Composite energy consumption device for preventing debris flow from impacting railway pier

Abstract

The invention discloses a composite energy dissipation device for preventing debris flow from impacting a railway pier. The composite energy dissipation device comprises a top layer steel plate, a bottom layer steel plate, a tensioning assembly and a two-way damper. The top steel plate and the bottom steel plate are horizontally arranged in parallel; the tensioning assembly is arranged in a central area between the top-layer steel plate and the bottom-layer steel plate; sliding grooves are formed in the edges of the two sides of the top-layer steel plate and the bottom-layer steel plate, and the bidirectional dampers are slidably connected between the top-layer steel plate and the bottom-layer steel plate through the sliding grooves; the bidirectional damper can dissipate impact energy through elastic deformation in the horizontal direction and the vertical direction. Prestress self-balancing is carried out by adopting a tensioning integral structure with a regular hexagon honeycomb design; a stable spatial form is formed by applying prestress, and the shock resistance stability and energy absorption efficiency of the device are improved; the bridge pier can restore stability after deformation under debris flow impact, the brittle failure risk of the bridge pier is reduced, and meanwhile the shock resistance is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of railway pier protection, and in particular relates to a composite energy dissipation device for preventing debris flows from impacting railway piers. Background Art

[0002] With the continuous expansion of the railway network, a large number of railway bridges inevitably need to cross mountainous areas with complex terrain and harsh geological conditions. These areas are often prone to debris flow disasters. Compared with the past, the number of railway bridge piers damaged by debris flow impacts is increasing. Therefore, the development and application of effective debris flow impact protection technology is of vital importance to ensure the safety of railway bridge structures and maintain the smooth operation of railway transportation.

[0003] Currently, the design of railway bridge pier protection against debris flow impact mainly follows two basic principles:

[0004] Improving the strength of the bridge pier itself: This method directly improves the impact resistance of the bridge pier itself by using high-strength materials, such as high-strength concrete, and attempts to use the strength of the bridge pier itself to resist the impact of debris flow.

[0005] Independent protective piers: This method involves installing independent protective structures, such as protective piers, in front of the railway piers that require protection. The core idea is to use the protective piers to initially withstand and absorb the impact energy of the debris flow, thereby reducing or preventing the debris flow from directly impacting the bridge piers.

[0006] However, both of the above two traditional protection methods have their corresponding limitations.

[0007] Improving the strength of bridge piers is generally only effective against debris flows carrying smaller rocks and relatively low impact energy. More critically, excessively increasing material strength often results in a decrease in toughness and an increase in brittleness. When violently impacted by a debris flow carrying large rocks, bridge piers are susceptible to stress concentration at the impact point, leading to brittle failure and potentially causing rapid failure of parts of the pier or even the entire structure. This creates an unstable and risky protective effect.

[0008] While independent protective piers can absorb some of the impact energy, they themselves can rebound, diverge, or change trajectory unpredictably when impacted by a debris flow, especially one carrying a large amount of rock. This dynamic change can easily cause the debris flow or its contents to impact adjacent bridge piers, bridge decks, or other railway infrastructure, creating the risk of a "secondary impact" and ultimately expanding the disaster's impact.

[0009] Therefore, the common defects of the above two methods are as follows:

[0010] 1. Faced with the reality that debris flows have variable impact directions, varying energy levels, and complex objects carried, traditional methods have limited protective effects and pose major safety risks.

[0011] 2. Whether it is the damaged high-strength bridge pier body or the impact-damaged protective pier, after suffering a severe impact, it is usually difficult to repair or cannot be reused, and needs to be replaced as a whole, resulting in waste of resources and high maintenance costs, and poor overall economic efficiency.

[0012] 3. Traditional methods focus on a single impact resistance or energy absorption mechanism, and lack comprehensive consideration of efficient impact energy dissipation, structural stability maintenance, and the recoverability / maintainability of the device itself. Summary of the Invention

[0013] The main purpose of the present invention is to provide a composite energy dissipation device for preventing debris flow from impacting railway bridge piers, which has good impact resistance and low cost.

[0014] The composite energy dissipation device for preventing debris flows from impacting railway bridge piers provided by the present invention includes a top steel plate, a bottom steel plate, a tensioning assembly and a bidirectional damper; the top steel plate and the bottom steel plate are arranged horizontally and parallel; the tensioning assembly is arranged in the central area between the top steel plate and the bottom steel plate; both side edges of the top steel plate and the bottom steel plate are provided with sliding grooves, and the bidirectional damper can be slidably connected between the top steel plate and the bottom steel plate through the sliding grooves; the bidirectional damper can dissipate impact energy through elastic deformation in both horizontal and vertical directions.

[0015] In one embodiment of the above-mentioned device, the tensioning assembly includes at least one monopole polygonal prism tensioning structure, and each monopole polygonal prism tensioning structure is composed of a rigid element and a flexible element; the rigid element is a plurality of compression rods, and the flexible element includes a plurality of inclined cables and a plurality of horizontal cables; the horizontal cables are divided into two groups, forming a top regular polygon and a bottom regular polygon respectively; the inclined cables connect the top surface node and the node separated by one on the bottom surface to form the side of the prism; the compression rods connect the top surface node and the node separated by two on the bottom surface, and all are placed inside the prism and do not touch each other.

[0016] In one embodiment of the above-mentioned device, the monopole polygonal prism tensioning structure is a regular hexagonal prism structure; there are 12 horizontal cables in total, 6 of which are connected end to end to form a regular hexagon on the top surface, and the other 6 form a regular hexagon on the bottom surface; there are 6 inclined cables in total, which connect the top surface node and the node one spaced apart from the bottom surface in a clockwise direction; there are 6 compression rods in total, which connect the top surface node and the node two spaced apart from the bottom surface in a clockwise direction.

[0017] In one embodiment of the above device, the compression rod is prefabricated with high-strength steel, and the inclined cables and horizontal cables are prefabricated with high-strength steel strands; the tensioning assembly forms a stable spatial structure by applying prestress.

[0018] In one embodiment of the above device, a horizontal slide rod is provided inside the slide groove, and a horizontal spring is sleeved on the horizontal slide rod; slot holes are provided in the slide grooves of the top steel plate and the bottom steel plate at fixed intervals for installing a bidirectional damper.

[0019] In one embodiment of the above-mentioned device, the bidirectional damper includes a damper, a sliding rod, an end connector and a spring; the damper is a fluid viscosity damper, and the internal liquid dissipates energy through the damping hole; the two sliding rods are respectively fixed at both ends of the damper; the two end connectors are respectively arranged on the outside of the sliding rod; the two springs are respectively mounted on the sliding rod, one end of which abuts the damper, and the other end abuts the end connector; the end connector is mounted on the horizontal sliding rod and abuts against the horizontal spring.

[0020] In one embodiment of the above device, the compression rods are straight rods in the front area of ​​the pier and curved rods in the arc area on the side of the pier to adapt to the shape of the pier.

[0021] A graded energy dissipation device set up using the above-mentioned device includes a composite energy dissipation device arranged around the periphery of a bridge pier column, and a buffer layer arranged around the periphery of the composite energy dissipation device; the buffer layer includes an outer steel plate and an intermediate filler, and the filler is made of waste and is filled between the two outer steel plates.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. A tensegrity structure with a regular hexagonal honeycomb design is used for prestressed self-balancing. By applying prestress, a stable spatial form is formed, improving the device's impact resistance and energy absorption efficiency. It can deform and then recover stability under the impact of debris flows, reducing the risk of brittle failure of bridge piers while enhancing seismic resistance.

[0024] 2. The integrated fluid viscous damper and spring combination achieves bidirectional buffering. It can flexibly buffer and automatically reset under impact in any direction, improving the device's adaptability to changes in the direction of debris flow slurry. It effectively absorbs impact energy and reduces the risk of secondary impact caused by rebound or diversion.

[0025] 3. The device adopts a prefabricated and modular design, and the tensioning structure and damper can be detachably combined. It can be flexibly adjusted based on the size of railway piers and debris flow characteristics, improving the versatility and installation efficiency of the device, reducing transportation and maintenance costs, and improving applicability in complex mountainous environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall disassembled structure of an embodiment of the present invention.

[0027] Figure 2 for Figure 1 Schematic diagram of the monopolar hexagonal tensile structure.

[0028] Figure 3 for Figure 1 Schematic diagram of the structure of the bidirectional damper, sliding rod and spring.

[0029] Figure 4 for Figure 3 Schematic diagram of the structure of the bidirectional damper.

[0030] Figure 5 This is an overhead view of the device in use around the bridge pier. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the relevant technical solutions. Obviously, the embodiments described are only some embodiments, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, the composite energy dissipation device for preventing debris flow from impacting railway bridge piers disclosed in this embodiment includes a top steel plate 1, a bottom steel plate 2, a tensioning assembly 3 and a bidirectional damper 4.

[0033] The top steel plate 1 and the bottom steel plate 2 are arranged horizontally, and a tensioning component 3 is provided at the center between them.

[0034] like Figure 2 As shown, the tensioning assembly 3 includes two monopole hexagonal prism tensioning structures, each of which is composed of multiple rigid elements and flexible elements. The rigid elements are six compression rods 31, and the flexible elements are six inclined cables 32 and 12 horizontal cables 33.

[0035] The 12 horizontal cables are divided into two groups: six connected end-to-end to form a regular hexagon on the top surface, and the other six to form a regular hexagon on the bottom surface. The six diagonal cables connect the top node and the node one spaced apart from the bottom in a clockwise direction, forming the sides of the hexagonal prism. The six compression rods connect the top node and the node two spaced apart from the bottom in a clockwise direction, and are all placed inside the hexagonal prism, without any contact between the compression rods.

[0036] The compression rods are prefabricated with high-strength steel, and the cables are prefabricated with high-strength steel strands, ensuring elastic deformation under impact. The tensioning components apply prestress to form a stable spatial structure.

[0037] When impacted by a debris flow, the outer and inner steel plates, acting as the surface structures of the device, transmit the impact force to the nodes of the tension structure; the nodes displace, causing the compression rods to compress and the cables to stretch, converting the debris flow impact energy into internal energy of the tension structure and reducing damage to the bridge piers.

[0038] The compression rods are straight rods on the front of the pier and curved rods on the side arc ends to adapt to the shape of the pier.

[0039] like Figure 3 As shown, a slide 5 is fixedly installed on both sides of the top steel plate 1 and the bottom steel plate 2. A horizontal slide rod 51 is installed inside the slide trough, and a spring 52 is mounted on the slide rod. Slots for installing bidirectional dampers are arranged at regular intervals in the upper and lower slides. Multiple bidirectional dampers 4 can be slidably connected between corresponding slots on the sides of the top steel plate 1 and the bottom steel plate 2.

[0040] like Figure 4 As shown, the bidirectional damper 4 includes a damper 41 , a sliding rod 42 , an end connecting piece 43 and a spring 44 .

[0041] The damper 41 is a fluid viscous damper, and the internal liquid dissipates energy through the damping hole; a sliding rod 42 is fixed at each end of the damper; end connectors 43 are provided on the outside of the sliding rods; two springs 44 are respectively mounted on the two sliding rods, one end of which contacts the fluid viscous damper and the other end of which contacts the end connector.

[0042] The connecting pieces 43 at both ends are respectively placed between the sliding rods 51 of the top steel plate 1 and the bottom steel plate 2 and contact with the spring 52, and can move with the expansion and contraction of the spring.

[0043] When the bidirectional damper is impacted by a debris flow, the spring is compressed in the vertical direction, and the sliding rod drives the piston in the fluid viscous damper to move, causing the liquid to pass through the damping hole to provide a buffering effect; when the impact disappears, it returns to its original state through the reset ability of the spring.

[0044] When the bidirectional damper is impacted by a debris flow, the impact force pushes the damper to move in the chute in the horizontal direction, and the spring in the chute provides buffering.

[0045] The top and bottom steel plates of this embodiment are 6.5m long and 4m wide. Four bidirectional dampers with a spacing of 1.3m are arranged on the upper and lower end slides respectively and connected through slots opened on the slides.

[0046] The tensioning component of the composite energy dissipation device is preferably a monopolar hexagonal prism tensioning structure, as described below:

[0047] This embodiment takes the Hetaogou Bridge as an example, where the pier height h = 12.5m, the pier bottom transverse width 6.56m, and the pier bottom longitudinal width 2.76m; the compression rod of the tensioning assembly is made of high-strength steel with an elastic modulus E c =200GPa, compressive strength σ c，max =500MPa; Geometric parameters length L = 80cm, diameter D = 4cm, cross-sectional area A c =1256.64mm 2, moment of inertia I=125663.7mm 4 , quantity n=6.

[0048] 1. Calculation of critical load of compression rod

[0049] 1. Euler buckling formula

[0050] Since the two ends of the compression rod are hinged (effective length coefficient K = 1), the critical buckling load is:

[0051]

[0052] Slenderness ratio verification:

[0053]

[0054] Since λ=80>λ lim =62.8, Euler's formula applies.

[0055] 2. Material compressive strength verification

[0056] Compressive bearing capacity of a single compression rod:

[0057] F c =σ c，max ×A c =500MPa×1256.64mm2=628.32KN

[0058] Buckling vs. Material Failure

[0059] F<F C

[0060] It can be seen that the compression rod fails due to compressive buckling, and the Euler buckling controls the bearing capacity.

[0061] 2. Overall bearing capacity calculation

[0062] 1. Total bearing capacity of compression rod

[0063] The bearing capacity of a single compression rod is F = 628.32KN, and the total bearing capacity of the 6 compression rods is:

[0064] P0=6×385.5KN=2313KN

[0065] 2. Overall bearing capacity

[0066] Since two tensegrity structures and eight dampers are set on one side, both sides can provide bearing capacity when impacted. Therefore, the bearing capacity of the device can meet the requirements for common debris flow impact loads.

[0067] In terms of strength, hexagonal tensegrity can meet the expected bearing capacity requirements;

[0068] From a cost perspective, increasing the number of compression rods and cables can improve impact resistance, but this will directly affect material costs and manufacturing and installation complexity, and lead to material waste due to redundant design;

[0069] From the perspective of structural form-finding, the more compression rods there are, the more complex the variables of the equilibrium equation using the force density method, and the more difficult it is to solve. Therefore, the hexagonal tensegrity can meet the strength requirements and reduce installation and material costs, making it the optimal solution for impact-resistant structures at present.

[0070] like Figure 5 As shown, when the composite energy dissipation device is used, the device is set around the periphery of the pier and column. When a debris flow carrying stones hits the composite energy dissipation device, the damage to the pier and column itself is reduced by converting the impact energy of the debris flow into the tensile integral structure and the internal energy of the buffer unit.

[0071] At the same time, a buffer layer is set on the periphery of the device, which is mainly composed of an outer steel plate and a middle filler; the filler is made of various waste materials such as waste tire chips, slag and the like, and is filled between the two steel plates.

[0072] The purpose of setting up a buffer layer is to add a layer of energy-absorbing device on the outermost layer to form graded energy absorption with the inner layer of energy-absorbing device. When subjected to the impact of debris flow, if the impact energy of the debris flow is small, it can be directly absorbed by the outer first-level energy-absorbing device. When the impact energy of the debris flow is large, after the first-level energy-absorbing device absorbs part of the energy, the second-level energy-absorbing device will resist the impact of the debris flow, thereby achieving the purpose of protecting the bridge piers.

[0073] In addition, the outer filling can be replaced and filled, and each internal device can also be replaced and disassembled.

[0074] The tensegrity structure is a steady-state spatial structure. Without prestressing, the spatial structure has no rigidity. Through on-site investigations at the railway pier locations and combined with simulation experiments, the debris flow failure mechanism and basic characteristics were analyzed. Based on this, the tensegrity spatial structure was prestressed to give it the corresponding rigidity, and buffer unit dampers of appropriate strength were set.

[0075] At this time, when the debris flow hits the composite energy dissipation device, the damper is compressed and the nodes of the tensegrity structure are displaced. The tensegrity structure can still maintain the stable state of the spatial structure after deformation.

[0076] The advantages of using this composite energy dissipation device are:

[0077] 1. The tensegrity structure, through its self-balancing prestressed design, can maintain a stable shape even when subjected to debris flow. At the same time, where debris flow disasters occur, earthquake disasters are often accompanied by them. The tensegrity structure has strong seismic resistance and energy absorption capabilities.

[0078] 2. When facing the impact of debris flow slurry, the bidirectional damper can fully utilize its flexibility to play a buffering role in response to the instability of the debris flow slurry; the fluid viscous damper and spring can provide a reaction force to achieve automatic reset after being compressed by the impact;

[0079] 3. The composite energy dissipation device is formed by combining a tensegrity structure with a bidirectional damper. Therefore, it can be flexibly installed and adjusted by prefabricating the rigid and flexible elements and dampers of various sizes in the tensegrity structure, taking into account the specific dimensions of the railway piers and the characteristics of debris flows. This greatly improves transportation and installation efficiency and reduces overall costs in mountainous areas prone to debris flows.

[0080] 4. The single-stage tensioning structure adopts a regular hexagonal honeycomb structure, which improves the overall space utilization and uses a smaller number of components to achieve sufficient impact resistance.

[0081] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A composite energy dissipation device for preventing debris flow from impacting railway bridge piers, characterized by: It includes top steel plate, bottom steel plate, tensioning components and bidirectional dampers; The top steel plate and the bottom steel plate are arranged horizontally and parallel; the tensioning component is arranged in the central area between the top steel plate and the bottom steel plate; the edges of both sides of the top steel plate and the bottom steel plate are provided with sliding grooves, and the bidirectional damper can be slidably connected between the top steel plate and the bottom steel plate through the sliding grooves; the bidirectional damper can dissipate impact energy through elastic deformation in both horizontal and vertical directions.

2. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 1, characterized in that: The tensioning assembly includes at least one monopolar polygonal prismatic tensioning structure, each monopolar polygonal prismatic tensioning structure consisting of a rigid element and a flexible element; The rigid elements are multiple compression rods, and the flexible elements include multiple oblique cables and multiple horizontal cables; the horizontal cables are divided into two groups, forming a regular polygon on the top surface and a regular polygon on the bottom surface respectively; the oblique cables connect the top surface node and the node one away from the bottom surface to form the side of the prism; the compression rods connect the top surface node and the node two away from the bottom surface, and all are placed inside the prism and do not touch each other.

3. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 2, characterized in that: The monopole polygonal prism tensioning structure is a regular hexagonal prism structure; there are 12 horizontal cables in total, 6 of which are connected end to end to form a regular hexagon on the top surface, and the other 6 form a regular hexagon on the bottom surface; there are 6 inclined cables in total, which connect the top surface node and the node one spaced apart from the bottom surface in a clockwise direction; there are 6 compression rods in total, which connect the top surface node and the node two spaced apart from the bottom surface in a clockwise direction.

4. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 2 or 3, characterized in that: The compression rods are prefabricated with high-strength steel, and the inclined cables and horizontal cables are prefabricated with high-strength steel strands; the tensioning components form a stable spatial structure by applying prestress.

5. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 1, characterized in that: A horizontal slide bar is provided inside the slide groove, and a horizontal spring is sleeved on the horizontal slide bar; slot holes are provided in the slide grooves of the top steel plate and the bottom steel plate at fixed intervals for installing a bidirectional damper.

6. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 5, characterized in that: The bidirectional damper includes a damper, a sliding rod, an end connecting piece and a spring; The damper is a fluid viscosity damper, and the internal liquid dissipates energy through the damping hole; the two sliding rods are respectively fixed at both ends of the damper; the two end connectors are respectively arranged on the outside of the sliding rods; the two springs are respectively mounted on the sliding rods, one end of which abuts the damper and the other end of which abuts the end connector; the end connector is mounted on the horizontal sliding rod and abuts against the horizontal spring.

7. The composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to claim 1, characterized in that: The compression rods are straight rods in the front area of ​​the pier and curved rods in the arc area on the side of the pier to adapt to the shape of the pier.

8. A graded energy dissipation device using the composite energy dissipation device for preventing debris flow from impacting railway bridge piers according to any one of claims 1 to 7, characterized in that: It includes a composite energy dissipation device arranged around the periphery of the pier column, and a buffer layer arranged around the periphery of the composite energy dissipation device; the buffer layer includes an outer steel plate and an intermediate filler, and the filler is made of waste and filled between the two outer steel plates.

Images