Disaster prevention evacuation platform for underground engineering

Abstract

The invention relates to a disaster prevention evacuation platform for underground engineering, which comprises a platform main body which is rotatably arranged on the wall surface of a tunnel, and the bottom end surface of the platform main body is positioned above the top end surface of a vehicle in the tunnel; one end of the first transverse support is fixed to the tunnel wall surface, and the other end of the first transverse support is rotationally connected with the platform body, so that the platform body rotates relative to the tunnel wall to be parallel or perpendicular to the tunnel wall; and two ends of the inclined strut are respectively fixed on the tunnel wall surface and the platform main body so as to lock the platform main body on the tunnel wall surface. The system has the advantages that the influence of factors such as water depth and flow velocity caused by backward flowing of rainwater is effectively prevented to a great extent, and personnel evacuation under the flood working condition is facilitated; meanwhile, the evacuation space does not need to be increased, the tunnel section width is reduced, investment is saved, and good economic value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of disaster prevention and evacuation in underground engineering, in particular to a disaster prevention and evacuation platform used in underground engineering. Background Art

[0002] With the rapid development of urban construction, in order to meet the rapid development of traffic and improve the efficiency of traffic conversion, many level crossings are passed through tunnels, which brings convenient traffic to the city, but also brings new challenges to the city. In some flood-prone areas, heavy rainfall or sudden mega-city flooding incidents, due to excessive precipitation during the rainy season, it is possible that rainwater will flow back into tunnels and underground spaces, posing a great threat to vehicles and people on board. Once a flood occurs, people and vehicles are trapped. When rescue cannot arrive in time, how to evacuate them safely in time is an urgent concern for people.

[0003] The evacuation platform is a special component installed in the subway track area. It is a longitudinal continuous passage for evacuating passengers when the train encounters a fire or other disaster. Now some places have equipped subway tunnels with evacuation platforms, but they are mainly set up based on the needs of personnel escape under fire conditions, and the impact of floods when floods strike is not fully considered. In the Zhengzhou 7.20 flood accident, the subway section tunnel had an evacuation platform flooded by rainwater, resulting in the inability to evacuate personnel in time, which ultimately caused casualties.

[0004] For existing underground projects such as urban tunnels and underground spaces, in order to reduce the impact of fire, fire-resistant decorative panels are usually installed on the side walls for protection, and fire partitions are set up. Fire doors or fire curtains are used to isolate personnel from fire sources and smoke in a timely manner to ensure personnel safety. However, the current standards and specifications do not specify how personnel can effectively carry out emergency evacuation and self-rescue when floods strike. In particular, when the water depth in the tunnel exceeds the safe wading depth for human beings, the efficiency of personnel evacuation in the water will be greatly reduced. Therefore, when rainwater backflows into underground projects such as urban tunnels and underground spaces and floods occur, how to take measures to ensure the evacuation effect is an issue that needs to be solved urgently. Summary of the invention

[0005] The present invention aims at the technical problems existing in the prior art and provides a disaster prevention and evacuation platform for underground projects, so that in underground projects such as urban tunnels and underground spaces, casualties can be effectively avoided under rainwater backflow conditions, and personnel escape can be achieved economically and efficiently.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: A disaster prevention and evacuation platform for underground engineering: comprising a platform body, which is rotatably arranged on the tunnel wall, and its bottom end surface is located above the top end surface of the vehicle in the tunnel;

[0007] A first cross brace, one end of which is fixed to the tunnel wall, and the other end of which is rotatably connected to the platform body, so that the platform body can be rotated relative to the tunnel wall to be arranged parallel or perpendicular thereto;

[0008] The two ends of the diagonal brace are respectively fixed to the tunnel wall and the platform body to lock the platform body on the tunnel wall.

[0009] As a further technical solution, an auxiliary support assembly is also included, which is arranged on the upper part of the platform body and along the length direction of the tunnel wall.

[0010] As a further technical solution, the auxiliary support assembly includes

[0011] A plurality of second cross braces are provided and are spaced apart along the length direction of the tunnel wall;

[0012] A support member, disposed at the bottom of the second cross brace to connect a plurality of the second cross braces;

[0013] Sliding members, which are provided in plurality and are located at the lower part of the supporting member so as to slide along the length direction thereof;

[0014] Wherein, the lateral distance between the support member and the tunnel surface is smaller than the length of the second cross brace.

[0015] As a further technical solution, the sliding member includes a slider, a connecting member, and a pull ring connected sequentially from top to bottom;

[0016] The sliding block is clamped in the sliding groove of the supporting member and slides along the length direction thereof.

[0017] As a further technical solution, the platform body is provided with a plurality of blocks along the length direction of the tunnel wall, and each platform body is provided with one diagonal brace on both sides along the length direction of the tunnel wall;

[0018] Each platform body is rotatably connected to the tunnel wall through at least two of the first cross braces.

[0019] As a further technical solution, it also includes a first electrically controlled rotating shaft, which simultaneously passes through a plurality of the first cross braces and is hinged to the platform body through hinges, so that the platform body rotates relative to the tunnel wall through the first electrically controlled rotating shaft and the hinges to be arranged parallel to or perpendicular to the tunnel wall;

[0020] Wherein, when the platform body is in an unfolded state, the first cross brace is located on the upper part of the platform body, so that the platform body can be rotated upward to be parallel to the tunnel surface.

[0021] As a further technical solution, the platform body is provided with a rotating guardrail and a second electrically-controlled rotating axis. The rotating guardrail is vertically arranged on the platform body, and its bottom is connected to the upper end surface of the platform body through the second electrically-controlled rotating axis, so that the rotating guardrail rotates along the platform body to a horizontal state or a vertical state with the second electrically-controlled rotating axis as the rotating axis.

[0022] As a further technical solution, a limiter for controlling the rotation angle of the rotating guardrail is also provided on the platform body.

[0023] As a further technical solution, a flexible ladder is also included, so that in the risk avoidance state, one end of the flexible ladder is in contact with the platform body, and the other end is located on the tunnel ground.

[0024] The beneficial effects of the present invention are:

[0025] 1. Applicable to the evacuation of personnel in underground projects such as urban tunnels and underground spaces under flood conditions caused by sudden floods and rainwater backflow;

[0026] 2. Use the original structural fireproof decoration panels in the tunnel as the main body of the platform, without adding new evacuation space, reducing the width of the tunnel section, saving investment and having good economic value;

[0027] 3. In this structural design, the platform body is located at a certain height on the tunnel wall, which can effectively prevent the influence of water depth and flow velocity caused by rainwater backflow to a large extent, facilitate the evacuation of personnel under flood conditions, and do not affect the daily use of the tunnel when there is no flood disaster;

[0028] 4. The design of the platform body, the first cross brace, the second cross brace and other structures can evacuate personnel efficiently and orderly, and ensure the safety of the evacuated personnel;

[0029] 5. The present invention has a simple structure, is easy to operate, has strong practicability, and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the cross-sectional structure of a disaster prevention and evacuation platform for underground engineering in a non-working state according to the present invention;

[0031] Figure 2 for Figure 1 Schematic diagram of the cross-section structure in the working state;

[0032] Figure 3 It is a schematic diagram of the three-dimensional structure in working state;

[0033] Figure 4 is a schematic diagram of the structure of the sliding member;

[0034] Figure 5 For Figure 1A schematic diagram of the enlarged structure of the middle part A;

[0035] Figure 6 , Figure 7 They are Figure 2 Schematic diagram of the enlarged structure of parts B and C in the middle.

[0036] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0037] Platform body 1, tunnel wall 2, first cross brace 3, diagonal brace 4, first electrically-controlled rotating shaft 5, hinge 6, first control button 7, second control button 7a, rotating guardrail 8, second electrically-controlled rotating shaft 9, limiter 10, second cross brace 11, support member 12, sliding member 13, slider 13a, connecting member 13b, pull ring 13c, flexible ladder 14. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0039] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0040] In the description of the present application, the term "for example" is used to mean "used as an example, illustration or description". Any embodiment described as "for example" in the present application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any technician in the field to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details to obscure the description of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in the present application.

[0041] In the past, conventional evacuation platform structures were mostly used in subway section tunnels. They were longitudinal continuous passages used to evacuate passengers when trains encountered disasters such as fires. The evacuation platforms occupied a certain space, increased the width of the tunnel section, and had a high cost. In addition, the evacuation platforms were small in width and had no protective facilities, resulting in poor escape and evacuation effects and safety performance. At the same time, the impact of floods when floods struck was not taken into consideration, and evacuation platforms have not yet been widely used in underground projects such as urban tunnels and underground spaces.

[0042] This embodiment provides a disaster prevention and evacuation platform for underground engineering that can effectively prevent the influence of water depth and flow rate caused by rainwater backflow without increasing the original evacuation space and the width of the tunnel section, thereby efficiently evacuating personnel under flood conditions. Figure 1-Figure 3 , specifically including a platform body 1, which is rotatably arranged on the tunnel wall 2, and its bottom end face is located above the top end face of the vehicle in the tunnel, so that when no disaster occurs in the tunnel, the normal use of the tunnel is not affected, and it can effectively resist the influence of water depth and flow rate caused by rainwater backflow to a large extent, and facilitate the evacuation of personnel under flood conditions; the platform body 1 here can be the original decoration board on the tunnel wall 2, which reduces the space demand of the evacuation platform, reduces the scale of civil engineering, reduces the project cost, is conducive to cost saving, has good practical value and application prospects, and has a good landscape effect; The platform body 1 is made of calcium steel plate or enameled steel plate, which has high strength and is fireproof; the first cross brace 3 is fixed to the tunnel wall 2 at one end and rotatably connected to the platform body 1 at the other end, so that the platform body 1 can be rotated relative to the tunnel wall 2 to be set parallel or vertically thereto, that is, when there is no disaster, the platform body 1 is parallel to the tunnel wall 2 (that is, vertically set); when there is a disaster and the platform body 1 needs to be used, the platform body 1 is rotated to form a 90° vertical state with the tunnel wall 2, so that people in disaster in the tunnel can take shelter on the platform body 1; the first cross brace 3 can be a keel.

[0043] In order to further enhance the connection stability between the platform body 1 and the tunnel wall 2, see Figure 1-Figure 3 , and further includes an oblique brace 4, the two ends of which are respectively fixed to the tunnel wall 2 and the platform body 1, so as to lock the platform body 1 on the tunnel wall 2, and the oblique brace 4 is preferably a flexible oblique rope. When the platform body 1 is parallel to the tunnel wall 2, that is, in a non-working state, the flexible oblique rope is in a free state, and at the same time, the platform body 1 and the tunnel wall 2 are tightened to maintain a parallel static state; when the platform body 1 is perpendicular to the tunnel wall 2, that is, in a working state, the flexible oblique rope is in a stretched state, and at the same time, the platform body 1 is prevented from tilting toward the ground, so as to enhance the stability between the platform body 1 and the tunnel wall 2;

[0044] For the convenience of use and maintenance, the platform body 1 is provided with several blocks and gaps along the length direction of the tunnel wall 2, and each of the platform bodies 1 is provided with a diagonal brace 4 on both sides along the length direction of the tunnel wall 2, that is, each of the platform bodies 1 is provided with a diagonal brace 4 on the left and right sides, so as to assist in pulling the platform body 1 to move or keep it in a stationary state with the tunnel wall 2 to improve stability; each of the platform bodies 1 is connected to the tunnel wall 2 through at least two of the first cross braces 3 to improve the rotation efficiency.

[0045] To achieve automatic control, convenient and effective, see Figure 1-Figure 3 , further comprising a first electrically-controlled rotating shaft 5, which simultaneously passes through a plurality of the first cross braces 3 and is hinged to the platform body 1 through a hinge 6, so that the platform body 1 rotates relative to the tunnel wall 2 through the first electrically-controlled rotating shaft 5 and the hinge 6 to be arranged parallel to or perpendicular to the tunnel wall 2, that is, each of the platform bodies 1 is provided with at least one hinge 6, and the first cross brace 3 is provided with a hole for the first electrically-controlled rotating shaft 5 to pass through and rotate along the first cross brace, so that the first electrically-controlled rotating shaft 5 passes through the holes on a plurality of the first cross braces 3 and is connected to the platform body 1 through the hinge 6, when the first electrically-controlled rotating shaft 5 is started, the platform body 1 connected thereto can be driven to rotate around the first electrically-controlled rotating shaft 5 to be parallel to or perpendicular to the tunnel wall 2, wherein the first cross brace 3 is located at the upper part of the platform body 1, so that the platform body 1 rotates upward to be parallel to the tunnel surface, at which time, there is a gap between the platform body 1 and the tunnel wall 2;

[0046] The first electrically controlled rotating shaft 5 in this embodiment is connected to the electrical signal of the controller installed in the tunnel wall 2, and its switch is controlled by a control button arranged at other positions on the tunnel wall 2. It should be noted that this is a technical solution that can be implemented in this embodiment and is not limited to this one. For example, the first electrically controlled rotating shaft 5 here can also be controlled by an external controller or operating terminal or power control box, and the specific control form is selected according to actual conditions.

[0047] In the specific implementation process, in order to strengthen the effective protection of personnel during the disaster and orderly and efficient disaster relief, see Figure 1-Figure 3 , Figure 5 , Figure 7, the platform body 1 is provided with a rotating guardrail 8 and a second electrically controlled rotating shaft 9, the rotating guardrail 8 is vertically arranged on the platform body 1, and its bottom is connected to the upper end surface of the platform body 1 through the second electrically controlled rotating shaft 9, so that the rotating guardrail 8 rotates along the platform body 1 to a horizontal state or a vertical state with the second electrically controlled rotating shaft 9 as the rotating shaft, that is, when the platform body 1 is rotated and is 90° vertical to the tunnel wall 2, the second electrically controlled rotating shaft 9 is turned on to make the rotating guardrail 8 rotate in a state of being stacked in parallel with the platform body 1, and change to a state vertical to the platform body 1. At this time, the rotating guardrail 8 is perpendicular to the platform body 1, and can be used by the people on the platform body 1 who are avoiding danger to hold on, thereby improving the safety factor; the working principle of the second electrically controlled rotating shaft 9 here is the same as that of the first electrically controlled rotating shaft 5, and is controlled by the same controller or different controllers, but is arranged at the same position, so it is not repeated;

[0048] More specifically, the longitudinal sections of the rotating guardrail 8 and the second electrically-controlled rotating shaft 9 are constructed as a frame type, and in order to maximize the space provided on the platform body 1, the rotating guardrail 8 is arranged on the side of the platform body 1 away from the tunnel wall 2; correspondingly, the second electrically-controlled rotating shaft 9 and the hinge 6 are arranged on the side of the platform body 1 close to the tunnel wall 2; and in order to control the rotation angle of the second electrically-controlled rotating shaft 9, the platform body 1 is also provided with a limiter 10 for controlling the rotation angle of the rotating guardrail 8, and the limiter 10 is vertically arranged along the platform body 1 and arranged at the intersection of the second electrically-controlled rotating shaft 9 and the rotating guardrail 8; optionally, the longitudinal section of the limiter 10 is L-shaped, and the surface where its horizontal side is located is arranged at the bottom of the second electrically-controlled rotating shaft 9 and is stacked with the platform body 1, and the surface where its vertical side is located is arranged on the side away from the tunnel wall 2 and simultaneously abuts against the second electrically-controlled rotating shaft 9 and the vertical rods of the rotating guardrail 8.

[0049] In a specific implementation scheme, the evacuation platform further includes an auxiliary support assembly, which is arranged on the upper part of the platform body 1 and arranged along the length direction of the tunnel wall 2, that is, the auxiliary support assembly is adapted to the length of the platform body 1, and there is a gap between the auxiliary support assembly and the platform body 1. When the evacuation platform is working, the evacuees can hold the auxiliary support assembly while on the platform body 1, further increasing the safety of the evacuees and avoiding falling; when the evacuation platform is in a non-working state, a space can be provided for the platform body 1 to be arranged parallel to the tunnel wall 2;

[0050] Furthermore, combined with Figure 5-Figure 7The auxiliary support assembly includes a second cross brace 11, which is provided with a plurality of second cross braces 11 and is spaced apart along the length direction of the tunnel wall 2. The second cross brace 11 here can be the same as the first cross brace 3 in size, structure and material. The only difference is that no hole is provided on the second cross brace 11; a support member 12 is provided at the bottom of the second cross brace 11 to connect a plurality of second cross braces 11. Optionally, the support member 12 is welded to the lower part of the second cross brace 11; a sliding member 13 is provided with a plurality of second cross braces 11 and is located at the lower part of the support member 12 to slide along the length direction thereof; wherein the lateral spacing between the support member 12 and the tunnel wall 2 is less than the length of the second cross brace 11, so as to facilitate the grasping of the people avoiding danger;

[0051] In the actual implementation process, see Figure 4 The sliding member 13 includes a slider 13a, a connecting member 13b, and a pull ring 13c which are connected in sequence from top to bottom; the slider 13a is clamped in the slide groove of the support member 12 and slides along its length direction; that is, the support member 12 can be selected as a channel steel with an opening downward, and the slider 13a is adapted to slide along the width direction of the channel steel. In order to prevent the slider 13a from falling out of the channel steel, the two end faces of the channel steel in the length direction are closed, and the channel steel can be welded to the lower part of the second cross brace 11; the connecting member 13b here can be stretched, and the pull ring 13c can be an anti-slip pull ring 13c.

[0052] In order to facilitate the escapers to enter the platform body 1, a flexible ladder 14 is also included. One end of the flexible ladder 14 is in contact with the platform body 1, and the other end is located on the tunnel ground. When in a non-evacuation state, the flexible ladder 14 is fixed in a folded state to the inner side of the platform body 1 (i.e., the side parallel to the tunnel surface, not indicated in the figure), and the fixing method can be a snap-on type or other methods.

[0053] The evacuation platform in this embodiment is located at the position of the original decoration board on the tunnel wall. Therefore, a first cross brace and a decoration board connected to the first cross brace are respectively provided on the tunnel walls at the upper and lower positions of the evacuation platform (the decoration board here is the original decoration board in the tunnel, and no diagonal braces, hinges, first electrically controlled rotating shaft and other structures are provided thereon). That is, the evacuation platform is at the position of the original decoration board, and the decoration board of the original height is cut into three sections from top to bottom, and the middle section is taken to make the evacuation platform in this embodiment, and the control button can be arranged in the lower section (in this embodiment, the switches controlling the first electrically controlled rotating shaft and the second electrically controlled rotating shaft are the first control button 7 and the second control button 7a, respectively).

[0054] The present invention is achieved in that:

[0055] After rainwater flows back into the tunnel, the water in the tunnel reaches a certain depth. When the water depth exceeds the safe wading depth of the human body, the efficiency of the vertical evacuation of personnel in the water is poor. The on-site start button manual control and remote wired or wireless control can be used. At this time, after the personnel presses the button on site or receives the remote start signal, the first electrically controlled rotating shaft 5 rotates, thereby driving the platform body 1 to rotate 90° to a horizontal state; then the second electrically controlled rotating shaft 9 is turned on to rotate the rotating guardrail 8 90°; then one end of the flexible ladder 14 is connected to the platform body 1, and the other end is located on the ground of the tunnel, so that the refugees can climb up the platform body 1 through the flexible ladder 14 to avoid danger.

[0056] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0057] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0058] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A disaster prevention and evacuation platform for underground projects, It is characterized in that include The platform body (1) is rotatably arranged on the tunnel wall (2), and its bottom end surface is located above the top end surface of the vehicle in the tunnel; A first cross brace (3), one end of which is fixed to the tunnel wall (2), and the other end of which is rotatably connected to the platform body (1), so that the platform body (1) can be rotated relative to the tunnel wall (2) to be arranged parallel to or perpendicular to the tunnel wall; The two ends of the diagonal brace (4) are respectively fixed to the tunnel wall (2) surface and the platform body (1) to lock the platform body (1) on the tunnel wall (2).

2. A disaster prevention and evacuation platform for underground engineering according to claim 1, It is characterized in that It also comprises an auxiliary support assembly, which is arranged on the upper part of the platform body (1) and is arranged along the length direction of the tunnel wall (2).

3. A disaster prevention and evacuation platform for underground engineering according to claim 2, It is characterized in that The auxiliary support assembly comprises A plurality of second cross braces (11) are provided and are spaced apart along the length direction of the tunnel wall (2); A support member (12) is disposed at the bottom of the second cross brace (11) to connect a plurality of the second cross braces (11); A plurality of sliding members (13) are provided and are located at the lower part of the support member (12) so as to slide along the length direction thereof; Wherein, the transverse distance between the support member (12) and the tunnel wall (2) is smaller than the length of the second cross brace (11).

4. A disaster prevention and evacuation platform for underground engineering according to claim 3, It is characterized in that The sliding member (13) comprises a sliding block (13a), a connecting member (13b), and a pull ring (13c) which are sequentially connected from top to bottom; The sliding block (13a) is clamped in the sliding groove of the supporting member (12) and slides along the length direction thereof.

5. A disaster prevention and evacuation platform for underground engineering according to claim 1, It is characterized in that The platform body (1) is provided with a plurality of blocks along the length direction of the tunnel wall (2), and each of the platform bodies (1) is provided with one diagonal brace (4) on both sides along the length direction of the tunnel wall (2); Each platform body (1) is rotatably connected to the tunnel wall (2) via at least two of the first cross braces (3).

6. A disaster prevention and evacuation platform for underground engineering according to claim 5, It is characterized in that It also comprises a first electrically controlled rotating shaft (5), which simultaneously passes through a plurality of the first cross braces (3) and is hingedly connected to the platform body (1) via hinges (6), so that the platform body (1) can rotate relative to the tunnel wall (2) via the first electrically controlled rotating shaft (5) and the hinges (6) to be arranged parallel to or perpendicular to the tunnel wall; Wherein, when the platform body (1) is in an unfolded state, the first cross brace (3) is located on the upper part of the platform body (1) so that the platform body (1) can be rotated upward to be parallel to the tunnel wall (2).

7. A disaster prevention and evacuation platform for underground engineering according to claim 1, It is characterized in that The platform body (1) is provided with a rotating guardrail (8) and a second electrically controlled rotating shaft (9); the rotating guardrail (8) is vertically arranged on the platform body (1), and its bottom is connected to the upper end surface of the platform body (1) through the second electrically controlled rotating shaft (9), so that the rotating guardrail (8) rotates along the platform body (1) to a horizontal state or a vertical state with the second electrically controlled rotating shaft (9) as the rotating axis.

8. A disaster prevention and evacuation platform for underground engineering according to claim 7, It is characterized in that The platform body (1) is also provided with a limiter (10) for controlling the rotation angle of the rotating guardrail (8).

9. A disaster prevention and evacuation platform for underground engineering according to any one of claims 1 to 8, It is characterized in that It also comprises a flexible ladder (14), so that in the risk avoidance state, one end of the flexible ladder (14) is in contact with the platform body (1), and the other end is located on the tunnel ground.

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