JP6244107B2 - Protection device for tunnel blasting - Google Patents

Description

  The present invention relates to a tunnel blast protection device used when blasting a tunnel.

  In mountain tunnel construction, the geology is often composed of rocks, so drilling by blasting is mainly adopted. However, when explosives are exploded, carbon monoxide is used in addition to harmless gases such as carbon dioxide and nitrogen. Depending on the type of explosive and the type of rock targeted for blasting, various toxic gases such as hydrogen chloride, sulfur dioxide, and hydrogen sulfide are generated.

  Therefore, when performing tunnel excavation by blasting, appropriate safety measures or environmental measures must be taken against these toxic gases, called post-gases, along with a large amount of dust generated at the same time.

  On the other hand, blast waves propagate through the air at the time of blasting, and stepping stones generated by blasting scatter around, so that these blasting and stepping stones do not damage the facilities in the tunnel and It is also essential to take appropriate measures so that safety is not threatened.

  As a measure capable of satisfying such countermeasures for gas and dust and blast and stepping stones, a protective device has been proposed in which a bag filled with air is erected in a wall shape in front of the face (Patent Document 1). ).

  In such a protective device, the space inside the tunnel is partitioned in front of the face to prevent diffusion of back gas or dust from the face side space to the well side space, and ventilation equipment and dust collection installed in the well side space. It is expected to treat the gas and dust with the equipment and protect the ventilation equipment and dust collection equipment from the blast and stepping stones that accompany blasting.

JP 2005-54364 A

  Here, the blast at the time of blasting propagates in the air as a shock wave due to the explosion of the explosive, and the flying stones are accelerated by the impact pressure and expansion gas generated by the explosive detonation, and the flying pieces fly out from the face at the time of the blast. When they act on or collide with the protective device, a large impact force is instantaneously applied to the protective device.

  Therefore, the above-described protective device is required to have sufficient impact resistance performance or impact absorption performance.

  However, if you try to support the impact force caused by the blast or stepping stones at the time of blasting with the strength of the bag body that makes up the protective device, the bag body will be damaged, making it impossible to use afterwards, or the entire protective device will fall over. There is a concern that rear gas and dust may flow out from the face side to the shaft side.

  On the other hand, when it is going to absorb the impact energy by the blast and flying stones at the time of blasting by the shrinkage of the bag body constituting the protective device, the outer peripheral edge of the bag body is detached from the bottom surface and inner peripheral surface of the tunnel by the shrinkage deformation of the bag body. In any case, it is difficult to maintain the airtightness of the face side space anyway.

  By the way, if the protective device is moved away from the face, it can prevent the protective device from being broken or toppled, but the prevention of diffusion of gas and dust is insufficient and it takes time for ventilation and dust collection. The result is that the entire construction period is prolonged.

  The present invention has been made in consideration of the above-mentioned circumstances, and for tunnel blasting capable of sufficiently absorbing impact energy from blast and stepping stones at the time of blasting while reliably maintaining the airtightness of the face side space. The purpose is to provide a protective device.

In order to achieve the above object, a tunnel blast protection device according to the present invention is a protective device that is positioned away from the face of the tunnel and is erected in a wall shape on the bottom surface of the tunnel, as described in claim 1. In the protective device for tunnel blasting with a bag body,
The protective bag body can be filled with air or other gas inside, and in a state in which the gas is filled, the space extending in front of the face can be kept airtight with respect to the well side space. It is composed of an air-tight bag and an impact-absorbing bag that can be filled with air or other gas inside and disposed on the face side so that the air-tight bag is not in communication with the inside. ,
The shock absorbing bag body is provided with a gas filled therein in response to a blast or flying stone at the time of blasting acting or colliding with the shock absorbing bag body. It is designed to be discharged from the exhaust port.

  In the tunnel blast protection device according to the present invention, the shock absorbing bag body is disposed in contact with the airtight bag body.

  In the tunnel blast protection device according to the present invention, the shock absorbing bag body is configured to be detachable from the airtight bag body.

  Further, in the tunnel blast protection device according to the present invention, the exhaust port is provided on the side where the air-tight bag is disposed, and the air-tight bag is formed so that the exhaust port is exposed to the well side space. Is.

  Moreover, the protection device for tunnel blasting according to the present invention comprises a mounting base that is placed on the bottom surface of the tunnel and to which the protection bag is attached.

  In the protective device for tunnel blasting according to the present invention, the protective bag body standing upright in the shape of a wall on the bottom surface of the tunnel is airtight with respect to the space on the wellhead side, with the space extending in front of the face in a state filled with gas. An air-tight bag body configured to be able to be held at the same time, and an impact-absorbing bag body disposed on the face side of the air-tight bag body so that the interior is not in communication with the air-tight bag body. When the blasting blast or stepping stone at the time of blasting acts on or collides with the shock absorbing bag body, the gas filled inside in response to them is an exhaust port provided in the shock absorbing bag body It comes to be discharged from.

  In this way, when the impact force of the blast or stepping stones acts, the shock absorbing bag body contracts as a whole while the filling gas inside is exhausted from the exhaust port, and the impact energy of the blast and stepping stones due to the contraction deformation. Is absorbed.

  On the other hand, since the airtight bag body is arranged on the well opening side of the shock absorbing bag body, the impact force due to the blast and flying stones mainly acts on the shock absorbing bag body, even if it acts on the airtight bag body There is no concern that airtightness will be lost.

  That is, the protective device for tunnel blasting according to the present invention comprises a protective bag body consisting of two bag bodies, an impact absorbing bag body and an airtight bag body, and the impact energy of blast and stepping stones is mainly used for shock absorbing. It is absorbed by the bag body, and the airtightness of the face side space is exclusively secured by the airtight bag body.

  The airtight bag body needs to be configured so that the space expanding before the face in a state filled with gas can be kept airtight with respect to the pit side space. It is sufficient that the gas and dust after the blasting are removed until the gas and dust are not substantially discharged into the wellhead side space. Typically, the outer peripheral edge of the airtight bag body is Although it is configured to substantially contact the inner peripheral surface and bottom surface of the tunnel, the outer peripheral edge of the airtight bag body does not necessarily have to be in contact with the inner peripheral surface and bottom surface of the tunnel. .

  For example, it is necessary to provide an opening for penetrating air supply pipes, intake pipes and other facilities in such a way that the side opposite to the inner peripheral surface and bottom surface of the tunnel is open. If it is possible to prevent the airtightness from being impaired by the opening, there may be a non-contact portion between the outer peripheral edge portion of the airtight bag body and the inner peripheral surface or bottom surface of the tunnel. Absent.

  The exhaust port provided in the shock absorbing bag body is sufficient if the filling gas can be discharged, and even if it is an air supply port for filling the gas inside, it is connected to the air supply port, for example. If the charged gas can be discharged from the air supply port by measures such as turning off the blower, the air supply port may be used as the exhaust port of the present invention.

  The shock absorbing bag body and the airtight bag body do not necessarily need to be in contact with each other, and if they are arranged with a gap between them, the above-described division of roles becomes clear, and each design becomes easy. If the shock-absorbing bag body is placed in contact with the air-tight bag body, the overall thickness of the protective bag body will be compact, easy to handle and relocate, and the impact force from blast and stepping stones will be reduced. A part of the airtight bag can also be borne.

  Although the shock absorbing bag body contracts and deforms in response to the impact force from the blast or stepping stone, the situation where excessive impact force acts is prevented to some extent, but it suffers certain damage as long as it assumes the shock absorption function. However, if the shock absorbing bag body is detachable from the airtight bag body, the damaged shock absorbing bag body can be easily replaced with a new shock absorbing bag body. Even if the number of blasting times is large because of the long tunnel, it is possible to quickly respond without delaying each blasting operation.

  The shock absorbing bag body absorbs the impact energy of the blast and stepping stones as the filling gas is discharged from the exhaust port in response to the action of the blast and the collision of stepping stones, and the whole contracts and deforms accordingly. However, as long as it is possible, the configuration is arbitrary. For example, by forming the shock absorbing bag body to be slightly smaller than the airtight bag body, the outer peripheral edge portion is separated from the bottom surface and inner peripheral surface of the tunnel. In addition, it is possible to adopt a configuration in which an exhaust port is provided in the outer peripheral edge portion, but the exhaust port is provided on the side facing the airtight bag body and the exhaust port is exposed to the well side space. If an airtight bag is configured, the gas in the shock absorbing bag is smoothly pushed out in the same direction as the direction of the impact force when an impact force from a blast or flying stone is applied. Rupture of While prevented breakage, it is possible to absorb the impact energy by the blast and scattered stones smoothly.

  In the above configuration, in order to configure the airtight bag body so that the exhaust port of the shock absorbing bag body is exposed to the well side space, for example, a configuration in which a plurality of bag bodies are arranged adjacent to each other. In addition, the bag body is not disposed in the space extending from the exhaust port to the wellhead side, and the bag body is disposed so as to surround the space, or the portion corresponding to the exhaust port is formed in an airtight shape. It is possible to adopt a configuration such as molding a bag body.

  The protective device for tunnel blasting according to the present invention may be the above-described protective bag body alone if it is a small-scale tunnel, but includes a mounting base that is placed on the bottom surface of the tunnel and to which the protective bag body is attached. In this case, the protective bag can be easily erected, and can be moved together with the mounting base during relocation, so that it can be easily applied to a large-scale tunnel.

The disassembled perspective view of the protective device 1 for tunnel blasting which concerns on this embodiment. It is a figure of the protective bag body 7 which comprises the protective device 1 for tunnel blasting, (a) is a longitudinal cross-sectional view, (b) is an arrow view seen from the AA line direction. Explanatory drawing which showed the effect | action of the protection apparatus 1 for tunnel blasting. The figure which showed the modification of the protection bag body which arrange | positions the airtight bag body 5 and the shock absorption bag body 6 apart. The longitudinal cross-sectional view which showed another modification of the protective bag body. The longitudinal cross-sectional view which showed a mode that the protective bag body 7 was attached to the attachment stand 61. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a tunnel blast protection device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an exploded perspective view showing a tunnel blast protection device according to the present embodiment. As shown in the figure, the tunnel blast protection device 1 according to the present embodiment is located at a position separated from the face 3 of the tunnel 2 and is substantially perpendicular to the tunnel axis so as to be substantially perpendicular to the wall. 4 is provided with a protective bag body 7 erected.

  The protective bag 7 includes an airtight bag 5 and an impact absorbing bag 6, both of which can be filled with air. The airtight bag 5 is shown in FIG. As described above, the outer peripheral edge 11 is configured to be substantially in contact with the bottom surface 4 and the inner peripheral surface 11 of the tunnel 2 in a state of being filled with air. The shape at the time is configured to substantially match the cross-sectional shape of the tunnel 2.

  The airtight bag body 5 has a thickness in the tunnel axis direction so that the airtightness of the space 13 on the front side of the face 3 is maintained, in other words, the outer peripheral edge portion 11 in contact with the bottom surface 4 and the inner peripheral surface 11 of the tunnel 2. The width is set appropriately. In the present embodiment, the shock absorbing bag body 6 is also formed so as to have the same shape as the airtight bag body 5 when viewed from the tunnel axis direction.

  The airtight bag body 5 and the shock absorbing bag body 6 are configured to inflate and expand from the contracted state to the above-described shape when filled with air. Can be configured by appropriately selecting from known materials according to elasticity, strength characteristics and other required performance. For example, if high strength characteristics are desired, the name “Zylon (registered trademark)” can be used. It can be composed of polyparaphenylene benzobisoxazole (PBO) fibers sold by Toyobo Co., Ltd.

  2A, the shock absorbing bag body 6 is disposed in contact with the face side of the airtight bag body 5, but is a separate bag body independent of the airtight bag body 5. As shown in FIG. The inside is not in communication.

  The shock-absorbing bag body 6 is provided with exhaust ports 14 through which air filled therein is discharged on the side where the air-tight bag body 5 is arranged so that there are a total of eight horizontal rows and four vertical rows. In addition, when a blast or flying stone at the time of blasting acts on or collides with the shock absorbing bag body 6, the filled air inside is discharged from the exhaust port 14 in response to them.

  On the other hand, the airtight bag body 5 is formed with an air discharge opening 16 at a position corresponding to the exhaust port 14 so that the exhaust port is exposed to the wellhead side space 15, and absorbs shock as shown in FIG. 2 (b). The air in the bag body 6 is discharged to the wellhead side space 15 through the exhaust port 14 and the air discharge opening 16.

  Note that the air discharge opening 16 is formed as an external space of the airtight bag body 5, and for example, through holes are formed at locations facing each other in the bag fabric constituting the airtight bag body 5. If the air exhaust pipe is inserted into the through hole and each end of the air exhaust pipe and each through hole are airtightly treated, the inner space of the air exhaust pipe becomes the air exhaust opening 16.

  In order to perform blasting using the tunnel blast protection device 1 according to the present embodiment, as shown in FIG. 3, the tunnel blast protection device 1 is installed at a position separated from the face 3 by a predetermined distance to prepare for blasting. .

  In order to install the protective device 1 for tunnel blasting, the air-tight bag 5 and the shock-absorbing bag 5 and the shock-absorbing bag 6 are filled with air by using a blower or the like, respectively. Each of the bag bodies 6 is inflated and deployed, and is erected on the bottom surface 4 of the tunnel 2 while being positioned so as to be orthogonal to the tunnel axis direction.

  Here, with respect to the airtight bag body 5, air by a blower or the like is maintained as necessary so that the contact state between the outer peripheral edge portion 11 and the bottom surface 4 and the inner peripheral surface 12 of the tunnel 2 is maintained before and after blasting. Continue filling.

  Further, the shock absorbing bag body 6 is configured so as to secure an air amount or air pressure sufficient to absorb the shock at the time of blasting. For example, the shock absorbing bag body 6 is normally closed and loaded with an impact force. An exhaust valve (not shown) configured to open is attached to the exhaust port 14.

  When the installation of the protective device 1 for tunnel blasting is completed, the face 3 is blasted and excavated as shown in FIG.

  In this way, when a blast acts on the shock absorbing bag body 6 with blasting or a stepping stone collides with the shock absorbing bag body, the shock absorbing bag body 6 has an internal structure as shown in FIG. While the filled air is exhausted from the exhaust port 13 and the air discharge opening 16 toward the well-side space 15, the whole contracts and the impact energy of the blast and flying stones is absorbed by the contraction deformation.

  On the other hand, since the airtight bag body 5 is arranged on the well opening side of the shock absorbing bag body 6, the impact force due to the blast and flying stone mainly acts on the shock absorbing bag body 6. Even if it acts, there is no concern that the outer peripheral edge portion 11 is separated from the bottom surface 4 or the inner peripheral surface 12 of the tunnel 2.

  When the blasting is completed, the rear gas and dust in the face side space 13 are sucked through a suction pipe (not shown) penetrating the tunnel blasting protective device 1 and the rear gas and dust are filtered. After processing with a dust collector or the like, the tunnel blast protection device 1 may be removed.

  As described above, according to the tunnel blast protection device 1 according to the present embodiment, the protective bag body 7 is composed of two bag bodies, the shock absorbing bag body 6 and the airtight bag body 5, The impact energy of the stepping stone is mainly absorbed by the shock absorbing bag body 6 and the air tightness of the face side space 13 is exclusively secured by the air tight bag body 5, so that the gas and dust generated at the time of blasting are collected on the face side. While being confined in the space 13, it becomes possible to absorb the blasting blast and impact energy caused by stepping stones in the blasting, and thus it can be processed in a short time without diffusing gas and dust later. It is possible to prevent the damage caused by the stepping stones and the harm to the workers.

  Although not particularly mentioned in the present embodiment, if the shock absorbing bag 6 is detachable from the airtight bag 5, the damaged shock absorbing bag 6 can be replaced with a new shock absorbing bag. Therefore, even if the number of times of blasting is large because of the long tunnel, it is possible to respond quickly without delaying each blasting operation.

  Further, in this embodiment, the airtight bag body 5 and the shock absorbing bag body 6 are arranged in contact with each other to form the protective bag body 7, but these do not necessarily need to be contacted, As shown in FIG. 4, it may be erected with a gap δ.

  In this way, it is possible to make the impact force hardly reach the airtight bag body 5, and the role sharing with the above-described shock absorbing bag body 6 becomes clearer.

  In addition, in the said structure, the air discharge opening of the airtight bag body 5 is shown in the figure so that the air discharged | emitted from the shock absorption bag body 6 may not act on the airtight bag body 5 at the time of impact force action. In this manner, the air discharge pipe 41 is configured and the base end side thereof is extended to the shock absorbing bag body 6 side and connected to the exhaust port 14.

  In this way, the air discharged from the shock absorbing bag body 6 is smoothly discharged to the wellhead side space 15 via the exhaust port 14 and the air discharge pipe 41 without acting on the airtight bag body 5. Is done.

  Further, in the present embodiment, the shape of the shock absorbing bag body 6 viewed from the tunnel axis direction is made substantially the same as that of the airtight bag body 5 so that the blast and flying stones do not reach the airtight bag body 5. However, in some cases, instead of this, as shown in FIG. 5, the protective bag of the present invention includes an airtight bag body 5a and an impact absorbing bag body 6a formed slightly smaller than the airtight bag body. You may make up your body.

  In this configuration, since the outer peripheral edge of the shock absorbing bag 6a is separated from the bottom surface 4 and the inner peripheral surface 12 of the tunnel 2, an exhaust port 51 can be provided at the outer peripheral edge, and the airtight bag 5a does not need to be provided with the air discharge opening 16 described in the above-described embodiment, and has a simpler structure.

  Although not particularly mentioned in the present embodiment, as shown in FIG. 6, a mounting base 61 placed on the bottom surface 4 of the tunnel 2 is separately provided, and the protective bag body 7 is attached to the mounting base. You may do it.

  According to such a configuration, as shown in the figure, the protective bag body 7 can be attached so as to be sandwiched between the mounting bases 61, so that it is easy to stand up, and for the protection together with the mounting bases 61 when moving. Since the bag body 7 can be moved, it can be easily applied to a large-scale tunnel.

DESCRIPTION OF SYMBOLS 1 Tunnel blasting protective device 2 Tunnel 3 Face 4 Tunnel bottom face 5, 5a Airtight bag body 6, 6a Shock absorbing bag body 7 Protective bag body 11 Outer peripheral edge 12 Tunnel inner peripheral surface 13 Face side space 14, 51 Exhaust port 15 Wellhead side space 16 Air discharge opening 61 Mounting stand

Claims (5)

In the protective device for tunnel blasting provided with a protective bag body standing on the bottom surface of the tunnel at a position separated from the face of the tunnel,
The protective bag body can be filled with air or other gas inside, and in a state in which the gas is filled, the space extending in front of the face can be kept airtight with respect to the well side space. It is composed of an air-tight bag and an impact-absorbing bag that can be filled with air or other gas inside and disposed on the face side so that the air-tight bag is not in communication with the inside. ,
The shock absorbing bag body is provided with a gas filled therein in response to a blast or flying stone at the time of blasting acting or colliding with the shock absorbing bag body. A protective device for tunnel blasting, characterized in that it is discharged from the exhaust port. The protection apparatus for tunnel blasting according to claim 1, wherein the shock absorbing bag body is disposed in contact with the airtight bag body. The protection apparatus for tunnel blasting according to claim 1, wherein the shock absorbing bag body is detachable from the airtight bag body. The said airtight bag body was shape | molded so that this exhaust port might be provided in the side by which the said airtight bag body is arrange | positioned, and this exhaust port is exposed to a well side space. Protection device for tunnel blasting. The protection apparatus for tunnel blasting as described in any one of Claims 1 thru | or 4 provided with the mounting stand mounted in the bottom face of the said tunnel, and the said protection bag body is attached.

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