JP5602902B2 - Tunnel fireproofing method - Google Patents

Description

The present invention relates to a fireproof construction method for a tunnel .

Japanese Patent Application Laid-Open No. H10-228667 discloses a fireproof structure for an assembly-type structure in which a recess of an assembly-type structure having a recess on its surface is closed with a fire-resistant lid and a fire-resistant coating material layer is provided to cover the surface of the lid. A covering structure is disclosed.
Patent Document 2 discloses a fire and heat resistant structure characterized in that a segment surface is covered with a fire and heat resistant part made of a fire and heat resistant castable material.

JP 2004-324371 A Japanese Patent Laid-Open No. 2002-357098

  For tunnel construction, the shield method and the submerged method are known. In the shield method, a tunnel is excavated by a shield machine, and a segment, which is a primary covering material that doubles as earth retaining and supporting work, is constructed on the inner wall of the excavated tunnel. In this case, the following methods are known as methods for fireproofing the inner wall of the tunnel.

One is a fireproof mortar spraying method. In this method, a mesh is attached to a segment by an anchor, and fireproof mortar is sprayed on the segment using the mesh as an aggregate.
The other is a fireproof panel mounting method. This is a method of attaching fireproof panels at the tunnel construction site.
Furthermore, the segment pre construction method is also known. This is a construction method in which a refractory material is preliminarily applied to a segment before construction in a tunnel.

  On the other hand, segments used for tunnel construction include a segment made of concrete and a segment made of steel plate. Among these, the steel plate segments are used when the ground is soft or when the tunnel has a vertical or horizontal bend. Concrete segments are used in the unbent part of the tunnel. And it can construct easily with any of a fireproof mortar spraying construction method, a fireproof panel mounting construction method, and a segment pre construction construction method to a concrete segment.

However, in the case of a segment made of a steel plate, any problems occur when the fireproof mortar spraying method, the fireproof panel mounting method, and the segment pre-construction method are applied.
First, in the refractory mortar spraying method, there is a hollow part in the segment made of steel plate, so when refractory mortar is sprayed, this refractory mortar gets into the hollow part and the mortar layer cannot be built and cannot be constructed There is.

In addition, in the refractory mortar spraying method, when the bending of the tunnel is large, it is necessary to cut and paste the refractory panel in order to follow the R of the wall surface, so the construction period becomes longer and the construction cost also increases. There is a bug.
Furthermore, in the segment pre-construction method, since the steel-made segment is thick (about 30 mm at the fireproof portion), there is a problem that the construction is difficult when the tunnel is greatly bent.

  Therefore, an object of the present invention is to enable a fireproof coating on a segment easily and at a low construction cost regardless of whether the segment is made of concrete or steel plate.

One aspect of the present invention is formed of a single flexible plate, provided with a mesh in which a plurality of through holes are continuously formed in the plate, and holds a refractory mortar on the surface of the plate. It is a member for holding refractory mortar.
In this case, a plurality of ribs may be further provided, and the mesh may be provided between the ribs.

Another aspect of the present invention is a first step of attaching a segment having a hollow portion to an inner wall of a tunnel, and the segment so as to cover the hollow portion of the segment attached to the tunnel after the first step. A second step of attaching a flexible refractory mortar holding member, and a third step of holding the refractory mortar by applying to the surface side of the refractory mortar holding member after the second step. This is a fireproof construction method for tunnels.
In this case, you may make it the said 3rd process spray the said refractory mortar with a spraying machine, and hold | maintain the said refractory mortar on the said surface side of the said member for refractory mortar holding | maintenance .
A direction in which the cuts open in a direction perpendicular to the length direction of the cuts after a plurality of cuts parallel to and extending through one side of the flexible single plate are put in the plate in a zigzag pattern. The refractory mortar holding member may be prepared by pulling the plate and making the plurality of cut lines into a mesh composed of a plurality of through holes each continuous in a honeycomb shape.
Further, in addition to putting the plurality of cuts in the zigzag shape, at least one portion that is not cut in the plate and is continuous with a certain width is provided, and the plate is pulled. Accordingly, the refractory mortar holding member may be prepared and prepared so that the portion having the constant width and not having the cut functions as a rib.

  According to one aspect of the present invention, first, a refractory mortar holding member is attached to a segment attached to a tunnel. And if the refractory mortar is held in the refractory mortar holding member, the refractory mortar is partly turned to the back side through the mesh through-hole, but is held on the surface of the refractory mortar holding member. The fire wall becomes a predetermined thickness. Further, since the refractory mortar does not almost completely enter the hollow portion, it can be applied even with a steel plate segment. Furthermore, since the refractory mortar holding member is a flexible plate, it can be bent and attached to a steel plate segment even in a tunnel with a large bend, and it is not necessary to cut and attach it like a refractory panel. Can be constructed.

  When the mesh is provided with ribs, even if the refractory mortar is held so as to have a certain thickness, the refractory mortar holding member does not sag and the strength can be maintained.

It is a top view of the member for refractory mortar holding which is one embodiment of the present invention. It is a partial enlarged plan view of the member for refractory mortar holding which is one embodiment of the present invention. It is a perspective view of the segment made from a steel plate. It is explanatory drawing explaining the 2nd process of the fireproof construction method of the tunnel which is one embodiment of this invention. It is explanatory drawing explaining the 3rd process of the fireproof construction method of the tunnel which is one embodiment of this invention. It is explanatory drawing explaining the 3rd process of the fireproof construction method of the tunnel which is one embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of the refractory mortar holding member 1 according to the present embodiment, and FIG. 2 is a partial enlarged plan view of a portion A of the refractory mortar holding member 1.

  The refractory mortar holding member 1 is formed of, for example, a single rectangular plate made of stainless steel and has flexibility. The refractory mortar holding member 1 includes a plurality of ribs 2, and a mesh 3 is formed between the ribs 2. A plurality of through holes 4 are continuously formed in the mesh 3 in a honeycomb shape in a direction parallel to the side of the plate surface of the refractory mortar holding member 1. The refractory mortar holding member 1 can be formed in various sizes. For example, the refractory mortar holding member 1 has a length of 580 mm and a width of 1500 mm. The surface of the fireproof mortar holding member 1 is a member for spraying fireproof mortar and holding the sprayed fireproof mortar to form a fireproof wall.

  In order to manufacture this refractory mortar holding member 1, the following is performed. First, a single plate made of stainless steel is prepared. Then, a cut is made through the plate at a position where the through hole 4 is formed. The cuts are staggered on the plate surface. In the example of FIG. 1, it is a cut | interruption which makes the horizontal direction (length direction of the rib 2) of the board used as the refractory mortar holding member 1 the length direction. Thereafter, the cut plate is pulled (in the short direction in the example of FIG. 1) to open each cut so that the cut becomes the through hole 4. Thereby, the member 1 for refractory mortar holding is completed.

Next, the fireproof construction method of a tunnel performed using the fireproof mortar holding member 1 will be described. This tunnel fireproofing construction method is carried out through the following first to third steps.
(1) First step In tunnel construction, a segment, which is a primary covering material that doubles as a retaining and supporting work, is constructed on the inner wall of the tunnel excavated by a shield machine. This segment is made of a steel plate when the ground is soft, or when the tunnel is bent up and down or left and right, and is made of concrete when it is not. FIG. 3 is a perspective view of the segment 11 made of steel plate. A large hollow portion 12 is formed in the steel sheet segment 11.

(2) 2nd process Next, in any case of the segment made from concrete, and the segment 11 made from a steel plate, the member 1 for refractory mortar holding | maintenance is attached to the surface part of the said segment. This attachment is performed by fastening the refractory mortar holding member 1 directly to the segment with bolts or anchors (see FIG. 4).

(3) Third Step Next, as shown in FIG. 5, the refractory mortar 22 is sprayed by the sprayer 21 onto the refractory mortar holding member 1 attached to the segment in the second step.

  A part of the refractory mortar 22 also turns to the back side on the blowing side through the through hole 4 of the mesh 3, but is held on the surface of the refractory mortar holding member 1. The state in which the refractory mortar 22 thus sprayed and held on the surface of the member 1 for holding the refractory mortar has reached a predetermined thickness is the state of reference numeral 31 in FIG. By leveling like the state of 32, it becomes a fire wall formed on the segment surface.

According to the refractory mortar holding member 1 and the tunnel refractory construction method of the present embodiment, the refractory mortar 22 does not almost completely enter the hollow portion 12 by spraying. Even the segment 11 can be constructed.

  In addition, since the refractory mortar holding member 1 is a flexible plate, it can be bent and attached to a steel plate segment 11 even in a tunnel portion with a large bend, and it is not necessary to cut and attach as small as a refractory panel. Easy to install.

  Further, since the ribs 2 are provided on the mesh 3, even if the refractory mortar 22 is sprayed so as to have a certain thickness, the refractory mortar holding member 1 does not hang down from the segment, and the strength of the refractory wall is increased. Can be maintained.

  In the above embodiment, the refractory mortar 22 is sprayed onto the refractory mortar holding member 1 so that the refractory mortar 22 is held on the surface of the refractory mortar holding member 1. The refractory mortar 22 may be held on the surface of the refractory mortar holding member 1 by applying the refractory mortar 22 to the refractory mortar holding member 1 by hand. You may hold | maintain on the surface of the member 1 for refractory mortar holding | maintenance.

DESCRIPTION OF SYMBOLS 1 Refractory mortar holding member 2 Rib 3 Mesh 4 Through-hole 11 Segment 22 Refractory mortar

Claims (4)

A first step of attaching a segment having a hollow portion to the inner wall of the tunnel;
After the first step, a second step of attaching a flexible refractory mortar holding member to the segment so as to cover a hollow portion of the segment attached to the tunnel;
After the second step, a third step of applying to the surface side of the refractory mortar holding member to hold the refractory mortar, and a fireproof construction method for a tunnel, characterized by comprising: 2. The fireproof construction method for a tunnel according to claim 1, wherein in the third step, the fireproof mortar is sprayed by a sprayer to hold the fireproof mortar on the surface side of the fireproof mortar holding member. A plurality of cuts parallel to and penetrating one side of a single flexible plate are staggered in the plate, and then the cut is opened in a direction perpendicular to the length direction of the cut. The refractory mortar holding member is prepared by pulling a plate so that the plurality of cuts are each formed into a mesh composed of a plurality of through-holes continuous in a honeycomb shape. 2. A fireproof construction method for a tunnel according to 2. In addition to putting the plurality of cuts in the zigzag shape, by providing at least one portion that is not cut in the plate and continuous with a certain width, and pulling the plate, 4. The fireproof construction method for a tunnel according to claim 3, wherein the fireproof mortar holding member is prepared and prepared so that the portion having the constant width and not having the cut functions as a rib.

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