Fabricated temporary bridge serving as foundation pit supporting structure

Abstract

The utility model provides an assembly type temporary bridge serving as a foundation pit supporting structure, which is used for crossing a foundation pit and comprises arched beams, longitudinal beams, supporting columns and beef tendon legs. The beef tendon legs are arranged on the sides, facing the foundation pit, of the top ends of the fender posts. The two ends of the arched beams are fixedly connected with the corresponding beef tendon legs on the two sides of the foundation pit respectively. The longitudinal beams are arranged above the arched beams, and the two ends of the longitudinal beams are fixedly connected with top beams at the top ends of fender posts on the two sides of the foundation pit correspondingly so that bridge deck slabs can be laid; the two ends of the supporting columns are fixedly connected with the longitudinal beams and the arched beams respectively. An inner supporting structure of the foundation pit and the temporary temporary bridge for ground traffic are combined into a whole, the temporary bridge is of a deck type arch structure, one span crosses over the foundation pit, no pier column is arranged, the temporary bridge is directly supported on a foundation pit fender post and a top beam, and a foundation pit supporting structure is fully utilized. Meanwhile, the structure is prefabricated in an assembly mode, in the foundation pit construction process, the structure is directly hoisted in place, and the construction period is greatly shortened.

Description

Technical Field

[0001] This utility model relates to the field of rail transit technology, specifically to a prefabricated temporary bridge that also serves as a foundation pit support structure. Background Technology

[0002] To improve the convenience of public transportation, adapt to construction conditions, achieve traffic connections, and optimize urban spatial layout, urban rail transit stations are mostly located under busy roads; among them, cut-and-cover stations are the most common.

[0003] During open-cut construction of railway stations, the excavation of the foundation pit will cause road traffic disruptions, requiring temporary diversions of surface traffic. However, with the increasing density of urban construction today, there are numerous structures around stations, and most open-cut station sites do not have the conditions for long-term traffic diversions, necessitating the construction of temporary bridges to ensure smooth surface traffic. However, traditional open-cut foundation pit temporary bridges do not fully utilize the foundation pit support structure, have a long construction period, and there are mutual constraints between the foundation pit and the temporary bridge in terms of space and stress. Furthermore, the foundation pit excavation and support and the temporary bridge construction involve overlapping operations. Utility Model Content

[0004] In view of the deficiencies in the existing technology, this utility model provides a prefabricated temporary bridge that also serves as a foundation pit support structure, so as to at least solve the technical problem that existing open-cut foundation pit temporary bridges fail to make full use of the foundation pit support structure.

[0005] To achieve the above objectives, this utility model employs the following technical solution:

[0006] A prefabricated temporary bridge that also serves as a foundation pit support structure, spanning a foundation pit, includes an arch beam, longitudinal beams, columns, and reinforcing legs; the reinforcing legs are located at the top of the retaining piles facing the foundation pit; the arch beam has at least two columns, with both ends fixedly connected to the corresponding reinforcing legs on both sides of the foundation pit; the longitudinal beam has at least two columns located above the arch beams, with both ends fixedly connected to the capping beams at the top of the retaining piles on both sides of the foundation pit for laying the bridge deck; the columns are fixedly connected at both ends to the longitudinal beams and the arch beams, respectively.

[0007] Optionally, the top of the retaining pile is provided with a notch on the side facing the foundation pit, and the end of the reinforcing leg away from the foundation pit is embedded in the notch.

[0008] Optionally, each of the two opposite side walls of the notch is provided with a first through hole penetrating the retaining pile, and one end of the reinforcing leg embedded in the notch is provided with a second through hole corresponding to the first through hole, so as to anchor the reinforcing leg to the retaining pile by means of anchor cable / rod.

[0009] Optionally, the top of the retaining pile is provided with a shoulder facing the pit, the top surface of the shoulder abuts against the bottom surface of the reinforcing leg, and the top surface of the shoulder is provided with a screw hole, and the surface of the reinforcing leg is provided with a through hole opposite to the screw hole, so as to fix the reinforcing leg to the retaining pile by means of a screw.

[0010] Optionally, the arch beam comprises multiple sequentially connected arch frame segments.

[0011] Optionally, each end of the arch frame segment is provided with a connecting plate, and the tendon leg is pre-installed with a screw for anchoring the connecting plate on the side facing the adjacent arch frame segment.

[0012] Optionally, the capping beam is located below the excavation line of the foundation pit, and a retaining wall is provided on the side of the capping beam away from the foundation pit, with the top of the retaining wall flush with the excavation line of the foundation pit; the end of the longitudinal beam is simultaneously fixedly connected to the corresponding capping beam and retaining wall.

[0013] As can be seen from the above technical solution, the beneficial effects of this utility model are:

[0014] This application provides a prefabricated temporary bridge that also serves as a foundation pit support structure. By combining the internal support structure of the foundation pit with a temporary bridge for ground traffic, the temporary bridge adopts an upper-bearing arch structure, spanning the foundation pit in one span. It does not require piers and is directly supported on the foundation pit retaining piles and capping beam, making full use of the foundation pit support structure. This structure serves as both an internal support structure for the foundation pit and a temporary bridge for ground traffic; it ensures smooth ground traffic flow without affecting the construction of the foundation pit and main structure. Furthermore, the structure is prefabricated, allowing for direct hoisting and placement during foundation pit construction, significantly shortening the construction period, and resulting in better overall construction quality for the prefabricated components. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0016] Figure 1 A cross-sectional view of a prefabricated temporary bridge that also serves as a foundation pit support structure;

[0017] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0018] Figure 3 An assembly diagram showing the installation of the reinforcing bar on a retaining pile with a notch or groove.

[0019] Figure 4 This is a schematic diagram of the foundation pit excavation.

[0020] Figure label:

[0021] 1-Retaining piles, 2-Cover beam, 3-Retaining wall, 4-Strut, 5-Arch beam, 6-Longitudinal beam, 7-Column, 8-Transverse distribution beam, 9-Bridge deck;

[0022] 11-Gap groove, 51-Arch frame segment. Detailed Implementation

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0024] Please see Figures 1-2 This utility model provides a prefabricated temporary bridge that also serves as a foundation pit support structure, spanning a foundation pit. It includes an arch beam 5, longitudinal beams 6, supports 7, and reinforcing legs 4. The reinforcing legs 4 are positioned at the top of the retaining piles 1 facing the foundation pit. At least two arch beams 5 are provided, with both ends fixedly connected to the corresponding reinforcing legs 4 on both sides of the foundation pit. At least two longitudinal beams 6 span the foundation pit and are positioned above the arch beams 5. Both ends of the longitudinal beams 6 are fixedly connected to the capping beams 2 at the top of the retaining piles 1 on both sides of the foundation pit, thus obtaining stable support through the capping beams 2 and the multiple retaining piles 1 below them. In other words, the capping beams 2, in addition to connecting the retaining piles 1, also serve as the abutment of the temporary bridge, facilitating the laying of bridge deck panels 9 between at least two adjacent longitudinal beams 6. Both ends of the supports 7 are fixedly connected to the longitudinal beams 6 and the arch beams 5, respectively, to enhance the structural stability of this temporary bridge. Among them, the support column 7 can be either the longitudinal beam 6 directly above the arch beam 5 or the adjacent arch beam 5 diagonally above. The support column 7 can be set vertically or diagonally.

[0025] As a further improvement to the above solution, the arch beam 5 includes multiple sequentially connected arch frame segments 51, which facilitates prefabrication and direct hoisting on-site for rapid assembly. In one embodiment, each end of the arch frame segment 51 is provided with a connecting plate, and adjacent arch frame segments 51 can be fastened together by high-strength bolts through the connecting plates. The connecting plates can be flange plates. The reinforcing leg 4 has a pre-installed bolt for anchoring the connecting plate on the side facing the adjacent arch frame segment 51. If the reinforcing leg 4 is cast in-situ, the connecting bolt can be pre-embedded before casting.

[0026] Generally, the crown beam 2 is arranged below the initial excavation line of the foundation pit, and a retaining wall 3 is arranged on the side of the crown beam 2 away from the foundation pit, the top end of the retaining wall 3 is flush with the initial excavation line of the foundation pit; the end of the longitudinal beam 6 is fixedly connected with the corresponding crown beam 2 and retaining wall 3, that is, the retaining wall 3 not only plays a retaining wall role for the foundation pit, but also acts as a back wall of the bridge abutment of the temporary bridge. Obviously, the base plate can be pre-laid on the top surface of the crown beam 2 when the crown beam 2 is cast, and the connecting steel plate can be pre-set on the surface of the retaining wall 3 when the retaining wall 3 is constructed.

[0027] In the application, the inner support structure of the foundation pit and the temporary bridge for ground traffic are combined into one, the temporary bridge adopts the upper bearing arch structure, one span of the temporary bridge crosses the foundation pit, no pier column is arranged, and the temporary bridge is directly supported on the foundation pit support pile 1 and the crown beam 2, and the foundation pit support structure is fully utilized. The structure is not only the inner support structure of the foundation pit, but also the temporary bridge for bearing the ground traffic; under the premise of meeting the smooth traffic of the ground, the construction of the foundation pit and the main structure is not affected. Meanwhile, the structure is of the assembly type and is prefabricated, in the construction process of the foundation pit, the structure is directly hoisted and positioned, the construction period is greatly shortened, and the overall construction quality of the assembly type component is better.

[0028] Embodiment I

[0029] In the embodiment, the temporary bridge is a steel temporary bridge, adopts the upper bearing arch structure, and is composed of the arch beam 5, the support column 7, the longitudinal beam 6, the transverse distribution beam 8 and the bridge deck 9. The arch beam 5 and the longitudinal beam 6 support the open foundation pit. Specifically, the arch beam 5 not only bears the load of the upper steel temporary bridge, but also bears the lateral earth pressure of the foundation pit, adopts the box type steel structure, every 4-5 meters is a segment, the end of the segment is welded with a connecting steel plate, and the segments are connected through the connecting steel plates by high-strength bolts; the arch beam 5 is connected with the cowhorn leg 4 through the connecting steel plate by high-strength bolts, and the transverse spacing of the adjacent arch beams 5 is controlled according to the spacing between the foundation pit support and the inner support. The support column 7 is arranged on the arch beam 5 and also adopts the box type steel structure, the end of the support column 7 is welded with a connecting steel plate, the bottom of the support column 7 is connected with the arch beam 5 through the connecting steel plate by high-strength bolts, the longitudinal beam 6 is arranged above the support column 7, and the longitudinal beam 6 is also connected with the support column 7 through the connecting steel plate by high-strength bolts. The longitudinal beam 6 is the upper structure of the steel temporary bridge, bears the load of the bridge deck and the lateral earth pressure of the foundation pit, and plays the role of the inner support of the foundation pit; the end of the longitudinal beam 6 is welded with a steel plate, the steel plate is welded with a pre-buried steel plate in the small retaining wall on the top of the crown beam 2, and the lower edge of the end of the longitudinal beam 6 is welded with a pre-buried steel plate on the top surface of the crown beam 2. The transverse distribution beam 8 adopts small size I-beams, is arranged above the longitudinal beam 6 at an interval of 2-3 meters, and the bridge deck 9 is arranged above the transverse distribution beam 8. The cowhorn leg 4 adopts the reinforced concrete structure and is integrally poured with the foundation pit support structure through the reserved reinforcing steel bars of the support pile 1. Embodiment I

[0030] Particularly, the cowhorn leg 4 can also be prefabricated in addition to being cast on site. The application is further improved for this purpose, please refer to Figure 3, the top end of the retaining pile 1 is provided with a notched groove 11 on the side facing the foundation pit, and the end of the cowhorn leg 4 away from the foundation pit is embedded in the notched groove 11. Generally, only the retaining piles on which the cowhorn legs are needed to be erected are provided with notched grooves, and the remaining retaining piles do not need to be notched. The notching of the retaining piles is generally directly completed when the retaining piles are cast in place outside the site, and the main reinforcement in the pile must not be damaged. The opposite two side walls of the notched groove 11 are each provided with a first through hole penetrating the retaining pile 1, and the end of the cowhorn leg 4 embedded in the notched groove 11 is provided with a second through hole corresponding to the first through hole, so as to be anchored with the retaining pile 1 by an anchor cable / rod. First, the cowhorn leg 4 is supported by the bottom of the notched groove 11 or partially supported, and after the cowhorn leg 4 is placed in place, the cowhorn leg 4 can be anchored on the retaining pile 1 by the anchor cable / rod. Obviously, the part of the cowhorn leg 4 embedded in the notched groove 11 can be replaced by a steel plate, so that the notched groove 11 can be made narrower to reduce the structural damage to the retaining pile 1. The notched groove 11 can be a hole groove or a long groove in communication with the top surface of the retaining pile 1 as shown in Figure 3 In addition, for the prefabricated cowhorn leg 4, the installation of the cowhorn leg 4 can also be completed by the following scheme, that is, the top end of the retaining pile 1 is provided with a shoulder (not shown in the figure) on the side facing the foundation pit, the top surface of the shoulder abuts against the bottom surface of the cowhorn leg 4, and the top surface of the shoulder is provided with a threaded hole or a pre-embedded screw rod, and the surface of the cowhorn leg 4 is provided with a through hole opposite to the threaded hole, so as to be fixedly connected with the retaining pile 1 by the screw rod. Obviously, since the opening / presetting of the shoulder on the retaining pile will damage the main reinforcement in the pile, all the retaining piles below the temporary bridge can be provided with shoulders, and a whole prefabricated cowhorn leg is arranged on the shoulders of the plurality of retaining piles and is locked and fixed respectively, so as to form a pull beam at the shoulder to improve the structural stability of all the retaining piles below the temporary bridge.

[0031] Particularly, the application also provides a construction step sequence of the assembled temporary bridge, which comprises the following steps:

[0032] S1: complete the construction of the retaining wall (also serving as the back wall of the abutment) and the retaining pile (also serving as the pile foundation of the abutment), and the corbel beam (also serving as the abutment body); reserve connecting steel plates on the top surface of the corbel beam and the inner side of the retaining wall; and reserve cowhorn leg connecting steel bars in the reinforcing cage of the retaining pile;

[0033] S2: excavate the foundation pit step by step, and set a pile-to-pile retaining plate; excavate to the cowhorn leg elevation; excavate according to the arch beam alignment (as shown in Figure 4 ); chisel out part of the protection layer of the retaining pile; weld the pre-embedded steel bars in the retaining pile with the steel bars of the cowhorn leg, and pour the cowhorn leg; at the same time, pre-embed the steel plate connected with the arch beam in the cowhorn leg; at this time, the foundation pit is still a cantilever pile plate structure;

[0034] S3: segmental hoisting arch segment, arch segment hoisting process, placed on the top of the excavated land, land to temporary vertical support; arch segment through the flange connection, arch beam through the connecting plate and reliable connection with the cow leg; at this time for open excavation pit, has been by cantilever pile plate structure, optimization for pile + single-layer arch internal support structure, for the bridge, the upper deck arch ring has been completed;

[0035] S4: hoisting steel support, steel support and arch beam through the connecting plate reliable connection;

[0036] S5: hoisting steel cross brace (also as bridge deck longitudinal beam); steel cross brace and steel support through the connecting plate reliable connection, steel cross brace and crown beam top, small retaining wall reserved steel plate bolted; at this time for the pit, the top of the lateral support has been completed, the pit formed two-way support; for steel bridge, the arch building longitudinal beam has been formed;

[0037] S6: hoisting transverse distribution beam (steel structure), using welding;

[0038] S7: paving temporary bridge deck, steel bridge is completed.

[0039] Finally, it should be noted that: the above examples are used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application.

Claims

1. A prefabricated temporary bridge serving as a foundation pit support structure for crossing a foundation pit, characterized in that, The utility model relates to a kind of prefabricated bridge, including: Calf leg (4), it is set in the top of enclosure stake (1) towards the side of foundation pit; Arch beam (5), its two ends are fixedly connected with the calf leg (4) corresponding to the two sides of foundation pit respectively; Longitudinal beam (6), it is set in the upper of arch beam (5), and its two ends are fixedly connected with the top of crown beam (2) of the two sides of foundation pit enclosure stake (1) respectively, to be used for laying bridge deck slab (9); Support (7), two ends are fixedly connected with longitudinal beam (6) and arch beam (5) respectively.

2. The prefabricated bridge for use as a foundation pit support structure according to claim 1, characterized in that, The top of the enclosure stake (1) towards the side of foundation pit is provided with notched groove (11), and the calf leg (4) is embedded in notched groove (11) away from the side of foundation pit.

3. The prefabricated bridge for use as a foundation pit support structure according to claim 2, characterized in that, The opposite two sides of the notched groove (11) are each provided with first through hole penetrating the enclosure stake (1), and the end embedded in the notched groove (11) of the calf leg (4) is provided with second through hole corresponding to the first through hole, so as to be anchored with the enclosure stake (1) by anchor cable / rod.

4. The prefabricated bridge for use as a foundation pit support structure according to claim 1, characterized in that, The top of the enclosure stake (1) towards the side of foundation pit is provided with shoulder, the top surface of the shoulder is in abutment with the bottom surface of the calf leg (4), and the top surface of the shoulder is provided with screw hole, and the surface of the calf leg (4) is provided with through hole corresponding to the screw hole, so as to be fixedly connected with the enclosure stake (1) by screw rod.

5. The prefabricated bridge for use as a foundation pit support structure according to any one of claims 1 to 4, characterized in that, The arch beam (5) includes multiple sequentially connected arch frame segments (51).

6. The prefabricated bridge serving as a foundation pit supporting structure according to claim 5, characterized in that, The two ends of the arch frame segment (51) are each provided with connecting plate, and the calf leg (4) is provided with screw rod for anchoring connecting plate towards the side of adjacent arch frame segment (51).

7. The prefabricated bridge according to claim 5, wherein the crown beam (2) is arranged below the starting excavation line of the foundation pit, the crown beam (2) is provided with a retaining wall (3) away from the side of the foundation pit, and the top of the retaining wall (3) is flush with the starting excavation line of the foundation pit; characterized in that, the end of the longitudinal beam (6) is fixedly connected with the corresponding crown beam (2) and retaining wall (3).

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