A force-storing reverse-top double-leg vertical arch large cantilever pier structure and construction technology

Abstract

The present invention provides a force-storing anti-top double-leg vertical arch large cantilever pier structure and a construction process. The force-storing anti-top double-leg vertical arch large cantilever pier structure includes a double-leg vertical arch large cantilever, an anti-top cross beam, and a fan-shaped portal arch. The double-leg vertical arch is provided with beam-end arch-foot constraints by the bottom bearing platform and the top prestressed steel tendons. The double-leg vertical arch large cantilever is pressurized by the jacking force of the anti-top cross beam, achieving the effect of the outer movement of the middle and lower parts of the vertical arch and the upward movement of the cantilever end of the upper part of the vertical arch, thereby improving the bearing capacity of the vertical arch cantilever. At the same time, the upward movement of the cantilever end of the upper part of the vertical arch will exert pressure on both ends of the fan-shaped portal arch, achieving the effect of the inward contraction of the fan-shaped portal arch, thereby improving the bearing capacity of the fan-shaped portal arch. The present invention makes full use of the compression characteristics of the arch structure and the compressive capacity of concrete, not only expanding the cantilever size, improving the cantilever bearing capacity, and reducing the risk of the bridge tipping due to eccentric load, but also reducing the width of the bottom pier column, lowering the height of the upper beam, saving materials and floor area, and increasing the road space above and below the bridge.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge structure design, and particularly relates to a force-storing type anti-top double-leg vertical arch large-cantilever bridge pier structure and a construction process thereof. Background Art

[0002] Conventional urban bridge piers usually consist of a pier column and a capping beam. Due to the limited size of the capping beam and the narrow upper bridge structure, traffic congestion occurs on the bridge. Moreover, the bottom of the pier column is wide, occupying a large area and causing congestion on the road under the bridge.

[0003] In related technologies, usually, measures such as increasing the cantilever length of the capping beam, setting side piers, and increasing the beam height are taken to solve the traffic congestion problem on the bridge. Among them, increasing the cantilever length of the capping beam leads to an increase in the beam height dimension of the capping beam, with complex construction, high cost, and cracking of the capping beam caused by prestress loss at the top of the capping beam, increasing the later operation and maintenance costs; increasing the beam height also has such problems, and the anti-unilateral load capacity is weak, increasing the risk of bridge overturning; setting side piers is neither beautiful, affecting the city appearance, nor economical in terms of land occupation, and the bottom width of the pier column does not decrease but increases, and the traffic congestion problem under the bridge cannot be fundamentally solved. Summary of the Invention

[0004] The present invention provides a force-storing type anti-top double-leg vertical arch large-cantilever bridge pier structure and a construction process thereof to solve the problems in related technologies such as the large land occupation and uneconomicalness of the bottom width of the pier column, the uneconomical and unaesthetic land occupation of adding side piers, the increased cost and high cracking maintenance cost brought by the increase of the capping beam and the beam height, as well as the weak anti-unilateral load capacity of the bridge and the high risk of bridge overturning. By making full use of the compressive characteristics of the arch structure and the compressive capacity of concrete, the urban space is expanded as much as possible with less consumables, fundamentally solving the traffic congestion problems on and under the urban bridge. Moreover, the double-leg vertical arch and the fan-shaped portal arch of the pier column have a soft curve and beautiful shape, and the hollow design increases the diversity of urban construction.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A force-storing type anti-top double-leg vertical arch large-cantilever bridge pier structure, comprising: a double-leg vertical arch large-cantilever, an anti-top cross beam, and a fan-shaped portal arch.

[0007] The middle part of the double-leg vertical arch large-cantilever is tightly connected to the anti-top cross beam, and the upper part of the double-leg vertical arch large-cantilever is tightly connected to the fan-shaped portal arch.

[0008] The double-leg vertical arch large-cantilever is provided with arch foot constraints at both ends by a bottom bearing platform and top prestressed steel bundles to form a vertical arch structure.

[0009] The anti-top cross beam includes a pre-cast section of the anti-top cross beam and a post-cast section of the anti-top cross beam.

[0010] The anti-top cross beam applies a jacking pressure to the double-leg vertical arch large-cantilever by a jack, and the jacking amount of the jack is determined according to the design requirements.

[0011] After the concrete of the post-cast section of the anti-top cross beam is poured, the jacking pressure of the jack is locked inside the structure to form a structural pre-pressure.

[0012] The structural pre-pressure presses on the double-leg vertical arch large cantilever in the form of the jacking force of the anti-top cross beam, achieving the effect that the middle and lower parts of the double-leg vertical arch large cantilever move outwards, and the cantilever end at the upper part of the double-leg vertical arch large cantilever rises, thereby improving the bearing capacity of the cantilever end of the vertical arch.

[0013] The rise of the cantilever end at the upper part of the double-leg vertical arch large cantilever presses on the fan-shaped portal arch, achieving the effect of the inward contraction of the fan-shaped portal arch, thereby improving the bearing capacity of the upper part of the portal arch.

[0014] The present invention also provides a construction process for a force-storing type anti-top double-leg vertical arch large cantilever pier structure, including the following steps:

[0015] Install the overall formwork, tie the steel bars, and groove and leave holes at the post-cast section of the anti-top cross beam and the hollow part of the fan-shaped portal arch;

[0016] Pour the concrete of the double-leg vertical arch large cantilever, the fan-shaped portal arch, and the pre-cast section of the anti-top cross beam, cure until the strength meets the requirements and remove the formwork;

[0017] Tension the prestressed steel bundle at the top of the fan-shaped portal arch;

[0018] Install a jack at the reserved hole of the post-cast section of the anti-top cross beam, push the double-leg vertical arch large cantilever to both sides to the designed position, lock the position, and then remove the jack;

[0019] Tension the prestressed steel bundle at the top of the fan-shaped portal arch again, and supplement the lost prestress during the jacking process to the designed value;

[0020] Pour the concrete of the post-cast section of the anti-top cross beam, and cure until the strength meets the requirements.

[0021] The beneficial effects brought by the technical solution provided by the present invention include: not only can it solve the problems in the related technologies such as the congestion and uneconomical occupation of land at the bottom width of the pier column, the unaesthetic increase in the land occupation of the side pier, the increase in the cost and the high cracking and maintenance cost brought by the increase of the capping beam and the beam height, as well as the weak anti-eccentric load capacity of the bridge and the high risk of bridge rollover. It can also make full use of the compression characteristics of the arch structure and the compressive capacity of concrete, both expand the cantilever size, improve the cantilever bearing capacity, and reduce the bottom pier column width, lower the upper beam height, save materials and land occupation, and fundamentally solve the congestion problems on and under the urban bridge. Moreover, the double-leg vertical arch of the pier column and the curve of the fan-shaped portal arch are soft and the shape is beautiful, and the hollow design increases the diversity of urban construction, and can be applied to the engineering design field of urban bridges, achieving multiple goals of expanding urban space, achieving architectural beauty, and promoting resource conservation. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the pouring partition of a force-storing anti-top double-leg vertical arch large cantilever pier structure provided by an embodiment of this application;

[0024] Figure 2 Front view of a force-storing anti-top double-leg vertical arch large cantilever pier structure provided by an embodiment of this application;

[0025] Figure 3 Schematic flow diagram of the construction process of a force-storing anti-top double-leg vertical arch large cantilever pier structure provided by an embodiment of this application.

[0026] Figure 4 Schematic flow diagram of improving the construction process of a force-storing anti-top double-leg vertical arch large cantilever pier structure to the three-top and three-pulling method provided by an embodiment of this application.

[0027] In the figure: 1 - double-leg vertical arch large cantilever, 2 - fan-shaped portal arch, 3 - anti-top cross beam, 31 - first-poured section of the anti-top cross beam, 32 - post-poured section of the anti-top cross beam, 4 - jack, 5 - prestressed steel bar, 6 - bearing platform. Specific embodiments

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

[0029] An embodiment of this application provides a force-storing anti-top double-leg vertical arch large cantilever pier structure and construction process, which can solve problems in related technologies such as wide bottom of the pier column, large floor area, long cantilever of the capping beam, high beam cross-section, uneconomical material consumption, concrete cracking caused by prestress loss of the capping beam or beam, weak anti-eccentric load capacity of the bridge, and high risk of bridge overturning, and fundamentally solve the problem of traffic jams on and under the urban road bridge.

[0030] See Figures 1 to 2As shown in the figure, a force-storing anti-top double-leg vertical arch large cantilever pier structure provided by an embodiment of the present invention includes a double-leg vertical arch large cantilever (1), an anti-top cross beam (3), and a fan-shaped portal arch (2). The middle of the double-leg vertical arch large cantilever (1) is tightly connected to the anti-top cross beam (3), and the upper part of the double-leg vertical arch large cantilever (1) is tightly connected to the fan-shaped portal arch (2).

[0031] The double-leg vertical arch large cantilever (1) is provided with arch foot constraints at both ends by a bottom bearing platform (6) and a top prestressed steel bundle (5) to form a vertical arch structure.

[0032] The anti-top cross beam (3) includes a pre-cast section (31) and a post-cast section (32) of the anti-top cross beam. The anti-top cross beam (3) applies a jacking pressure to the double-leg vertical arch large cantilever (1) through a jack (4).

[0033] After the concrete of the post-cast section (32) of the anti-top cross beam is poured, the jacking pressure of the jack (4) is locked inside the structure to form a structural pre-pressure. The pre-pressure stored inside the vertical arch structure will make the force state of the arch structure more reasonable.

[0034] The structural pre-pressure presses on the double-leg vertical arch large cantilever in the form of the jacking force of the anti-top cross beam (3), achieving the effect of outward movement of the middle and lower parts of the double-leg vertical arch large cantilever (1) and rising of the upper cantilever end of the double-leg vertical arch large cantilever (1). Thus, the bearing capacity of the upper cantilever end of the vertical arch is improved. The rising of the upper cantilever end of the double-leg vertical arch large cantilever (1) will press on the fan-shaped portal arch (2), achieving the effect of inward contraction of the fan-shaped portal arch (2), thereby improving the bearing capacity of the upper part of the portal arch.

[0035] The design and construction technology of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Design a vase pier with a height of 11 m, a width of 25 m for the pier top cross beam, a width of 1.6 m for the single-leg arch foot, a height of 1.4 m for the cantilever end, a thickness of 2.1 m for the pier body, a height of 6.17 m from the bottom of the fan-shaped portal arch to the vertical arch foot, and a thickness of 2.27 m for the top of the fan-shaped portal arch. Two 15.24-15 prestressed tendons are arranged at the top of the fan-shaped portal arch. The dimensions of the vase pier, the setting of prestressed steel bars, the position of the cross beam, and the opening size of the fan-shaped portal arch are calculated and determined according to the actual situation.

[0037] Embodiment 1:

[0038] See Figure 3 As shown in the figure, a construction technology of a force-storing anti-top double-leg vertical arch large cantilever pier structure provided by an embodiment of the present invention is characterized by including the following steps:

[0039] S1: Erect the formwork as a whole, bind the steel bars, and cut grooves and leave holes at the hollow parts of the post-cast section (32) of the anti-top cross beam and the fan-shaped portal arch (2).

[0040] S2: Pour the concrete for the double-leg vertical arch large cantilever (1), the fan-shaped portal arch (2), and the first-poured section (31) of the inverted top cross beam, and cure until the strength meets the requirements and then remove the formwork;

[0041] S3: Tension the prestressed steel bundle (5) at the top of the fan-shaped portal arch;

[0042] S4: Place a jack (4) at the reserved hole of the post-poured section (32) of the inverted top cross beam, push the double-leg vertical arch large cantilever (1) to the design position on both sides, lock the position, and then remove the jack;

[0043] S5: Tension the prestressed steel bundle (5) at the top of the fan-shaped portal arch again, and replenish the prestress lost during the jacking process to the design value;

[0044] S6: Pour the concrete for the post-poured section (32) of the inverted top cross beam, and cure until the strength meets the requirements.

[0045] Embodiment 2:

[0046] It is designed that during the jacking process of the inverted top cross beam, tensile stress will appear at the bottom of the fan-shaped portal arch. To avoid the bottom of the fan-shaped portal arch from being cracked due to tension during the jacking process, the design can be further improved: According to the actual calculation results, hollow out the locally tensioned areas at the bottom of the fan-shaped portal arch and the bottom of the vertical arch during the jacking process, which not only avoids the structure from being cracked due to tension during the jacking process, but also optimizes the design, saves materials, and reduces costs. The design improvement of this embodiment is as follows: The vase pier is 11 m high, the width of the pier top cross beam is 25 m, the width of the single-leg arch foot is 1.6 m, the height of the cantilever end is 1.4 m, the thickness of the pier body is 2.1 m, the distance from the bottom of the fan-shaped portal arch to the arch foot of the vertical arch is 6.17 m, and the thickness of the top of the fan-shaped portal arch is 1.6 m; Two 15.24-15 prestressed tendons are arranged at the top of the fan-shaped portal arch.

[0047] Embodiment 3:

[0048] During the jacking process of the inverted top cross beam, part of the prestress of the prestressed steel bundle at the top of the fan-shaped portal arch will be lost. To avoid the bottom of the fan-shaped portal arch from being cracked due to tension during the jacking process caused by prestress loss, the construction process can be further optimized to the three-jacking and three-tensioning method: Refer to Figure 4 As shown, a construction process of a force-storing type inverted top double-leg vertical arch large cantilever pier structure provided by an embodiment of the present invention is characterized by including the following steps:

[0049] S1: Erect the formwork as a whole, bind the steel bars, and cut grooves and leave holes at the post-poured section (32) of the inverted top cross beam and the hollowed-out part of the fan-shaped portal arch;

[0050] S2: Pour the concrete for the double-leg vertical arch large cantilever (1), the fan-shaped portal arch (2), and the first-poured section (31) of the inverted top cross beam, and cure until the strength meets the requirements and then remove the formwork;

[0051] S3: Place the jack (4) at the reserved hole of the post-cast section (32) of the inverted top cross beam, and push the double-leg vertical arch large cantilever (1) to both sides for the first time to 30% of the designed jacking force;

[0052] S4: Tension the prestressed steel bundles (5) at the top of the fan-shaped portal arch for the first time to 70% of the designed value;

[0053] S5: Push the double-leg vertical arch large cantilever (1) to both sides for the second time to 70% of the designed jacking force;

[0054] S6: Tension the prestressed steel bundles (5) at the top of the fan-shaped portal arch for the second time to 90% of the designed value;

[0055] S7: Push the double-leg vertical arch large cantilever (1) to both sides for the third time to 100% of the designed jacking force, lock the position, and then withdraw the jack;

[0056] S8: Tension the prestressed steel bundles (5) at the top of the fan-shaped portal arch for the third time to 100% of the designed value;

[0057] S9: Pour the concrete of the post-cast section (32) of the inverted top cross beam and cure it until the strength meets the requirements.

[0058] Therefore, the present invention adopts a force-storing type inverted top double-leg vertical arch large cantilever pier structure to replace the ordinary pier columns and capping beams in the prior art. It can not only solve the problems in the related technologies such as the large occupied area and uneconomical of the bottom width of the pier columns, the increased occupied area of the side piers which is not beautiful, the increased cost and high cracking maintenance cost caused by the increase of the capping beam and the beam height, as well as the weak anti-eccentric loading capacity of the bridge and the high risk of bridge rollover. It can also make full use of the compression characteristics of the arch structure and the compressive capacity of the concrete, expand the cantilever size, improve the cantilever bearing capacity, reduce the bottom pier column width, lower the upper beam height, save materials and the occupied area, and fundamentally solve the congestion problems on and under the urban bridge. The specific design and construction process can be calculated according to the actual situation and corresponding improvements and enhancements can be made. For example, in the second embodiment of the present invention, the tensioned area is hollowed out in the design and the three-push-three-tension method is adopted for staged jacking during the construction process, which can effectively improve the structural safety factor during the construction process and enable each part of the structure to give full play to its role. Moreover, the double-leg vertical arch of the pier column and the curve of the fan-shaped portal arch are soft and the shape is beautiful. The hollow design increases the diversity of urban construction and can be applied to the engineering design field of urban bridges to achieve multiple goals of expanding urban space, achieving architectural beauty, and promoting resource conservation.

Claims

1. A construction technology for a force-storing reverse-top double-limb vertical arch large cantilever pier structure, characterized in that Including: A double-leg vertical arch with a large cantilever (1), a reaction top cross beam (3) and a fan-shaped portal arch (2). The middle of the double-leg vertical arch with a large cantilever (1) is connected to the reaction top cross beam (3), and the upper part of the double-leg vertical arch with a large cantilever (1) is connected to the fan-shaped portal arch (2); The double-leg vertical arch with a large cantilever (1) is provided with arch foot constraints at both ends by a bottom bearing platform (6) and top prestressed steel tendons (5) to form a vertical arch structure; The reaction top cross beam (3) includes a pre-cast section (31) of the reaction top cross beam and a post-cast section (32) of the reaction top cross beam; The reaction top cross beam (3) uses a jack (4) to apply a jacking pressure to the double-leg vertical arch with a large cantilever (1). After the concrete of the post-cast section (32) of the reaction top cross beam is poured, the jacking pressure of the jack (4) is locked inside the structure to form a structural pre-pressure; Specifically, it includes the following steps: Set up the overall formwork, tie the steel bars, and cut grooves and leave holes at the hollow parts of the post-cast section (32) of the reaction top cross beam and the fan-shaped portal arch (2); Pour the concrete of the double-leg vertical arch with a large cantilever (1), the fan-shaped portal arch (2), and the pre-cast section (31) of the reaction top cross beam, cure until the strength meets the requirements and remove the formwork; Tension the prestressed steel tendons (5) at the top of the fan-shaped portal arch; Place a jack (4) at the reserved hole of the post-cast section (32) of the reaction top cross beam, jack the double-leg vertical arch with a large cantilever (1) to both sides to the design position, lock the position, and then remove the jack; Tension the prestressed steel tendons (5) at the top of the fan-shaped portal arch again, and replenish the prestress lost during the jacking process to the design value; Pour the concrete of the post-cast section (32) of the reaction top cross beam, cure until the strength meets the requirements; The structural pre-pressure presses on the double-leg vertical arch with a large cantilever in the form of the jacking force of the reaction top cross beam (3), achieving the effect of the middle and lower parts of the double-leg vertical arch with a large cantilever (1) moving outwards and the upper cantilever end of the double-leg vertical arch with a large cantilever (1) rising, thereby improving the bearing capacity of the upper cantilever end of the vertical arch. The rising of the upper cantilever end of the double-leg vertical arch with a large cantilever (1) will press on the fan-shaped portal arch (2), achieving the effect of the fan-shaped portal arch (2) moving inwards, thereby improving the bearing capacity of the upper part of the portal arch.

Images