Method and device for eliminating downwarping stress of barge type overwater overhead steel truss

Abstract

The invention discloses a barge type overwater overhead steel truss downwarping stress elimination method and device, and the method comprises the steps: 1, injecting water into a cabin of a barge, enabling the barge to gradually descend to a preset depth on the water surface, and enabling the highest position of the barge to be just lower than the height of a lower chord of an overhead steel truss needing downwarping stress elimination; secondly, the barge runs to the position under the position, close to the middle, of the lower chord of the overhead steel truss needing down-warping stress elimination; 3, fixing the front and rear ends of the barge on anchorage piers by steel wire ropes, fixing the left and right ends by ship anchors, and controlling the barge to move; fourthly, water in all cabins in the barge is pumped away evenly through a plurality of water pumps at the same time, so that the barge generates buoyancy, and the barge floats upwards evenly and slowly till the upper end of the barge makes contact with and pushes the lower chord of the steel truss upwards; and the down-warping stress of the corresponding steel truss can be effectively eliminated.

Description

Technical Field

[0001] The present invention belongs to the field of eliminating the deflection stress of steel trusses. Background Art

[0002] Common bridge-type steel structure waterborne overhead steel trusses are as Figure 1 shown. Due to construction on water with a large structural span exceeding 100 meters, during the installation of the overhead steel truss, the construction is completed by hoisting. During the hoisting process, the steel truss will generate deflection stress. Therefore, an upward jacking force needs to be evenly applied near the middle position of the lower chord of each section of the steel truss to eliminate the corresponding deflection stress of the steel truss. This solution creatively implements the above process and designs relevant devices. Summary of the Invention

[0003] Object of the Invention: In order to overcome the deficiencies in the prior art, the present invention provides a method and device for eliminating the deflection stress of barge-type waterborne overhead steel trusses, which can effectively eliminate the corresponding deflection stress of the steel truss.

[0004] Technical Solution: To achieve the above object, the method for eliminating the deflection stress of the barge-type waterborne overhead steel truss of the present invention

[0005] Step 1: Fill the cabins of the barge with water so that the barge gradually descends to a predetermined depth on the water surface, and the highest position of the barge is just lower than the height of the lower chord of the overhead steel truss where the deflection stress needs to be eliminated.

[0006] Step 2: The barge runs to directly below the middle position near the lower chord of the overhead steel truss where the deflection stress needs to be eliminated.

[0007] Step 3: Fix the front and rear ends of the barge to the anchor piers with steel wires and fix the left and right ends with ship anchors to control the movement of the barge.

[0008] Step 4: Simultaneously and evenly pump out the water in each cabin of the barge with multiple water pumps, so as to generate buoyancy for the barge. The barge slowly floats up evenly until the upper end of the barge touches and pushes up the lower chord of the steel truss, thereby transmitting the upward buoyancy to the steel truss. The steel truss receives an upward jacking force. When the jacking force gradually increases to reach the designed jacking force, the steel truss begins to arch upward, thereby gradually eliminating the deflection stress. The entire jacking process is carried out in stages. During the process of the barge floating up by discharging water, the water intake situation of the barge is monitored, and the displacement of the barge floating up is measured. Through the monitoring data of the displacement of the barge floating up and the displacement change of the camber of the steel truss, the stress change of the steel truss is determined.

[0009] The device for eliminating the deflection stress of the barge-type waterborne overhead steel truss includes a barge, and several water pumps capable of pumping water into the cabins and pumping out the water in the cabins are arranged in the barge.

[0010] Furthermore, an adaptive double-column balanced jacking device is installed in the middle of the upper side of the barge. The front and rear ends of the upper part of the adaptive double-column balanced jacking device are respectively provided with an adaptive front jacking column and an adaptive rear jacking column; the upper ends of the adaptive front jacking column and the adaptive rear jacking column are respectively vertically connected with a front push jacking pillow and a rear push jacking pillow extending in the left-right direction.

[0011] Furthermore, the adaptive front jacking column and the adaptive rear jacking column are linked through a linkage structure. When the adaptive front jacking column makes an upward extending movement, the adaptive rear jacking column makes a downward retracting movement, and vice versa. When the adaptive front jacking column makes a downward retracting movement, the adaptive rear jacking column makes an upward extending movement.

[0012] Furthermore, the adaptive double-column balanced jacking device includes a barge attitude balance seat extending in the front-rear direction. A balance counterweight moving groove extending in the front-rear direction is provided in the middle of the barge attitude balance seat, and a rectangular balance counterweight is movably arranged in the balance counterweight moving groove.

[0013] Furthermore, guide rails are arranged on the left and right inner side walls of the balance counterweight moving groove along the length direction. Sliders are fixed on both sides of the balance counterweight. The balance counterweight is guided and matched with the guide rails through the sliders. A locking device is arranged on the sliders. In the locked state, the sliders are locked with the guide rails, so that the sliders cannot slide along the guide rails.

[0014] Furthermore, a transmission groove extending in the front-rear direction is arranged at the bottom of the balance counterweight moving groove. A transmission gear with an axis parallel to the left-right direction is rotatably installed in the middle of the transmission groove through a bearing; a linear rack a is fixedly arranged on the lower side of the balance counterweight along the front-rear direction, and the upper part of the transmission gear meshes with the linear rack a;

[0015] Vertical front hydraulic cylinder cavities and rear hydraulic cylinder cavities are respectively arranged at the front and rear ends of the barge attitude balance seat. A front lifting hydraulic piston and a rear lifting hydraulic piston are respectively arranged in the front hydraulic cylinder cavity and the rear hydraulic cylinder cavity. Hydraulic oil is filled on the lower sides of the front lifting hydraulic piston and the rear lifting hydraulic piston. The lower ends of the adaptive front jacking column and the adaptive rear jacking column are respectively fixedly connected with the front lifting hydraulic piston and the rear lifting hydraulic piston.

[0016] A front piston channel extending in the front-rear direction is arranged in the bottom wall of the front part of the barge attitude balance seat. The front end of the front piston channel is communicated with the bottom of the front hydraulic cylinder cavity through a front communication channel. A front translation piston is arranged in the front piston channel, and a front piston rod is coaxially fixedly connected to the rear end of the front translation piston.

[0017] There is a rear piston channel extending in the front - rear direction along the bottom wall at the rear of the barge attitude balance seat. The rear end of the rear piston channel is connected to the bottom of the rear hydraulic column cavity through a rear communication channel. A rear translation piston is arranged in the rear piston channel, and the front end of the rear translation piston is coaxially and fixedly connected to a rear piston rod; a b linear rack extending in the front - rear direction is meshed with the lower side of the transmission gear, and the front and rear ends of the b linear rack are respectively fixedly connected to the front piston rod and the rear piston rod.

[0018] Furthermore, restraint rollers are arranged at the front - rear sum of the upper ends in both the front hydraulic column cavity and the rear hydraulic column cavity. The restraint rollers are rotatably installed on their respective roller supports, and the front and rear sides of the self - adaptive front top column and the self - adaptive rear top column are both in rolling fit with the restraint rollers.

[0019] Working method of the barge - type water - borne overhead steel truss downward deflection stress elimination device: During the process of "Step Four", when the barge slowly floats upward and either the front push - top pillow or the rear push - top pillow just touches and pushes the lower chord of the steel truss first, immediately release the locking relationship between the slider and the guide rail so that the slider can freely slide along the guide rail.

[0020] Beneficial effects: The present invention can effectively eliminate the downward deflection stress of the corresponding steel truss. When either the front push - top pillow or the rear push - top pillow of the present invention just touches and pushes the lower chord of the steel truss first, the self - adaptive double - column balance jacking device of this scheme can make the other push - top pillow touch and push the steel truss as soon as possible, preventing the attitude of the barge from further deteriorating due to unbalanced forces; at the same time, on the basis of hydraulic linkage, the balance counterweight automatically shifts, causing the center of gravity of the barge to shift, thereby suppressing the attitude change of the barge and making the barge return to an ideal horizontal state. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a common bridge - type steel structure water - borne overhead steel truss;

[0022] Figure 2 It is an overall schematic diagram during the construction process of downward deflection stress elimination;

[0023] Figure 3 It is a schematic diagram of the structure of the self - adaptive double - column balance jacking device;

[0024] Figure 4 It is the first cross - sectional view of the self - adaptive double - column balance jacking device;

[0025] Figure 5 It is the second cross - sectional view of the self - adaptive double - column balance jacking device. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] As shown in the atta Figures 1 to 5As shown in the figure, the barge in this case is a 1000T barge. For every 0.02m decrease of the 1000T barge, it can carry 8 tons, that is, the buoyancy is 80KN (Note: According to the barge performance table, the draft of the barge when it is empty is 0.2m); the jacking force for eliminating the downward deflection stress in this case is: 3028KN (provided by the design unit); the rough calculation of the total displacement of the jacking support is: 3028÷80×0.02 = 0.757m; the rough calculation of the total draft of the barge is: 0.2 + 0.757 = 0.957m.

[0028] General method for eliminating the downward deflection stress of the barge-type overhead steel truss on water:

[0029] Step 1: Inject water into the cabin of the barge 6 to gradually lower the barge 6 to a predetermined depth on the water surface, so that the highest position of the barge 6 is just lower than the lower chord height of the overhead steel truss 4 where the downward deflection stress needs to be eliminated; observe the sinking depth of the barge in real time. Note: According to the barge performance table, the draft of the barge when it is empty is 0.2m

[0030] Step 2: The barge 6 runs to directly below the middle position of the lower chord of the overhead steel truss 4 where the downward deflection stress needs to be eliminated;

[0031] Step 3: Fix the front and rear ends of the barge 6 to the anchor pier 8 with steel wire ropes, and fix the left and right ends with ship anchors to control the movement of the barge;

[0032] Step 4: Use multiple water pumps to simultaneously and evenly pump out the water in each cabin of the barge 6, so as to generate buoyancy for the barge 6. The barge 6 slowly floats up evenly until the upper end of the barge 6 touches and pushes up the lower chord of the steel truss 4, thereby transmitting the upward buoyancy to the steel truss 4. The steel truss 4 receives an upward jacking force. When the jacking force gradually increases to the jacking support force given by the design, the steel truss 6 begins to arch upward, thereby gradually eliminating the downward deflection stress; the entire jacking support process is carried out in stages. During the process of the water-discharging barge floating up, monitor the water intake of the barge 6 and measure the displacement of the barge floating up; through the monitoring data of the displacement of the barge floating up and the displacement change of the camber of the steel truss 4, determine the stress change of the steel truss 4 to ensure that the floating-up process is uniform and stable.

[0033] Barge - type water - borne overhead steel truss deflection stress elimination device, including a barge 6. Inside the barge 6, there are several water pumps capable of pumping water into the cabin and pumping the water in the cabin out. In the middle of the upper side of the barge 6, an adaptive double - column balance jacking device 5 is installed. At the front and rear ends of the upper part of the adaptive double - column balance jacking device 5, an adaptive front jacking column 7a and an adaptive rear jacking column 7b are respectively arranged. The upper ends of the adaptive front jacking column 7a and the adaptive rear jacking column 7b are respectively vertically connected with a front push - top pillow 14a and a rear push - top pillow 14b extending in the left - right direction. Through the double - support action of the front push - top pillow 14a and the rear push - top pillow 14b, the steel truss 4 in "Step Four" receives a more uniform upward jacking force, avoiding stress concentration. However, if a front - rear double - jacking structure is designed, there are the following problems. During the process of the barge 6 slowly floating upward in "Step Four", theoretically, the front push - top pillow 14a and the rear push - top pillow 14b should contact and push the lower chord of the steel truss 4 upward simultaneously. However, since the structure inside the barge 6 is not completely uniform in the front - rear direction, during the process of the barge 6 gradually draining water outward, the center of gravity of the barge 6 will shift in the front - rear direction from a top - down view. At the same time, there are also external factors such as wind and waves. Therefore, during the process of the barge 6 gradually floating upward, its own posture will swing back and forth in the front - rear direction, resulting in the situation that the front push - top pillow 14a and the rear push - top pillow 14b cannot contact and push the lower chord of the steel truss 4 upward simultaneously, and further resulting in the uneven force on the front push - top pillow 14a and the rear push - top pillow 14b. The advantage of the double - support action is lost. To solve this problem, the following structure is designed:

[0034] As Figure 3 、 4 、shown in Figure 5, the adaptive front jacking column 7a and the adaptive rear jacking column 7b are linked by a linkage structure. The linkage structure makes the adaptive front jacking column 7a extend upward while the adaptive rear jacking column 7b retracts downward, and vice versa, when the adaptive front jacking column 7a retracts downward, the adaptive rear jacking column 7b extends upward.

[0035] The adaptive double-column balance jacking device 5 includes a barge attitude balance seat 05 extending in the front-rear direction. In the middle of the barge attitude balance seat 05, there is a balance counterweight movable groove 9 extending in the front-rear direction. A rectangular balance counterweight 3 is movably arranged in the balance counterweight movable groove 9. Guide rails 2 are arranged along the length direction on the left and right inner side walls of the balance counterweight movable groove 9. Sliders 1 are fixed on the left and right sides of the balance counterweight 3. The balance counterweight 3 is guided and fitted with the guide rails 2 through the sliders 1. A locking device is arranged on the sliders 1. In the locked state, the sliders 1 are locked with the guide rails 2, so that the sliders 1 cannot slide along the guide rails 2. The locking device between the sliders and the guide rails is a conventional locking structure, such as a hydraulic locking device, etc. A transmission groove 13 is arranged along the front-rear direction at the bottom of the balance counterweight movable groove 9. A transmission gear 11 with an axis parallel to the left-right direction is rotatably installed in the middle of the transmission groove 13 through a bearing. A straight rack 10 is fixedly arranged along the front-rear direction on the lower side of the balance counterweight 3. The upper part of the transmission gear 11 meshes with the straight rack 10. Vertical front hydraulic cylinder chambers 18a and rear hydraulic cylinder chambers 18b are respectively arranged at the front and rear ends of the barge attitude balance seat 05. Front lifting hydraulic pistons 17a and rear lifting hydraulic pistons 17b are respectively arranged in the front hydraulic cylinder chambers 18a and rear hydraulic cylinder chambers 18b. Hydraulic oil is filled in the lower sides of the front lifting hydraulic pistons 17a and rear lifting hydraulic pistons 17b. The lower ends of the adaptive front jacking column 7a and the adaptive rear jacking column 7b are respectively fixedly connected to the front lifting hydraulic piston 17a and the rear lifting hydraulic piston 17b.

[0036] A front piston channel 20a extending in the front-rear direction is arranged in the bottom wall of the front part of the barge attitude balance seat 05. The front end of the front piston channel 20a is connected to the bottom of the front hydraulic cylinder chamber 18a through a front communication channel 19a. A front translation piston 21a is arranged in the front piston channel 20a. A front piston rod 22a is coaxially and fixedly connected to the rear end of the front translation piston 21a.

[0037] A rear piston channel 20b extending in the front-rear direction is arranged in the bottom wall of the rear part of the barge attitude balance seat 05. The rear end of the rear piston channel 20b is connected to the bottom of the rear hydraulic cylinder chamber 18b through a rear communication channel 19b. A rear translation piston 21b is arranged in the rear piston channel 20b. A rear piston rod 22b is coaxially and fixedly connected to the front end of the rear translation piston 21b. A straight rack 12 extending in the front-rear direction meshes with the lower side of the transmission gear 11. The front and rear ends of the straight rack 12 are respectively fixedly connected to the front piston rod 22a and the rear piston rod 22b.

[0038] Restraining rollers 15 are arranged at the front, rear, left and right of the upper ends in the front hydraulic cylinder chambers 18a and rear hydraulic cylinder chambers 18b. The restraining rollers 15 are rotatably installed on their respective roller supports 16. The front and rear sides of the adaptive front jacking column 7a and the adaptive rear jacking column 7b are in rolling fit with the restraining rollers 15, so as to prevent the front hydraulic cylinder chambers 18a and rear hydraulic cylinder chambers 18b from tilting in the front-rear direction.

[0039] The core function of the above-mentioned adaptive double-column balanced jacking device is specifically reflected in the process of the "fourth step":

[0040] In the process of the "fourth step", when the barge 6 slowly floats upward, theoretically, the front push pillow 14a and the rear push pillow 14b should always rise at the same height, so that the front push pillow 14a and the rear push pillow 14b should theoretically contact and push the lower chord of the steel truss 4 upward at the same time. However, since the internal cabin of the barge 6 is not a completely uniform structure in the front-rear direction, during the process of the barge 6 gradually draining water outward, the center of gravity of the barge 6 will shift in the front-rear direction from a top-down perspective. At the same time, there are external factors such as wind and waves. Therefore, during the process of the barge 6 gradually floating upward, its own attitude will swing back and forth, which will cause the front push pillow 14a and the rear push pillow 14b to be unable to contact and push the lower chord of the steel truss 4 upward evenly at the same time, and then cause the situation that the forces on the front push pillow 14a and the rear push pillow 14b are uneven; this makes the advantage of the double-support function lost, and the present solution effectively solves the above problems, and the principle is as follows:

[0041] In the initial state, the slider 1 is locked with the guide rail 2, so that the balance counterweight 3 is locked in the central position in the front-rear direction of the balance counterweight moving slot 9. At the same time, the front push pillow 14a and the rear push pillow 14b are at the same height in the initial state. During the process of the barge 6 slowly floating upward, the attitude of the barge 6 itself will swing back and forth, resulting in the front push pillow 14a and the rear push pillow 14b becoming unequal in height; during the process of the barge 6 slowly floating upward, when any one of the front push pillow 14a and the rear push pillow 14b just touches and pushes the lower chord of the steel truss 4 first, the locking relationship between the slider 1 and the guide rail 2 is immediately released, so that the slider 1 can freely slide along the guide rail 2;

[0042] If the front push pillow 14a contacts the push steel truss 4 first, it indicates that the barge 6 has changed its attitude with the front high and the rear low. During the process of the barge 6 continuing to slowly float upward, the adaptive front top column 7a is preferentially stressed, thereby pushing the front lifting hydraulic piston 17a to displace downward relatively. Subsequently, under the push of the hydraulic pressure, the front piston rods 22a, b, the linear rack 12, and the rear piston rod 22b displace backward as a whole, and then the rear translation piston 21b moves backward. Further, under the action of the hydraulic pressure, the rear lifting hydraulic piston 17b is driven to displace upward relatively, so that the rear push pillow 14b displaces upward relatively, so that the rear push pillow 14b can contact and push the push steel truss 4 as soon as possible, thereby preventing the attitude of the barge 6 from deteriorating further due to unbalanced forces; at the same time, during the process of the front piston rods 22a, b, the linear rack 12, and the rear piston rod 22b displacing backward as a whole, the transmission gear 11 is driven at the same time, and then the transmission gear 11 drives the a linear rack 10, so that the balance weight 3 moves forward, and the center of gravity of the barge 6 moves forward, thereby suppressing the attitude change of the barge 6 with the front high and the rear low, and making the barge 6 return to an ideal horizontal state;

[0043] Similarly, if the rear push pillow 14b contacts the push steel truss 4 first, the front push pillow 14a will displace upward relatively under the action of hydraulic linkage, so that the front push pillow 14a can contact and push the push steel truss 4 as soon as possible, preventing the attitude of the barge 6 from deteriorating further due to unbalanced forces; at the same time, on the basis of hydraulic linkage, the balance weight 3 moves backward, and the center of gravity of the barge 6 moves backward, thereby suppressing the attitude change of the barge 6 with the front low and the rear high, and making the barge 6 return to an ideal horizontal state

[0044] At the same time, in the subsequent process, the rear push pillow 14b and the front push pillow 14a compensate each other under the action of hydraulic linkage, so as to achieve the effect of balanced pushing.

[0045] The above is only the preferred embodiment of the present invention. It should be noted that: for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A method for eliminating the downward bending stress of a barge-type overhead steel truss, characterized in that: Step 1: Fill the cabin of the barge (6) with water to gradually lower the barge (6) to a predetermined depth on the water surface, so that the highest position of the barge (6) is just below the lower chord height of the overhead steel truss (4) that needs to be subjected to downward deflection stress elimination; Step 2: The barge (6) moves to a position just below the lower chord of the overhead steel truss (4) where downward bending stress elimination is required, close to the middle position; Step 3, fix the front and rear ends of the barge (6) to the anchor pier (8) with steel wire ropes, and fix the left and right ends with anchors to control the movement of the barge; Step 4: Use multiple water pumps to evenly pump out the water in each hold of the barge (6) at the same time, so that the barge (6) generates buoyancy, and the barge (6) floats up evenly and slowly until the upper end of the barge (6) contacts and pushes up the lower chord of the steel truss (4), thereby transmitting the upward buoyancy to the steel truss (4). The steel truss (4) is subjected to an upward jacking force. When the jacking force gradually increases and reaches the designed jacking force, the steel truss (6) begins to arch upward, thereby gradually eliminating the downward bending stress; the entire jacking process is carried out in stages, and the draft of the barge (6) is monitored during the process of the barge floating up, and the displacement of the barge floating up is measured; the stress change of the steel truss (4) is determined by monitoring the displacement of the barge floating up and the displacement of the camber change of the steel truss (4).

2. Barge type overhead steel truss downward deflection stress elimination device, characterized by: The barge (6) comprises a plurality of water pumps which can pump water into the cabin and pump water out of the cabin.

3. The barge-type overhead steel truss downward bending stress elimination device according to claim 2 is characterized in that: An adaptive double-column balanced jacking device (5) is installed in the middle of the upper side of the barge (6), and the front and rear ends of the upper part of the adaptive double-column balanced jacking device (5) are respectively provided with an adaptive front jacking column (7a) and an adaptive rear jacking column (7b); the upper ends of the adaptive front jacking column (7a) and the adaptive rear jacking column (7b) are respectively vertically connected with a front push jacking pillow (14a) and a rear push jacking pillow (14b) extending in the left and right directions.

4. The barge-type overhead steel truss downward bending stress elimination device according to claim 3 is characterized in that: The adaptive front top column (7a) and the adaptive rear top column (7b) are linked via a linkage structure, and the linkage structure enables the adaptive front top column (7a) to move upwards and the adaptive rear top column (7b) to move downwards, while the adaptive front top column (7a) moves downwards and the adaptive rear top column (7b) to move upwards.

5. The barge-type overhead steel truss downward bending stress elimination device according to claim 4 is characterized in that: The self-adaptive double-column balancing jack (5) comprises a barge posture balancing seat (05) extending in the front-rear direction, wherein a balancing weight movable groove (9) extending in the front-rear direction is arranged in the middle of the barge posture balancing seat (05), and a rectangular balancing weight (3) is movably arranged in the balancing weight movable groove (9).

6. The barge-type overhead steel truss downward bending stress elimination device according to claim 5 is characterized in that: Guide rails (2) are provided on the left and right inner walls of the balancing weight movable groove (9) extending in the length direction, and sliders (1) are fixed on the left and right sides of the balancing weight (3). The balancing weight (3) is guided to match the guide rails (2) through the sliders (1), and a locking device is provided on the sliders (1). In the locked state, the sliders (1) are locked with the guide rails (2), so that the sliders (1) cannot slide along the guide rails (2).

7. The barge-type overhead steel truss downward bending stress elimination device according to claim 6 is characterized in that: A transmission groove (13) is provided at the bottom of the movable groove (9) of the balancing weight along the front-rear direction, and a transmission gear (11) with an axis parallel to the left-right direction is rotatably mounted in the middle of the transmission groove (13) through a bearing; a linear rack (10) is fixedly provided at the lower side of the balancing weight (3) along the front-rear direction, and the upper part of the transmission gear (11) is meshed with the linear rack (10); The front and rear ends of the barge posture balance seat (05) are respectively provided with a vertical front hydraulic column chamber (18a) and a rear hydraulic column chamber (18b), and the front hydraulic column chamber (18a) and the rear hydraulic column chamber (18b) are respectively provided with a front lifting hydraulic piston (17a) and a rear lifting hydraulic piston (17b), and the lower sides of the front lifting hydraulic piston (17a) and the rear lifting hydraulic piston (17b) are filled with hydraulic oil, and the lower ends of the adaptive front top column (7a) and the adaptive rear top column (7b) are respectively fixedly connected to the front lifting hydraulic piston (17a) and the rear lifting hydraulic piston (17b); A front piston channel (20a) is provided in the front bottom wall of the barge posture balance seat (05) extending in the front-to-back direction, the front end of the front piston channel (20a) is connected to the bottom of the front hydraulic column chamber (18a) through the front connecting channel (19a), a front translation piston (21a) is provided in the front piston channel (20a), and the rear end of the front translation piston (21a) is coaxially fixedly connected to a front piston rod (22a); A rear piston channel (20b) is provided in the rear bottom wall of the barge posture balance seat (05) extending in the front-to-back direction, and the rear end of the rear piston channel (20b) is connected to the bottom of the rear hydraulic column chamber (18b) through a rear connecting channel (19b). A rear translation piston (21b) is provided in the rear piston channel (20b), and the front end of the rear translation piston (21b) is coaxially fixedly connected to a rear piston rod (22b); a b linear rack (12) extending in the front-to-back direction is meshed on the lower side of the transmission gear (11), and the front and rear ends of the b linear rack (12) are respectively fixedly connected to the front piston rod (22a) and the rear piston rod (22b).

8. The barge-type overhead steel truss downward bending stress elimination device according to claim 7 is characterized in that: Constraint rollers (15) are provided at the front and rear ends of the front hydraulic column chamber (18a) and the rear hydraulic column chamber (18b), and the constraint rollers (15) are rotatably mounted on respective roller supports (16). The front and rear sides of the adaptive front top column (7a) and the adaptive rear top column (7b) are rollingly matched with the constraint rollers (15).

9. The working method of the barge type overhead steel truss downward bending stress elimination device according to claim 7 is characterized in that: During the process of "step four", when the barge (6) slowly floats up, when any one of the front push pillow (14a) and the rear push pillow (14b) just contacts the lower chord of the push steel truss (4), the locking relationship between the slider (1) and the guide rail (2) is immediately released, so that the slider (1) can slide freely along the guide rail (2).

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