Arch bridge tie bar installation method

Abstract

According to the tie bar installation method of the arch bridge, the channel between the beams is arranged, a river-crossing hanging system and a traction system do not need to be arranged during tie bar installation, tie bar installation is directly carried out on the bridge floor and the channel between the beams, the construction process is simplified, the construction period is shortened, input of construction equipment and materials is reduced, and the construction cost is reduced; and the safety risk caused by river-crossing operation is avoided, and the construction safety is improved.

Description

Technical Field

[0001] The invention relates to the technical field of arch bridge construction, in particular to a method for installing tie rods of an arch bridge. Background Art

[0002] The construction of a mid-span tie-arch bridge is generally carried out by first installing the arch and then the beam. After the arch ribs and steel beams are installed, a large horizontal thrust will be generated on the arch seat. Therefore, before installing the steel beams, the ties are installed first to balance the horizontal thrust on the arch seat through the tension of the ties. The conventional tie installation method is generally to install the tie-rod hanging and traction system on the arch ribs, and then use the tie-rod traction system to drag the ties into place one by one through the aerial hanging system. Considering shipping safety, multiple navigation closures are required when installing the tie-rod hanging system, traction system and tie installation, and the tie surface is easily damaged. Therefore, the construction cost, safety risk, navigation closure fee and social and economic losses caused by the navigation closure are very high.

[0003] The object of the present invention is to provide a tie rod installation method for an arch bridge to solve the problems mentioned in the above background technology. Summary of the invention

[0004] To achieve the above object, the present invention provides a method for installing tie rods of an arch bridge, comprising the following steps:

[0005] a. Simulation calculation of working conditions, including installation of S1+S2 beam section, installation of S9+S10 beam section, installation of S5+S6 beam section, installation and tensioning of tie rods after installation of inter-beam channel;

[0006] b. Install the beam sections in sections, bury the observation points in the foundation, and then install the S1+S2 beam section, S9+S10 beam section, and S5+S6 beam section;

[0007] c. Installation of the inter-beam channel: First, the inter-beam channel is made on the shore. The inter-beam channel is composed of symmetrically arranged main longitudinal beams and a plurality of cross beams. A plurality of cross beam arrays are distributed on the symmetrical main longitudinal beams. The cross beams are used to connect two main longitudinal beams to form a construction platform. After the inter-beam channel is assembled, it is installed between each beam section in step b by an 80T floating crane;

[0008] d. Layout of winches: a 5T winch is installed on each side of the collapsed bridge deck, one for tie rod traction and the other for recovering traction wire rope to assist tie rod installation;

[0009] e. Installation of tie rods: a cable-releasing rack is set at the pier position, and the coiled tie rod is installed on the cable-releasing rack. The cable is released by pulling the 5T winch. The tie rod is pulled through the anchor plate and pre-buried cable tube of the arch leg anchor block at one end of the bridge deck by the traction of the 5T winch wire rope, and passes through the beam sections and the inter-beam passages in steps b and c in sequence, until it passes through the pre-buried cable tube and anchor plate of the arch leg anchor block at the other end of the bridge deck. The above step e is repeated until all tie rods are installed;

[0010] f. Tie rod tensioning: After the tie rods are installed in sequence, tensioning equipment is installed at both ends. According to the monitoring instructions, the tie rods are tensioned symmetrically in stages to the designed tonnage.

[0011] As a further improvement of the present invention, in step a, after working condition simulation verification, in the absence of tie rods, after installing multiple beam sections, an outward horizontal thrust of about 1598t is generated on the main pier cap, and after tensioning the tie rods, an inward horizontal thrust of about 2400t is generated on the main pier.

[0012] As a further improvement of the present invention, during the installation of the beam sections in step b, observation points are buried in the foundation in advance to strengthen process observation and conduct comparative analysis with theoretical values.

[0013] As a further improvement of the present invention, in step c, the crossbeam includes channel steel 1 and channel steel 2, the channel steel 1 is fixed to the outer side of the symmetrical main longitudinal beam, the opposite side of the symmetrical main longitudinal beam is connected and fixed by channel steel 2, a plurality of supporting wheels are installed on the top of channel steel 2, and a guardrail is also provided on the symmetrical channel steel 1.

[0014] As a further improvement of the present invention, the contact surface between the supporting wheel and the tie rod is provided with a protective layer to prevent the tie rod from being damaged.

[0015] As a further improvement of the present invention, in step f, before tensioning the tie rod, the HDPE sheaths on the surfaces of both ends of the tie rod are first stripped off to expose the internal steel strands, and the length of the stripped HDPE sheath exceeds the sum of the tensioning working length and the designed elongation by 5 to 10 cm, and then the anchor is installed to connect the anchor to the steel strand.

[0016] As a further improvement of the present invention, after all tie rods are tensioned, the steel strands exposed outside the anchor are cut off, the steel strands are subjected to anti-corrosion treatment, and a protective cover is installed to protect them.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] By setting up the inter-beam channel, the present invention eliminates the need to set up a cross-river hook and traction system when installing the tie rod. The tie rod installation is directly carried out on the bridge deck and the inter-beam channel, which simplifies the construction process, shortens the construction period, reduces the investment in construction equipment and materials, reduces the construction cost, avoids the safety risks brought by cross-river operations, and improves construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the installation of the S1+S2 beam section of the present invention;

[0020] Figure 2 This is a schematic diagram of the installation of the S9+S10 beam section of the present invention;

[0021] Figure 3 This is a schematic diagram of the installation of the S5+S6 beam section of the present invention;

[0022] Figure 4 This is the first viewing angle of the inter-beam channel of the present invention;

[0023] Figure 5 This is the second viewing angle of the inter-beam channel of the present invention;

[0024] Figure 6 For the present invention Figure 5 Section 1-1.

[0025] In the figure: 1. S1+S2 beam section; 2. S9+S10 beam section; 3. S5+S6 beam section; 4. Main longitudinal beam; 5. Cross beam; 51. Channel steel one; 52. Channel steel two; 6. Support wheel; 7. Guardrail. DETAILED DESCRIPTION

[0026] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] Embodiment 1:

[0030] See also Figure 1-6The present invention provides a method for installing tie rods of an arch bridge, comprising the following steps:

[0031] a. Simulation calculation of working conditions, including installation of S1+S2 beam segment 1, installation of S9+S10 beam segment 2, installation of S5+S6 beam segment 3, and installation and tensioning of tie rods after installation of inter-beam channels;

[0032] b. Install the beam segments in sections, bury the observation points in the cap, and then install the S1+S2 beam segment 1, S9+S10 beam segment 2, and S5+S6 beam segment 3;

[0033] c. Installation of the inter-beam channel: First, the inter-beam channel is made on the shore. The inter-beam channel is composed of a symmetrically arranged main longitudinal beam 4 and a plurality of cross beams 5. The plurality of cross beams 5 are arrayed and distributed on the symmetrical main longitudinal beams 4. The cross beams 5 are used to connect two main longitudinal beams 4 to form a construction platform. After the inter-beam channel is assembled, it is installed between each beam section in step b by an 80T floating crane;

[0034] d. Layout of winches: a 5T winch is installed on each side of the collapsed bridge deck, one for tie rod traction and the other for recovering traction wire rope to assist tie rod installation;

[0035] e. Installation of tie rods: a cable-releasing rack is set at the pier position, and the coiled tie rod is installed on the cable-releasing rack. The cable is released by pulling the 5T winch. The tie rod is pulled through the anchor plate and pre-buried cable tube of the arch leg anchor block at one end of the bridge deck by the traction of the 5T winch wire rope, and passes through the beam sections and the inter-beam passages in steps b and c in sequence, until it passes through the pre-buried cable tube and anchor plate of the arch leg anchor block at the other end of the bridge deck. The above step e is repeated until all tie rods are installed;

[0036] f. Tie rod tensioning: After the tie rods are installed in sequence, tensioning equipment is installed at both ends. According to the monitoring instructions, the tie rods are tensioned symmetrically in stages to the designed tonnage.

[0037] In step a, after working condition simulation and verification, in the absence of tie rods, after installing multiple beam segments, an outward horizontal thrust of about 1598t is generated on the main pier cap, and after tensioning the tie rods, an inward horizontal thrust of about 2400t is generated on the main pier.

[0038] In actual construction, the model simulation calculations were first performed for four working conditions: installation of S1+S2 beam segment 1, installation of S9+S10 beam segment 2, installation of S5+S6 beam segment 3, and installation and tensioning of tie rods after installation of the inter-beam channel. After calculations, in the absence of tie rods, after installing multiple beam segments, an outward horizontal thrust of about 1598t was generated on the main pier cap, and after tensioning the tie rods, an inward horizontal thrust of about 2400t was generated on the main pier. With this scheme, the force was within the controllable range and the scheme was feasible as a whole. Then, multiple beam segments were installed separately. During installation, the inter-beam channels can be assembled on the shore first, and then the assembled inter-beam channels can be installed between each beam section in turn through an 80T floating crane. The design of the inter-beam channels can be used to install tie rods, eliminating the conventional cross-river hook and traction system. The tie rods are installed directly on the bridge deck and the inter-beam channels, which simplifies the construction process, shortens the construction period, reduces the investment in construction equipment and materials, reduces construction costs, avoids safety risks brought by cross-river operations, and improves construction safety.

[0039] During the installation of the beam sections in step b, observation points should be buried in the foundation in advance to strengthen process observation and conduct comparative analysis with theoretical values.

[0040] Specifically, by burying observation points in the foundation in advance and strengthening process observation, the actual data of the beam section installation can be obtained in real time. By comparing and analyzing the actual observation values ​​with the theoretical values, deviations in the installation process can be discovered in time, which will help construction personnel to adjust the construction plan in time and ensure the smooth progress of subsequent installation. Accurate observation and comparative analysis will help ensure the overall quality and safety of the bridge. Quality problems caused by improper installation can be avoided by timely adjusting and correcting deviations.

[0041] like Figure 4-6 In step c, the cross beam 5 includes channel steel 1 51 and channel steel 2 52, the channel steel 1 51 is fixed to the outer side of the symmetrical main longitudinal beam 4, the opposite side of the symmetrical main longitudinal beam 4 is connected and fixed by channel steel 2 52, a plurality of supporting wheels 6 are installed on the top of the channel steel 2 52, and a guardrail 7 is also provided on the symmetrical channel steel 1 51.

[0042] Specifically, when the inter-beam channel is assembled, the main longitudinal beam 4 of the inter-beam channel is 16.5 meters long, with two Ⅰ56 I-beams as the main longitudinal beam 4, and No. 10 channel steel is used as the cross beam 5 to connect to form a construction platform with a total width of 3.75 meters. A supporting wheel 6 for installing the tie rod is arranged in the middle, and the supporting wheel 6 is arranged between the two main longitudinal beams 4. The main longitudinal beams 4 on both sides are used as construction channels, and guardrails 7 are provided at the top ends of the cross beams 5 connected to the main longitudinal beams 4 to ensure construction safety. Through the setting of the inter-beam channel, the construction platforms and channels on both sides can be connected in advance, and it is beneficial to reduce the load-bearing of the arch ribs and reduce the horizontal thrust of the arch ribs on the abutments on both sides.

[0043] The contact surface between the supporting wheel 6 and the tie rod is provided with a protective layer to prevent the tie rod from being damaged.

[0044] Specifically, the protective layer at the contact portion between the supporting wheel 6 and the tie rod may be a geotextile or other similar material to wrap the outside, so as to avoid damaging the surface of the tie rod.

[0045] In step f, before the tie rod is tensioned, the HDPE sheaths on the surfaces of both ends of the tie rod are stripped off to expose the internal steel strands, and the length of the stripped HDPE sheath exceeds the sum of the tensioning working length and the designed elongation by 5 to 10 cm. Then, the anchor is installed and the anchor is connected to the steel strand.

[0046] Specifically, stripping off the HDPE sheath in advance and preparing for anchor installation can make the construction process smoother and reduce the need for temporary adjustments or repairs at the construction site, thereby improving construction efficiency and overall progress. After stripping off the HDPE sheath, the steel strands are exposed, which makes the installation of anchors easier and more accurate. The anchors need to be tightly fixed on the steel strands to ensure that they do not slip or fall off during the tensioning process. The practice of stripping off the HDPE sheath to a length that exceeds the sum of the tensioning working length and the designed elongation by 5 to 10 cm is to prevent insufficient elongation due to various reasons during the actual tensioning process. This reserved extra length can be used as a safety margin to ensure that there is enough steel strand length during the tensioning process to meet the designed elongation requirements.

[0047] After all tie rods are tensioned, the steel strands exposed outside the anchor are cut off, anti-corrosion treatment is performed on the steel strands, and protective covers are installed to protect them.

[0048] Specifically, after all the tie rods are tensioned, the excess steel strands exposed outside the anchor need to be cut off. To ensure the durability and safety of the steel strands, the cut steel strands need to be treated with anti-corrosion to prevent them from corrosion. To further protect the steel strands, protective covers need to be installed to provide physical protection for them to prevent damage from external factors.

[0049] The above is an exemplary description of the present invention in combination with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for installing tie rods of an arch bridge, characterized in that: The following steps are included: a. Simulation calculation of working conditions, including installation of S1+S2 beam section (1), installation of S9+S10 beam section (2), installation of S5+S6 beam section (3), installation and tensioning of tie rods after installation of inter-beam channel; b. Install the beam segments in sections. Set observation points in the foundation. Then install the S1+S2 beam segment (1), the S9+S10 beam segment (2), and the S5+S6 beam segment (3). c. Installation of the inter-beam channel: first, the inter-beam channel is made on the shore. The inter-beam channel is composed of a symmetrically arranged main longitudinal beam (4) and a plurality of cross beams (5). The plurality of cross beams (5) are arrayed and distributed on the symmetrical main longitudinal beams (4). The cross beams (5) are used to connect two main longitudinal beams (4) to form a construction platform. After the inter-beam channel is assembled, it is installed between each beam section in step b by an 80T floating crane; d. Layout of winches: a 5T winch is installed on each side of the collapsed bridge deck, one for tie rod traction and the other for recovering traction wire rope to assist tie rod installation; e. Installation of tie rods: a cable-releasing rack is set at the pier position, and the coiled tie rod is installed on the cable-releasing rack. The cable is released by pulling the 5T winch. The tie rod is pulled through the anchor plate and pre-buried cable tube of the arch leg anchor block at one end of the bridge deck by the traction of the 5T winch wire rope, and passes through the beam sections and the inter-beam passages in steps b and c in sequence, until it passes through the pre-buried cable tube and anchor plate of the arch leg anchor block at the other end of the bridge deck. The above step e is repeated until all tie rods are installed; f. Tie rod tensioning: After the tie rods are installed in sequence, tensioning equipment is installed at both ends. According to the monitoring instructions, the tie rods are tensioned symmetrically in stages to the designed tonnage.

2. The method for installing tie rods of an arch bridge according to claim 1, characterized in that: In step a, after working condition simulation and verification, in the absence of tie rods, after installing multiple beam segments, an outward horizontal thrust of about 1598t is generated on the main pier cap, and after tensioning the tie rods, an inward horizontal thrust of about 2400t is generated on the main pier.

3. The method for installing tie rods of an arch bridge according to claim 1, characterized in that: During the installation of the beam sections in step b, observation points should be buried in the foundation in advance to strengthen process observation and conduct comparative analysis with theoretical values.

4. The method for installing tie rods of an arch bridge according to claim 1, characterized in that: In step c, the cross beam (5) comprises channel steel one (51) and channel steel two (52), the channel steel one (51) is fixed to the outer side of the symmetrical main longitudinal beams (4), the opposite side of the symmetrical main longitudinal beams (4) is connected and fixed by channel steel two (52), a plurality of supporting wheels (6) are installed on the top of the channel steel two (52), and a guardrail (7) is also provided on the symmetrical channel steel one (51).

5. The method for installing tie rods of an arch bridge according to claim 4, characterized in that: The contact surfaces of the supporting wheel (6) and the tie rod are both provided with a protective layer to prevent the tie rod from being damaged.

6. The method for installing tie rods of an arch bridge according to claim 1, characterized in that: In step f, before the tie rod is tensioned, the HDPE sheaths on the surfaces of both ends of the tie rod are stripped off to expose the internal steel strands, and the length of the stripped HDPE sheath exceeds the sum of the tensioning working length and the designed elongation by 5 to 10 cm. Then, the anchor is installed and the anchor is connected to the steel strand.

7. The method for installing tie rods of an arch bridge according to claim 6, characterized in that: After all tie rods are tensioned, the steel strands exposed outside the anchor are cut off, anti-corrosion treatment is performed on the steel strands, and protective covers are installed to protect them.

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