A protective net used when dismantling a bridge across a railway

Abstract

The utility model relates to the technical field of railway engineering, and discloses a protective net used when dismantling a bridge across a railway, comprising a crossbeam and a steel cable net installed on the pier of the bridge to be dismantled; the pier of the bridge to be dismantled is used as a fulcrum to tension the protective net under the bridge body, and the protective net can buffer and descend when it catches the falling blocks, effectively reducing the impact effect and destructive force of the falling blocks. The protective net uses the piers and pier columns of the bridge to be dismantled as pillars, making full use of existing structures, which is convenient and fast. The protective net has the characteristics of simple structure, convenient assembly, low comprehensive cost, short installation and disassembly time, etc., and provides a simple and practical device for protecting the existing railway under the bridge to be dismantled.

Description

Technical Field

[0001] The utility model relates to the field of railway engineering, in particular to a protective net used when dismantling a bridge across a railway. Background Art

[0002] Some urban railway bridges are no longer able to meet the needs of rapid urban development due to disrepair and huge loads. Demolition of old bridges and construction of new underpass frame bridges have become the main options. How to safely and efficiently demolish existing bridges across railways is a key technical issue.

[0003] Some technologies propose to build a protective scaffolding under the bridge to be demolished to protect the railway below, but it is difficult to promote it widely due to its complex structure, inconvenient construction, long installation and demolition period, and high cost. In fact, it is an ideal choice to use the existing piers and pier columns of the bridge to be demolished to develop a flexible, simple and low-cost protective net. Utility Model Content

[0004] In order to solve the technical problem that some technologies propose to build a protective scaffolding under the bridge to be demolished to protect the railway below, but it has the disadvantages of complex structure, inconvenient construction, long installation and demolition period, high cost, etc., which makes it difficult to promote it widely, the utility model provides a protective net used when dismantling a bridge across a railway.

[0005] The utility model is implemented by the following technical scheme: a protective net used when dismantling a bridge across a railway, comprising a crossbeam and a steel cable net installed on the pier of the bridge to be dismantled; a fixed clamp with the same diameter and spacing as the pier of the bridge to be dismantled is welded on the crossbeam, and the crossbeam can be fixed on the pier of the bridge to be dismantled after the fixed clamp and the matching movable clamp are assembled; a series of slots are evenly arranged on the crossbeam, and the main cable of the steel cable net can be installed on the crossbeam through the slots; one end of the main cable of the steel cable net is fixed in the crossbeam slot on one side, and the other end passes through the crossbeam slot on the other side and extends to the middle and lower part of the pier. After the steel cable net connected to the counterweight catches the falling block, it can be buffered and lowered under the impact force of the falling block, and the steel cable net can stop when it drops above the safety limit of the railway.

[0006] When the utility model is actually used, when a falling block falls on the protective net, the protective net can be buffered and lowered under the action of the deadweight and impact force of the falling block, and the steel cable net can stop when it drops above the safety limit of the railway, thereby effectively reducing the impact effect and destructive force of the falling block; the protective net utilizes the piers and columns of the bridge to be demolished as pillars (the piers are often demolished after the bridge deck is demolished), and there is no need to build new columns, thus making full use of the existing structures, which is convenient and fast; the protective net has the characteristics of simple structure, easy assembly, low comprehensive cost, short installation and disassembly time, etc., and provides a simple and practical device for protecting the existing railway under the bridge to be demolished.

[0007] As a further improvement of the above scheme, the inner diameter of the movable clamp and the fixed clamp on the beam is equal to the outer diameter of the bridge pier to be demolished, and the movable clamp and the fixed clamp are fixedly connected with bolts based on matching bolt holes on the movable clamp and the fixed clamp.

[0008] As a further improvement of the above scheme, fixed hoops with the same diameter and spacing as the piers of the bridge to be demolished are welded on the crossbeam. After the fixed hoops are assembled with matching movable hoops, the crossbeam can be fixed on the piers of the bridge to be demolished. The crossbeam is welded by horizontal plates, vertical plates, arc plates and stiffening ribs, and a series of slots are evenly arranged on the upper part of the outer vertical plates for the main cables of the steel cable net to pass through or be fixed.

[0009] As a further improvement of the above scheme, one end of the main cable of the steel cable net is fixed in the slot of the beam on one side, and the other end passes through the slot of the beam on the other side and extends to the middle and lower part of the pier to connect with the counterweight. The steel cable net is composed of the main cable net connected to the beam and the fine mesh net laid and tied on the upper part of the main cable net; the main cable net transfers the load to the beams at both ends; the fine mesh net has holes no larger than 5cm×5cm and can hold the falling block. After the steel cable net holds the falling block, it can buffer and descend under the impact of the falling block, and the steel cable net can stop when it descends above the railway safety limit.

[0010] As a further improvement to the above scheme, the counterweight can be made of bagged soil (or water), and the connection between the main cable and the counterweight should be effective and firm. When a falling block accidentally falls from the bridge deck that is being dismantled, it is first caught by the protective net, which is pulled downward by the deadweight of the falling block and the impact force. When the impact force is large, the downward displacement of the protective net is relatively large. The movable end of the main cable is connected to a counterweight, and the downward pull of the protective net will inevitably cause the counterweight to rise. The potential energy of the rising counterweight consumes the falling impact energy of the falling block. By setting the fixed position of the movable steel cable, the steel cable net can be stopped when it descends above the safety limit of the railway, ensuring the safety of the existing operating railway below.

[0011] As a further improvement of the above solution, a curved flexible casing is provided at the slot position on the crossbeam to protect the steel cable, so as to prevent the steel cable from being sheared by the slot and failing under the action of stress concentration.

[0012] As a further improvement of the above scheme, the installation method of the protective net is:

[0013] According to the diameter and spacing of the bridge piers to be demolished, matching steel structure components are processed and manufactured in advance. Two crossbeams are installed on the bridge piers to be demolished that span both sides of the railway.

[0014] Make a steel cable net in advance, fix one end of the main cable of the steel cable net in the slot of the beam on one side, and pass the other end through the slot of the beam on the other side and extend to the middle and lower part of the pier to connect with the counterweight. At this point, the protective net is installed. When a falling block accidentally falls from the bridge deck that is being demolished, the protective net will be pulled down by the deadweight and impact force of the falling block. The pulling down of the protective net will inevitably cause the counterweight to rise. The steel cable net can stop when it drops above the safety limit of the railway, ensuring the safety of the existing operating railway below. Remove the falling block and restore the initial state of the protective net, and the protective net will continue to play a role. After use, remove the protective net, and then cut and remove the bridge piers to be demolished. At this point, the entire old bridge is demolished.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. When a falling block falls on the protective net, the protective net can be buffered and lowered under the action of the deadweight and impact force of the falling block, and the steel cable net can stop when it drops above the railway safety limit, effectively reducing the impact effect and destructive force of the falling block.

[0017] 2. The utility model protective net utilizes the piers and columns of the bridge to be demolished as pillars (the piers are often demolished after the bridge deck is demolished), without the need to build new columns, making full use of existing structures, which is convenient and quick.

[0018] 3. The protective net of the utility model has the characteristics of simple structure, convenient assembly, low comprehensive cost, short installation and disassembly time, etc., and provides a simple and practical equipment for protecting the existing railway under the bridge to be demolished. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The three-dimensional orientation of the front crossbeam for the utility model assembly Figure 1 ;

[0020] Figure 2 The three-dimensional orientation of the front crossbeam for the utility model assembly Figure 2 ;

[0021] Figure 3 It is the three-dimensional orientation diagram of the crossbeam after assembly of the utility model;

[0022] Figure 4 The three-dimensional orientation of the assembly of the utility model crossbeam and the bridge pier to be dismantled Figure 1 ;

[0023] Figure 5 The three-dimensional orientation of the assembly of the utility model crossbeam and the bridge pier to be dismantled Figure 2 ;

[0024] Figure 6 This is a top view of the utility model protective net after assembly;

[0025] Figure 7It is a three-dimensional orientation diagram of the protective net of the utility model after assembly;

[0026] Figure 8 This is the front view of the utility model protective net after assembly;

[0027] Fig. 9 It is a schematic diagram of the protective net of the utility model catching the fallen blocks.

[0028] Description of main symbols:

[0029] 1. Movable clamp; 2. Crossbeam; 3. Fixed clamp; 4. Slot; 5. Bolt; 6. Pier of the bridge to be demolished; 7. Cable net; 8. Counterweight; 9. Railway; 10. Drop block. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0031] Please combine Figure 1-Figure 9 The present embodiment proposes a protective net used when dismantling a bridge across a railway, comprising a crossbeam 2 and a steel cable net 7 installed on a pier 6 of the bridge to be dismantled; a fixed clamp 3 with the same diameter and spacing as the pier 6 of the bridge to be dismantled is welded on the crossbeam 2, and the fixed clamp 3 can be assembled with a matching movable clamp 1 to fix the crossbeam 2 on the pier 6 of the bridge to be dismantled; a series of slots 4 are evenly arranged on the crossbeam 2, and the main cable of the steel cable net 7 can be installed on the crossbeam 2 through the slots 4; one end of the main cable of the steel cable net 7 is fixed in the slot 4 of the crossbeam 2 on one side, and the other end passes through the slot 4 of the crossbeam 2 on the other side and extends to the middle and lower part of the pier. After the steel cable net 7 connected to the counterweight 8 holds the falling block 10, it can be buffered and lowered under the impact force of the falling block 10, and the steel cable net 7 can stop when it drops above the safety limit of the railway 9.

[0032] The inner diameter of the movable hoop 1 and the fixed hoop 3 on the beam 2 is equal to the outer diameter of the bridge pier 6 to be demolished, and the movable hoop 1 and the fixed hoop 3 are fixedly connected by bolts 5 based on the matching bolt holes on the movable hoop 1 and the fixed hoop 3. Figure 1 and Figure 2 As shown, after connection Figure 3 shown.

[0033] The cross beam 2 is welded with a fixed clamp 3 with the same diameter and spacing as the bridge pier 6 to be demolished. After the fixed clamp 3 is assembled with the matching movable clamp 1, the cross beam 2 can be fixed on the bridge pier 6 to be demolished. Figure 4 and Figure 5 shown.

[0034] The cross beam 2 is welded by a horizontal plate, a vertical plate, an arc plate, and a stiffening rib. A series of slots 4 are evenly arranged on the upper part of the outer vertical plate for the main cable of the cable net 7 to pass through or be fixed. The main cable of the cable net 7 is connected to the cross beam 2 as shown in the figure. Figure 6 and Figure 7 shown.

[0035] One end of the main cable of the cable net 7 is fixed in the slot 4 of the cross beam 2 on one side, and the other end passes through the slot 4 of the cross beam 2 on the other side and extends to the middle and lower part of the pier to be connected to the counterweight 8. Figure 7 shown.

[0036] The cable net 7 is composed of a main cable net connected to the cross beam 2 and a fine mesh net laid and tied on the upper part of the main cable net; the main cable net transfers the load to the cross beams 2 at both ends; the fine mesh net has a hole no larger than 5cm×5cm and can catch the falling blocks (the fine mesh net is not in the Figure 6 and Figure 7 After the steel cable net 7 holds the falling block 10, it can be buffered and lowered under the impact force of the falling block 10, and the steel cable net 7 can stop when it is lowered above the safety limit of the railway 9.

[0037] The counterweight 8 can be made of bagged soil (or water), and the connection between the main cable and the counterweight 8 should be effective and firm. When the falling block 10 accidentally falls from the bridge deck that is being dismantled, it is first caught by the protective net, which is pulled downward by the deadweight of the falling block 10 and the impact force. When the impact force is large, the downward displacement of the protective net is relatively large. The movable end of the main cable is connected to the counterweight 8, and the downward pull of the protective net will inevitably cause the counterweight 8 to rise. The potential energy of the rising counterweight 8 consumes the falling impact energy of the falling block 10. By setting the fixed position of the movable steel cable, the steel cable net 7 can stop when it descends above the safety limit of the railway 9, ensuring the safety of the existing operating railway 9 below.

[0038] After the protective net is installed Figure 8 As shown, when the falling block 10 is held, Fig. 9 shown.

[0039] A curved flexible casing is provided at the position of the clamping slot 4 on the cross beam 2 to protect the steel cable, so as to prevent the steel cable from being cut by the clamping slot 4 and becoming ineffective under the action of stress concentration.

[0040] Installation method of protective net:

[0041] According to the diameter and spacing of the bridge piers to be demolished, matching steel structure components are processed and manufactured in advance. The two cross beams 2 are installed on the bridge piers 6 to be demolished across the railway 9. Figure 4 and Figure 5 shown.

[0042] A steel cable net 7 is made in advance, one end of the main cable of the steel cable net 7 is fixed in the slot 4 of the cross beam 2 on one side, and the other end passes through the slot 4 of the cross beam 2 on the other side and extends to the middle and lower part of the pier to be connected with the counterweight 8, as shown in FIG. Figure 7 shown.

[0043] At this point, the installation of the protective net is complete. Later, when the falling block 10 accidentally falls from the bridge deck that is being demolished, the protective net will be pulled downward under the deadweight and impact force of the falling block 10. The pulling down of the protective net will inevitably cause the counterweight 8 to rise, and the steel cable net 7 can stop when it drops above the safety limit of the railway 9, ensuring the safety of the existing operating railway 9 below. Fig. 9 Remove the falling block 10 and restore the initial state of the protective net (as shown in Figure 8 The subsequent protective net continues to play a role.

[0044] After use, the protective net is removed, and then the bridge pier 6 to be demolished is cut and removed, and the entire old bridge is demolished.

[0045] When the utility model is actually applied, when the falling block 10 falls on the protective net, the protective net can be buffered and lowered under the action of the deadweight and impact force of the falling block 10, and the steel cable net 7 can stop when it drops above the safety limit of the railway 9, effectively reducing the impact effect and destructive force of the falling block 10; the protective net uses the piers and pier columns of the bridge to be demolished as pillars (the piers are often demolished after the bridge deck is demolished), without the need to build new columns, making full use of existing structures, which is convenient and fast; the protective net has the characteristics of simple structure, easy assembly, low comprehensive cost, short installation and disassembly time, etc., and provides a simple and practical device for protecting the existing railway 9 under the bridge to be demolished.

[0046] The attached drawings only show part of the shape and part of the connection method of the new protective net. According to the idea, the structural method and moving method of the protective net can be used to form other related types of protective nets that can undergo buffering and descent. These are all equivalent modifications and changes to the present utility model and will not be described in detail here.

[0047] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A protective net used when dismantling a bridge across a railway, characterized in that: It comprises a crossbeam and a steel cable net installed on the piers of the bridge to be demolished; fixed hoops with the same diameter and spacing as the piers of the bridge to be demolished are welded on the crossbeam, and the fixed hoops and matching movable hoops can be assembled to fix the crossbeam on the piers of the bridge to be demolished; a series of slots are evenly arranged on the crossbeam, and the main cables of the steel cable net can be installed on the crossbeam through the slots; one end of the main cable of the steel cable net is fixed in the crossbeam slot on one side, and the other end passes through the crossbeam slot on the other side and extends to the middle and lower part of the pier to be connected with the counterweight; after the steel cable net catches the falling block, it can be buffered and lowered under the action of the impact force of the falling block, and the steel cable net can stop when it descends above the safety limit of the railway.

2. A protective net for use when dismantling a bridge across a railway as claimed in claim 1, characterized in that: The inner diameters of the movable clamp and the fixed clamp on the crossbeam are equal to the outer diameter of the bridge pier to be demolished, and the movable clamp and the fixed clamp are fixedly connected by bolts based on matching bolt holes on the movable clamp and the fixed clamp.

3. The protective net used when dismantling a bridge across a railway as claimed in claim 1, characterized in that: The crossbeam is welded by a cross plate, a vertical plate, an arc plate and stiffening ribs, and a series of slots are evenly arranged on the upper part of the outer vertical plate for the main cable of the steel cable net to pass through or be fixed.

4. The protective net used when dismantling a bridge across a railway as claimed in claim 1, characterized in that: The cable net is composed of a main cable net connected to the crossbeam and a fine mesh net laid and tied on the upper part of the main cable net; the main cable net transfers the load to the crossbeams at both ends; The holes of the fine mesh net are no larger than 5cm×5cm and can catch fallen objects.

5. The protective net used when dismantling a bridge across a railway as claimed in claim 1, characterized in that: A curved flexible protective sleeve is arranged at the position of the clamping groove on the cross beam to protect the steel cable, so as to prevent the steel cable from being cut by the clamping groove and becoming ineffective under the action of stress concentration.

6. The protective net used when dismantling a bridge across a railway as claimed in claim 1, characterized in that: The counterweight should be bagged soil weight, and the connection between the main cable and the counterweight should be effective and firm.

7. The protective net used when dismantling a bridge across a railway as claimed in claim 1, characterized in that: The two cross beams are installed on the piers of the bridge to be demolished that spans both sides of the railway.

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