CN116024906A - A kind of construction method of steel truss bridge without support - Google Patents

Abstract

The method comprises the steps of constructing a site ground assembly jig frame at a construction site, transporting each girder section of the steel truss bridge from a processing plant to the construction site, and welding, riveting and assembling each girder section of the steel truss bridge on the site ground assembly jig frame; after the assembly of the steel truss bridge is completed on the ground, the erection of the steel truss bridge on the bridge pier is completed by a double crane lifting method; the construction method of the steel truss bridge without the support omits the traditional construction process of building the high-altitude support frame, so that the construction period and the construction cost are greatly reduced, and the construction safety is also greatly improved; meanwhile, when bolting, welding and assembling of each girder section of the steel truss bridge are carried out on the ground, the assembly linearity of the steel truss bridge is more convenient to measure and adjust, so that the construction difficulty is reduced, and the construction efficiency and the construction quality are also greatly improved.

Description

A kind of construction method of steel truss bridge without support

technical field

The invention relates to the technical field of steel truss bridge construction, in particular to a support-free construction method for steel truss bridges.

Background technique

Steel truss bridge is a main structural form of highway or railway bridge, and its span is usually long. Due to transportation conditions such as road, railway, waterway, etc., it is necessary to split the steel truss bridge structure into several beam sections to facilitate transportation; therefore, the current The on-site construction method of the bridge with steel truss is as follows: several beam sections disassembled from the steel truss bridge are transported to the construction site in the processing plant, and assembly operations such as high-altitude bolting and welding are carried out on the construction site to complete the construction of the overall structure of the steel truss bridge; Steel truss bridges need to build high-altitude support frames before on-site construction, and high-altitude assembly is required. Therefore, there are problems such as long construction period, high cost, and high-altitude operations for high-altitude support frames. At the same time, high-altitude operations are also difficult to construct and difficult to control construction quality. And many other problems, so it needs to be solved and improved.

Contents of the invention

In order to overcome the deficiencies in the background technology, the present invention discloses a construction method for a steel truss bridge without support. The method builds a tire frame assembled on the ground at the construction site, and each beam section of the steel truss bridge is transported from the processing plant to the construction site. Welding and riveting assembly of each beam section of the steel truss bridge are carried out on the tire frame assembled on the ground; after the assembly of the steel truss bridge is completed on the ground, the erection of the steel truss bridge on the pier is completed by lifting with double cranes.

In order to achieve the purpose of the invention, the present invention adopts the following technical solutions: a construction method for a steel truss bridge without supports, leveling the site at the construction site, and building the on-site ground assembly tire frame; each beam section of the steel truss bridge is transported from the processing plant to the construction site , the welding and riveting construction of each beam section of the steel truss bridge is carried out on the ground assembly tire frame at the site, and the ground assembly of the steel truss bridge is completed, and then the erection of the steel truss bridge on the pier is completed by lifting with double cranes; the construction method It solves many problems in the traditional construction method of steel truss bridges, such as long period of construction of high-altitude support frames, high cost, high risk of high-altitude construction, difficult construction, and difficulty in controlling construction quality.

Further, the on-site ground-assembled tire frame is a brand-new structure, which adopts a standardized modular structure design and has the characteristics of reusability. Compared with the traditional high-altitude support frame, it has the advantages of short construction period and low cost; the on-site ground-assembled tire frame The frame includes a backing plate, an adjustable bracket, a supporting distribution beam, and a supporting column; the backing plate is laid flat on the ground of the assembly site, the adjustable bracket is fixed on the backing plate, the supporting distribution beam is fixed on the top of the adjustable bracket, and the supporting column is fixed on the The top of the supporting distribution beam; each beam section of the steel truss bridge is set on the top of the support column, and the construction personnel can complete the welding and bolting assembly of each beam section of the steel truss bridge on the ground at the construction site; since the assembly work of the steel truss bridge is carried out on the ground , so the construction work is safer, and the measurement, adjustment, and control of various parameters of the steel truss bridge are more convenient during construction, which greatly reduces the construction difficulty and improves the construction efficiency. At the same time, the construction quality is well controlled.

Further, the construction method of the on-site ground-assembled tire frame is as follows:

S1. Construction of on-site ground assembly tire frame: Pre-level the assembly site at the construction site, use a vibratory roller to repeatedly roll it 6-8 times, and then flatten the 600*600, 50mm thick backing plate on the compaction according to the design position On the ground, the adjustable support is temporarily set on the backing plate, the support distribution beam is fixed on the top of the adjustable support, and the support column is fixed on the top of the support distribution beam to complete the preliminary construction of the ground assembly tire frame on the construction site; the support distribution beam is set There are two, adjust the parallelism of the two supporting distribution beams, and then fix the adjustable bracket on the top of the backing plate;

S2. Adjustment of the on-site ground assembly tire frame: measure the height of all adjustable supports with a laser level; when adjusting, there is a height difference of 1-2mm between the adjustable supports set on the same supporting distribution beam, and they are located on the same The height of the adjustable bracket in the middle of the support distribution beam is greater than the height of the adjustable brackets on both sides, so that the support distribution beam is in an upwardly raised arc; this adjustment method for the tire frame assembled on the ground on site is to prevent the same support distribution beam from being located in the middle Due to the small pressure of the adjustable support in the early stage, uneven settlement of the steel truss bridge in the later stage of assembly operation resulted in poor alignment control of the steel truss bridge after assembly;

S3. Settlement adjustment of the on-site ground-assembled tire frame: hoist each beam section of the steel truss bridge on the support column of the ground-assembled tire frame piece by piece, adjust the position, and let it stand for 3-5 days; during this period, every Twelve hours, use a laser level to measure the height of the adjustable bracket once. If the height of the adjustable bracket changes, adjust it in time, and finally make the height of all adjustable brackets consistent, and ensure that the two support distribution beams are in the same position. The same height, and in a horizontal state; although the steel truss bridge is assembled by using the on-site ground-assembled tire frame, in order to stabilize the settlement of the on-site ground-assembled tire frame, it needs to stand for three days, but it is different from the traditional high-altitude support frame. Compared with the required period of about 15 days for the construction of pipe pile holes, construction of cast-in-place piles (including platform sinking), and construction of high-altitude support frames, the construction period can still be greatly reduced;

S4. Adjustment of the height difference between the beam sections of the steel truss bridge: After the settlement of the assembled tire frame on the site tends to be stable, use hydraulic jacks to jack up each beam section, and adjust the beams of the steel truss bridge by setting gaskets on the supporting columns The height difference between sections is used to control the pre-deformation of the steel truss bridge after the ground assembly is completed, so as to ensure that the line shape of the steel truss bridge reaches the required control line shape after the bridge is completed.

Preferably, in some construction sites, if the ground of the site is soft soil such as silty soil or collapsible loess, and the load capacity is insufficient, the position of the backing plate on the site is partially replaced by the method of replacing the cushion layer with a well-graded Replace the original foundation soil layer with crushed stone and clay mixture; the area of partial cushion replacement method is 1.5-2 times the area of the backing plate, and the depth is not less than 0.5m; -8 times to ensure the settlement stability of the tire frame assembled on the ground on site.

Furthermore, before the double cranes are officially lifted, a pre-lift test must be carried out; the stability of the crane is tested by the pre-lift, and then the steel truss bridge is reset on the adjusted ground assembly frame of the simulated pier support, and the steel truss bridge is bridged. Face deflection test.

Further, the actual lifting weight of each crane shall not be greater than 70-80% of the nominal maximum lifting weight of the crane.

Further, after the steel truss bridge is hoisted on the pier and placed in place according to the design requirements, it must be pre-fixed first, and then the hoisting hook can be disengaged to ensure the safety of the fixed construction of the steel truss bridge.

Due to the adoption of the above-mentioned technical scheme, the present invention has the following beneficial effects: a steel truss bridge without support construction method disclosed by the present invention, the method builds on-site ground-assembled tire frames at the construction site, and each beam section of the steel truss bridge is processed from The steel truss bridge is transported to the construction site, and the steel truss bridge is welded and riveted on the ground assembly tire frame; after the steel truss bridge is assembled on the ground, the steel truss bridge is lifted on the pier by double cranes. The erection of the steel truss bridge without supports saves the traditional construction process of building high-altitude support frames, so the construction period and construction costs are greatly reduced, and the construction safety is also greatly improved; at the same time, the steel truss bridge is carried out on the ground. During the bolting and welding assembly of each beam section, it is more convenient to measure and adjust the linearity of the steel truss bridge assembly, which reduces the construction difficulty and greatly improves the construction efficiency and construction quality.

Description of drawings

Figure 1 is a schematic diagram of on-site assembly of steel truss bridges;

Figure 2 is a schematic diagram of the construction of a steel truss bridge with two cranes;

Figure 3 is a schematic diagram of the tire frame assembled on the ground on site;

Figure 4 is a partially enlarged schematic diagram of the on-site ground-assembled tire frame structure;

Figure 5 is a schematic diagram of the appearance of the adjustable bracket;

Figure 6 is a schematic diagram of the explosion of the adjustable bracket structure;

Figure 7 is a schematic view of the appearance of the bracket seat.

In the figure: 1. On-site ground assembly tire frame; 1.1, backing plate; 1.2, adjustable bracket; 1.2.1, bracket seat; 1.2.1.1, support sleeve; 1.2.1.1.1, anti-rotation pin groove; 1.2. 1.2.1. Magnetic base hole; 1.2.1.2. Support base; 1.2.1.3. Sleeve flange; 1.2.2. Lead screw; 1.2.2.1. Anti-rotation pin; 1.2.2.2. Anti-rotation bolt; 1.2.3 , adjusting nut; 1.2.4, top plate; 1.2.5, press block; 1.2.6, magnetic base; 1.2.7, bolt; 1.3, supporting distribution beam; 1.4, supporting column; 1.5, connecting sleeve; 2, steel truss Bridge; 3. Crane; 4. Pier.

Detailed ways

The present invention can be explained in detail through the following examples, and the purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

Embodiment one:

A construction method for a steel truss bridge without support. The site is leveled at the construction site, and the on-site ground assembly tire frame 1 is built; each beam section of the steel truss bridge is transported from the processing plant to the construction site, and the steel truss bridge is constructed on the site ground assembly tire frame 1. The welding and riveting construction of each beam section completes the assembly of the steel truss bridge 2; the erection of the steel truss bridge 2 on the pier 4 is completed by lifting the double crane 3;

In the steel truss bridge without support construction method, the on-site ground assembly tire frame 1 is adopted. The on-site ground assembly tire frame 1 includes: backing plate 1.1, adjustable bracket 1.2, support distribution beam 1.3, and support column 1.4. For details, refer to the appendix of the manual Figure 3-7; Backing plate 1.1 adopts 600*600, 50mm thick structural steel plate; Adjustable bracket 1.2 includes bracket base 1.2.1, lead screw 1.2.2, adjusting nut 1.2.3, top plate 1.2.4, pressing block 1.2 .5; the bracket seat 1.2.1 includes a cylindrical support sleeve 1.2.1.1, the bottom of which is welded with a channel steel support base 1.2.1.2, and a welding bracket is also arranged between the support sleeve 1.2.1.1 and the support base 1.2.1.2. Four reinforcing ribs, the bottom of the support base 1.2.1.2 is symmetrically provided with a magnetic seat hole 1.2.1.2.1; the top of the support sleeve 1.2.1.1 is welded with a ring-shaped support flange, and there are several diameters on the end surface of the support flange. The side wall of the support sleeve 1.2.1.1 is symmetrically provided with anti-rotation pin grooves 1.2.1.1.1; the screw 1.2.2 is provided with an anti-rotation pin hole near the lower end, and the screw 1.2.2 is movable. In the round hole of the bracket base 1.2.1, an anti-rotation pin 1.2.2.1 is fixedly arranged in the anti-rotation pin hole, and the anti-rotation pin 1.2.2.1 extends to the anti-rotation pin groove 1.2.1.1.1 of the bracket base 1.2.1; The adjusting nut 1.2.3 is movably set on the lead screw 1.2.2, located at the top of the support seat 1.2.1, the bottom surface is in contact with the upper end surface of the supporting flange, and the upper and lower end surfaces of the adjusting nut 1.2.3 are provided with radial oil storage tanks. Grease is smeared in the oil storage tank between the flange and the contact surface of the adjusting nut 1.2.3, and six crowbar holes are evenly distributed on the outer circumference of the adjusting nut 1.2.3; .4 fixedly arranged on the support plate at the top of the lead screw 1.2.2, and fixedly connected by welding; there are connecting bolt holes on the top plate 1.2.4, and the pressure block 1.2.5 is movably connected to the top surface of the top plate 1.2.4 through bolts; The adjustment bracket 1.2 is equipped with a magnetic base 1.2.6, which is cylindrical, with a compression ring on the outer circumference and a rotary knob on the top;

The supporting distribution beam 1.3 is made of double I-shaped steel profiles, and several connecting bolt holes are provided on the upper and lower plates; Four connection through holes are evenly arranged around the axis of the supporting column body on the column backing plate;

The construction method of the on-site ground-assembled tire frame 1 is as follows:

S1. Construction of on-site ground assembly tire frame 1: Pre-level the assembly site at the construction site, roll it repeatedly eight times with a vibratory roller, and then spread the backing plate 1.1 of 600*600 and thickness of 50mm on the compaction according to the design position On the ground, the adjustable bracket 1.2 is temporarily set on the backing plate 1.1, and the magnetic base 1.2.6 is set in the magnetic base hole 2.1.2.1; the support distribution beam 1.3 is fixed on the top of the adjustable bracket 1.2, and the adjustable bracket 1.2 is adjusted position, and then lock the bolts of the pressure block 1.2.5, so that the support distribution beam 1.3 is fixedly connected to the top of the adjustable bracket 1.2; the support column 1.4 is provided with several according to actual needs, and the support column 1.4 is fixed on the support distribution beam 1.3 The top is fixedly connected with the support distribution beam 1.3 by bolts to complete the preliminary construction of the ground assembly tire frame 1 on the construction site; there are two support distribution beams 1.3, adjust the parallelism of the two support distribution beams 1.3, and then rotate the magnetic base 1.2. 6, the adjustable bracket 1.2 is fixedly connected with the backing plate 1.1 by rotating the compression ring of the magnetic base 1.2.6;

S2. Adjustment of the on-site ground assembly tire frame 1: measure the height of all adjustable brackets 1.2 with a laser level; when there is a difference in the height of the adjustable brackets 1.2, insert a crowbar into the crowbar hole of the adjustment nut 1.2.3, Rotate the adjusting nut 1.2.3 to make the screw screw 1.2.2 go up and down; when adjusting, a height difference of 1-2mm is provided between the top plate 1.2.4 of the adjustable bracket 1.2 of the same supporting distribution beam 1.3, And the height of the top plate 1.2.4 of the adjustable support 1.2 located in the middle of the same support distribution beam 1.3 is higher than the height of the top plate 1.2.4 of the adjustable support 1.2 on both sides; after the adjustment is completed, the support distribution beam 1.3 is slightly raised upward;

S3. Settlement adjustment of the on-site ground-assembled tire frame 1: hoist each beam section of the steel truss bridge on the support column 1.4 of the ground-assembled tire frame one by one, adjust the position, and let it stand for three days; during this period, every Twelve hours, measure the height of the adjustable bracket 1.2 once with a laser level, if it is found that the height of the top plate 1.2.4 of the adjustable bracket 1.2 changes, use a crowbar to rotate the adjustment nut 1.2. The height of the adjustable support 1.2 is kept consistent to ensure that the two supporting distribution beams 1.3 are at the same height and are in a horizontal state;

S4. Adjustment of the height difference between the beam sections of steel truss bridge 2: After the settlement of the ground-assembled tire frame 1 tends to be stable, use a hydraulic jack to lift each beam section, and adjust the steel truss by setting gaskets on the support column 1.4 The height difference between the beam sections of the bridge 2 controls the pre-deformation of the steel truss bridge 2 after the ground assembly is completed;

The assembly of each beam section of the steel truss bridge is completed on the field ground assembly frame 1; during the assembly process of each beam section of the steel truss bridge, the height of the adjustable support 1.2 is dynamically monitored with a laser level. When the height of the adjustable support 1.2 changes beyond the design When the setting is 2.0mm, use the crowbar to rotate the adjusting nut 1.2.3 in time to adjust the height of the adjustable bracket 1.2 to keep it within the set range;

After the steel truss bridge is assembled on the ground, the overall hoisting of the double crane 3 is carried out; when selecting the crane, the actual lifting weight of the crane 3 should be calculated, and the actual lifting weight of each crane 3 should not be greater than 70% of the nominal maximum lifting weight of the crane 3; For example, the total hoisting weight of the steel truss bridge 2 is 400 tons, and the actual hoisting weight of each crane 3 is 200 tons. Based on the calculation of 70% of the nominal maximum hoisting weight of the crane 3, a crane of 286 tons should be selected, and the maximum nominal hoisting weight is finally selected as 300-ton crane; before the double crane 3 is formally lifted, a pre-lift test must be carried out; the pre-lift test is to test the stability of the crane 3, and then the steel truss bridge 2 is reset on the adjusted on-site ground assembly tire frame 1, and the deflection of the bridge deck is carried out Test, after passing the test, the steel truss bridge 2 is hoisted on the pier 4 by the overall lifting of the double crane 3, and adjusted in place according to the design requirements, first pre-fixed, and then the hoisting hook can be disengaged, and then the steel truss bridge Formal fixed construction.

In some construction sites, if the foundation of the site is soft soil such as silt soil or collapsible loess, and the load capacity is insufficient, the position of the backing plate 1.1 on the site ground shall be partially replaced with the cushion layer method, and the well-graded crushed stone shall be used. , clay mixture to replace the original foundation soil layer; the area of the partial pad replacement method is twice the area of the pad, and the depth is 1.0m; after the pad is replaced, it is rolled 8 times by a vibratory roller to ensure that the ground The settlement stability of the assembled tire frame.

The unspecified parts of the present invention are prior art.

Claims (7)

1. A steel truss bridge bracket-free construction method is characterized by comprising the following steps: building a site ground assembling jig frame (1) on a construction site leveling site; transporting each girder segment of the steel truss bridge from a processing plant to a construction site, and carrying out welding and riveting construction on each girder segment of the steel truss bridge on an on-site ground assembly jig frame (1) to complete the assembly of the steel truss bridge (2); the erection of the steel truss bridge (2) on the bridge pier (4) is completed by a double crane (3) lifting method.

2. The steel truss bridge bracket-free construction method of claim 1, wherein the method comprises the following steps: the field ground assembling jig frame (1) comprises a base plate (1.1), an adjustable bracket (1.2), a supporting and distributing beam (1.3) and a supporting column (1.4); backing plate (1.1) tiling is in assembling scene ground, and adjustable support (1.2) are fixed to be set up on backing plate (1.1), and support distribution roof beam (1.3) are fixed to be set up at adjustable support (1.2) top, and support column (1.4) are fixed at support distribution roof beam (1.3) top.

3. The steel truss bridge bracket-free construction method according to claim 2, wherein the method comprises the following steps: the construction method of the site ground assembly jig frame (1) comprises the following steps:

s1, building a site ground assembling jig frame (1): pre-flattening an assembly site in a construction site, repeatedly rolling for a plurality of times by using a vibratory roller, then spreading a base plate (1.1) on the compacted ground according to a designed position, and temporarily arranging an adjustable bracket (1.2) on the base plate (1.1); fixedly arranging a supporting distribution beam (1.3) at the top of an adjustable bracket (1.2); the support columns (1.4) are fixedly arranged at the tops of the support distribution beams (1.3), and the preliminary construction of the ground assembly jig frame (1) on the construction site is completed; two support distribution beams (1.3) are arranged, the parallelism of the two support distribution beams (1.3) is adjusted, and then the adjustable bracket (1.2) is fixedly connected to the upper part of the base plate (1.1);

s2, adjusting the field ground assembling jig frame (1): measuring the heights of all adjustable brackets (1.2) by a laser level meter; when in adjustment, the height difference of 1-2mm is arranged between the adjustable brackets (1.2) arranged on the same supporting and distributing beam (1.3), and the height of the adjustable brackets (1.2) positioned in the middle of the same supporting and distributing beam (1.3) is larger than the height of the adjustable brackets (1.2) on two sides, so that the supporting and distributing beam (1.3) is in an upward-raised radian;

s3, sedimentation adjustment of the field ground assembly jig frame (1): each beam section of the steel truss bridge is hung on a supporting column (1.4) of the ground assembly jig frame section by section, the position is adjusted, and the steel truss bridge stands for 3-5 days; during the period, the height of the adjustable support (1.2) is measured and measured once every twelve hours by using a laser level meter, if the height of the adjustable support (1.2) is found to be changed, the height of all the adjustable supports (1.2) is adjusted in time, and finally, the heights of the two support distribution beams (1.3) are kept consistent, so that the two support distribution beams are in the same height and are in a horizontal state;

s4, adjusting the height difference among beam sections of the steel truss bridge (2): the spacer is arranged on the supporting column (1.4), so that the height difference between beam sections of the steel truss bridge (2) is adjusted, and the pre-deformation of the steel truss bridge (2) after the ground assembly is completed is controlled.

4. The steel truss bridge bracket-free construction method according to claim 3, wherein the method comprises the following steps: if necessary, the position of the base plate (1.1) placed on the ground on site adopts a local pad-changing method, and the original basic soil layer is replaced by crushed stone and clay mixture with good grading; the area of the local filling layer replacement method is 1.5-2 times of the area of the backing plate, and the depth is not less than 0.5m; after the cushion layer is replaced, the cushion layer is compacted by a vibratory roller.

5. The steel truss bridge bracket-free construction method of claim 1, wherein the method comprises the following steps: before the double cranes (3) are formally lifted, pre-lifting test is needed; and (3) testing the stability of the crane by pre-hanging, and then resetting the steel truss bridge (2) on the adjusted field ground assembly jig frame (1) to test the deflection of the bridge deck.

6. The steel truss bridge bracket-free construction method of claim 1, wherein the method comprises the following steps: the actual lifting weight of each crane (3) is not more than 70-80% of the nominal maximum lifting weight of the crane (3).

7. The steel truss bridge bracket-free construction method of claim 1, wherein the method comprises the following steps: after the steel truss bridge (2) is hoisted in place, the steel truss bridge is pre-fixed firstly, and then the hoisting hook can be detached.

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