Construction method of steel truss beam non-jump transfer stress drag and pull system

Abstract

The present application belongs to the technical field of steel truss beam crossing obstacle dragging construction, and particularly relates to a dragging construction method of a steel truss beam non-sudden change conversion stress dragging system; a fixed sliding block is installed above a first pier column from a cantilever section of the steel truss beam as a fixed stress support point in the dragging process; a first movable sliding block from the fixed sliding block slowly reduces the pressure on the sliding guide beam along with the dragging process; when the height difference between the top surface of the sliding guide beam and the bottom of the steel truss beam in the downhill section of the sliding guide beam is greater than the height of the movable sliding block, the pressure of the movable sliding block on the sliding guide beam completely disappears, and the movable sliding block is cut off before the first pier column and falls on the sliding guide beam for recycling; the steel truss beam is dragged by using the method, the movable sliding block stress nodes are slowly separated from the sliding guide beam in sequence during the advancing process, the steel truss beam and the cantilever guide beam node stress conversion is smooth, the steel truss beam and the cantilever guide beam avoid the phenomenon of sudden increase of tremor and deflection, the movable sliding block is cut off and moved from above the operating line to the rear safe area, and the safety risk is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel truss beam crossing obstacle dragging construction, and particularly relates to a dragging construction method of a steel truss beam non-mutation conversion stress dragging system. BACKGROUND

[0002] The steel truss beam pushing technology is widely applied due to the maximum reduction of the influence of pushing construction on the safety of the operating line and the good crossing property. The steel truss beam pushing needs to set a sliding guide beam, the steel truss beam is supported on the sliding guide beam through a sliding block, and the sliding block slides on the sliding guide beam through a pushing jack. The top surface of the sliding guide beam is usually set to be flush with the top of the pier. When pushing, the sliding block is out of the end of the sliding guide beam. The specific state of the sliding block before being out of the sliding guide beam is shown in the attached Figure 1 .

[0003] As shown in the attached Figure 1 , the traditional sliding guide beam top surface is set to be flush with the top of the pier. Before the sliding block is out, due to the action of the front cantilever segment and the rear counterweight (the rear end does not need the counterweight if the weight is enough), the first movable sliding block bears a great pressure, the second movable sliding block bears a very small pressure or even no pressure, and the third movable sliding block and the sliding blocks behind gradually bear a larger pressure. At the moment when the first movable sliding block is out of the sliding guide beam, the first movable sliding block is suspended, the pressure disappears, and the moment is transferred to the second movable sliding block. The steel truss beam stress system instantaneously produces mutation, and the stress state of the steel truss beam is extremely unfavorable. Especially in the dragging construction on the railway operating line, the safety risk is particularly large. After the sliding block is out, it is above the existing line, and the safety risk is extremely large when being recovered. The recovery operation is not convenient. The state of the sliding block out of the sliding guide beam is shown in the attached Figure 2 . SUMMARY

[0004] The present application is to solve the problems of the traditional steel truss beam dragging method, such as the instantaneous mutation of the steel truss beam stress system and the difficulty in recovering the sliding block.

[0005] The present application provides the following technical scheme: a steel truss beam non-mutation conversion stress dragging system dragging construction method. A fixed sliding block is installed above the first pier column from the cantilever segment of the steel truss beam as a fixed stress support point in the dragging process, and a downhill segment is arranged on the top surface of the sliding guide beam. The slope bottom of the downhill segment is from the beam end of the sliding guide beam, and the straight line distance from the slope top to the slope bottom is the longest movable sliding block installation interval. The pressure of the first movable sliding block from the fixed sliding block on the sliding guide beam is slowly reduced along with the dragging process. When the height difference between the top surface of the sliding guide beam on the downhill segment and the beam bottom of the steel truss beam is greater than the height of the movable sliding block, the pressure of the movable sliding block on the sliding guide beam completely disappears, and the movable sliding block is cut off before the first pier column and falls on the sliding guide beam, and then is recovered.

[0006] Further, a temporary support is arranged under the sliding guide beam, and at least one temporary support is arranged at the section change of the sliding guide beam.

[0007] Further, the movable sliding block is arranged at the node of the steel truss beam.

[0008] Further, the sliding guide beam installation comprises the following steps:

[0009] S1: measuring the elevation of the top surface of the foundation;

[0010] S2: installing the lattice steel column on the top of the temporary pier foundation embedded part, and arranging the longitudinal and transverse distribution beams between the sliding guide beam and the steel column, and the transverse distribution beam is free of longitudinal slope along the bridge direction;

[0011] S3: hoisting the sliding guide beam in sections and fixing the sliding guide beam and the distribution beam of the steel column;

[0012] S4: performing butt welding between the beam sections of the sliding guide beam.

[0013] Further, the fixed sliding block is installed in the following manner: the fixed sliding block is reversely arranged on the top of the first pier column through the embedded part; the top surface of the fixed sliding block is provided with a circular arc transition section at both ends along the longitudinal direction of the bridge, and the fixed sliding block is welded with a baffle on both sides to limit the transverse movement of the sliding plate; and the MGE sliding plate is filled and circulated between the bottom of the steel truss beam and the fixed sliding block during the dragging construction process.

[0014] Further, a sliding block receiving platform is arranged at the bottom side of the downhill section of the sliding guide beam, the top elevation of the sliding block receiving platform is flush with the top surface elevation of the sliding guide beam, and the sliding block receiving platform is connected with the chute.

[0015] Compared with the prior art, the advantages of the present application are that:

[0016] The stress system of the steel truss beam is free of instantaneous mutation; the first support position of the steel truss beam adopts the fixed sliding block, the dragging process bears the full-range pressure, the second support pressure is slowly reduced, and the internal stress of the steel truss beam changes slowly. The dragging precision of the steel truss beam is high, the posture stability is good during the dragging process due to the absence of mutation, the risk of deviation is small, and the in-place precision after dragging is high.

[0017] The sliding block is simple to recycle; the sliding block is detached above the sliding guide beam, falls on the sliding guide beam after cutting, and is then slid to the ground by using the chute. The sliding block is safe to recycle; the sliding block can be recycled without entering the range of the span (railway operating line). The loss and engineering quantity of the sliding block are small; compared with the traditional method, the recycled sliding block does not need to be additionally supported and protected, and the loss caused by the falling of the sliding block is reduced.

[0018] The steel truss is pulled by the method, the movable sliding block stress joint is separated from the sliding guide beam in sequence slowly in the advancing process, the stress conversion of the steel truss and the cantilever guide beam joint is smooth, the steel truss and the cantilever guide beam avoid the phenomena of tremor and sudden increase of deflection, the safety risk is reduced, the movable sliding block cannot fall off from the front end of the sliding guide beam suddenly, the cutting movable sliding block is moved from above the operating line to a safe area at the back, the safety risk is further reduced, the psychological pressure of the operating personnel is reduced, and remarkable social benefits are obtained. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a state diagram before the first movable sliding block is separated.

[0020] Figure 2 It is a state diagram after the first movable sliding block is separated.

[0021] Figure 3 It is a structural schematic diagram of the method.

[0022] Figure 4 It is a movable sliding block recycling schematic diagram.

[0023] In the drawings, 1 is the first movable sliding block, 2 is the second movable sliding block, 3 is the third movable sliding block, 4 is an existing line, 5 is a steel truss, 6 is a counterweight, 7 is a sliding guide beam, 8 is a temporary support, 9 is a fixed sliding block, 10 is a first pier column, and 11 is a downhill section. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0025] As shown in Figure 3 , Figure 4 : a steel truss non-sudden conversion stress pulling system pulling construction method, a fixed sliding block 9 is installed on the first pier column 10 above the cantilever section of the steel truss 5 as a fixed stress support point in the pulling process, and a downhill section 11 is arranged on the top surface of the sliding guide beam 7, the slope bottom of the downhill section 11 is from the end of the sliding guide beam, and the straight line distance from the slope top to the slope bottom is the longest movable sliding block installation spacing; the first movable sliding block from the fixed sliding block 9 slowly reduces the pressure on the sliding guide beam 7 with the pulling process, when the height difference between the top surface of the sliding guide beam 7 and the bottom of the steel truss on the downhill section 11 of the sliding guide beam is greater than the height of the movable sliding block, the pressure of the movable sliding block on the sliding guide beam 7 disappears completely, and the cutting is completed in front of the first pier column 10 and falls on the sliding guide beam 7, and then recycling is carried out.

[0026] The temporary support 8 must be arranged under the sliding guide beam 7 to bear the weight of the steel truss 5 and transmit the weight of the steel truss 5 to the temporary support and the pier. In order to make the force of the sliding guide beam 7 reasonable, a temporary support 8 must be arranged at the section change of the sliding guide beam 7.

[0027] The lower part of the movable sliding block is a steel box plate, and the upper part is a MEG plate. The MEG plate is a sliding surface. The weight of the steel truss 5 is transmitted to the sliding guide beam 7 through the movable sliding block. The movable sliding block is generally arranged at the nodes of the steel truss 5 in intervals. Therefore, the arrangement interval of the movable sliding block on the sliding guide beam is determined according to the design type of the steel truss and the interval of the nodes.

[0028] The sliding guide beam 7 is divided into an upper sliding surface, a web plate and a lower bottom plate. The sliding guide beam 7 bears the weight of the steel truss 5 and transmits the weight of the steel truss 5 to the temporary support and the pier. The sliding guide beam 7 is arranged according to the following principles:

[0029] 1) In order to make the sliding block separate smoothly, the elevation of the top surface of the beam must be lowered at the beam end.

[0030] 2) In order to make the sliding block separate smoothly, an arc surface is arranged to lower the elevation smoothly.

[0031] 3) In order to make the first movable sliding block separate, the second movable sliding block has not reached the slope change point of the sliding guide beam 7. The length from the slope change point of the sliding guide beam 7 to the end is not greater than the installation interval of the movable sliding block.

[0032] The installation of the sliding guide beam includes the following steps:

[0033] S1: The elevation of the top surface of the foundation is measured.

[0034] S2: The lattice steel column is installed on the top of the temporary pier foundation pre-embedded part. The longitudinal and transverse distribution beams are arranged between the steel column and the sliding guide beam. The transverse distribution beam is without longitudinal slope along the bridge direction.

[0035] S3: The sliding guide beam is hoisted and installed in sections. The sliding guide beam is fixed with the distribution beam of the steel column.

[0036] S4: The butt welding between the beam sections of the sliding guide beam is performed.

[0037] The movable sliding block is welded into a box shape with a steel plate of 20 mm. The length is 650 mm, the width is 600 mm, and the height is not equal to 200-320 mm (different heights of sliding blocks are selected according to the pre-camber curve of the steel truss). The MGE engineering alloy sliding plate is installed below the sliding block, and the surrounding welding baffle limits the movement of the sliding plate.

[0038] The installation mode of the fixed sliding block 9 is that the fixed sliding block 9 is reversely arranged on the top of the first pier column 10 through the pre-embedded part. The top surface of the fixed sliding block 9 is provided with a circular arc transition section along the longitudinal direction of the bridge. The baffle is welded on both sides of the fixed sliding block 9 to limit the transverse movement of the sliding plate. The MGE sliding plate is cyclically filled between the bottom of the steel truss 5 and the fixed sliding block 9 during the dragging construction process, and the sliding is passed.

[0039] A sliding block receiving platform is arranged at the bottom side of the downhill section of the sliding guide beam 7, the top height of the sliding block receiving platform is flush with the top surface height of the sliding guide beam, and the sliding block receiving platform is connected with the chute. After the bottom surface of the movable sliding block is separated from the top surface of the sliding guide beam, the stress system conversion of the steel truss beam is completed, at this time, acetylene is used for cutting to peel off the movable sliding block from the steel truss beam and drop it onto the sliding guide beam. After the movable sliding block falls on the sliding guide beam and stops sliding on the sliding guide beam, a push rod is used to push it horizontally until it slides onto the sliding block receiving platform and slides down the chute to the ground.

[0040] During the dragging and pressing process of the steel truss beam, it is observed whether the anchoring state of the anchoring end is normal, whether the anchoring point slip and the clamping piece loosening occur. It is observed whether all the steel strands are located in the guide groove, and whether there are jamming, winding and relaxation phenomena. During the pressing process, it is observed whether the deformation of the connection part between the jack and the jack support occurs, if the gap between the cross section of the jack and the temporary flange becomes larger, the vehicle should be stopped immediately, and the height of the tail of the jack should be adjusted to eliminate the gap.

[0041] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Accordingly, the application is not to be limited to these embodiments shown herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steel truss beam non-jump conversion stress drag and pull system drag construction method, characterized by: The fixed sliding block (9) is installed above the first pier (10) from the cantilever section of the steel truss beam (5) as the fixed stress support point in the dragging process, and the downhill section (11) is arranged on the top surface of the sliding guide beam (7), the slope bottom of the downhill section (11) is from the beam end of the sliding guide beam, and the straight line distance from the slope top to the slope bottom is the longest installation interval of the movable sliding block, and the movable sliding blocks are arranged at intervals under the nodes of the steel truss beam (5); the first movable sliding block from the fixed sliding block (9) slowly reduces the pressure on the sliding guide beam (7) along with the dragging process, when the height difference between the top surface of the sliding guide beam (7) and the bottom of the steel truss beam on the downhill section (11) of the sliding guide beam is greater than the height of the movable sliding block, the pressure of the movable sliding block on the sliding guide beam (7) disappears completely, and the cutting is completed before the first pier (10) and falls on the sliding guide beam (7), and then the recycling is carried out. The sliding block receiving platform is arranged on the slope bottom side of the downhill section of the sliding guide beam (7), the top elevation of the sliding block receiving platform is flush with the top surface elevation of the sliding guide beam (7), and the sliding block receiving platform is connected with the chute.

2. The steel truss non-sudden change transfer force drag and pull system drag and pull construction method according to claim 1, characterized in that: The temporary support (8) is arranged under the sliding guide beam (7), and at least one temporary support (8) is arranged at the section change of the sliding guide beam (7).

3. The steel truss non-sudden change transfer force drag and pull system drag and pull construction method according to claim 1, characterized in that, The sliding guide beam (7) is installed Comprising the following steps: S1: measuring the top surface elevation of the foundation; S2: installing the lattice steel column on the top of the temporary pier foundation embedded part, and arranging the longitudinal and transverse distribution beams between the steel column and the sliding guide beam (7), and the transverse distribution beam is without longitudinal slope along the bridge direction; S3: hoisting the sliding guide beam (7) in sections, and fixing the sliding guide beam (7) and the steel column distribution beam; S4: carrying out the butt welding between the beam sections of the sliding guide beam.

4. The steel truss non-sudden change transfer force drag and pull system drag and pull construction method according to claim 3, characterized in that, The installation mode of the fixed sliding block (9) is that the fixed sliding block (9) is reversely arranged on the top of the first pier (10) through the embedded part; the top surface of the fixed sliding block (9) is provided with a circular arc transition section along the longitudinal direction of the bridge, and the baffle is welded on both sides of the fixed sliding block (9) to limit the transverse movement of the sliding plate; the MGE sliding plate is filled between the beam bottom of the steel truss beam (5) and the fixed sliding block (9) in the dragging construction process, and the sliding is passed.

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