber bearing 15 produces shear deformation when subjected to force, adapts to the lateral displacement during the differential pushing process, and realizes the adjustment of the longitudinal displacement during the differential pushing process; the second step-type jack is arranged on the outside of the curved bridge. Compared with the first step-type jack, the second step-type jack does not include the plate rubber bearing 15, and the other structures are the same.

[0073] like Figure 6 As shown, the base 11 includes a bottom plate 111, a slide 112, a limit bar 113, an end plate 114, a push jack fixing block 115, and a push jack 116. Two limit bars 113 are symmetrically arranged on both sides of the slide, and the space between the two limit bars 113 forms the slide 112. An end plate 114 is provided on one side of the slide 112, and the end plate 114 is welded to the bottom plate 111. A push jack fixing block 115 is fixed on the side of the end plate 114 away from the slide 112. The push jack fixing block 115 has a hole in the middle, and a push jack 116 is installed in the hole. The bottom plate 111 is made of smooth stainless steel plate or polytetrafluoroethylene plate.

[0074] like Figure 7As shown, the longitudinal sliding box 12 includes a longitudinal sliding box frame 121, a longitudinal sliding box space 122, a longitudinal sliding box ear plate 123, a correction jack fixing block 125, and a correction jack 124; the longitudinal sliding box frame 121 is a rectangular box structure with an upper opening, and the length of the longitudinal sliding box frame 121 is the same as the distance between the two limit bars 113 on the base 11, ensuring that the longitudinal sliding box frame 121 does not produce lateral displacement, and produces longitudinal displacement under the action of the jacking jack 116 to push the bridge; the longitudinal sliding box frame 121 is close to A longitudinal slide box ear plate 123 is fixedly provided in the middle position of the long side of one side of the end plate 114. There are two longitudinal slide box ear plates 123 and they are arranged in parallel. There is a round hole in the middle of the longitudinal slide box ear plate 123. The longitudinal slide box frame 121 is connected to the push jack 116 through the longitudinal slide box ear plate 123. The internal space of the longitudinal slide box frame 121 is the longitudinal slide box space 122. A correction jack fixing block 125 is welded in the middle position of the short side of one side of the longitudinal slide box frame 121, and a correction jack 124 is set in the middle position of the correction jack fixing block 125.

[0075] like Figure 8 As shown, the transverse sliding box 13 includes a transverse sliding box frame 131, a transverse sliding box space 132, and a transverse sliding box ear plate 133; the transverse sliding box frame 131 is a regular quadrangular prism, and the side length of the transverse sliding box frame 131 is the same as the short side of the longitudinal sliding box space 122, ensuring that the transverse sliding box 12 does not produce longitudinal displacement, and produces transverse displacement under the action of the correction jack 124 to correct the bridge; the cylindrical space formed by the opening on the top of the transverse sliding box frame 131 serves as the transverse sliding box space 132, and a transverse sliding box ear plate 133 is fixedly provided in the middle position of the transverse sliding box frame 131 near the side of the correction jack 124. There are two transverse sliding box ear plates 133 and they are arranged in parallel. There is a hole in the middle of the transverse sliding box ear plate 133, and the transverse sliding box frame 131 is connected to the correction jack 124 through the transverse sliding box ear plate 133.

[0076] like Figure 9 As shown, the vertical jack 14 includes a vertical jack housing 141 and a vertical jack piston 142; the vertical jack housing 141 is a cylinder, and the diameter of the vertical jack housing 141 is the same as the inner diameter of the horizontal slide box space 132, to ensure that the vertical jack 14 does not move linearly, but only produces free rotation, to adapt to the rotation of the bridge during the differential jacking process; the vertical jack piston 142 is also a cylinder, and its diameter is smaller than that of the vertical jack housing 141. The vertical jack piston 142 is installed in the vertical jack housing 141 to adjust the vertical height of the jacking bridge.

[0077] like Figure 10As shown, the plate rubber bearing 15 includes a rubber block 151 and a steel plate 152; the rubber block 151 is a solid cylinder, and the steel plate 152 is a circular steel plate 152. The diameter of the steel plate 152 is smaller than that of the rubber block 151. Multiple steel plates 152 are evenly stacked and arranged in the rubber block 151 to rib the rubber block 151; under the action of horizontal load, the plate rubber bearing 15 can undergo shear deformation along the load direction. Through reasonable bearing design, the purpose of adapting to the lateral displacement and longitudinal differential distance of the beam during differential jacking is achieved.

[0078] like Figure 11 As shown, the correcting jack 124 includes a correcting jack housing 1241, a correcting jack piston 1242, a correcting jack piston connecting rod 1243, and a latch 1244; the correcting jack housing 1241 and the correcting jack piston 1242 are both cylindrical, the correcting jack piston 1242 is installed in the correcting jack housing 1241, the correcting jack piston connecting rod 1243 is located at the end of the correcting jack piston 1242, and a small hole is opened at the front end of the correcting jack piston connecting rod 1243, the diameter of the small hole is the same as the diameter of the hole of the transverse slide box ear plate 133, the latch 1244 passes through the small hole at the front end of the correcting jack piston connecting rod 1243 and the hole of the transverse slide box ear plate 133, and the correcting jack 124 is fixedly connected to the transverse slide box 13 through the latch 1244. The diameter of the middle portion of the latch pin 1244 is the same as the diameter of the small hole, and the diameter of the end portion of the latch pin 1244 is larger than the diameter of the small hole.

[0079] A method for pushing a curved bridge differential pushing walking jack comprises the following steps:

[0080] Step 1: Design the placement of the walking jacks. Arrange two walking jacks in each group. The first walking jack is placed on the inner side of the curved bridge, and the second walking jack is placed on the outer side of the curved bridge. The slideway 112 is along the arc secant direction of the outer side of the curved bridge. The first walking jack and the second walking jack are arranged in parallel. Arrange multiple groups of walking jacks longitudinally with appropriate longitudinal spacing, such as Figure 12 For a double narrow steel box girder curved bridge, the first walking jack is arranged on the bottom surface of the inner main girder 31, the second walking jack is arranged on the bottom surface of the outer main girder 32, and a group of walking jacks is arranged every four cross beams 33 (cross beam spacing is about 5m), for a total of five groups;

[0081] Step 2: If Figure 1In the figure, O represents the center of the curved bridge, R1 and R2 represent the arc radius of the inner and outer jack positions respectively, and the inner and outer pushing jacks are placed at points n1 and n2 respectively. The ideal state is to push to points n3 and n4 respectively. The walking jack can only move in a straight line, and the pushing path is not along the arc S1 and S2. Assume that the jack at n2 pushes along the secant L1, and L2 is the inner arc secant parallel to L1. The inner jack does not push along L2 because at the initial position, the distance between the inner and outer jacks is B. During the pushing process, the distance will remain unchanged. When the outer jack walks to n i At point n, the inner jack is at j Point position, n j The point is located at the intersection of the L4 line and the n i At the intersection of the circle with B as the center and B as the radius, the L4 line is from point O to n i The connection of the points, at this time, can ensure that n i Point to n j The distance between points is B, and the distance traveled by the inner and outer jacks also satisfies the differential ratio R1:R2. j The polyline formed by connecting the points is denoted as L3, which is a curve. Because the jacking jacks can only be arranged along a straight line, the inner jacks can only be arranged along the secant line. At this time, the lateral distance Δ2 between L2 and L3 is not applicable to ordinary walking jacks. At the same time, the beam body will rotate significantly during the jacking process, as shown by the angle θ in the figure. Ordinary walking jacks limit this rotation angle. When using ordinary walking jacks to push the beam at the same point, the outer jack travels a distance D to reach point n4, and the inner jack also travels a distance D to reach point n5. The distance between points n1 and n3 is D1, and the distance between points n3 and n5 is Δ1, where D = D1 + Δ1. If the inner jack travels less than Δ1, it will be exactly on the arc, thus meeting the differential jacking requirements. The differential jacking method achieves the purpose of differential speed by controlling the travel distance of the inner and outer jacks.

[0082] Calculate the differential distance Δ1. The arc radius of the first crawler jack position is R1, the arc radius of the second crawler jack position is R2, and the longitudinal distance of a single push is D. Then the differential distance is:

[0083]

[0084] like Figure 13The inner main beam 31 and the outer main beam 32 are connected by a crossbeam 33. The first step crawler jack is arranged on the bottom surface of the inner main beam 31 and the top surface of the foundation 4. The second step crawler jack is arranged on the bottom surface of the outer main beam 32 and the top surface of the foundation 4. The transverse distance between the inner main beam 31 and the outer main beam 32 is 5.8m. The radius of the central circle of the curved bridge is 150m. Then R1 = 150-5.8 / 2 = 147.1m, R2 = 150+5.8 / 2 = 152.9m, and the longitudinal distance of a single push D = 500mm. The differential distance is:

[0085]

[0086] Step 3: Calculate the vertical reaction force of the walking jack during the jacking process of the curved bridge, and establish a finite element model for the jacking construction of the curved bridge, such as Figure 14 , the jacking process is simulated and analyzed, and the vertical reaction force value of each step jack in the jacking process is obtained. Figure 15 Take the four pushing conditions in the example as an example, Figure 15 From top to bottom are the schematic diagrams of working conditions 1, 2, 3, and 4. Figure 15 1#~10# represent the numbers of 10 walking jacks respectively. The vertical reaction force of the jack in working condition 1 is as follows: Figure 16 As shown in (unit: kN), the vertical reaction force of the inner jack under the four working conditions can be analyzed and obtained by the same method as shown in Figure 17 , the vertical reaction force of the outer jack is as follows Figure 18 As can be seen from the figure, the vertical reaction forces of the two groups of walking jacks (1#, 2# and 9#, 10#) on the longitudinal bridge vary greatly. For example, the vertical reaction force of the 1# jack decreases from 600kN to 100kN, while the vertical reaction force of the middle jacks varies relatively little, especially the vertical reaction force of the middle group (5#, 6#) of jacks, which hardly changes at 500kN. The main consideration is the change of the vertical reaction force of the inner jacks. Figure 17 , the maximum vertical reaction force of the jack N imax Take it as 600kN.

[0087] Step 4: According to the differential distance Δ1 and the maximum vertical reaction force N of the jack imax Design of plate rubber bearing 15:

[0088] 4-1) Maximum vertical reaction force of the jack N imax Design area A of plate rubber bearing;

[0089]

[0090] Where, σ is the actual compressive stress of the plate rubber bearing, [σ] is the maximum allowable compressive stress of the plate rubber bearing, and [σ] is taken as 10 MPa;

[0091] According to step 3, the maximum vertical reaction force of the jack is Nimax =600kN, then

[0092]

[0093] When designed as a circular support, the diameter Φ≥276mm, take Φ=280mm.

[0094] 4-2) Design the thickness t of the rubber layer of the plate rubber bearing e ;

[0095] t e ≥2Δ1

[0096] The rubber layer needs to be thick enough to achieve the required shear deformation, t e It should not exceed the support diameter. If the support is too high, it will affect the stability of the work.

[0097] Therefore:

[0098] t e ≥2Δ1=37.94mm

[0099] Take t e =60mm, the thickness of a single rubber layer is 5mm (the thickness of the rubber layer on the top and bottom surfaces is 2.5mm), the thickness of the steel plate 152 is 2mm, then there are a total of 12 layers of steel plates 152 and 13 layers of rubber layers, and the total thickness of the plate rubber bearing 15 is 84mm.

[0100] Step 5: Verify the performance of the plate rubber bearing;

[0101] like Figure 19 This is the displacement component diagram (unit: mm) of the outer walking jack for the curved bridge jacking condition 1, which pushes along the outer arc for a stroke D = 500 mm. Assuming that only walking jacks 4# and 8# are pushing, and the other support positions are frictionless and can slide freely, the geometric nonlinear option is turned on during the finite element model simulation analysis, and the displacement is calculated as follows: Figure 20 , Figure 20 The thin line is the structural line before deformation, and the thick line is the structural line after deformation. It can be seen that the inner and outer arc lines basically coincide with each other. The local displacement diagram of the 3# and 4# positions is as follows: Figure 21 It can be seen that the displacement of the 4# side is about one pushing stroke D=500mm, and the displacement of the 3# side is 481.035mm. When the differential distance Δ1 is considered, the theoretical displacement of the inner arc is D-Δ1=500-18.97=481.033mm, which is consistent with the calculation results of the finite element model. This shows that if the friction resistance in the pushing process is not considered, only two walking jacks on the outside are needed to achieve differential pushing.

[0102] In actual multi-point pushing, multiple ordinary walking jacks are used for synchronous pushing. Assuming that the walking jacks 1#~8# push along the outer arc in the bending bridge pushing working condition 1 for a stroke of 500mm (the pushing displacement of the inner 1#~7# is the same as that of the outer 2#~8#), the displacement is as follows: Figure 22 , the thin line in the figure is the structure line before deformation, and the thick line is the structure line after deformation. The local displacement diagram of 3# and 4# positions is as follows Figure 23 , we can see that the beams are not parallel before and after deformation, and the structural stress diagram is as follows Figure 24 , the maximum stress is 304MPa, the stress is very large, the support reaction force is as follows Figure 25 It can be seen that each support position has a large horizontal support reaction force. For example, the horizontal reaction force of the 5# support is 658kN, which is larger than the vertical reaction force of 507.5kN under the action of its own weight. This shows that it is impossible for the walking jacks 1# to 8# to push the main beam to the predetermined position, because a large horizontal reaction force is generated between the walking jacks and the main beam, and horizontal sliding will occur between the two.

[0103] The above analysis is equivalent to using a rigid connection between the walking jack and the main beam to constrain displacement in three directions, if a plate rubber bearing 15 is placed on the inner walking jack.

[0104] 5-1) Calculate the shear stiffness k of the designed plate rubber bearing G ;

[0105]

[0106] Where G e is the shear elastic modulus of the plate rubber bearing, G e =1MPa;

[0107] Using k G =1.03kN / mm stiffness for finite element model calculation. For the bending bridge jacking working condition 1, after adding plate rubber bearing 15 on the inside, walking jacks 1#~8# push along the outer arc for a stroke of 500mm. The schematic diagram is as follows Figure 26 , the thin line in the figure is the structure line before deformation, and the thick line is the structure line after deformation. The local displacement diagram of 3# and 4# positions is as follows Figure 27 、 Figure 28 , we can see that the displacement of the 4# side is about one jacking stroke D=500mm, the jacking displacement of the 3# support is 500mm, and the displacement of the 3# side main beam is 481.9mm, which is consistent with the theoretical displacement of the inner arc when the differential distance Δ1 is considered, which is D-Δ1=500-18.97=481.03mm. This shows that the differential jacking effect is achieved by the plate rubber support 15. Structural stress is as follows Figure 29 , the maximum stress is 14.7MPa, and the additional stress generated by the jacking is small. Figure 30It can be found that the horizontal reaction forces of the inner 1#, 3#, 5# and 7# supports are all to the right and are close in size, about 18kN. G =1.03kN / mm, so the shear deformation is 18.5mm, which is basically consistent with the differential distance Δ1. However, it should be noted that the outer walking jack and the main beam cannot slide, and the main beam can be pushed to the predetermined position.

[0108] 5-2) Use finite element model simulation to analyze the structural stress of a push stroke, and enable the geometric nonlinearity option during the analysis;

[0109] 5-3) Obtain the calculation results of the finite element model: displacement, stress, and support reaction force. Observe whether the displacement meets the differential distance and whether the additional stress from the jacking is excessive. Verify the anti-sliding stability of the outer walking jack and the main beam.

[0110] H i <μN i

[0111] Where H i is the horizontal support reaction force calculated by the finite element model, N i is the deadweight vertical support reaction force calculated by the finite element model, μ is the friction coefficient of the contact surface between the walking jack and the main beam, and μ = 0.2 when rubber contacts steel;

[0112] Such as 4#, H i =45.1kN<μN i =0.2×369.8=73.96kN, which meets the requirements. If the differential distance, additional push stress, and anti-sliding stability do not meet the requirements, increase the thickness of the rubber layer of the plate rubber bearing;

[0113] Step 6: Pre-pushing to check the accuracy of design parameters:

[0114] 6-1) Finite element model calibration and model correction: The measured vertical support reaction force of the jack is compared with the deadweight vertical support reaction force calculated by the finite element model. If the relative error exceeds 10%, the finite element model is corrected to make the vertical support reaction force of the jack calculated by the finite element model close to the measured vertical support reaction force of the jack. The material bulk density and elastic modulus of the structure are selected as correction parameters, and the measured vertical support reaction force of the jack is used as the target value. The two-parameter response surface method is used to correct the model;

[0115] 6-2) Plate rubber bearing design verification must meet the maximum bearing reaction pressure requirements calculated by the modified finite element model and compare the measured bearing shear deformation Δ 1c and differential distance Δ1, if the ratio η=Δ1 / Δ 1cIf the difference from 1 exceeds 10%, adjust the thickness of the rubber layer of the plate rubber bearing and take η·t e Redesigned plate rubber bearings;

[0116] Step 7: Formal jacking construction, the first crawler jack 1 is arranged on the bottom surface of the inner main beam 31 of the curved bridge, and the second crawler jack 2 is arranged on the bottom surface of the outer main beam 32 of the curved bridge. Continuously push to the designed position. During the jacking process, if the lateral deviation of the bridge exceeds the allowable value, perform lateral correction, such as Figure 19 The second walking jack 2 on the bottom surface of the outer main beam 32 of the curved bridge pushes a stroke D, and the outer main beam 32 moves forward a distance D. Figure 20 In the first step, the crawler jack 1 pushes the bottom surface of the inner main beam 31 of the curved bridge by a stroke D, and the plate rubber bearing 15 undergoes shear deformation Δ1. The inner main beam 31 of the curved bridge moves forward a distance D1, D1=D-Δ1. Through the shear deformation of the plate rubber bearing 15, the purpose of differential pushing of the curved bridge is achieved.

[0117] The above embodiment describes in detail that the first crawler jack 1 is arranged on the bottom surface of the main beam 31 on the inner side of the curved bridge, and the second crawler jack 2 is arranged on the bottom surface of the main beam 32 on the outer side of the curved bridge. The arrangements can also be exchanged, and the plate rubber bearing 15 can be designed according to the similar method mentioned above.

Claims

1. A curved bridge differential pushing walking jack, comprising a first walking jack and a second walking jack, characterized in that: The first step crawler jack is arranged on the inner side of the curved bridge. The first step crawler jack includes a base, a longitudinal slide box, a transverse slide box, a vertical jack and a plate rubber bearing; the longitudinal slide box is placed on the slideway of the base, the transverse slide box is placed in the longitudinal slide box space and can only move transversely, and the vertical jack is placed in the transverse slide box space and can rotate freely to adapt to the rotation of the bridge during the differential pushing process; the plate rubber bearing is placed on the vertical jack and is located under the pushing bridge. The plate rubber bearing produces shear deformation when subjected to force, adapts to the lateral displacement during the differential pushing process, and realizes the adjustment of the longitudinal displacement during the differential pushing process; the second step crawler jack is arranged on the outside of the curved bridge. Compared with the first step crawler jack, the second step crawler jack does not include a plate rubber bearing, and the other structures are the same.

2. The curved bridge differential pushing walking jack according to claim 1, characterized in that: The base includes a bottom plate, a slide, a limit bar, an end plate, a push jack fixing block, and a push jack; two limit bars are symmetrically arranged on both sides of the slide, and the space between the two limit bars forms a slide, an end plate is provided on one side of the slide, and the end plate is welded to the bottom plate, and a push jack fixing block is fixed on the side of the end plate away from the slide, and a hole is opened in the middle of the push jack fixing block, and a push jack is arranged in the hole.

3. The curved bridge differential pushing walking jack according to claim 2, characterized in that: The bottom plate is made of a smooth stainless steel plate or a polytetrafluoroethylene plate.

4. The curved bridge differential pushing walking jack according to claim 2, characterized in that: The longitudinal slide box includes a longitudinal slide box frame, a longitudinal slide box space, a longitudinal slide box ear plate, a correction jack fixing block, and a correction jack; the longitudinal slide box frame is a rectangular box structure with an upper opening, and the length of the longitudinal slide box frame is the same as the distance between the two limit bars on the base; a longitudinal slide box ear plate is fixedly provided at the middle position of the long side of the longitudinal slide box frame close to the end plate, and there are two longitudinal slide box ear plates in total and they are arranged in parallel. There is a circular hole in the middle of the longitudinal slide box ear plate, and the longitudinal slide box frame is connected to the push jack through the longitudinal slide box ear plate. The internal space of the longitudinal slide box frame is the longitudinal slide box space, and a correction jack fixing block is welded at the middle position of the short side of one side of the longitudinal slide box frame, and a correction jack is arranged in the middle position of the correction jack fixing block.

5. The curved bridge differential pushing walking jack according to claim 4, characterized in that: The transverse sliding box includes a transverse sliding box frame, a transverse sliding box space, and a transverse sliding box ear plate; the transverse sliding box frame is a regular quadrangular prism, the side length of the transverse sliding box frame is the same as the short side of the longitudinal sliding box space, the cylindrical space formed by the opening on the top of the transverse sliding box frame serves as the transverse sliding box space, and a transverse sliding box ear plate is fixedly provided at the middle position of the transverse sliding box frame near the side of the correction jack. There are two transverse sliding box ear plates in total and they are arranged in parallel. There is a hole in the middle of the transverse sliding box ear plate, and the transverse sliding box frame is connected to the correction jack through the transverse sliding box ear plate.

6. The curved bridge differential pushing walking jack according to claim 5, characterized in that: The vertical jack includes a vertical jack housing and a vertical jack piston; the vertical jack housing is a cylinder, and the diameter of the vertical jack housing is the same as the inner diameter of the horizontal sliding box space; the vertical jack piston is also a cylinder, and the vertical jack piston is installed in the vertical jack housing to adjust the vertical height of the jacking bridge.

7. The curved bridge differential pushing walking jack according to claim 6, characterized in that: The plate-type rubber bearing includes a rubber block and a steel plate; the rubber block is a solid cylinder, and the steel plate is a circular steel plate. The diameter of the steel plate is smaller than that of the rubber block. Multiple steel plates are evenly stacked and arranged in the rubber block to rib the rubber block.

8. The curved bridge differential pushing walking jack according to claim 7, characterized in that: The correcting jack includes a correcting jack housing, a correcting jack piston, a correcting jack piston connecting rod, and a latch; the correcting jack housing and the correcting jack piston are both cylindrical, the correcting jack piston is installed in the correcting jack housing, the correcting jack piston connecting rod is located at the end of the correcting jack piston, a small hole is opened at the front end of the correcting jack piston connecting rod, the diameter of the small hole is the same as the diameter of the hole of the transverse slide box ear plate, the latch passes through the small hole at the front end of the correcting jack piston connecting rod and the hole of the transverse slide box ear plate, and the correcting jack is fixedly connected to the transverse slide box through the latch.

9. The curved bridge differential pushing walking jack according to claim 8, characterized in that: The diameter of the middle part of the plug is the same as the diameter of the small hole, and the diameter of the end part of the plug is larger than the diameter of the small hole.

10. A method for pushing a curved bridge using a differential pushing walking jack, characterized in that: The following steps are involved: Step 1: Design the placement of the walking jacks. Arrange two walking jacks in each group. The first walking jack is placed on the inner side of the curved bridge, and the second walking jack is placed on the outer side of the curved bridge. The slideway is along the secant line of the arc on the outer side of the curved bridge. The first walking jack and the second walking jack are arranged parallel to each other, and multiple groups of walking jacks are arranged longitudinally. Step 2: Calculate the differential distance Δ1. The arc radius of the first crawler jack position is R1, the arc radius of the second crawler jack position is R2, and the longitudinal distance of a single push is D. The differential distance is: Step 3: Calculate the vertical reaction force of the walking jack during the jacking process of the curved bridge, establish a finite element model for the jacking construction of the curved bridge, simulate and analyze the jacking process, obtain the vertical reaction force values of each walking jack during the jacking process, and take the maximum vertical reaction force N of the jack according to its change law. imax ; Step 4: According to the differential distance Δ1 and the maximum vertical reaction force N of the jack imax Design of plate rubber bearings: 4-1) Maximum vertical reaction force of the jack N imax Design area A of plate rubber bearing; Where, σ is the actual compressive stress of the plate rubber bearing, [σ] is the maximum allowable compressive stress of the plate rubber bearing; 4-2) Design the thickness t of the rubber layer of the plate rubber bearing e ; t e ≥2Δ1 Determine t e Finally, the total thickness of the plate rubber bearing is obtained based on the thickness of the middle single rubber layer of 5mm, the thickness of the top and bottom rubber layers of 2.5mm, and the thickness of the steel plate of 2mm; Step 5: Verify the performance of the plate rubber bearing; 5-1) Calculate the shear stiffness k of the designed plate rubber bearing G ; Where G e is the shear elastic modulus of the plate rubber bearing; 5-2) Use finite element model simulation to analyze the structural stress of a push stroke, and enable the geometric nonlinearity option during the analysis; 5-3) Obtain the calculation results of the finite element model: displacement, stress, and support reaction force. Observe whether the displacement meets the differential distance and whether the stress is excessive. Verify the anti-slip stability of the outer walking jack and the main beam. H i <μN i Where H i is the horizontal support reaction force calculated by the finite element model, N i is the deadweight vertical support reaction force calculated by the finite element model, μ is the friction coefficient of the contact surface between the walking jack and the main beam; If the differential distance, stress, and anti-slip stability do not meet the requirements, increase the thickness of the rubber layer of the plate rubber bearing; Step 6: Pre-pushing to check the accuracy of design parameters: 6-1) Finite element model calibration and model correction: The measured vertical support reaction force of the jack is compared with the deadweight vertical support reaction force calculated by the finite element model. If the relative error exceeds 10%, the finite element model is corrected to make the vertical support reaction force of the jack calculated by the finite element model close to the measured vertical support reaction force of the jack. The material bulk density and elastic modulus of the structure are selected as correction parameters, and the measured vertical support reaction force of the jack is used as the target value. The two-parameter response surface method is used to correct the model; 6-2) Plate rubber bearing design verification must meet the maximum bearing reaction pressure requirements calculated by the modified finite element model and compare the measured bearing shear deformation Δ 1c and differential distance Δ1, if the ratio η=Δ1 / Δ 1c If the difference from 1 exceeds 10%, adjust the thickness of the rubber layer of the plate rubber bearing and take η·t e Redesigned plate rubber bearings; Step 7: Formal jacking construction, the first step crawler jack is arranged on the bottom surface of the inner main beam of the curved bridge, and the second step crawler jack is arranged on the bottom surface of the outer main beam of the curved bridge, and it is continuously pushed to the designed position. When the lateral deviation of the bridge exceeds the allowable value during the pushing process, the lateral deviation is corrected. The second step crawler jack on the bottom surface of the outer main beam pushes a stroke D, and the outer main beam moves forward a distance D. The first step crawler jack on the bottom surface of the inner main beam pushes a stroke D, the plate rubber bearing undergoes shear deformation Δ1, and the inner main beam moves forward a distance D1, D1=D-Δ1. The purpose of differential jacking of the curved bridge is achieved through the shear deformation of the plate rubber bearing.

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