A construction method and tensioning device for suspended, cantilevered concrete bridge decks.

Abstract

This application relates to the field of bridge construction, and more particularly to a construction method and tensioning device for suspended, cantilevered concrete bridge decks. Specifically, a precast beam is placed above a cap beam, and bridge decks are poured in three sections at the top of the precast beams on the same bridge deck. During the pouring of the cantilevered bridge deck, the first-poured bridge deck section is used as a support to tension the pouring formwork. By adopting the above technical solution, the first bridge deck section is poured first, and this completed section serves as the platform and support for subsequent pouring operations. When constructing the second and third bridge deck sections, the first section is used as a support to tension the pouring formwork, thus eliminating the need for ground-based support frames. This allows the construction of suspended, cantilevered concrete bridge decks to be unrestricted by the terrain of the construction area and the bridge height, reducing both construction difficulty and cost.

Description

Technical Field

[0001] This application relates to the field of bridge construction, and in particular to a method and tensioning device for constructing suspended, cantilevered concrete bridge decks. Background Technology

[0002] The construction of the bridge superstructure mainly includes the installation of precast beams and the pouring of bridge deck. Specifically, the precast beams, which are prefabricated in the factory, are hoisted onto the poured cap beams, and a pouring joint is left between two adjacent precast beams. During the construction of the bridge deck, a pouring formwork is erected in the pouring joint and a concrete bridge deck is poured on the top of the precast beam, thereby connecting multiple precast beams into a whole.

[0003] In traditional bridges, most bridge decks are flush with the ends of the precast beams, but there are still some cantilevered or suspended bridge decks, where the ends of the bridge decks are cantilevered or suspended outside the precast beams. When casting such cantilevered or suspended bridge decks, the ground is generally used as the support, and a support frame is erected to support the working platform and the casting formwork.

[0004] The existing construction method of building a support frame on the ground is suitable for situations where the terrain of the construction area is not too undulating and the bridge height is relatively low. However, when the terrain of the construction area is undulating and the bridge height exceeds 100 meters, building a support frame directly on the ground is not only difficult to construct, but also has a high construction cost. Summary of the Invention

[0005] To facilitate the casting of suspended and cantilevered concrete bridge decks in situations where the terrain in the construction area is undulating and the bridge is high, this application provides a construction method and tensioning device for suspended and cantilevered concrete bridge decks.

[0006] On the one hand, this application provides a construction method for suspended, cantilevered concrete bridge decks, which adopts the following technical solution:

[0007] Precast beams are laid on top of the cap beam, and the bridge deck is divided into left and right bridge decks by the central divider. The total number of precast beams on the same bridge deck is n. The precast beam closer to the central divider is the first precast beam, and the precast beam farther from the central divider is the nth precast beam.

[0008] Specifically, the following steps are included:

[0009] S1: Install the bottom formwork in the pouring joint between two adjacent precast beams, and then pour the first section of the bridge deck on the left and right bridge decks respectively on the precast beams and bottom formwork on both sides of the central divider of the bridge deck. The first section of the bridge deck is erected on the top of the m-th to n-th precast beams, 1≤m<n.

[0010] S2: Set up a casting template at the cantilever point on the left and right sides of the bridge deck, and install a pulling device for pulling the casting template with the first section of the bridge deck as support. Then, cast the second section of the bridge deck on the left and right sides of the bridge deck on the casting template and the nth precast beam respectively.

[0011] S3: Set up a casting template at the cantilever on the side of the left and right bridge decks that are close to each other, and install a pulling device for pulling the casting template with the first section of bridge panel on both sides of the central divider of the bridge deck as support. Then, cast the third section of bridge panel on the left and right bridge decks respectively on the precast beams and casting templates on both sides of the central divider of the bridge deck. The third section of bridge panel is erected on the top of the first precast beam to the m-th precast beam.

[0012] S2 and S3 can be performed in any order, or S2 and S3 can be performed simultaneously.

[0013] By adopting the above technical solution, the concrete bridge deck on the same bridge surface is divided into three sections for casting. The first section of the bridge deck is cast first and then used as a platform and support for subsequent casting operations. When constructing the second and third sections of the bridge deck, the first section of the bridge deck is used as a support to pull the casting formwork for the cantilever bridge deck, eliminating the need to erect a support frame on the ground. This allows the construction of suspended and cantilever concrete bridge decks to be free from the limitations of the terrain and bridge height in the construction area, reducing both the difficulty and cost of construction.

[0014] In one specific implementation, S1 includes:

[0015] S11: Set the bottom formwork inside the pouring joint and weld the exposed reinforcing bars of the bottom formwork to the exposed reinforcing bars of the precast beam;

[0016] S12: Install steel reinforcement;

[0017] S13: Pouring concrete.

[0018] By adopting the above technical solution, the exposed steel bars on the bottom formwork are welded together with the exposed steel bars on the precast beam, and the bottom formwork and the precast beam are connected as a whole, so that the bottom formwork becomes a permanent support structure for the bridge deck, thereby improving the overall structural strength of the bridge deck and thus improving the load-bearing capacity of the bridge deck.

[0019] In one specific implementation, S2 includes:

[0020] S21: The first section of bridge deck on the same span as the casting template is used as a support to install the tensioning device. The first hinge point and the first tensioning point are respectively set at the opposite ends of the casting template. The first tensioning point is set near the central divider of the bridge deck. The tensioning beam of the tensioning device is connected to the first hinge point and the first tensioning point respectively.

[0021] S22: Adjust the vertical distance between the traction beam of the traction device and the first hinge point and the first traction point respectively;

[0022] S23: Install steel reinforcement;

[0023] S24: Pouring concrete;

[0024] S25: Remove the pouring formwork;

[0025] S26: Move the traction device and pour the formwork to the next construction position, and repeat S21-S25 until the construction is completed.

[0026] By adopting the above technical solution, the tensioning device is erected on the first section of the bridge deck on the same span as the casting formwork, thereby shortening the horizontal distance between the tensioning device and the casting formwork. This saves on the production cost of the tensioning device and frees up more working space for construction. The tensioning device is connected to the first tension point and the first hinge point on the casting formwork. By adjusting the vertical distance between the tensioning beam of the tensioning device and the first tension point and the first hinge point, the elevation and slope of the casting formwork can be adjusted, thereby meeting the construction requirements of the cantilever bridge deck and improving the construction quality of the cantilever bridge deck.

[0027] In one specific implementation, S25 includes:

[0028] S251: Disconnect the traction device from the first traction point;

[0029] S252: A second traction point is set at the bottom of the casting template. The second traction point is located at the end of the casting template away from the first hinge point. The casting template is pulled down by the second traction point, so that the casting template rotates downward around the first hinge point and separates from the cast second section of bridge deck.

[0030] By adopting the above technical solution, a second traction point is set at the bottom of the casting template. When the casting template adheres to the cast second bridge deck during demolding and the casting template cannot fall and separate from the concrete by its own weight, the casting template can be pulled down by the second traction point, so that the casting template rotates downward around the first hinge point and separates from the cast second bridge deck.

[0031] In one specific implementation, S3 includes:

[0032] S31: The first section of bridge deck on both sides of the central divider of the bridge deck is used as a support to install the tensioning device. The second hinge point and the third tensioning point are respectively set at the opposite ends of the casting template. The second hinge point is set close to the central divider of the bridge deck. The tensioning beam of the tensioning device is connected to the second hinge point and the third tensioning point respectively, so that the casting template is suspended on the side of the bridge deck with a smaller cantilever width.

[0033] S32: Adjust the vertical distance between the traction beam of the traction device and the second hinge point and the third traction point respectively;

[0034] S33: Install steel reinforcement;

[0035] S34: The third section of the bridge deck with a smaller cantilever width is cast on the precast beam and casting template on one side of the central divider of the bridge deck.

[0036] S35: Disconnect the traction device from the third traction point, so that the casting template is separated from the cast-in-place third bridge deck and rotated around the second hinge point to the other side of the central divider of the bridge deck, and then connect the traction device to the third traction point.

[0037] S36: Adjust the vertical distance between the traction beam of the traction device and the second hinge point and the third traction point respectively;

[0038] S37: Install steel reinforcement;

[0039] S38: The third section of the bridge deck with a large cantilever width is cast on the precast beams and casting templates on the other side of the central divider of the bridge deck.

[0040] S39: Remove the casting formwork and move the traction device and casting formwork to the next construction position. Repeat S31-S38 until the construction is completed.

[0041] By adopting the above technical solution, a traction device is erected using the first bridge deck sections on both sides of the central divider as supports. The force on the traction device is distributed to the first bridge deck sections on both sides, thereby improving the stability of the traction device. By adjusting the vertical distance between the traction beam of the traction device and the second hinge point and the third traction point, the height of the casting template at both ends can be adjusted respectively, thereby achieving the adjustment of the casting template elevation and slope, so that the cast bridge deck meets the construction requirements. After the third bridge deck section on one side of the central divider is cast, the casting template can be rotated around the second hinge point to the other side of the central divider, serving as the bottom formwork for the third bridge deck section on the other side of the central divider, thereby improving the utilization rate of the casting template. Furthermore, without moving the traction device, the third bridge deck sections on both sides of the central divider can be cast sequentially on the same bridge deck, thereby improving the casting efficiency of the concrete bridge deck.

[0042] On the other hand, the present application provides a tensioning device for the above-mentioned construction method of suspended and cantilevered concrete bridge decks, which adopts the following technical solution:

[0043] In one specific implementation scheme, at least two sets of traction components are included, the at least two sets of traction components are arranged in parallel, and adjacent sets of traction components are connected to each other;

[0044] The traction assembly includes a support frame, a traction beam, and connecting components;

[0045] The tension beam is connected to the support frame;

[0046] The connector is located between the tie beam and the casting template and is used to connect the tie beam and the casting template.

[0047] By adopting the above technical solution, the traction device is erected on the pre-cast bridge deck, and the casting template is connected to the traction beam using connectors. The casting template is then hoisted at the cantilevered part of the bridge deck, and the pre-cast bridge deck is used as a support to pull the casting template. This eliminates the limitations of terrain and bridge height when casting suspended or cantilever bridge decks, reduces construction difficulty, and saves on the construction cost of erecting support frames.

[0048] In one specific implementation, the connector includes a boom and a pull rope;

[0049] One axial end of the suspension rod is hinged to the tie beam, and the other end is hinged to the casting template;

[0050] One end of the pull rope is connected to the pull beam, and the other end is connected to the end of the casting formwork away from the hanger.

[0051] By adopting the above technical solution, the suspending rod and the pulling rope are located at opposite ends of the casting formwork. The casting formwork is suspended below the pulling beam using the suspending rod and the pulling rope. The suspending rod is hinged to the casting formwork, so that the casting formwork can be rotated around the hinge point by adjusting the position of the pulling rope, thereby achieving the purpose of adjusting the slope of the casting formwork.

[0052] In one specific implementation, the boom includes a threaded rod with both positive and negative threads and two sleeves;

[0053] The positive and negative threaded rods are coaxially arranged with the sleeves, and the positive and negative threaded rods are arranged between the two sleeves. The two axial ends of the positive and negative threaded rods are respectively threaded to the two sleeves.

[0054] One end of one of the sleeves, away from the threaded rod, is hinged to the tension beam, and the other end of the sleeve, away from the threaded rod, is hinged to the casting template.

[0055] By adopting the above technical solution, rotating the positive and negative threaded screws can extend or shorten the entire suspension rod, thereby lowering or raising the cast-in-place formwork. At the same time, the corresponding adjustment of the traction rope can achieve the adjustment of the elevation and slope of the cast-in-place formwork, so that the cast-in-place cantilever bridge deck meets the construction requirements.

[0056] In one specific implementation, the pull rope is connected to the pull beam via turnbuckles.

[0057] By adopting the above technical solution, the turnbuckle is fixed to the tie beam and the tie rope is connected to the turnbuckle. The pouring formwork is raised or lowered by rotating the adjusting rod on the turnbuckle. Compared with the method of directly stretching the tie rope, the turnbuckle is more precise and convenient for adjusting the height of the pouring formwork. This allows for precise adjustment of the elevation and slope of the pouring formwork, so that the poured cantilever bridge deck meets the construction requirements.

[0058] In summary, this application includes at least one of the following beneficial technical effects:

[0059] 1. The proposed construction method for suspended and cantilevered concrete bridge decks divides the concrete bridge deck on the same bridge surface into three sections for casting. The first section of the bridge deck is cast first and then used as a platform and support for subsequent casting operations. When constructing the second and third sections of the bridge deck, the first section of the bridge deck is used as a support to pull the casting formwork for the cantilevered bridge deck, eliminating the need to erect a support frame on the ground. This allows the construction of suspended and cantilevered concrete bridge decks to be free from the limitations of the terrain and bridge height, reducing both the difficulty and cost of construction.

[0060] 2. The designed construction method for cantilevered concrete bridge decks involves erecting a tensioning device using the first bridge deck sections on both sides of the central divider as supports. The force on the tensioning device is distributed to the first bridge deck sections on both sides, thereby improving the stability of the tensioning device. By adjusting the vertical distance between the tension beam of the tensioning device and the second hinge point and the third tension point, the height of the casting formwork at both ends can be adjusted respectively, thereby adjusting the elevation and slope of the casting formwork to ensure that the cast bridge deck meets the construction requirements. After the third bridge deck section on one side of the central divider is cast, the casting formwork can be rotated around the second hinge point to the other side of the central divider to serve as the bottom formwork for the third bridge deck section on the other side of the central divider, thereby improving the utilization rate of the casting formwork. Furthermore, without moving the tensioning device, the third bridge deck sections on both sides of the central divider can be cast sequentially on the same bridge deck, thus improving the casting efficiency of the concrete bridge deck.

[0061] 3. The designed tensioning device is erected on the pre-cast bridge deck. The casting formwork is connected to the tensioning beam using connectors, thereby suspending the casting formwork at the cantilever point of the bridge deck. The pre-cast bridge deck serves as support to tension the casting formwork. This eliminates the limitations imposed by terrain and bridge height when casting suspended or cantilever bridge decks, reducing construction difficulty and saving on the construction cost of erecting support frames. Attached Figure Description

[0062] Figure 1 This is a schematic diagram showing the completion of the overall bridge deck pouring in the embodiment of this application.

[0063] Figure 2 This is a schematic diagram of the usage state of the first type of traction device in Embodiment 1 of this application.

[0064] Figure 3 This is a partial structural schematic diagram of the first type of traction device in Embodiment 1 of this application.

[0065] Figure 4 This is a schematic diagram of the demolding after the second bridge deck section is cast and formed in Embodiment 1 of this application.

[0066] Figure 5 This is a schematic diagram of the usage state of the second type of traction device in Embodiment 1 of this application.

[0067] Figure 6 This is a partial structural schematic diagram of the second type of traction device in Embodiment 1 of this application.

[0068] Figure 7 This is a schematic diagram of the flipping of the casting template after the third section of the bridge deck on one side of the central divider in Embodiment 1 of this application has been poured.

[0069] Figure 8 This is a schematic diagram of the casting of the third bridge deck section on the other side of the central divider in Embodiment 1 of this application.

[0070] Explanation of reference numerals in the attached drawings: 1. Precast beam; 11. Casting joint; 2. Bottom formwork; 3. Casting formwork; 4. First bridge deck section; 5. Second bridge deck section; 6. Third bridge deck section; 7. Tensioning assembly; 71. Bracket; 711. Support rod; 712. Side rod; 713. Crossbar; 714. Diagonal tie rod; 715. Auxiliary rod; 716. Steel pad; 717. Counterweight; 718. Locking caster wheel 719. Reinforcing rod; 72. Tie beam; 721. Tie section; 722. Connecting section; 73. Connector; 731. Hanger rod; 7311. Threaded rod; 7312. Sleeve; 7313. Limiting rod; 7314. Limiting rope; 732. Tie rope; 74. Turnbuckle; 75. Auxiliary rope; 76. Hand-operated hoist; 77. Demolding rope; 8. Cap beam; 9. Central divider of bridge deck. Detailed Implementation

[0071] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0072] This application discloses a construction method and tensioning device for suspended, cantilevered concrete bridge decks.

[0073] Example 1

[0074] Firstly, this embodiment discloses a construction method for suspended, cantilevered concrete bridge decks, referring to... Figure 1 A precast beam 1 is placed at the top of the cap beam 8, and the bridge deck is divided into a left and right deck by the central divider 9. Concrete bridge deck panels are poured in three sections at the top of the precast beams 1 on each deck. Let the total number of precast beams 1 on each deck be n. The precast beam 1 closest to the central divider 9 is the first precast beam, and the precast beam 1 furthest from the central divider 9 is the nth precast beam. The first section of bridge deck panel 4 is formed and erected at the top of the m-th to n-th precast beams, where 1 ≤ m < n. The second section of bridge deck panel 5 is formed and erected at the top of the n-th precast beam, and the third section of bridge deck panel 6 is formed and erected at the top of the first to m-th precast beams. The first section of bridge deck panel 4 is located between the second section of bridge deck panel 5 and the third section of bridge deck panel 6. The joint between the first section of bridge deck panel 4 and the second section of bridge deck panel 5 is located on the n-th precast beam. The joint between bridge deck 4 and the third bridge deck 6 is located on the m-th precast beam; the value of m can be 1, 2, or 3, as long as the entire bridge deck is finally cast; in this embodiment, the value of m is 2. Before the first bridge deck 4 is cast, when the beam transport vehicle is transporting the precast beam 1, the left and right wheels of the beam transport vehicle are respectively located on the top of the first precast beam on both sides of the central divider 9 of the bridge deck, and steel plates need to be erected between the two adjacent precast beams 1 in advance to form a passage for the beam transport vehicle to walk; since the first bridge deck 4 will serve as a platform for subsequent casting operations after it is cast, the larger the area of ​​the first bridge deck, the better, so as to leave sufficient working space for subsequent construction. Therefore, in this embodiment, the value of m is 2, so as to maximize the forming area of ​​the first bridge deck 4 without affecting the normal passage of the beam transport vehicle.

[0075] A construction method for suspended, cantilevered concrete bridge decks specifically includes the following steps:

[0076] S1: Reference Figure 1 and Figure 2 Install the bottom formwork 2 in the pouring joint 11 between two adjacent precast beams 1, and then pour the first section of bridge deck 4 on the left and right bridge decks respectively on the precast beams 1 and bottom formwork 2 on both sides of the central divider 9 of the bridge deck.

[0077] S1 specifically includes the following:

[0078] S11: Set the bottom formwork 2 inside the pouring joint 11, and weld the exposed steel bars on the bottom formwork 2 to the exposed steel bars on the precast beam 1. The bottom formwork 2 is made of precast concrete slab.

[0079] S12: Install reinforcing bars, lay horizontal and longitudinal reinforcing bars above the bottom formwork 2 and at the top of the precast beam 1, and weld them in place;

[0080] S13: Pour concrete. After the first section of the bridge deck 4 is poured and formed, the bottom formwork 2 is not removed and serves as the permanent support structure for the bridge deck.

[0081] S2: Reference Figure 2 and Figure 3 A casting template 3 is set at the cantilevered part of the left and right bridge decks that are far apart from each other. A traction device is erected to pull the casting template 3 with the first section of the bridge deck 4 as support. Then, the second section of the bridge deck 5 on the left and right bridge decks is cast on the casting template 3 and the nth precast beam respectively.

[0082] S2 specifically includes the following steps:

[0083] S21: A traction device is erected with the first section of bridge deck 4, which is on the same bridge deck as the casting template 3, as a support. A first hinge point and a first traction point are respectively set at opposite ends of the casting template 3. The first traction point is set near the central divider 9 of the bridge deck. The traction beam 72 of the traction device is connected to the first hinge point and the first traction point respectively.

[0084] S22: Adjust the vertical distance between the tension beam 72 of the tensioning device and the first hinge point and the first tensioning point respectively, so as to adjust the slope and elevation of the pouring formwork 3 to meet the requirements of bridge deck construction;

[0085] S23: Install reinforcing bars, lay out transverse and longitudinal reinforcing bars on the casting formwork 3, and weld them in place;

[0086] S24: Pouring concrete;

[0087] S25: Reference Figure 3 and Figure 4 Remove the casting formwork 3;

[0088] S25 specifically includes the following steps:

[0089] S251: Disconnect the traction device from the first traction point;

[0090] S252: A second traction point is set at the bottom of the casting formwork 3. The second traction point is located at the end of the casting formwork 3 away from the first hinge point. The casting formwork 3 is pulled down through the second traction point, so that the casting formwork 3 rotates downward around the first hinge point and separates from the cast second section of bridge deck 5. Personnel or equipment pulling down the casting formwork 3 must be at least 8m away from directly below the casting formwork 3. Traffic must be temporarily blocked during road construction to avoid safety accidents.

[0091] S26: Move the traction device and pour the formwork 3 to the next construction position, and repeat S21-S25 until the construction is completed.

[0092] S3: Reference Figure 5 and Figure 6 A casting template 3 is set at the cantilevered part of the left and right bridge decks that are close to each other, and a pulling device for pulling the casting template 3 is installed on the first section of bridge panel 4 on both sides of the central divider 9 of the bridge deck. Then, the third section of bridge panel 6 on the left and right bridge decks is cast on the precast beams 1 and casting template 3 on both sides of the central divider 9 of the bridge deck.

[0093] S3 specifically includes the following steps:

[0094] S31: The first section of bridge deck 4 on both sides of the central divider 9 of the bridge deck is used as a support to install the tensioning device. The second hinge point and the third tensioning point are respectively set at the opposite ends of the casting template 3. The second hinge point is set close to the central divider 9 of the bridge deck. The tensioning beam 72 of the tensioning device is connected to the second hinge point and the third tensioning point respectively, so that the casting template 3 is suspended on the side of the bridge deck with a smaller cantilever width.

[0095] S32: Adjust the vertical distance between the tension beam 72 of the tensioning device and the second hinge point and the third tensioning point respectively, thereby adjusting the elevation and slope of the casting formwork 3;

[0096] S33: Install reinforcing bars, lay horizontal and longitudinal reinforcing bars above the casting formwork 3 and at the top of the precast beam 1, and weld them in place;

[0097] S34: The third section of the bridge deck 6, with a smaller cantilever width, is cast on the precast beam 1 and casting template 3 on one side of the central divider 9 of the bridge deck. When casting the bridge deck, because the elevation and slope of the cantilevered bridge decks on both sides of the central divider 9 are different, they need to be cast separately. When casting the curved bridge deck, because the width of the inner bridge deck is greater than the outer bridge deck, and the width difference is mainly concentrated on the cantilevered bridge decks on both sides of the central divider 9, there is a difference in width between the cantilevered bridge decks on both sides of the curved section. Based on this, when casting the third section of the bridge deck 6 on both sides of the central divider 9, because the same casting template 3 is used, and the bridge deck... The gap in the central divider 9 is too small to accommodate two casting templates 3 side by side. If the bridge deck with the larger cantilever width is cast first, when rotating the casting template 3, in order to ensure that the casting template 3 is flush with the top of the first precast beam, the entire traction device needs to be moved to the side of the cast third bridge deck 6. However, at this time, the cast third bridge deck 6 will block the movement of the traction device, so that the casting template 3 cannot be successfully flipped and flush with the top of the first precast beam. Therefore, when casting the third bridge deck 6 on the curved bridge deck, the side with the smaller cantilever width should be constructed first, so as to reserve sufficient working space for the construction of the third bridge deck 6 on the other side.

[0098] S35: Reference Figure 7 and Figure 8 Disconnect the traction device from the third traction point, so that the casting template 3 is separated from the cast third section of the bridge deck 6 and rotated around the second hinge point to the other side of the central divider 9 of the bridge deck. Then connect the traction device to the third traction point.

[0099] S36: Adjust the vertical distance between the tension beam 72 of the tensioning device and the second hinge point and the third tensioning point respectively, thereby adjusting the slope and elevation of the casting formwork 3;

[0100] S37: Install reinforcing bars, lay horizontal and longitudinal reinforcing bars above the casting formwork 3 and at the top of the precast beam 1, and weld them in place;

[0101] S38: The third section of the bridge deck 6 with a larger cantilever width is cast on the precast beam 1 and casting template 3 on the other side of the central divider 9 of the bridge deck.

[0102] S39: Remove the casting formwork 3 and move the traction device and casting formwork 3 to the next construction position. Repeat S31-S38 until the construction is completed.

[0103] Secondly, this embodiment discloses two types of traction devices, which are used in steps S2 and S3 of the above-mentioned construction method for suspended and cantilevered concrete bridge decks, respectively.

[0104] Reference Figure 2 The first type of traction device is used in step S2 of the above construction method. It includes at least two sets of traction components 7, which are arranged in parallel. Adjacent sets of traction components 7 are welded together by connecting rods, which are made of channel steel. The number of traction components 7 can be two, three, or four. In the specific construction process, the appropriate number of traction components 7 can be selected according to the length of the bridge deck to be poured and the construction progress. In this embodiment, the number of traction components 7 is two. The traction component 7 includes a bracket 71, a traction beam 72, and a connector 73.

[0105] Reference Figure 2 The bracket 71 includes a support rod 711, a side rod 712, a cross rod 713, and two diagonal tie rods 714. The support rod 711, side rod 712, cross rod 713, and diagonal tie rods 714 are all made of channel steel. The support rod 711 and the side rod 712 are both vertically arranged, and the length of the support rod 711 is greater than the length of the side rod 712. The cross rod 713 is located between the support rod 711 and the side rod 712, and the cross rod 713 is located at the bottom end of the support rod 711. The long side of the cross rod 713 is perpendicular to the long side of the support rod 711. One end of the long side of the cross rod 713 is welded to the support rod 711, and the other end is welded to the side rod 712.

[0106] Reference Figure 2 The tension beam 72 is made of channel steel. The tension beam 72 is located above the crossbar 713, and the long side of the tension beam 72 is parallel to the long side of the crossbar 713. The tension beam 72 is welded to the support rod 711 and the side rod 712 respectively. The tension beam 72 is divided into a tension section 721 and a connecting section 722 with the support rod 711 as the boundary. The connecting section 722 is located close to the side rod 712. The length of the tension section 721 is greater than the length of the connecting section 722.

[0107] Reference Figure 2 Both diagonal tie rods 714 are installed above the tension beam 72, and the two diagonal tie rods 714 are respectively inclined on opposite sides of the support rod 711; one end of the diagonal tie rod 714 closer to the side rod 712 is welded to the top of the support rod 711, and the other end is welded to the top of the side rod 712; one end of the other diagonal tie rod 714 is welded to the top of the support rod 711, and the other end is welded to the end of the tension section 721 away from the support rod 711.

[0108] Reference Figure 2 An auxiliary rod 715 is provided below the tension section 721. The auxiliary rod 715 is set vertically and its top end is welded to the tension section 721. During construction, in order to improve the support stability of the support 71, a steel pad 716 is inserted at the bottom of the auxiliary rod 715, and a counterweight 717 is placed on the crossbar 713 to prevent the support 71 from overturning during the tensioning and pouring of the formwork 3. The counterweight 717 can be made of concrete block, steel or sand and gravel.

[0109] Reference Figure 2 Both the support rod 711 and the side rod 712 are bolted to the bottom end with lockable caster wheels 718, which facilitates the movement of the entire traction device.

[0110] Reference Figure 2 and Figure 3 The connector 73 includes a lifting rod 731 and a pulling rope 732; the lifting rod 731 is vertically arranged at the end of the pulling section 721 away from the support rod 711; the lifting rod 731 includes a threaded rod 7311 and two sleeves 7312, the threaded rod 7311 and the two sleeves 7312 are coaxially arranged, the threaded rod 7311 is arranged between the two sleeves 7312, and the two axial ends of the threaded rod 7311 extend into the two sleeves 7312 respectively and are threadedly connected to the sleeves 7312.

[0111] Reference Figure 2 Limiting rods 7313 are welded to the periphery of both sleeves 7312, and a limiting rope 7314 is connected between the two limiting rods 7313. The length of the lifting rod 731 is limited by the limiting rope 7314 to prevent the positive and negative threaded rods 7311 from detaching from the sleeves 7312.

[0112] Reference Figure 2 The sleeve 7312, which is away from the casting template 3, is hinged to the tension section 721 by a pin, and the sleeve 7312, which is close to the casting template 3, is hinged to the casting template 3 by a pin. A guardrail crossbar is installed between two adjacent hangers 731, and the guardrail crossbar is welded to the sleeve 7312, so that the sleeve 7312 and the guardrail crossbar together form a construction guardrail, thereby improving the construction safety factor. The hinge point between the hanger 731 and the casting template 3 is the first hinge point.

[0113] Reference Figure 2 It also includes turnbuckle 74; the pull rope 732 is made of steel wire rope, and three ear plates are welded on the side of the pull section 721 near the casting template 3. Three ear plates are also welded on the end of the casting template 3 away from the hanger 731. The turnbuckle 74 is connected to the ear plates on the pull section 721. One end of the pull rope 732 is connected to the turnbuckle 74, and the other end is connected to the ear plates on the casting template 3. The connection point between the pull rope 732 and the casting template 3 is the first pull point.

[0114] Reference Figure 2 and Figure 3 It also includes an auxiliary rope 75 and a hand-operated hoist 76; the auxiliary rope 75 is made of steel wire rope, and the hand-operated hoist 76 is connected to the ear plate of the pulling section 721, and the hand-operated hoist 76 is located between the turnbuckle 74 and the auxiliary rod 715; one end of the auxiliary rope 75 is connected to the hand-operated hoist 76, and the other end is connected to the ear plate on the casting template 3.

[0115] Reference Figure 3 It also includes a demolding rope 77, which is made of steel wire rope. The demolding rope 77 is connected to the ear plate at the bottom of the casting template 3. The end of the demolding rope 77 away from the casting template 3 hangs down naturally to the bottom of the casting template 3. The connection point between the demolding rope 77 and the casting template 3 is the second tension point.

[0116] Reference Figure 5 and Figure 6 The second type of traction device is used in step S3 of the above construction method. The difference between the second type of traction device and the first type of traction device is that:

[0117] The bracket 71 includes two support rods 711, two auxiliary rods 715, and two reinforcing rods 719, all made of channel steel. The tops of the two support rods 711 are welded to the two ends of the long side of the tension beam 72, and each end of the support rod 711 away from the tension beam 72 is bolted with a lockable caster wheel 718. Two auxiliary rods 715 are positioned between the two support rods 711, with the long side of the auxiliary rod 715 aligned with the long side of the support rod 711. The auxiliary rod 715 is set in parallel with the top of the tie beam 72. Two reinforcing rods 719 are located at both ends of the long side of the tie beam 72. One end of the reinforcing rod 719 is welded to the tie beam 72, and the other end is welded to the support rod 711. The hanger 731 is set in the middle of the tie beam 72, and the tie beam 72 is divided into a left half and a right half with the hanger 731 as the boundary. Two ear plates for connecting turnbuckle 74 and hand chain hoist 76 are welded on the left half and the right half respectively. The hinge point between the hanger 731 and the casting template 3 is the second hinge point, and the connection point between the tie rope 732 and the casting template 3 is the third tie point.

[0118] The implementation principle of Example 1: The entire concrete bridge deck is cast in three sections.

[0119] Construction of the first section of bridge deck:

[0120] The bottom formwork 2 is welded and fixed in the casting joint 11 between two adjacent precast beams 1. Then, the first section of the bridge deck 4 on the left and right bridge decks is cast on the precast beams 1 and bottom formwork 2 on both sides of the central divider 9 of the bridge deck. After the first section of the bridge deck 4 is cast, the bottom formwork 2 is not removed and serves as the permanent support structure of the bridge deck.

[0121] Second section of bridge deck construction:

[0122] The first type of traction device is moved to the first section of bridge deck 4 that has been cast and formed, so that the bottom end of the support rod 711 is fixed to the top end of the (n-1)th precast beam, the bottom end of the side rod 712 is fixed to the top end of the (n-2)th precast beam, and the bottom end of the auxiliary rod 715 is located at the top end of the nth precast beam. Steel pads 716 are inserted between the auxiliary rod 715 and the bridge deck, thereby reducing the cantilever length of the traction beam 72 and improving the traction stability of the traction device.

[0123] The counterweight 717 is placed on the crossbar 713 to improve the stability of the first type of traction device and prevent the first type of traction device from shaking or even overturning during the process of traction of the casting formwork 3.

[0124] The casting formwork 3 is suspended at the casting position of the cantilever bridge deck using the hanger 731 and the pull rope 732. A PVC pipe is fitted on the pull rope 732 to separate the concrete from the pull rope 732, preventing the pull rope 732 from sticking to the concrete and facilitating the removal of the pull rope 732 later. At the same time, the auxiliary rope 75 and the demolding rope 77 are both connected to the casting formwork 3, and a PVC pipe is also fitted on the auxiliary rope 75.

[0125] Rotate the adjusting rods on the positive and negative thread screws 7311 and the turnbuckle 74 to adjust the elevation and slope of the casting template 3;

[0126] After installing the reinforcing bars and pouring the concrete, once the concrete reaches the required strength, the formwork 3 is removed. Specifically, the auxiliary rope 75 is pulled by the hand chain hoist 76, the turnbuckle 74 is disconnected from the pull rope 732, and then the hand chain hoist 76 is adjusted to lower the formwork 3 smoothly.

[0127] If the formwork 3 sticks to the concrete and cannot detach from the concrete under its own weight, then pull the formwork removal rope 77 from below the formwork 3 to separate the formwork 3 from the concrete.

[0128] When the casting formwork 3 falls to a point where it is basically parallel to the lifting rod 731 and the auxiliary rope 75 is no longer under tension, disconnect the auxiliary rope 75 from the hand chain hoist 76, and thread both the auxiliary rope 75 and the pulling rope 732 through the reserved PVC pipe hole.

[0129] Finally, move the first type of traction device and the casting template 3 to the next construction position, and repeat the above construction steps until the construction is completed.

[0130] Third section of bridge deck construction:

[0131] The second type of traction device is moved to the first section of bridge deck 4, so that the two support rods 711 are respectively located at the top of the second precast beam on both sides of the central divider 9 of the bridge deck, and the two auxiliary rods 715 are respectively located at the top of the first precast beam on both sides of the central divider 9 of the bridge deck.

[0132] The casting template 3 is hoisted to the casting position on one side of the central divider 9 of the bridge deck using the hoist 731 and the pull rope 732. The casting template 3 is connected to the hand-operated hoist 76 using the auxiliary rope 75. PVC pipes are fitted onto both the pull rope 732 and the auxiliary rope 75. A steel pad 716 is inserted into the bottom end of the auxiliary rod 715 on the other side of the central divider 9 of the bridge deck. Then, the adjusting rods on the positive and negative threaded screws 7311 and the turnbuckle 74 are adjusted to make the elevation and slope of the casting template 3 meet the construction requirements.

[0133] After installing the reinforcing bars and pouring the concrete, once the concrete reaches the required strength, use a hand chain hoist 76 to pull the auxiliary rope 75, then disconnect the pull rope 732 from the turnbuckle 74, adjust the hand chain hoist 76, and slowly lower the pouring template 3 until the auxiliary rope 75 is no longer under tension. Then disconnect the auxiliary rope 75 from the hand chain hoist 76, and pass the auxiliary rope 75 and pull rope 732 out through the reserved PVC pipe holes respectively.

[0134] PVC pipes are then fitted onto the tension rope 732 and auxiliary rope 75. The auxiliary rope 75 is connected to the hand chain hoist 76 on the other side of the central divider 9 of the bridge deck. The hand chain hoist 76 is adjusted so that the casting template 3 is rotated to the other side of the central divider 9 of the bridge deck under the action of the auxiliary rope 75. The tension rope 732 is then connected to the tension beam 72 through the turnbuckle 74. The elevation and slope of the casting template 3 are adjusted. Finally, the reinforcing steel is installed and the concrete is poured.

[0135] When the concrete reaches the required strength, disconnect the pull rope 732 from the turnbuckle 74, adjust the hand chain hoist 76, lower the pouring formwork 3 until the auxiliary rope 75 is no longer under tension, then disconnect the auxiliary rope 75 from the hand chain hoist 76, and pass the auxiliary rope 75 and pull rope 732 out through the reserved PVC pipe hole respectively.

[0136] Finally, move the second type of traction device and the casting template 3 to the next construction position, and repeat the above construction steps until the construction is completed.

[0137] Example 2

[0138] Reference Figure 1 This embodiment discloses a construction method for a suspended, cantilevered concrete bridge deck. The difference between Embodiment 2 and Embodiment 1 is that S3 precedes S2. That is, after the first section of bridge deck 4 is cast, the second type of tensioning device described in Embodiment 1 is first set on the first section of bridge deck 4 on both sides of the central divider 9 of the bridge deck, and then the third section of bridge deck 6 is cast. After the third section of bridge deck 6 is cast, the first type of tensioning device described in Embodiment 1 is set on the first section of bridge deck 4 on both sides of the central divider of the bridge deck, and then the second section of bridge deck 5 is cast.

[0139] The third bridge deck 6, which is cast first, together with the first bridge deck 4, forms a platform for subsequent construction work, thus providing ample working space for the casting of the second bridge deck 5.

[0140] Example 3

[0141] Reference Figure 1 This embodiment discloses a construction method for a suspended, cantilevered concrete bridge deck. The difference between Embodiment 3 and Embodiment 1 is that S2 and S3 are carried out simultaneously. That is, after the first section of the bridge deck 4 is cast and formed, the first type of traction device and the second type of traction device described in Embodiment 1 are set on the first section of the bridge deck 4 on both sides of the central divider of the bridge deck, and then the second section of the bridge deck 5 and the third section of the bridge deck 6 are cast simultaneously.

[0142] Simultaneously pouring the second bridge deck section 5 and the third bridge deck section 6 shortens the construction period and improves construction efficiency.

[0143] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A construction method for a suspended, cantilevered concrete bridge deck, characterized in that: Precast beams (1) are laid on top of the cap beam, and the bridge deck is divided into left and right bridge decks by the central divider (9). The total number of precast beams (1) on the same bridge deck is n. The precast beam (1) close to the central divider (9) is the first precast beam, and the precast beam (1) far from the central divider (9) is the nth precast beam. Specifically, the following steps are included: S1: Install the bottom formwork (2) in the pouring joint (11) between two adjacent precast beams (1), and then pour the first section of bridge deck (4) on the precast beams (1) and bottom formwork (2) on both sides of the central divider (9) of the bridge deck. The first section of bridge deck (4) is erected on the top of the m-th precast beam to the n-th precast beam, 1≤m<n; S1 includes: S11: Set the bottom formwork (2) inside the pouring joint (11) and weld the exposed steel bars of the bottom formwork (2) to the exposed steel bars of the precast beam (1); S12: Install steel reinforcement; S13: Pouring concrete; S2: Set up a casting template (3) at the cantilevered part of the left and right bridge decks away from each other, and install a pulling device for pulling the casting template (3) with the first section of the bridge deck (4) as support. Then cast the second section of the bridge deck (5) on the left and right bridge decks respectively on the casting template (3) and the nth precast beam. S3: Set up a casting template (3) at the cantilever on the side of the left and right bridge decks that are close to each other, and install a pulling device for pulling the casting template (3) with the first section of bridge panel (4) on both sides of the central divider (9) of the bridge deck as support. Then, cast the third section of bridge panel (6) on the left and right bridge decks respectively on the precast beams (1) and casting template (3) on both sides of the central divider (9). The third section of bridge panel (6) is formed and erected on the top of the first precast beam to the mth precast beam. S2 and S3 can be performed in any order, or S2 and S3 can be performed simultaneously. S3 includes: S31: The first section of bridge deck (4) on both sides of the central divider (9) of the bridge deck is used as a support to install the traction device. The second hinge point and the third traction point are respectively set at the opposite ends of the casting template (3). The second hinge point is set close to the central divider (9) of the bridge deck. The traction beam (72) of the traction device is connected to the second hinge point and the third traction point respectively, so that the casting template (3) is suspended on the side of the bridge deck with a smaller cantilever width. S32: Adjust the vertical distance between the traction beam (72) of the traction device and the second hinge point and the third traction point respectively; S33: Install steel reinforcement; S34: The third section of the bridge deck (6) with a smaller cantilever width is cast on the precast beam (1) and casting template (3) on one side of the central divider (9) of the bridge deck; S35: Disconnect the traction device from the third traction point, so that the casting template (3) is separated from the cast third section of the bridge deck (6) and rotated around the second hinge point to the other side of the central divider (9) of the bridge deck. Then connect the traction beam (72) of the traction device to the third traction point. S36: Adjust the vertical distance between the traction beam (72) of the traction device and the second hinge point and the third traction point respectively; S37: Install steel reinforcement; S38: The third section of the bridge deck (6) with a larger cantilever width is cast on the precast beam (1) and casting template (3) on the other side of the central divider (9) of the bridge deck; S39: Remove the casting formwork (3) and move the traction device and casting formwork (3) to the next construction position. Repeat S31-S38 until the construction is completed.

2. The construction method for suspended, cantilevered concrete bridge decks according to claim 1, characterized in that: S2 includes: S21: The first section of bridge deck (4) on the same bridge deck as the casting template (3) is used as a support to install the traction device. The first hinge point and the first traction point are respectively set at the opposite ends of the casting template (3). The first traction point is set close to the central divider (9) of the bridge deck. The traction beam (72) of the traction device is connected to the first hinge point and the first traction point respectively. S22: Adjust the vertical distance between the traction beam (72) of the traction device and the first hinge point and the first traction point respectively; S23: Install steel reinforcement; S24: Pouring concrete; S25: Remove the pouring formwork (3); S26: Move the traction device and pouring formwork (3) to the next construction position, and repeat S21-S25 until the construction is completed.

3. The construction method for suspended, cantilevered concrete bridge decks according to claim 2, characterized in that: S25 includes: S251: Disconnect the traction device from the first traction point; S252: A second traction point is set at the bottom of the casting template (3). The second traction point is located at the end of the casting template (3) away from the first hinge point. The casting template (3) is pulled down by the second traction point, so that the casting template (3) rotates downward around the first hinge point and separates from the cast second bridge deck (5).

4. A tensioning device for use in the construction method of suspended, cantilevered concrete bridge decks as described in any one of claims 1-3, characterized in that: It includes at least two sets of traction components (7), the at least two sets of traction components (7) are arranged in parallel, and adjacent sets of traction components (7) are connected to each other; The traction assembly (7) includes a bracket (71), a traction beam (72), and a connector (73); The tension beam (72) is connected to the bracket (71); The connector (73) is located between the tie beam (72) and the casting template (3) and is used to connect the tie beam (72) and the casting template (3); The connector (73) includes a boom (731) and a pull rope (732); One axial end of the suspension rod (731) is hinged to the tie beam (72), and the other end is hinged to the casting template (3); One end of the pull rope (732) is connected to the pull beam (72), and the other end is connected to the end of the casting formwork (3) away from the hanger (731); The boom (731) includes a threaded rod (7311) with both positive and negative threads and two sleeves (7312); The positive and negative threaded screw (7311) is coaxially arranged with the sleeve (7312), the positive and negative threaded screw (7311) is arranged between the two sleeves (7312), and the two axial ends of the positive and negative threaded screw (7311) are respectively threaded to the two sleeves (7312); One end of the sleeve (7312) away from the threaded rod (7311) is hinged to the tension beam (72), and the other end of the sleeve (7312) away from the threaded rod (7311) is hinged to the casting template (3).

5. The traction device according to claim 4, characterized in that: The pull rope (732) is connected to the pull beam (72) by turnbuckle (74).

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