Three-arch bridge structure to resist unbalanced horizontal thrust

Abstract

The present application provides a three-arch bridge structure for resisting unbalanced horizontal thrust, comprising four arch seats arranged in sequence along a preset path of the arch bridge and tie rods passing through the arch seats, wherein the tie rods are detachably connected to the arch seats; a tie rod is provided between two adjacent arch seats to connect the two, and the two arch seats in the middle are each provided with two rows of tie rod holes arranged in layers up and down and extending along the longitudinal direction of the bridge, so that the tie rods corresponding to the two adjacent spans of the arch ring are arranged in layers up and down, and the two ends of the tie rods are respectively fixed to the two adjacent arch seats by anchors, and both ends of the tie rods can be used as tensioning ends. By tensioning the tie rods before the construction of each stage of the arch bridge, the unbalanced horizontal tension on the arch seats during the construction process can be offset, thereby improving the structural stability of the arch seats; the tie rods are detachably connected to the arch seats, and the tie rods can be removed for turnover use after the construction of the entire bridge is completed, thereby improving the efficiency of the tie rods and reducing costs.

Description

Technical Field

[0001] The present application relates to the technical field of bridge construction, and in particular to a three-arch bridge structure for resisting unbalanced horizontal thrust. Background Art

[0002] Arch bridges are a common bridge structure with a long history. Their graceful lines, excellent mechanical properties, and superior spanning capacity have led to their widespread application in various bridge projects. In particular, with the large-scale construction of infrastructure such as highways and high-speed railways, arch bridges are increasingly favored by engineers and owners as spanning structures. These structures are being successfully applied in practical projects, achieving significant economic and social benefits.

[0003] During the construction of the arch ring and the superstructure of the existing continuous arch bridge, the arch ring arch foot will generate an unbalanced horizontal thrust on the arch seat, which will affect the stability of the arch seat and pose a great safety hazard. Summary of the Invention

[0004] The purpose of this application is to provide a structurally stable three-arch bridge structure that can resist unbalanced horizontal thrust.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] A three-arch bridge structure for resisting unbalanced horizontal thrust includes four arch seats arranged in sequence along a preset path of the arch bridge and tension rods passing through the arch seats, wherein the tension rods are detachably connected to the arch seats; a tension rod connecting the two adjacent arch seats is provided between the two adjacent arch seats, and the two arch seats in the middle are provided with two rows of tension rod holes extending along the longitudinal direction of the bridge, which are arranged in layers up and down, so that the tension rods corresponding to the two adjacent spans of the arch rings are arranged in layers up and down, and the two ends of the tension rod are respectively fixed to the two adjacent arch seats by anchors, and the two ends of the tension rod can be used as tensioning ends.

[0007] It is further provided that: the tie rods include precision-rolled threaded steel bars.

[0008] It is further provided that the length of the end of the tie rod exposed from the anchor is not less than 6 times the pitch of the finished rolled threaded steel bar, and the length of the end of the tie rod exposed from the anchor is not less than 1.5 times the outer diameter of the finished rolled threaded steel bar.

[0009] It is further configured that nuts for locking the tie rods are provided at both ends of the tie rods.

[0010] It is further configured that anchor plates are provided at both ends of the arch seat located at the tie rod holes.

[0011] It is further configured that: each row of the tie rod holes is provided with a plurality of holes along the transverse direction of the bridge, and the plurality of tie rod holes include basic holes and reserved holes, and the reserved holes are used to increase the tie rods for tensioning when the displacement and / or stress of the arch foot is too large.

[0012] It is further configured that: the reserved holes are provided with at least two groups, and the two groups of the reserved holes are symmetrically arranged on both sides of the basic hole.

[0013] Further configuration: the two arch seats on both sides are provided with mounting holes, the mounting holes are used to add temporary pull rods to tension and balance the horizontal thrust of the two arch seats on both sides, and the mounting holes and the pull rod holes are arranged in layers up and down.

[0014] It is further arranged that the two rows of tie rod holes of the two middle arch seats are arranged opposite to each other in the vertical direction, and the tie rod holes and the mounting holes of the two arch seats on both sides are arranged opposite to each other in the vertical direction.

[0015] It is further provided that the tie rod holes and the mounting holes are both formed by pre-buried pipes embedded in the arch seat, and the pre-buried pipes include PVC pipes.

[0016] Compared with the existing technology, the solution of this application has the following advantages:

[0017] In the arch bridge structure for resisting unbalanced horizontal thrust of the present application, the tie rods can be tensioned step by step before each stage of construction, based on the progress of bridge construction and the unbalanced horizontal thrust caused by the arch ring and arch foot on the arch seat at different construction stages. This can effectively offset the unbalanced horizontal thrust caused to the arch seat at different construction stages, avoid unbalanced deformation of the arch seat during construction, and ensure the structural stability of the arch seat. Before removing the tie rods, the tie rods are gradually unloaded, which can avoid unbalanced thrust on the arch seat after the tension of the tie rods is instantly unloaded, thereby helping to maintain the structural stability of the arch seat.

[0018] Additional aspects and advantages of the present application will be given in part in the following description, which will become apparent from the following description, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 This is a schematic diagram of the structure of a three-arch bridge structure for resisting unbalanced horizontal thrust in this application;

[0021] Figure 2 for Figure 1 A magnified schematic diagram of part A;

[0022] Figure 3A schematic diagram of the second arch abutment in the three-arch bridge structure for resisting unbalanced horizontal thrust in this application;

[0023] Figure 4 This is a schematic diagram of the tie rod holes on the second arch seat of the three-arch bridge structure for resisting unbalanced horizontal thrust in this application.

[0024] In the figure, 11, first arch seat; 12, second arch seat; 13, third arch seat; 14, fourth arch seat; 100, mounting hole; 2, arch ring; 3, tension rod; 4, nut; 51, base hole; 52, reserved hole. DETAILED DESCRIPTION

[0025] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0026] Please combine Figures 1 to 4 The present application relates to a three-arch bridge structure for resisting unbalanced horizontal thrust, which includes four arch seats arranged in sequence along a preset extension path of the arch bridge and three arch rings 2 erected on the four arch seats. Each arch ring 2 is erected between two adjacent arch seats. When constructing the three-arch bridge structure, the middle arch ring must be constructed first and then the arch rings on both sides. Since unbalanced horizontal thrust will be generated on the arch seats on both sides during the construction process, a tension rod 3 can be set on two adjacent arch seats. By tensioning the tension rod 3, the unbalanced horizontal thrust received by the arch seat during the construction process can be offset, thereby improving the stability of the arch bridge structure.

[0027] The arch seat includes a first arch seat 11, a second arch seat 12, a third arch seat 13 and a fourth arch seat 14 arranged in sequence along the preset extension path of the arch bridge, and a tension rod 3 extending along the longitudinal direction of the bridge is provided between each two adjacent arch seats. In addition, a row of tension rod holes for inserting the tension rods 3 is provided on the first arch seat 11 and the fourth arch seat 14 (not shown in the figure, the same below), and two rows of tension rod holes for inserting the tension rods 3 are provided on the second arch seat 12 and the third arch seat 13. The two rows of tension rod holes are arranged in layers up and down, so that the tension rods 3 corresponding to the two adjacent spans of the arch ring 2 are arranged in layers up and down. At the same time, the two ends of the tension rod 3 are respectively fixed to the arch seat to which they are connected by anchors, and the two ends of the tension rod 3 can serve as tensioning ends.

[0028] Since the three-arch bridge structure requires the construction of the middle arch ring first and then the construction of the arch rings on both sides, before constructing the third arch ring, the tie rods 3 between the arch seats on both sides (i.e., the second arch seat 12 and the third arch seat 13) need to be tensioned. The two ends of the tie rods 3 can be tensioned respectively as tensioning ends, so that the second arch seat 12 and the third arch seat 13 can be subjected to the tensioning force of the inward tie rods, so as to have the ability to resist the unbalanced horizontal thrust exerted on them by the arch foot of the middle arch ring. Subsequently, the arch rings 2 on both sides are constructed simultaneously and symmetrically. At this time, the tie rods 3 between the first arch seat 11 and the second arch seat 12 and between the third arch seat 13 and the fourth arch seat 14 can be tensioned. The tie rods 3 are also tensioned at both ends respectively to ensure that the four arch seats have the ability to resist the unbalanced horizontal thrust exerted by the arch feet of the arch rings on both sides.

[0029] Preferably, the tie rods 3 are made of high-quality rolled threaded steel bars, and the length of each end of the tie rods 3 exposed from the anchor is not less than 6 times the pitch of the high-quality rolled threaded steel bars. At the same time, the length of each end of the tie rods 3 exposed from the anchor is also less than 1.5 times the outer diameter of the high-quality rolled threaded steel bars. The present application adopts a single-end tensioning method for tensioning the tie rods 3, that is, when tensioning, one end of the tie rods 3 is fixed and the other end is tensioned by a jack. By limiting the length of the end of the tie rods 3 exposed from the anchor, it is ensured that it has sufficient length for tensioning during the tensioning process, while ensuring the stability of the fixed end of the tie rods 3.

[0030] As a further preference, the finish-rolled threaded steel in this embodiment adopts PSB830Φ32 finish-rolled threaded steel, and the maximum tensile force that a single piece of the finish-rolled threaded steel can withstand is about 660KN.

[0031] At the same time, nuts 4 are sleeved on both ends of the tie rod 3 , and the tie rod 3 is locked by tightening the nuts 4 .

[0032] Furthermore, an anchor plate (not shown in the figure, the same below) is provided at the end of each arch seat located at the tension rod hole. The anchor plate is arranged vertically to the embedded pipe. The anchor plate adopts a precision-rolled threaded steel gasket, which can diffuse the stress generated during tensioning into the arch seat concrete when the tension rod 3 is tensioned.

[0033] In addition, a row of mounting holes 100 are provided on each of the first arch seat 11 and the fourth arch seat 14. The mounting holes and the three holes for the tie rods in the arch seats are arranged in layers above and below. The mounting holes 100 can be used to add temporary tie rods (not shown in the figure, the same below). The temporary tie rods can be tensioned to further balance the unbalanced horizontal thrust exerted on the first arch seat 11 and the fourth arch seat 14.

[0034] Preferably, the mounting holes 100 of the first arch seat 11 and the fourth arch seat 14 are arranged opposite to the tie rod holes in the arch seats in the vertical direction, and the two rows of tie rod holes of the second arch seat 12 and the fourth arch seat 14 are also arranged opposite to each other in the vertical direction, that is, each of the arch seats is provided with two hole positions along the vertical direction for interpolating the tie rods 3 or temporary tie rods.

[0035] Each row of the tie rod holes and each row of the mounting holes 100 are provided with multiple ones along the transverse direction of the bridge. The multiple tie rod holes and the mounting holes 100 all include basic holes 51 and reserved holes 52. The reserved holes 52 can be used as a temporary tension rod added in the reserved holes 52 for tensioning when the arch foot of the arch ring 2 is displaced and / or the stress is too large, so as to make timely adjustments to the tensioning requirements of the arch seat.

[0036] As a preferred embodiment, please combine Figure 4 Each row of tie rod holes or mounting holes 100 is provided with eight holes, six of which are selected as basic holes 51, and the remaining two are reserved holes 52. The two reserved holes 52 are located on either side of the six basic holes 51. The six basic holes 51 can be divided into three groups, each group containing two basic holes 51. The spacing between the two basic holes 51 in each group is 50 cm, and the spacing between two adjacent groups of basic holes 51 is 120 cm. The spacing between the reserved holes 52 and the adjacent basic holes 51 is 120 cm.

[0037] Preferably, the above-mentioned tie rod holes and mounting holes 100 are formed by embedded pipes embedded in the arch seat, and the embedded pipes include PVC pipes, and the diameter of the embedded pipes in this application is 5 cm. The layout elevation of the embedded pipes is between +23 and +25 m, and the ground elevation is between +25.5 and +26 m, that is, the tie rods 3 are arranged within a height range of 25.5 to 26 m from the arch seat to the ground of its base.

[0038] In addition, it should be noted that when burying the embedded pipe in the arch seat, when the tie rod hole or the installation hole 100 conflicts with the position of the main reinforcement in the arch seat, the position of the main body in the arch seat needs to be adjusted. At the same time, the position of the tie rod 3 and the temporary tie rod should avoid the arch frame column of the arch ring support for construction.

[0039] The arch bridge structure of the present application that resists unbalanced horizontal thrust requires that all the tie rods 3 be installed first, and before constructing the arch ring 2 and the arch structure, the tie rods 3 in each arch seat are pre-tensioned. The same pair of tie rods 3 can be tensioned from both ends respectively, so that the two adjacent arch seats corresponding to the same span of the arch ring 2 are first subjected to the inward tensioning force of the tie rods 3, thereby offsetting the unbalanced horizontal tension that the arch seats are subjected to during the construction of the arch ring 2 and the arch structure.

[0040] At the same time, the temporary pull rods added to the first abutment 11 and the fourth abutment 14 can further balance the unbalanced horizontal thrusts exerted on the first abutment 11 and the fourth abutment 14 .

[0041] In order to verify the stress condition of the arch seat at each construction stage and ensure the safety of the structural stress, the midascivil finite element software can be used to establish a double-span bridge model and conduct analysis at the construction stage. The maximum unbalanced force for the tensioning and removal of the tie rod 3 is determined by the thrust resistance of each arch seat, and the difference in force value of the tensioning force of the tie rod 3 in adjacent stages shall not be greater than the thrust resistance of each arch seat.

[0042] Specifically, the thrust resistance of each arch seat of the present application is 80 tons, and the horizontal thrust of the cast arch ring 2 on the arch seats on both sides is about 150 tons. If it is controlled at 160 tons, then before casting the arch ring 2, the tensioning force of the tie rod 3 is tensioned at 80 tons. At this time, two tie rods 3 are arranged in the arch seat corresponding to the arch ring 2, and each tie rod 3 is tensioned at 40 tons. In addition, both ends of the tie rod 3 of the present application serve as tensioning ends. The tie rod connects the two arch seats of the span arch ring 2. After tensioning one of the arch seats, the other end of the tie rod is tensioned on the other arch seat.

[0043] The total horizontal thrust after the construction of the arch structure (including the arch wall and the bridge deck) is controlled at 240 tons, and the tension rod 3 should be loaded and tensioned by 160 tons to meet the anti-thrust requirements of the arch seat. At this time, six tension rods 3 should be arranged in the arch seat corresponding to the arch ring and pre-tensioned at 40 tons per rod.

[0044] In addition, it should be noted that the tie rods 3 are symmetrically arranged in sequence from the middle of each row of tie rod holes to both sides. Before the construction of the arch ring 2, the tie rods are first arranged in the two basic holes 51 in the middle and tensioned. After the construction of the arch ring is completed and before the construction of the arch structure, the tie rods are arranged in the four basic holes 51 on both sides and tensioned to 240 tons.

[0045] The temporary tension rods added to the first arch seat 11 and the fourth arch seat 14 can further tension the arch seats on both sides of the arch bridge to meet the stress requirements of the arch bridge.

[0046] The tensioning of the tie rods 3 and temporary tie rods should also adopt a "dual control" approach. The following will specifically describe the tie rods 3, focusing on controlling the tensioning force of the tie rods 3 and verifying their elongation. During tensioning, a single tensioning method is used to tension the tie rods 3 to the designed tension. After tensioning, the measured elongation of the tie rods 3 should be within ±6% of the theoretical elongation. The tensioning speed must be carefully controlled during the tensioning process to prevent accidents such as breakage of the tie rods 3.

[0047] Furthermore, the tie rods 3 and the temporary tie rods and the arch seats to which they are connected are all detachably connected. After the construction of the entire bridge is completed, the tie rods 3 and the temporary tie rods can be dismantled to be used for the construction of the next bridge, thereby increasing the utilization rate of the tie rods 3 and the temporary tie rods and reducing costs. In addition, when dismantling the tie rods 3 and the temporary tie rods, they should be unloaded step by step from both sides of the arch bridge to the middle. After unloading, all the tie rods 3 and the temporary tie rods should be removed from both sides of the arch bridge to the middle. Specifically, taking a single row of tie rods on a single arch seat as an example, the unbalanced horizontal thrust during unloading of the tie rods 3 is controlled at 80 tons, and two are unloaded symmetrically in the order from both sides to the middle each time, and the unloading is completed in three times. After all the tie rods 3 are unloaded, all the tie rods 3 are removed.

[0048] In summary, the three-arch bridge structure of the present application for resisting unbalanced horizontal thrust can be tensioned step by step before each stage of construction according to the progress of bridge construction and the unbalanced horizontal thrust caused by the arch foot of the arch ring 2 on the arch seat in different construction stages. If necessary, temporary tie rods can be added to the two arch seats on the left and right sides of the bridge to offset the unbalanced horizontal thrust caused to the arch seat in different construction stages, avoid unbalanced deformation of the arch seat during the construction process, and ensure the structural stability of the arch seat. Before removing the tie rods 3 and temporary tie rods, the tie rods 3 and temporary tie rods are unloaded step by step to avoid unbalanced thrust on the arch seat after the tension of the tie rods 3 and temporary tie rods is instantly unloaded, which helps to maintain the structural stability of the arch seat.

[0049] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A three-arch bridge structure for resisting unbalanced horizontal thrust, characterized in that: It includes four arch seats arranged in sequence along the preset path of the arch bridge and tie rods passing through the arch seats, and the tie rods are detachably connected to the arch seats; a tie rod connecting the two adjacent arch seats is provided between the two adjacent arch seats, and the two arch seats in the middle are provided with two rows of tie rod holes arranged in layers up and down and extending along the longitudinal direction of the bridge, so that the tie rods corresponding to the two adjacent spans of the arch ring are arranged in layers up and down, and the two ends of the tie rod are respectively fixed to the two adjacent arch seats by anchors, and the two ends of the tie rod can be used as tensioning ends, and the two arch seats on both sides are provided with mounting holes, and the mounting holes are used to add temporary tie rods The horizontal thrust of the two arch seats on both sides is balanced by tensioning, and the mounting holes and the tie rod holes are arranged in layers up and down. The two rows of tie rod holes of the two middle arch seats are arranged opposite each other in the vertical direction, and the tie rod holes and the mounting holes of the two arch seats on both sides are arranged opposite each other in the vertical direction. There are multiple tie rod holes in each row along the transverse direction of the bridge, and the multiple tie rod holes include basic holes and reserved holes. The reserved holes are used to increase the tie rods for tensioning when the displacement and / or stress of the arch foot are too large. There are at least two groups of reserved holes, and the two groups of reserved holes are symmetrically arranged on both sides of the basic hole.

2. The three-arch bridge structure for resisting unbalanced horizontal thrust according to claim 1, characterized in that: The tie rods include precision-rolled threaded steel bars.

3. The three-arch bridge structure for resisting unbalanced horizontal thrust according to claim 2, characterized in that: The length of the end of the tie rod exposed to the anchor is not less than 6 times the pitch of the finished rolled threaded steel bar, and the length of the end of the tie rod exposed to the anchor is not less than 1.5 times the outer diameter of the finished rolled threaded steel bar.

4. The three-arch bridge structure for resisting unbalanced horizontal thrust according to claim 2, characterized in that: Both ends of the tie rod are provided with nuts for locking the tie rod.

5. The three-arch bridge structure for resisting unbalanced horizontal thrust according to claim 2, characterized in that: The arch seat is provided with anchor plates at both ends of the tie rod hole.

6. The three-arch bridge structure for resisting unbalanced horizontal thrust according to claim 1, characterized in that: The tie rod holes and the mounting holes are both formed by pre-buried pipes embedded in the arch seat, and the pre-buried pipes include PVC pipes.

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