A construction method for incremental launching of variable-height steel girders by walking jacks

Abstract

The present invention discloses a walking jacking construction method for variable-height steel girders; by installing detachable pads at the bottom of the girder to change the height and alignment of the girder bottom, making the girder bottom change from a large-slope broken line to a horizontal line; by installing detachable short columns on the temporary pier supports to change the height of the temporary pier supports; enabling the walking jacks to always act vertically on the bottom of the steel girder and smoothly implementing the jacking action. The cross-sectional height of the variable-height steel girder has a large linear change within a short distance, and the alignment of the girder bottom is a broken line with a large slope. When using the walking jacking construction, since the acting direction of the walking jack must be perpendicular to the bottom of the girder, therefore, the walking jack cannot directly jack the variable-height steel girder with a large-slope broken line at the bottom of the girder. The method proposed in this patent solves the bottleneck problem in the construction of variable-height steel girders using the walking jacking method. The method proposed in this patent solves the bottleneck problem in the construction of variable-height steel girders using the walking jacking method. It is simple to operate, easy to promote, and has a fast construction speed; the materials of the pads and temporary supports can be reused, and the construction cost is low.

Description

Technical Field

[0001] The present invention relates to the field of incremental launching construction of bridges, and more specifically to a walking type incremental launching construction method for variable height steel girders. Background Art

[0002] The walking type incremental launching method is a bridge construction method that has gradually become popular in recent years. The construction equipment for walking type incremental launching is walking type jacks. Through the four actions of "rearward movement, lifting, forward movement, and beam lowering" of the walking type jacks as a cycle, the steel girder can be pushed out a certain distance. After multiple cycles, the steel girder is pushed and transported to the designed position. The walking type incremental launching method has obvious advantages: the bridge can be assembled at a favorable site and then pushed and transported to the designed position section by section or as a whole. When crossing valleys, traffic lines, and navigable rivers, the incremental launching construction method often becomes the most ideal construction method. However, the walking type jacks are installed on the temporary pier supports and apply a jacking force to the bottom of the steel girder. It is required that the acting direction of the jacks is perpendicular to the bottom of the beam. Objectively, it is required that the alignment of the beam bottom is straight. Therefore, the walking type incremental launching method cannot directly carry out incremental launching construction on variable height girders with a broken line alignment at the beam bottom (see Figure 1 ). In recent years, there have been cases where due to restrictions such as construction environment and navigable clearance conditions, variable height girders have to be constructed by walking type incremental launching. How to push variable height girder segments will become a thorny problem. Summary of the Invention

[0003] Therefore, to solve the above deficiencies, the present invention provides a walking type incremental launching construction method for variable height steel girders here. The cross-sectional height of the variable height steel girder changes greatly within a short distance, and the alignment of the beam bottom is a broken line with a large slope. When using the walking type incremental launching construction, since the acting direction of the walking type jacks must be perpendicular to the bottom of the beam, the walking type jacks cannot directly push variable height steel girders with a large slope broken line at the beam bottom. The method proposed in this patent solves the bottleneck problem of constructing variable height steel girders by the walking type incremental launching method.

[0004] The present invention is realized as follows. A walking type incremental launching construction method for variable height steel girders is constructed, characterized in that; by installing detachable pads at the bottom of the beam (see the triangular inclined pads and transition pads K1-K6 in Figure 2 ), the height and alignment of the beam bottom are changed, so that the beam bottom changes from a large slope broken line to a horizontal line, and at the same time, the height of the beam bottom is changed; by installing detachable short columns on the temporary pier supports (see the columns Z1-Z3 in Figure 3 ), the height of the temporary pier supports is changed; so that the walking type jacks always act vertically on the bottom of the steel girder, and the jacking action is successfully implemented; specifically, it consists of the following three operation processes:

[0005] Process 1, installation and removal of temporary pier short columns and pads;

[0006] Process 2, the jacking construction operation of the front variable-height section;

[0007] Process 3, the jacking construction operation of the rear variable-height section.

[0008] According to a walking jacking construction method for variable-height steel girders of the present invention, it is characterized in that; Process 1 is specifically;

[0009] (1) The installation and removal of the short columns on the temporary pier supports can be constructed by using a truck crane, a chain block, etc.;

[0010] (2) The triangular inclined pads and transition pads can be vertically lifted from the ground or the support by using a chain block and fixed to the beam bottom with high-strength bolts. The removal process is the opposite.

[0011] According to a walking jacking construction method for variable-height steel girders of the present invention, it is characterized in that;

[0012] For Process 2, the jacking construction method of the front variable-height section is specifically;

[0013] Step 1: Push the front variable-height section of the steel girder to the front of the rear support of the temporary pier, and install triangular inclined pads and 6 groups of transition pads K at the beam bottom;

[0014] Step 2: Continue to jack up the steel girder and move it forward by a distance L1, remove 1 group of transition pads K, install a short column Z3 on the rear support, and lower the beam;

[0015] Step 3: Continue to jack up the steel girder and move it forward by a distance L2, lower the beam, remove 3 groups of transition pads K at the beam bottom, lift the walking jack, install a short column Z3 on the middle support, and lower the walking jack;

[0016] Step 4: Continue to jack up the steel girder and move it forward by a distance of L4 mm, remove 2 groups of transition pads K at the beam bottom, install a short column Z3 on the front support, and lower the beam;

[0017] After the above four steps, the front variable-height section has completely passed through the temporary pier and entered the equal-height section. Continue to push forward. When the front variable-height section approaches the next temporary pier, start the next cycle from Step 1.

[0018] According to a walking jacking construction method for variable-height steel girders of the present invention, it is characterized in that;

[0019] For Process 3, the jacking construction method of the rear variable-height section is specifically;

[0020] Step 1: Push the rear variable-height section of the steel girder to the rear support of the temporary pier and install triangular inclined pads;

[0021] Step 2: Jack up the steel girder, remove the short column Z3 on the rear support of the temporary pier, install a group of transition pads K at the beam bottom, and lower the beam after pushing it forward by a distance of L1;

[0022] Step 3: Lift the walking jack, remove the short column Z3 on the middle support bracket, lower the walking jack, and install 4 groups of transition pads K at the bottom of the beam;

[0023] Step 4: Use the walking jack to lift the steel beam and move it forward by a distance L2 to reach the front support, and then lower the beam;

[0024] Step 5: Lift the steel beam, remove the short column Z3 on the front support of the temporary pier, install a group of transition pads K at the bottom of the beam, and lower the beam after moving forward by a distance L3;

[0025] After the above five cycles, the higher part at the rear of the steel beam has become an equal-height part by installing pads; continue to push the steel beam forward, and remove all the transition pads K before the higher part at the rear reaches the next temporary pier, then start the next cycle from Step 1.

[0026] The present invention has the following advantages: The present invention provides a construction method for incremental launching of variable-depth steel beams. The cross-sectional height of the variable-depth steel beam changes greatly within a short distance, and the bottom line of the beam is a broken line with a large slope. When using the incremental launching construction method, since the acting direction of the walking jack must be perpendicular to the bottom of the beam, the walking jack cannot directly push this kind of variable-depth steel beam with a large-slope broken line at the bottom. The method proposed in this patent solves the bottleneck problem in the construction of variable-depth steel beams using the incremental launching method. The method proposed in this patent solves the bottleneck problem in the construction of variable-depth steel beams using the incremental launching method. It is simple to operate, easy to promote, and has a fast construction speed; the materials of the pads and temporary supports can be reused, and the construction cost is low. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of a variable-depth beam;

[0028] Figure 2 Layout diagram of pads at the bottom of the variable-depth part of the beam;

[0029] Figure 3 Structural diagram of the temporary pier used for incremental launching;

[0030] Figure 4 Lifting and installation of pads;

[0031] Figure 5 It is the schematic diagram corresponding to Step 1 of Process 2 in this method;

[0032] Figure 6 It is the schematic diagram corresponding to Step 2 of Process 2 in this method;

[0033] Figure 7 It is the schematic diagram corresponding to Step 3 of Process 2 in this method;

[0034] Figure 8 It is the schematic diagram corresponding to Step 4 of Process 2 in this method;

[0035] Figure 9 It is a schematic diagram corresponding to Step 1 of Process 3 in this method;

[0036] Figure 10 It is a schematic diagram corresponding to Step 2 of Process 3 in this method;

[0037] Figure 11 It is a schematic diagram corresponding to Step 3 of Process 3 in this method;

[0038] Figure 12 It is a schematic diagram corresponding to Step 4 of Process 3 in this method;

[0039] Figure 13 It is a schematic diagram corresponding to Step 5 of Process 3 in this method;

[0040] Figure 14 It is a schematic diagram of Process 3 in this method after the above five cycles. Specific Embodiments

[0041] The present invention will be described in detail below in conjunction with the attached Figures 1 - 14 The present invention will be described in detail. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] The present invention provides a variable-height steel beam walking jacking construction method through improvement. The construction method of this patent is proposed according to the characteristic that the acting direction of the walking jack must be perpendicular to the beam bottom. By installing detachable pads at the beam bottom (see the triangular inclined pads and transition pads K in Figure 2 ), the height and linearity of the beam bottom are changed, so that the beam bottom changes from a large-slope broken line to a horizontal line, and at the same time, the height of the beam bottom is changed. By installing detachable short columns on the temporary pier supports (see the columns Z1-Z3 in Figure 3 ), the height of the temporary pier supports is changed. So that the walking jack always acts vertically on the steel beam bottom, and the jacking action is successfully implemented. Specifically, it consists of the following three operation processes:

[0043] Process 1, installation and removal of temporary pier short columns and pads;

[0044] (1) The installation and removal of short columns on the temporary pier supports can be constructed by using a truck crane, a chain block, etc.

[0045] (2) The triangular inclined pads and transition pads can be vertically lifted from the ground or the support by using a chain block and fixed to the beam bottom with high-strength bolts. The removal process is the opposite. As shown in Figure 4 .

[0046] Process 2, the incremental launching construction method for the front variable-height section;

[0047] Step 1: Push the front variable-height section of the steel girder to the position in front of the rear support of the temporary pier, and install triangular inclined cushion blocks and 6 groups of transition cushion blocks K at the bottom of the girder. As shown in Figure 5 ;

[0048] Step 2: Continue to jack up the steel girder and move it forward by a distance L1, remove 1 group of transition cushion blocks K, install a short column Z3 on the rear support, and lower the girder. As shown in Figure 6 ;

[0049] Step 3: Continue to jack up the steel girder and move it forward by a distance L2, lower the girder, remove 3 groups of transition cushion blocks K at the bottom of the girder, lift the walking jack, install the Z3 short column on the middle support, and lower the walking jack. As shown in Figure 7 ;

[0050] Step 4: Continue to jack up the steel girder and move it forward by a distance of L4 mm, remove 2 groups of transition cushion blocks K at the bottom of the girder, install a short column Z3 on the front support, and lower the girder. As shown in Figure 8 ;

[0051] After the above four steps, the front variable-height section has completely passed through the temporary pier and entered the equal-height section. Continue to push forward. When the front variable-height section approaches the next temporary pier, start the next cycle from Step 1.

[0052] Process 3, the incremental launching construction method for the rear variable-height section, specifically;

[0053] Step 1: Push the rear variable-height section of the steel girder to the position of the rear support of the temporary pier, and install triangular inclined cushion blocks. As shown in Figure 9 ;

[0054] Step 2: Jack up the steel girder, remove the short column Z3 on the rear support of the temporary pier, install a group of transition cushion blocks K at the bottom of the girder, and push it forward by a distance of L1 and then lower the girder. As shown in Figure 10 ;

[0055] Step 3: Lift the walking jack, remove the short column Z3 on the middle support bracket, lower the walking jack, and install 4 groups of transition cushion blocks K at the bottom of the girder. As shown in Figure 11 ;

[0056] Step 4: The walking jack jacks up the steel girder and moves it forward by a distance of L2, reaches the front support, and lowers the girder. As shown in Figure 12 ;

[0057] Step 5: Jack up the steel girder, remove the short column Z3 on the front support of the temporary pier, install a group of transition cushion blocks K at the bottom of the girder, and move it forward by a distance of L3 and then lower the girder. As shown in Figure 13 ;

[0058] After the above five cycles, the height-increasing section at the rear of the steel girder has become a section with equal height by installing cushion blocks. Continue to push the steel girder forward. Before the height-increasing section at the rear reaches the next temporary pier, remove all the transition cushion blocks K, and then start the next cycle from Step 1. As Figure 14 ;

[0059] This patent has the following advantages and beneficial effects: The method proposed in this patent solves the bottleneck problem in the construction of variable-height steel girders using the walking jacking method. It is simple to operate, easy to promote, and has a fast construction speed; the materials of the cushion blocks and temporary supports can be reused, and the construction cost is low.

Claims

1. A construction method for incremental launching of variable-height steel girders by walking jacks, characterized in that: The height and alignment of the beam bottom are changed by installing removable cushion blocks at the beam bottom, so that the alignment of the beam bottom changes from a large-slope broken line to a horizontal line; the height of the temporary pier support is changed by installing removable short columns on the temporary pier support; so that the walking jack always acts vertically on the steel beam bottom, and the jacking operation is successfully implemented; specifically, it consists of the following three operation processes: Process 1, installation and removal of the short columns and cushion blocks of the temporary pier; the specific operation is as follows: (1) The installation and removal of the short columns on the temporary pier support are constructed by using a truck crane or a chain block. (2) The triangular inclined cushion blocks and transition cushion blocks are vertically lifted from the ground or the support by a chain block and fixed to the beam bottom with high-strength bolts; the removal process is the opposite. Process 2, jacking construction operation of the front variable-height section, specifically: Step 1: When the front variable-height section of the steel beam is jacked to the front of the rear support of the temporary pier, install triangular inclined cushion blocks and 6 groups of transition cushion blocks K at the beam bottom. Step 2: Continue to jack up the steel beam and move it forward by a distance L1, remove 1 group of transition cushion blocks K, install a short column Z3 on the rear support, and lower the beam. Step 3: Continue to jack up the steel beam and move it forward by a distance L2, lower the beam, remove 3 groups of transition cushion blocks K at the beam bottom, lift the walking jack, install a short column Z3 at the middle support, and lower the walking jack. Step 4: Continue to jack up the steel beam and move it forward by a distance of L4mm, remove 2 groups of transition cushion blocks K at the beam bottom, install a short column Z3 on the front support, and lower the beam. After the above four steps, the front variable-height section has completely passed through the temporary pier and entered the equal-height section. Continue to jack it forward. When the front variable-height section approaches the next temporary pier, start from Step 1 to enter the next cycle. Process 3, jacking construction operation of the rear variable-height section, specifically: Step 1: When the rear variable-height section of the steel beam is jacked to the rear support of the temporary pier, install triangular inclined cushion blocks. Step 2: Jack up the steel beam, remove the short column Z3 on the rear support of the temporary pier, install a group of transition cushion blocks K at the beam bottom, and lower the beam after jacking it forward by a distance L1. Step 3: Lift the walking jack, remove the short column Z3 on the middle support bracket, lower the walking jack, and install 4 groups of transition cushion blocks K at the beam bottom. Step 4: The walking jack jacks up the steel beam and moves it forward by a distance L2 to reach the front support, and lower the beam. Step 5: Jack up the steel beam, remove the short column Z3 on the front support of the temporary pier, install a group of transition cushion blocks K at the beam bottom, and lower the beam after moving it forward by a distance L3. After the above five cycles, the rear variable-height section of the steel beam has become an equal-height section by installing cushion blocks; continue to jack up the steel beam forward. Before the rear variable-height section reaches the next temporary pier, remove all the transition cushion blocks K, and start from Step 1 to carry out the next cycle.

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