Steel structure arch installation sectional construction method

Abstract

The application provides a steel structure arch mounting segmented construction method, including the following steps: 1) drilling hole pile foundation, detail bearing platform and pier body construction; 2) erecting arch plate assembly support on the bridge deck; 3) hoisting main arch segment from two ends of arch foot to one side of the middle arch top; 4) symmetrically removing the arch plate assembly support from the arch middle to the two ends of the arch foot, and synchronously installing the tension cable between the arch surface and the bridge deck in sequence; 5) after completing the arch surface coating, detecting the coating thickness. By adopting the above method and related structure, the application solves the problems of difficult control of the alignment precision and low installation efficiency of the steel arch mounting in the prior art.

Description

Technical Field

[0001] This invention relates to the field of bridge arch frame construction technology, specifically a segmented construction method for installing steel structure arch frames. Background Technology

[0002] During the installation of bridge steel arch frames, the arch feet are pre-embedded in the arch foot supports. During the subsequent installation of the steel arch panels, it is necessary to gradually align the pre-embedded arch feet to achieve the overall installation of the arch panels. However, due to the large span and overall size of the arch panels, the installation accuracy requirements are high and the construction is difficult.

[0003] In addition, after the overall arch slab is installed, the tensioning cables need to be installed simultaneously when the support is dismantled. Currently, the installation of the cables relies on personnel climbing to the top of the arch slab. During this process, the safety of personnel cannot be guaranteed, and the installation efficiency is low. As a result, the dismantling of the support can only continue after the installation and tensioning of the cables are completed, which prolongs the entire construction period. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a segmented construction method for the installation of steel arch frames, which solves the problems of difficult control of the alignment accuracy and low installation efficiency of steel arch frame installation in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a segmented construction method for installing steel structure arch frames, characterized by including the following steps:

[0006] 1) Construction of bored pile foundations, detailed pile caps and pier bodies;

[0007] 2) Erect arch panel assembly supports on the bridge deck;

[0008] 3) Hoist the main arch segment from both ends of the arch foot toward the central arch crown;

[0009] 4) The arch plate assembly support is dismantled symmetrically from the center of the arch towards the arch feet at both ends, and the tensioning cables between the arch surface and the bridge deck are installed simultaneously in sequence;

[0010] 5) After the arch surface is coated, the coating thickness is tested.

[0011] In the preferred embodiment, the rib assembly support consists of four steel pipe columns, which are reinforced by horizontal welded pipes. The welded pipe at the top of the rib assembly support serves as a construction platform for welding the main arch segment connection joints.

[0012] In a preferred embodiment, the top of the rib assembly bracket is provided with a distribution beam, and an adjustment device is provided on the distribution beam, with the arch surface resting on the adjustment device.

[0013] In the preferred solution, the two ends of the single segment of the arch surface are placed on the top of the adjacent two rib assembly supports, and the height adjustment of the two ends of the arch plate is realized through the adjustment device on the top of the rib assembly support.

[0014] In the preferred solution, the bottom surface of the arch plate is provided with a leveling wedge, and the leveling wedge is in contact with the adjustment device.

[0015] In the preferred solution, when the arch plate assembly support is removed, the remaining support parts on both sides of the central arch plate assembly support are removed first, and the central arch plate assembly support is reserved as a support for the upper end installation platform of the tensioning cable.

[0016] In the preferred solution, the installation of the tensioning cable further includes a work basket that can move on the top of the arch plate, and the installation work of the upper anchor point of the tensioning cable is carried out by the construction personnel through the work basket, and the steps include:

[0017] 1) Install a winch device on the top of the central arch plate assembly support, and pull two work baskets from the arch foot at both ends to the arch top;

[0018] 2) Remove the supports from both sides of the central arch plate assembly support to the arch foot direction in sequence;

[0019] 3) During the removal of the arch plate assembly support, the work basket moves to both ends of the arch plate and synchronously installs the upper end anchor connection work of the tensioning cable of the removed arch plate assembly support part.

[0020] In the preferred solution, after the installation of the tensioning cable is completed, the tensioning of the previous tensioning cable is carried out at the same time as the installation of the next tensioning cable.

[0021] In the preferred solution, after the installation work of all the tensioning cables is completed, the work basket and the winch device are recovered, and the central arch plate assembly support is removed.

[0022] The steel structure arch installation segmented construction method provided by the present application has the following beneficial effects by adopting the above structure:

[0023] (1) By erecting multiple assembly supports, the precise alignment of the connection points between the arch plate segments is realized, and a construction platform is provided for high-altitude welding and leveling work, ensuring the alignment accuracy of the rigid arch plate parts;

[0024] (2) The assembly support is used as a traction platform for the hoisting of the work basket, which realizes the more safe and fast installation of the tensioning cable anchor point, and speeds up the progress of the support removal and the installation and tensioning of the cable. BRIEF DESCRIPTION OF DRAWINGS

[0025] The present application will be further described below in conjunction with the drawings and examples:

[0026] Figure 1A structural schematic diagram in the construction process of the present application.

[0027] Figure 2 A top view structural schematic diagram after the construction of the present application is completed.

[0028] Figure 3 A structural schematic diagram of the top of an arch plate assembly support of the present application.

[0029] Figure 4 A structural schematic diagram in the installation process of an upper anchor point of a tensioning sling of the present application.

[0030] Figure 5 Another structural schematic diagram in the installation process of an upper anchor point of a tensioning sling of the present application.

[0031] In the figure: arch plate assembly support 1, steel pipe column 2, welded pipe 3, distribution beam 4, adjusting device 5, leveling wedge 6. DETAILED DESCRIPTION

[0032] Example 1

[0033] A steel structure arch installation segmented construction method, comprising the following steps:

[0034] 1) Drill hole pile foundation, detail pile cap and pier body construction;

[0035] 2) erecting an arch plate assembly support 1 on the bridge deck;

[0036] 3) hoisting the main arch segment from both ends of the arch foot to one side of the middle arch top;

[0037] 4) symmetrically removing the arch plate assembly support 1 from the middle of the arch to the direction of both ends of the arch foot, and simultaneously installing the tensioning sling between the arch surface and the bridge deck in sequence;

[0038] 5) after completing the arch surface painting, detecting the coating thickness.

[0039] In this embodiment, a single steel arch is arranged symmetrically on both sides except for the first segment which is a pre-buried segment, and the middle segment is the highest segment of the arch top and is also the last closing segment. Due to the influence of the small construction site, the on-site hoisting is gradually pushed from both ends to the middle.

[0040] The crane keeps the height of the beam segment unchanged and slowly moves to the side of the designed installation position. During the lifting process, the ground workers control the in-air posture of the beam segment using a sway rope to avoid collision with the bridge pier or other objects. Then the beam segment is slowly lifted, the bottom of the steel structure bridge is about 0.5 m higher than the bridge pier or support, the in-air posture of the beam segment is adjusted using the sway rope, the beam segment is hoisted to the designed installation position of the beam segment and slowly lowered to the top of the adjusting device.

[0041] Example 2

[0042] On the basis of embodiment 1, the rib assembly support 1 is composed of four steel pipe columns 2, the steel pipe columns 2 are connected by horizontal welded pipes 3, and the welded pipe 3 at the uppermost part of the rib assembly support 1 is used as a construction platform for welding the main arch segment connecting joint.

[0043] In the preferred scheme, the rib assembly support 1 is provided with a distribution beam 4 at the top, the distribution beam 4 is provided with an adjusting device 5, the arch surface is arranged on the adjusting device 5, and the adjusting device 5 can adopt a sand box or a jack.

[0044] In the preferred scheme, the two ends of the single segment arch surface are arranged on the top of the adjacent two rib assembly supports 1, and the height adjustment of the two ends of the arch plate is realized through the adjusting device 5 at the top of the rib assembly support 1.

[0045] In the preferred scheme, the bottom surface of the arch plate is provided with a leveling wedge 6, and the leveling wedge 6 is in contact with the adjusting device 5.

[0046] Embodiment 3:

[0047] On the basis of embodiment 1, when the arch plate assembly support 1 is removed, the remaining support parts on both sides of the central arch plate assembly support 1 are removed first, and the central arch plate assembly support 1 is reserved as an upper end installation platform support for the tensioning cable.

[0048] In the preferred scheme, the installation of the tensioning cable further includes a work basket capable of moving on the top of the arch plate, and the installation of the upper anchor point of the tensioning cable is performed by the construction personnel through the work basket, and the steps include:

[0049] 1) Install a winch device on the top of the central arch plate assembly support 1, and pull two work baskets from the arch foot to the arch top;

[0050] 2) Remove the supports from both sides of the central arch plate assembly support 1 to the arch foot direction in sequence;

[0051] 3) During the removal of the arch plate assembly support 1, the work basket moves to the two ends of the arch plate and synchronously installs the upper end anchor connection work of the tensioning cable of the removed arch plate assembly support 1 part.

[0052] In the above scheme, as shown in Figure 4 When the winch device is installed on the top of the arch plate assembly support 1 and the unilateral basket is pulled, the support 1 will receive a unilateral horizontal tension, which will affect the stability of the support 1, so it is recommended to symmetrically arrange two baskets to ensure the stability of the arch plate assembly support 1.

[0053] In addition, the winch device can also be directly arranged on the top of the arch support to pull the basket, so as to solve the shaking of the arch plate assembly support 1 caused by the lateral force.

[0054] In a preferred embodiment, the installation of the tensioning cable is completed and the tensioning of the previous tensioning cable is performed at the same time as the installation of the next tensioning cable.

[0055] In a preferred embodiment, after the installation of all the tensioning cables is completed, the operation basket and the hoisting equipment are recovered, and the center arch plate assembly support 1 is removed.

[0056] In this embodiment, the cable is made of Φ5mm-55 specification low relaxation prestressed galvanized steel wire, with a standard tensile strength of 1570MPa, a relaxation value of <7.5% stress loss after 1000h, and an appearance diameter of Φ55mm. The finished cable anchor head is a double-ear inner rotating sleeve adjustment type anchor head. The anchor head on the bridge deck is the tensioning end, and the anchor head on the arch plate is the fixed end. The adjustment sleeve adjustment amount is 100mm. The cable has a basic longitudinal spacing of 5m along the arch plate, and the spacing between the two cables at the midspan is 1m.

[0057] The cable installation is performed on site by the manufacturing unit. The finished bridge cable force is 50KN. The tensioning of the cable is controlled by using a qualified oil pressure gauge. The cable tensioning is performed simultaneously from the middle to both ends.

[0058] In addition, the supports are removed in the order from top to bottom. After the removal of each support is completed, the next support can be removed. When removing the support, the adjustment device is first unloaded. The unloading is performed by continuously circulating the sand volume of 10mm height with a measuring cup until the adjustment device is separated from the steel arch. After the adjustment device is separated, the adjustment device, the distribution beam, and the support are removed respectively. When removing the support, a traction rope is arranged at the bottom of the support to prevent the support from swinging during hoisting.

[0059] Example 4:

[0060] On the basis of Example 2, the steel pipe column 2 of the arch plate assembly support 1 is made of spiral steel pipe with a brand Q235B. The spiral steel pipe is full-welded to the embedded part, and the height of the fillet weld is not less than 8mm. Four steel pipe columns form a force combination. The spacing between the steel pipe columns is 3.0m*5.0m, of which the horizontal direction is 5.0m and the longitudinal direction is 3.0m. Welded pipes are used for strengthening connection between the steel pipe columns, and a group of welded pipe supports is arranged every 5m in height. The highest layer of welded pipe is used as a construction operation platform and is provided with a handrail. The distribution beam is a 7.0m long box type steel beam 400*400*10*10mm arranged horizontally on the top of the column. The height of the adjustment device between the distribution beam and the steel arch is 330mm. The adjustment height of the adjustment device is 0~-80mm.

[0061] Two temporary supports at the ends of the closure section are transversely provided with two groups of four Ф14mm cable wind ropes, which are symmetrically fixed on the anchor plate of the cable by 3T hoists; and the four groups of temporary supports at the longitudinal ends of the steel arch are connected and reinforced by a truss of channel steel [25a.

[0062] The support is 5m in section and 12m in length, and each section is connected by bolts. After being spliced on site, the whole is hoisted. Each section is connected by steel pipe diagonal bracing.

[0063] Example 5

[0064] Considering that the overall size of the arch plate segment is large, its width usually exceeds the transportation limit, so it is divided into two symmetrical segments, which meets the design requirements of the selection of the crane during hoisting. After being divided into two symmetrical segments in the transverse width direction, each segment is an open box structure. In order to avoid deformation of the open box segment during transportation and hoisting, first, all welding and grinding work inside the segment is completed before the segment is split, reducing welding and stress deformation. Second, the partition is reinforced on the side without web before splitting.

[0065] Example 6

[0066] In order to control the alignment accuracy of the arch plate segment:

[0067] (1) All incoming components must be pre-assembled in the workshop before entering the site. According to the assembly sequence in the workshop and combined with the actual construction situation on site, the assembly line type is measured on site, the design camber is superimposed during the measurement process, the gap between the segments is fixed by using an ear plate during pre-assembly in the workshop, and the 100mm excess at both ends of the closure segment is cut off after measurement. All segments must have at least two coordinate points on the bridge deck, and the coordinate values must match the urban coordinates on site.

[0068] The allowable deviation of the steel beam segment after installation is shown in the following table:

[0069] Table 4.3-6 Segment Installation Allowable Deviation Table

[0070]

[0071]

[0072] (2) Choose to close on cloudy days, and choose to close in the morning in summer (i.e. the temperature of each structure of the bridge is basically the same);

[0073] (3) Measure the relationship curve between "environmental temperature and closure gap distance" for 24 hours in advance for 2 segments to determine the appropriate closure temperature and determine the low-temperature stable time period;

[0074] (4) The closure segment is processed in advance and transported to the bridge site, waiting for on-site cutting. Pay attention to summarize the quality points of the girth weld after the longitudinal beam is cut on site in the past to ensure the quality of the girth weld;

[0075] (5) The crane is positioned for hoisting, and adjustment welding is performed after completion.

[0076] Example 7:

[0077] The engineering quality control is as follows:

[0078] (1) The center axis of the arch frame is measured and placed on the temporary support, and the position and elevation of the arch anchor plate are measured and marked. The installation of the site will coincide the mark line and point on the support with the mark line and point of the segment, and control the elevation and deviation of the segment within the allowable range of design and specification.

[0079] (2) The installation of steel arch frame has a camber value which is the superposition of the camber value of steel arch frame and the pre-camber value.

[0080] (3) Temperature influence monitoring

[0081] 1) The measurement of the on-site axis spacing and camber value should be carried out during the time period closest to 20℃ of the day, and the temperature at each measurement should be recorded. The temperature difference of each measurement should be controlled within 5℃.

[0082] 2) The tools and instruments used for measurement should be regularly inspected and verified by the national secondary measurement department, and the same measurement method should use the same measurement tool.

[0083] 3) During the installation on site, the axis spacing, camber value and settlement of the temporary support should be determined by the monitoring personnel.

[0084] 4) In order to reduce the influence of welding on the size of the bridge body and the camber, the ring seam between each single arch segment is symmetrically constructed from both ends to the middle, and the temperature difference during construction should be as small as possible and closest to 20℃.

Claims

1. A method for segmented construction of steel structure arch frame installation, characterized in that... Includes the following steps: 1) Construction of bored pile foundations, detailed pile caps and pier bodies; 2) Erect arch panel assembly supports on the bridge deck (1); 3) Hoist the main arch segment from both ends of the arch foot toward the central arch crown; 4) Dismantle the arch plate assembly support symmetrically from the center of the arch towards the arch feet at both ends (1), and simultaneously install the tensioning cables between the arch surface and the bridge deck in sequence; 5) After completing the arch surface coating, the coating thickness is checked; When the arch plate assembly bracket (1) is dismantled, the remaining bracket parts on both sides of the central arch plate assembly bracket (1) are dismantled first, and the central arch plate assembly bracket (1) is reserved as the upper installation platform support for the tensioning cable; The installation of the tensioning cables also includes a working scaffold that can move on top of the arch slab. Construction workers use the working scaffold to install the anchor points on the tensioning cables. The steps include: 1) Install a winch on the top of the central arch plate assembly support (1) and pull two work baskets from the arch feet at both ends to the top of the arch; 2) The supports are dismantled sequentially from both sides of the central arch plate assembly support (1) towards the arch foot; 3) During the dismantling of the arch plate assembly bracket (1), the working basket moves to both ends of the arch plate and simultaneously installs the upper end anchoring operation of the tensioning cable of the dismantled arch plate assembly bracket (1).

2. The method for segmented construction of steel structure arch frame installation according to claim 1, characterized in that: The arch plate assembly support (1) consists of four steel pipe columns (2). The steel pipe columns (2) are reinforced by horizontal welded pipes (3). The welded pipe (3) at the top of the arch plate assembly support (1) serves as a construction platform for welding the main arch segment connection joints.

3. The method for segmented construction of steel structure arch frame installation according to claim 2, characterized in that: The top of the arch plate assembly support (1) is provided with a distribution beam (4), and an adjustment device (5) is provided on the distribution beam (4). The main arch segment is placed on the adjustment device (5).

4. The segmented construction method for installing a steel structure arch frame according to claim 2, characterized in that: The two ends of the main arch segment are placed on the top of two adjacent arch plate assembly brackets (1), and the height of the two ends of the main arch segment is adjusted by the adjustment device (5) on the top of the arch plate assembly bracket (1).

5. The method for segmented construction of steel structure arch frame installation according to claim 4, characterized in that: The bottom surface of the main arch segment is provided with a leveling wedge (6), which is in contact with the adjustment device (5).

6. The method for segmented construction of steel structure arch frame installation according to claim 1, characterized in that: After the installation of the tensioning cable is completed, the previous tensioning cable is tensioned while the next tensioning cable is being installed.

7. The method for segmented construction of steel structure arch frame installation according to claim 6, characterized in that: After completing the installation of all tensioning cables, retrieving the work basket and winch equipment, dismantle the central arch plate assembly support (1).

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