Bridge cantilever box girder construction hanging basket pre-pressing loading device

Abstract

The invention belongs to the technical field of bridge construction, and particularly relates to a bridge cantilever box girder construction hanging basket pre-pressing loading device which comprises a truss mechanism, a bottom die supporting mechanism and a set of loading mechanisms. The loading mechanism comprises an outer barrel, an inner barrel and a connecting assembly; the lower end of the outer cylinder is fixedly connected with a base; a group of operation ports are uniformly distributed at the bottom of the outer cylinder; a jack is arranged between the lower end of the inner barrel and the base; the top of the inner barrel is fixedly connected with a water conveying pipe; in the loading test process, the inner barrel is located in the outer barrel all the time, the inner barrel can be prevented from shaking and swinging in the test process through the limiting and guiding effects of the outer barrel, the loading stability is improved, the adverse effect on the test result is reduced, potential safety hazards are reduced, even if the hanging rod is broken, the inner barrel can only fall into the outer barrel, and the safety performance is improved. Therefore, operators are prevented from being injured by the inner barrel, and construction safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, in particular to a pre-compression loading device for a hanging basket for construction of a cantilever box girder of a bridge. Background Art

[0002] The construction basket for cantilever box girders of bridges is an important equipment for bridge construction. It is mainly used for pouring and supporting cantilever construction sections in bridge construction. During actual construction, the elastic deformation of the basket must meet technical and safety requirements. Before pouring each section of concrete box girders, it is necessary to detect the deflection value of the elastic deformation of the front and rear lower beams of the bottom formwork support mechanism under the gravity of the concrete to be poured, and before the actual pouring construction, the front and rear lower beams are deformed in the opposite direction according to the deflection value to be generated, so as to improve the dimensional accuracy and construction strength of the cantilever box girder section. Therefore, before the cantilever box girder section of the cast-in-place bridge, it is necessary to simulate the pre-stressing loading of the basket to test the deformation amount of the front and rear lower beams of the bottom formwork support mechanism after the simulated pre-stressing loading.

[0003] A Chinese patent application CN103362074B discloses a preloading device for a construction basket of a bridge cantilever box girder. The key points of the technical solution are: it includes a suspension truss, a suspension truss track, a pair of outer sliding beams, an upper cross beam, a suspension truss track moving trolley, a bottom mold support frame and several suspension buckets respectively filled with water. The suspension truss is supported on the suspension truss track, and the suspension truss track is supported on the cantilever box girder section of the poured bridge through multiple rows of track pad beams. The bottom mold support frame includes multiple lower longitudinal beams, a front lower cross beam and a rear lower cross beam fixedly connected to the front and rear ends of the multiple lower longitudinal beams, and the two ends of the bottom mold support frame are respectively suspended under the suspension truss, and several suspension buckets filled with water are suspended under the front lower cross beam. This technology uses several water-filled suspension buckets suspended under the front lower cross beam to simulate the downward pressure load of the bridge cantilever box girder to be poured on the bottom mold support frame, which can flexibly realize segmented loading.

[0004] However, the above technology often has the following defects: it uses a hanging bucket to perform pre-stress loading test on the bottom mold support mechanism, but the weight of the hanging bucket is large after being filled with water, and it is lifted up by only one hanging rod. Therefore, during the test, the hanging bucket is easy to shake and swing, which will not only affect the test results, but also pose certain safety hazards. Once the hanging rod breaks, the falling hanging bucket is likely to injure surrounding workers.

[0005] To this end, the present invention provides a pre-compression loading device for a construction hanging basket of a bridge cantilever box girder. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows: the preloading device for the construction of a cantilever box girder of a bridge of the present invention comprises a truss mechanism, a bottom mold support mechanism and a group of loading mechanisms;

[0008] The loading mechanism is used to perform a pre-compression loading test on the bottom mold support mechanism to obtain its deformation amount; the loading mechanism includes an outer barrel, an inner barrel and a connecting assembly;

[0009] The lower end of the outer cylinder is fixedly connected to a base; the bottom of the outer cylinder is evenly distributed with a group of operation ports;

[0010] The inner barrel is slidably connected to the inner part of the outer barrel; a jack is arranged between the lower end of the inner barrel and the base; a water pipe is fixedly connected to the top of the inner barrel; one end of the water pipe extends to the bottom of the inner barrel, and the other end of the water pipe extends to the outside of the bottom of the outer barrel;

[0011] The connecting assembly is arranged inside the top of the inner barrel; the connecting assembly is used to connect and fix the inner barrel and the bottom mold supporting mechanism.

[0012] Preferably, a group of support arms are evenly distributed on the surface of the base; and the ends of the support arms are threadedly connected with adjustment columns.

[0013] Preferably, a group of guide wheels are evenly distributed on the side wall of the outer cylinder, and the guide wheels are rotatably connected to the outer cylinder; the guide wheels are in contact with the outer surface of the inner barrel.

[0014] Preferably, a notch is provided on one side of the outer cylinder; an observation window is provided on the surface of the inner barrel at a position corresponding to the notch; a transparent plate is fixedly connected to the inside of the observation window; and a group of water level scale lines are provided on the surface of the transparent plate.

[0015] Preferably, the connection assembly comprises a connection ring and a suspension rod;

[0016] A group of support plates are evenly distributed between the connecting ring and the inner barrel; a group of slide grooves are evenly distributed inside the connecting ring; an inclined block is slidably connected inside the slide groove; an elastic member 1 is fixedly connected between the inclined block and the slide groove;

[0017] The upper end of the suspension rod is fixedly connected to the bottom mold supporting mechanism, and the lower end of the suspension rod is fixedly connected to a cylindrical combining block; and an annular groove is arranged on the surface of the combining block.

[0018] Preferably, a control sleeve is fixedly connected to the outer side of the connecting ring at the corresponding position of the slide groove; a movable column is slidingly and sealingly connected inside the control sleeve; a pull plate is fixedly connected to the outer end of the movable column; a traction rope is fixedly connected between the pull plate and the inclined block; the control sleeve is connected to a hose; and one end of the hose extending to the outside of the bottom of the outer cylinder is connected to an elastic hollow ball.

[0019] Preferably, a supporting ring is slidably connected to the bottom of the outer cylinder, and the inner cylinder is placed on the upper side of the supporting ring; a group of buffer springs are evenly distributed between the supporting ring and the base.

[0020] Preferably, a group of receiving grooves are evenly distributed on the side wall of the outer cylinder; a pressure block is slidably connected inside the receiving groove; a second elastic member is fixedly connected between the pressure block and the receiving groove; a friction pad is fixedly connected to the side of the pressure block close to the inner cylinder;

[0021] An "L"-shaped guide groove is provided on the side wall of the outer cylinder below the storage groove, and the lower end of the guide groove is located below the supporting ring; an "L"-shaped locking plate is slidably connected inside the guide groove; an elastic member three is fixedly connected between the lower end of the locking plate and the guide groove, and the upper end of the locking plate is inserted into the bottom of the pressing block.

[0022] Preferably, a cavity is provided inside the pressing block; a friction enhancing agent is added inside the cavity; and a ramp is provided between the bottom of the cavity and the surface of the friction pad.

[0023] Preferably, a blocking plate is slidably connected inside the pressing block; one end of the blocking plate is fixedly connected to the receiving groove, and the other end of the blocking plate is fitted with the ramp.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. In the pre-stressing loading device for the construction hanging basket of the bridge cantilever box girder described in the present invention, during the loading test, the inner barrel is always located inside the outer barrel. The limiting and guiding functions of the outer barrel can prevent the inner barrel from shaking and swinging during the test, thereby improving the loading stability, reducing the adverse effects on the test results, and reducing safety hazards. Even if the suspension rod breaks, the inner barrel will only fall into the outer barrel, thereby preventing the inner barrel from injuring the workers and ensuring construction safety. In addition, the present invention adopts a water pump to pump out the water in the inner barrel instead of directly discharging the water downward, which is conducive to storing and reusing the water source and effectively reducing the slippery phenomenon of the working ground below.

[0026] 2. The preloading device for the construction of a cantilever box girder of a bridge described in the present invention can observe the water level inside the inner barrel through the transparent plate and the scale lines on its surface when filling water into the inner barrel. When the predetermined height is reached, the water filling is stopped, and the height change of the inner barrel inside the outer barrel before and after the water filling can be observed through the relative change of the scale lines and the outer barrel, thereby reflecting the degree of downward deformation of the bottom mold support assembly after loading.

[0027] 3. The pre-stressing loading device for the construction hanging basket of the bridge cantilever box girder described in the present invention utilizes a jack to drive the inner barrel to lift upward during installation, and then the combining block is inserted into the interior of the connecting ring, pushing the inclined block to move into the interior of the slide groove. When the inclined block is aligned with the annular groove, the elastic member pushes the inclined block into the interior of the annular groove to achieve a quick connection between the hanger rod and the inner barrel. During disassembly, the construction personnel squeeze the hollow ball on the ground, and the air inside the hollow ball enters the interior of the control sleeve through the hose, driving the movable column to move away from the slide groove, and then the pull plate drives the inclined block to be pulled out of the annular groove and re-entered into the slide groove through the traction rope. At this time, the combining block and the connecting ring are in a separated state, that is, quick disassembly is achieved. The loading device of the present invention can be operated on the ground when used, without the need to set up a ladder or for construction personnel to climb high to operate, thereby further improving construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 It is a loading schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the loading mechanism in the present invention;

[0031] Figure 3 It is a structural schematic diagram of the base in the present invention;

[0032] Figure 4 It is a structural schematic diagram of the connection component in the present invention;

[0033] Figure 5 is a cross-sectional view of the loading mechanism of the present invention;

[0034] Figure 6 yes Figure 5 A partial enlarged view of the middle part;

[0035] Figure 7 yes Figure 5 A partial enlarged view of point B in the middle;

[0036] Figure 8 yes Figure 5 A partial enlarged view of point C in the middle.

[0037] In the figure: truss mechanism 1, bottom mold supporting mechanism 2, loading mechanism 3, outer cylinder 31, inner barrel 32, base 33, operating port 34, jack 35, water pipe 36, supporting arm 37, adjusting column 38, guide wheel 39, notch 40, transparent plate 41, connecting ring 42, suspension rod 43, supporting plate 44, slide groove 45, inclined block 46, elastic member 1 47, combining block 48, annular groove 49, control sleeve 50, movable column 51, pull plate 52, traction rope 53, hose 54, hollow ball 55, supporting ring 56, buffer spring 57, receiving groove 58, pressing block 59, elastic member 2 60, friction pad 61, guide groove 62, locking piece 63, elastic member 3 64, cavity 65, ramp 66, blocking plate 67. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0039] like Figures 1 to 8 As shown, the preloading device for the construction of a cantilever box girder of a bridge according to the present invention comprises a truss mechanism 1, a bottom formwork support mechanism 2 and a group of loading mechanisms 3;

[0040] The loading mechanism 3 is used to perform a pre-compression loading test on the bottom mold support mechanism 2 to obtain its deformation amount; the loading mechanism 3 includes an outer barrel 31, an inner barrel 32 and a connecting assembly;

[0041] The lower end of the outer cylinder 31 is fixedly connected to a base 33; a group of operation ports 34 are evenly distributed at the bottom of the outer cylinder 31;

[0042] The inner barrel 32 is slidably connected to the inner part of the outer barrel 31; a jack 35 is provided between the lower end of the inner barrel 32 and the base 33; a water pipe 36 is fixedly connected to the top of the inner barrel 32; one end of the water pipe 36 extends to the bottom of the inner barrel 32, and the other end of the water pipe 36 extends to the outside of the bottom of the outer barrel 31;

[0043] The connecting assembly is arranged in the top of the inner barrel 32; the connecting assembly is used to connect and fix the inner barrel 32 and the bottom mold supporting mechanism 2.

[0044] The prior art uses a hanging bucket to perform a pre-stress loading test on the bottom mold support mechanism 2. However, the weight of the hanging bucket is relatively large after being filled with water, and it is lifted up by only one hanging rod 43. Therefore, the hanging bucket is prone to shaking and swinging during the test, which not only affects the test results, but also poses certain safety hazards. Once the hanging rod 43 breaks, the falling hanging bucket is likely to injure surrounding workers.

[0045] When in use, the present invention moves the loading mechanism 3 to the ground below the bottom mold support mechanism 2, uses the jack 35 to drive the inner barrel 32 to move upward, connects and fixes the inner barrel 32 and the bottom mold support mechanism 2 through a connecting assembly, and then controls the jack 35 to retract, so that the inner barrel 32 is suspended inside the outer cylinder 31, and then connects the water pipe 36 to the water pump, and injects water into the inner barrel 32 to increase the weight, so as to perform a loading test on the bottom mold support mechanism 2 and observe the deformation degree of the bottom mold support mechanism 2. After loading, the water pipe 36 is connected to the water pump to pump the water in the inner barrel 32 outward, and then the connecting assembly is released to fix the inner barrel 32 so as to lower and reset.

[0046] During the loading test, the inner barrel 32 is always located inside the outer barrel 31. The limiting and guiding functions of the outer barrel 31 can prevent the inner barrel 32 from shaking or swinging during the test, thereby improving the loading stability, reducing the adverse effects on the test results, and reducing safety hazards. Even if the suspension rod 43 breaks, the inner barrel 32 will only fall into the outer barrel 31, thereby preventing the inner barrel 32 from injuring the operator and ensuring construction safety. In addition, the present invention uses a water pump to pump out the water in the inner barrel 32 instead of directly discharging the water downward, which is conducive to storing and reusing the water source and effectively reducing the slippery phenomenon of the working ground below.

[0047] It is worth mentioning that the truss mechanism 1 and the bottom mold support mechanism 2 in the above scheme are both part of the cantilever construction hanging basket, which is the existing technology well known to those skilled in the art. Its detailed structure, working principle and specific loading calculation method can be found in CN103362074B.

[0048] As a preferred embodiment of the present invention, a group of support arms 37 are evenly distributed on the surface of the base 33; the ends of the support arms 37 are threadedly connected with adjustment columns 38. The support arms 37 and the adjustment columns 38 can be used to further support the loading mechanism 3, thereby improving its stability in use. The height of the loading mechanism 3 can be adjusted by rotating the adjustment columns 38 respectively, and the base 33 can be adjusted to a level, so that the outer barrel 31 and the inner barrel 32 remain in a vertical state, which is convenient for the inner barrel 32 to be connected to the bottom mold support mechanism 2 and for the loading test to be carried out.

[0049] As a preferred embodiment of the present invention, a group of guide wheels 39 are evenly distributed on the side wall of the outer cylinder 31, and the guide wheels 39 are rotatably connected to the outer cylinder 31; the guide wheels 39 are in contact with the outer surface of the inner cylinder 32. By providing the guide wheels 39, the resistance of the inner cylinder 32 to the up and down movement inside the outer cylinder 31 can be reduced, and the inner cylinder 32 does not directly contact the outer cylinder 31 during the test, so as to avoid the inner cylinder 32 being subjected to the static friction of the outer cylinder 31, which affects the force applied to the inner cylinder 32 in the vertical direction, and further improve the accuracy of the test.

[0050] As a preferred embodiment of the present invention, a notch 40 is provided on one side of the outer barrel 31; an observation window is provided on the surface of the inner barrel 32 at a position corresponding to the notch 40; a transparent plate 41 is fixedly connected inside the observation window; and a group of water level scale lines are provided on the surface of the transparent plate 41. When water is poured into the inner barrel 32, the water level inside the inner barrel 32 can be observed through the transparent plate 41 and the scale lines on its surface. When the water level reaches a predetermined height, the water filling is stopped, and the height change of the inner barrel 32 inside the outer barrel 31 before and after the water filling can also be observed through the relative change of the scale lines and the outer barrel 31, thereby reflecting the degree of downward deformation of the bottom mold support assembly after loading.

[0051] As a preferred embodiment of the present invention, the connection assembly includes a connection ring 42 and a suspension rod 43;

[0052] A group of support plates 44 are evenly distributed between the connecting ring 42 and the inner barrel 32; a group of slide grooves 45 are evenly distributed inside the connecting ring 42; an inclined block 46 is slidably connected inside the slide groove 45; an elastic member 47 is fixedly connected between the inclined block 46 and the slide groove 45;

[0053] The upper end of the suspension rod 43 is fixedly connected to the bottom mold supporting mechanism 2 , and the lower end of the suspension rod 43 is fixedly connected to a cylindrical coupling block 48 ; an annular groove 49 is provided on the surface of the coupling block 48 .

[0054] A control sleeve 50 is fixedly connected to the outer side of the connecting ring 42 at the corresponding position of the slide groove 45; a movable column 51 is slidably and sealably connected inside the control sleeve 50; a pull plate 52 is fixedly connected to the outer end of the movable column 51; a traction rope 53 is fixedly connected between the pull plate 52 and the inclined block 46; a hose 54 is connected to the control sleeve 50; one end of the hose 54 extends to the outside of the bottom of the outer tube 31 and is connected to an elastic hollow ball 55.

[0055] During installation, the loading mechanism 3 is moved to the bottom of the suspension rod 43, and the jack 35 is used to drive the inner barrel 32 to lift upward, and then the coupling block 48 is inserted into the connecting ring 42 to push the inclined block 46 to move into the slide groove 45, so that the elastic member 47 is in a compressed energy storage state. When the inclined block 46 is aligned with the annular groove 49, the elastic member 47 pushes the inclined block 46 into the annular groove 49 to achieve a quick connection between the suspension rod 43 and the inner barrel 32.

[0056] During disassembly, the construction workers squeeze the hollow ball 55 on the ground with their hands or tools, and the air inside the hollow ball 55 enters the control sleeve 50 through the hose 54, driving the movable column 51 to move in the direction away from the slide groove 45, and then the pull plate 52 drives the inclined block 46 to be pulled out of the annular groove 49 through the traction rope 53 and re-entered into the slide groove 45. At this time, the combining block 48 and the connecting ring 42 are in a separated state, that is, quick disassembly is achieved. The loading device of the present invention can be operated on the ground when used, without the need to set up a ladder or for construction workers to climb high to operate, thereby further improving construction safety.

[0057] As a preferred embodiment of the present invention, a supporting ring 56 is slidably connected to the bottom of the outer cylinder 31, and the inner barrel 32 is placed on the upper side of the supporting ring 56; a group of buffer springs 57 are evenly distributed between the supporting ring 56 and the base 33. The jack 35 drives the inner barrel 32 to lift upward, and after the suspension rod 43 is connected and fixed to the inner barrel 32, the jack 35 can be taken out through the operation port 34. If the suspension rod 43 or the connecting component breaks during the subsequent test, the inner barrel 32 filled with water falls and hits the supporting ring 56, and the impact force of the inner barrel 32 is buffered and reduced under the action of the buffer spring 57, which prevents the loading mechanism 3 from tipping over and injuring people due to excessive impact force on the one hand, and on the other hand, it can also reduce the violent shaking that causes the water in the inner barrel 32 to spill outward in large quantities.

[0058] As a preferred embodiment of the present invention, a group of receiving grooves 58 are evenly distributed on the side wall of the outer cylinder 31; a pressure block 59 is slidably connected inside the receiving groove 58; an elastic member 60 is fixedly connected between the pressure block 59 and the receiving groove 58, and the elastic member 60 is in a compressed state; a friction pad 61 is fixedly connected to the side of the pressure block 59 close to the inner barrel 32;

[0059] An L-shaped guide groove 62 is provided on the side wall of the outer cylinder 31 below the receiving groove 58, and the lower end of the guide groove 62 is located below the supporting ring 56; an L-shaped locking piece 63 is slidably connected inside the guide groove 62; an elastic member 64 is fixedly connected between the lower end of the locking piece 63 and the guide groove 62, and the upper end of the locking piece 63 is inserted into the bottom of the pressing block 59.

[0060] Under normal circumstances, the empty inner barrel 32 can be supported by the supporting ring 56 and the buffer spring 57. The supporting ring 56 is always located above the bottom end of the locking plate 63. If the suspension rod 43 or the connecting assembly breaks during the test, the inner barrel 32 filled with water falls and hits the supporting ring 56, driving the supporting ring 56 to move downward, and then the supporting ring 56 pushes the locking plate 63 downward, so that the upper end of the locking plate 63 is pulled out from the bottom of the pressure block 59. At this time, the elastic member 60 quickly pushes the pressure block 59 and presses the friction pad 61 against the surface of the inner barrel 32, thereby performing emergency braking on the inner barrel 32 to prevent the inner barrel 32 from repeatedly shaking up and down under the action of the buffer spring 57, further reducing safety hazards and reducing water spilling out.

[0061] As a preferred embodiment of the present invention, a cavity 65 is provided inside the pressing block 59; a friction enhancer is added inside the cavity 65; a ramp 66 is provided between the bottom of the cavity 65 and the surface of the friction pad 61; the friction enhancer can increase the friction coefficient and can be in the form of dry powder or granules. Commonly used friction enhancers include silica, alumina, zircon, etc.

[0062] A blocking plate 67 is slidably connected inside the pressing block 59 ; one end of the blocking plate 67 is fixedly connected to the receiving groove 58 , and the other end of the blocking plate 67 is in contact with the ramp 66 .

[0063] Under normal circumstances, the end of the blocking plate 67 is located inside the cavity 65 and blocks the ramp 66, so that the friction-enhancing agent in the cavity 65 will not flow out spontaneously. When the elastic member 60 pushes the pressure block 59 to move out of the storage groove 58, the end of the blocking plate 67 is synchronously separated from the ramp 66. At this time, the friction-enhancing agent can be discharged outward through the ramp 66 and applied to the surface of the inner barrel 32, thereby increasing the friction resistance between the friction pad 61 and the inner barrel 32, thereby improving the braking efficiency of the inner barrel 32, ensuring that the inner barrel 32 stops quickly, and eliminating unstable factors.

[0064] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0065] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A preloading device for a hanging basket for construction of a cantilever box girder of a bridge, comprising a truss mechanism (1), a bottom formwork support mechanism (2) and a group of loading mechanisms (3); Features: The loading mechanism (3) is used to perform a pre-compression loading test on the bottom mold support mechanism (2) to obtain its deformation amount; the loading mechanism (3) comprises an outer barrel (31), an inner barrel (32) and a connecting assembly; The lower end of the outer cylinder (31) is fixedly connected to a base (33); a group of operating ports (34) are evenly distributed on the bottom of the outer cylinder (31); The inner barrel (32) is slidably connected to the inside of the outer barrel (31); a jack (35) is provided between the lower end of the inner barrel (32) and the base (33); a water pipe (36) is fixedly connected to the top of the inner barrel (32); one end of the water pipe (36) extends to the bottom of the inner barrel (32), and the other end of the water pipe (36) extends to the outside of the bottom of the outer barrel (31); The connecting component is arranged inside the top of the inner barrel (32); the connecting component is used to connect and fix the inner barrel (32) and the bottom mold support mechanism (2).

2. The preloading device for the construction of a cantilever box girder of a bridge according to claim 1 is characterized in that: A group of support arms (37) are evenly distributed on the surface of the base (33); and an adjustment column (38) is threadedly connected to the end of the support arm (37).

3. The preloading device for the construction of a cantilever box girder of a bridge according to claim 1 is characterized in that: A group of guide wheels (39) are evenly distributed on the side wall of the outer cylinder (31), and the guide wheels (39) are rotatably connected to the outer cylinder (31); the guide wheels (39) and the outer surface of the inner barrel (32) are in contact with each other.

4. The preloading device for the construction of a cantilever box girder of a bridge according to claim 1 is characterized in that: A notch (40) is provided on one side of the outer barrel (31); an observation window is provided on the surface of the inner barrel (32) at a position corresponding to the notch (40); a transparent plate (41) is fixedly connected to the inside of the observation window; and a group of water level scale lines are provided on the surface of the transparent plate (41).

5. The preloading device for the construction of a cantilever box girder of a bridge according to claim 1 is characterized in that: The connection assembly comprises a connection ring (42) and a suspension rod (43); A group of support plates (44) are evenly distributed between the connecting ring (42) and the inner barrel (32); a group of slide grooves (45) are evenly distributed inside the connecting ring (42); an inclined block (46) is slidably connected inside the slide groove (45); an elastic member (47) is fixedly connected between the inclined block (46) and the slide groove (45); The upper end of the suspension rod (43) is fixedly connected to the bottom mold support mechanism (2), and the lower end of the suspension rod (43) is fixedly connected to a cylindrical connecting block (48); the surface of the connecting block (48) is provided with an annular groove (49).

6. The preloading device for the construction of a cantilever box girder of a bridge according to claim 5 is characterized by: A control sleeve (50) is fixedly connected to the outer side of the connecting ring (42) at a position corresponding to the slide groove (45); a movable column (51) is slidably and sealingly connected inside the control sleeve (50); a pull plate (52) is fixedly connected to the outer end of the movable column (51); a traction rope (53) is fixedly connected between the pull plate (52) and the inclined block (46); the control sleeve (50) is connected to a hose (54); one end of the hose (54) extending to the outside of the bottom of the outer cylinder (31) is connected to an elastic hollow ball (55).

7. The preloading device for the construction of a cantilever box girder of a bridge according to claim 1 is characterized by: A supporting ring (56) is slidably connected to the bottom of the outer cylinder (31), and the inner cylinder (32) is placed on the upper side of the supporting ring (56); a group of buffer springs (57) are evenly distributed between the supporting ring (56) and the base (33).

8. The preloading device for the construction of a cantilever box girder of a bridge according to claim 7 is characterized in that: The side wall of the outer cylinder (31) is evenly distributed with a group of receiving grooves (58); a pressure block (59) is slidably connected inside the receiving groove (58); a second elastic member (60) is fixedly connected between the pressure block (59) and the receiving groove (58); a friction pad (61) is fixedly connected to the side of the pressure block (59) close to the inner barrel (32); An "L"-shaped guide groove (62) is provided on the side wall of the outer cylinder (31) below the receiving groove (58), and the lower end of the guide groove (62) is located below the supporting ring (56); an "L"-shaped locking piece (63) is slidably connected inside the guide groove (62); an elastic member 3 (64) is fixedly connected between the lower end of the locking piece (63) and the guide groove (62), and the upper end of the locking piece (63) is inserted into the bottom of the pressing block (59).

9. The preloading device for the construction of a cantilever box girder of a bridge according to claim 8 is characterized in that: The pressing block (59) is provided with a cavity (65) inside; a friction-increasing agent is added inside the cavity (65); and a ramp (66) is provided between the bottom of the cavity (65) and the surface of the friction pad (61).

10. The preloading device for the construction of a cantilever box girder of a bridge according to claim 9, characterized in that: A blocking plate (67) is slidably connected inside the pressing block (59); one end of the blocking plate (67) is fixedly connected to the receiving groove (58), and the other end of the blocking plate (67) is in contact with the ramp (66).

Images