JP5162296B2 - Method for preventing fallen objects from falling from structures - Google Patents

Description

  The present invention relates to a construction method for preventing fallen objects from falling from a structure, and in particular, from falling structures from structures such as lining concrete, bricks, blocks, viaduct concrete in tunnels such as railways and roads. The present invention relates to a method for preventing a fallen object falling from a structure using a resin-impregnated multiaxial assembly fabric, which is used for preventing, easy to carry in and fix, and excellent in water conductivity.

  There is an accident in which a part of the structure using lining concrete in a tunnel such as a railway or a road, concrete such as a brick, a block or a bridge is peeled off due to aging or an earthquake.

  As a method for repairing such a structure, a sheet construction method in which carbon fiber or aramid fiber is bonded with epoxy resin, acrylic resin, or the like, or a net-like object composed of fibers is fixed to a wall surface with an anchor and mortar is blown. A construction method has been proposed.

  Patent Document 1 proposes a method in which the surface of a structure is ground-treated, and a fiber sheet is impregnated and cured using a thermosetting resin such as an epoxy resin, and then adhered. However, this construction method may not be able to ensure the necessary adhesive force between the structure surface and the fiber sheet depending on the surface state of the structure, such as the surface of the structure being wet. In addition, since the curing time of the thermosetting resin is long when it is cold, it may not be applicable to construction that requires short-time construction. Furthermore, since the water-tightness of the cured body is high, the fiber sheet may be peeled off due to the backside water pressure from the structure, freeze-thaw, or the expansion pressure of water vapor. In addition, since it is difficult to visually observe the progress of deterioration of the structure, it is difficult to observe the deterioration state of the structure and find out the occurrence of peeling pieces.

  Patent Document 2 describes a method of forming an adhesive layer on one side of a braid and attaching it to concrete with adhesive force. However, if the surface state of the structure is bad, it cannot be attached. Even if the adhesive can be attached normally, if the pressure-sensitive adhesive deteriorates, the fall-off performance of the peeled pieces may be reduced, and the braid itself may be peeled off. Patent Document 3 describes a method of forming an adhesive layer on one side of a lattice-shaped plastic material or fiber-reinforced plastic material and sticking it to concrete with adhesive force. Is included.

  Patent Document 4 proposes a construction method for preventing falling pieces from falling by spraying and applying mortar after installing a braid on a structure. However, the process of attaching the braid to the structure requires labor and time, and there is a problem in workability in a short time. Furthermore, in this case as well, it is difficult to visually observe the progress of deterioration of the structure, so it is difficult to observe the deterioration of the structure and find out the occurrence of peeling pieces.

  Patent Document 5 discloses a method of fixing FRP lattices with anchor bolts. Generally, FRP lattices are easily damaged by unevenness or peeling pieces on the surface of the structure, and are likely to break. In order to avoid this, it is necessary to thicken the fiber bundle and increase the amount of resin to be impregnated. For this reason, the flexural rigidity of the FRP bars increases, and it becomes difficult to fix the grid bars along a curved surface with a small radius when the surface of the structure is uneven. Furthermore, since it is naturally impossible to wind the FRP lattices to a small diameter, it is difficult to carry them into the construction site.

  Patent Document 6 proposes a braided fabric that can observe deterioration of the structure over time and can be wound up in a roll shape, but has a biaxial lattice shape. When a pull-out test is performed with two axes, a square or rectangular lattice is deformed into a rhombus or a parallelogram and stretched. For this reason, when assuming a tunnel, even if the stripped piece can be received, there is a drawback in that it is difficult to secure a sufficient cross-sectional area because the sagging distance increases and the building limit is violated.

  Patent Document 7 proposes a braid having a void that allows visual observation of aged deterioration in a concrete structure, but this method is a method of fixing the braid with an embedded anchor and bonding it with a transparent resin. is there. In this case, the necessary adhesion force between the structure surface and the fiber sheet may not be ensured depending on the surface state of the structure, such as the surface of the structure being wet as in Patent Document 1. In addition, since the water-tightness of the cured body is high, the braid may peel off due to the backside water pressure from the structure, freezing and thawing, or the expansion pressure of water vapor.

In Patent Document 8, a woven fabric having a hardness of 10 cm or more and 100 cm or less is heat-cured to a structure by a 45 degree cantilever method in which intersections of multiaxial non-woven fabric or woven fabric made of ultra high molecular weight polyethylene are bonded with a thermoplastic resin. A method of adhering and fixing with an adhesive resin or cement-based mortar has been proposed. Also in this case, the necessary adhesion force between the structure surface and the woven fabric may not be ensured depending on the surface state of the structure, such as the surface of the structure being wet as in Patent Document 1. In addition, since the cured body has high water tightness, the woven fabric may be peeled off due to the backside water pressure from the structure, freeze-thaw, or the expansion pressure of water vapor.
JP 2003-213624 A JP 2006-16703 A JP 2006-291668 A JP-A-2005-97882 JP 2006-9266 A JP 2004-293150 A JP 2001-355343 A Japanese Patent Laid-Open No. 2004-132015

The peeled object fall prevention method is required to satisfy the following conditions from the viewpoint of workability, safety, durability and maintenance management.
(1) Shorten workability and construction time: The railway must be able to be constructed in a short period of time, from the last train to the first train.
-Ease of construction level: Ease of construction technology that can ensure a certain level of construction even if it is not a selected worker.
・ Non-land correspondence: It should be possible to cope with some uneven shapes present on the surface of the structure.
・ Water conductivity: Do not let water leak out of the system between the structure and the resin sheet, and drop it into the tunnel space or under the viaduct concrete.

(2) Safety / peeling resistance: It must be strong enough to withstand the falling load of the peeled piece of lining concrete, and the displacement due to the load must not violate the building limits.
-Wet surface adhesiveness: Adhesive strength can be secured even on a leaked surface.
-Fire resistance: Non-flammable or self-extinguishing materials are preferred to ensure the time required for evacuation of users, especially in closed spaces such as tunnels, regardless of roads or railways.
・ Non-conductivity: In the case of tunnels such as railways, short circuits such as power lines and signal lines should be prevented, or short circuits such as electric motors should not occur even if the fabric is removed.

(3) Durability, maintenance management and quality stability: Strong against deterioration such as corrosion.
・ Maintenance management: It is easy to observe the deterioration of the structure and to find the peeled pieces. In addition, it should be easy to repair again after construction.

  In view of the above conditions, the main object of the present invention is to reduce the surface treatment work on the surface of the target structure, and even if the surface of the structure is wet or the work environment is low temperature, the surface of the structure It is an object to provide a method for preventing fallen objects from falling from a structure that can stably secure a fixing force between the fabric and the braid for a long period of time and can further reduce the work time.

  In addition, the progress of deterioration of the structure can be observed, and if a stripped piece hangs on the fabric, for example, the fabric of that part is cut, the stripped piece is removed, and the cross section of the stripped portion is repaired. It is to provide a fallen fall prevention method from a structure that can be easily repaired, for example, by attaching a braid like a patchwork.

  In addition, surface leakage such as water leakage from concrete lining of tunnels or water leakage from joints found in brick linings is difficult to deal with by the water-conducting method, but the structure is assembled with a transparent sheet. It is to provide a method for preventing fallen objects from falling off the structure, in which surface water conduction (water leakage is drained through between the structure and the sheet) can be easily performed.

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a resin sheet is disposed on a structure, and a resin is impregnated into a multiaxial assembly fabric in which fiber bundles are disposed on three or more axes on the resin sheet. The resin-impregnated multiaxial assembly fabric having an opening ratio of 50 to 80% obtained by drying is disposed , and the resin-impregnated multiaxial assembly fabric is fixed to the structure via the resin sheet by an anchor. It is a fallen fall prevention method from a characteristic structure.

  According to a second aspect of the present invention, in the method for preventing fallen objects from falling off from the structure according to the first aspect, the mesh opening of the resin-impregnated multiaxial assembly is formed so that a 6-13 mm round bar can pass through. It is characterized by being.

  According to a third aspect of the present invention, in the method for preventing fallen objects from falling off from the structure according to the first or second aspect, the anchor is formed by using the resin-impregnated multiaxial assembly fabric as a structure through a resin packing. It is fixed.

  According to the invention according to claim 1, by impregnating a resin into a multiaxial assembly fabric in which fiber bundles are arranged in three or more axes, and using a resin-impregnated multiaxial assembly fabric having an opening ratio of 50 to 80%, the working environment is improved. Appropriate flexibility and rigidity can be realized. In flexibility, the braided fabric can be arranged and fixed along the unevenness on the surface of the structure, and the outer fabric is wound around a small-diameter cylindrical body having a diameter of about 7.5 to 20 cm to form a roll. Manufacture or storage, delivery to the construction site, and layout work for the work are facilitated. Also, in terms of rigidity, when placing a braid along the unevenness on the surface of the structure while unraveling the roll, the braid is in close contact with the surface of the structure, facilitating the placement of the braid. Can be performed.

  In addition, since the resin-impregnated multiaxial assembly fabric is fixed to the structure through the resin sheet, the durability against the falling load of the peeled piece can be increased and surface water can be supplied compared to the case of only the assembly fabric. It becomes.

  According to the invention according to claim 2, since the mesh opening of the resin-impregnated multiaxial assembly fabric is formed so that a 6 to 13 mm round bar can pass through, the outer diameter of 6 mm or more and 13 mm or less is obtained without damaging the assembly fabric. It becomes possible to use the anchor bolt which has. As a result, the durability of the braided fabric can be improved, and a sufficient holding force can be exerted by the anchor even on a piece peeled off from a structure composed of concrete or the like.

  According to the invention of claim 3, since the anchor fixes the resin-impregnated multiaxial assembly to the structure through the resin packing, the assembly can be fixed to the structure without damaging the assembly. It becomes possible. Even when the braid is pulled in a direction parallel or perpendicular to the surface of the structure by the stripping piece, the braid is held by the packing so that the movement of the braid is suppressed and the braid Can be prevented. Further, it is possible to prevent fatigue fracture due to aging by buffering a repeated load received by the resin-impregnated braid, such as a change in atmospheric pressure accompanying passage of a train as in the case of a railway tunnel.

Hereinafter, the fallen fall prevention method from the structure of the present invention will be described in detail.
The fallen object fall prevention method from the structure of the present invention comprises impregnating a resin into a multiaxial assembly fabric in which fiber bundles are arranged in three or more axes, and a resin-impregnated multiaxial assembly fabric having an opening ratio of 50 to 80%. The anchor is fixed to the structure through a resin sheet.

  The greater the number of resin-impregnated multiaxial braids that support the fallen fallen material, the smaller the deformation when the net of the braid is subjected to a load, and the greater the load at break. High fall prevention performance. Ideally, a fabric with a large number of shafts is preferred, especially for peeled materials. On the other hand, in the production of multi-shaft fabrics, as the number of shafts increases, mass production technology suddenly becomes difficult, and the production price of the fabric also increases. Therefore, in reality, the number of axes is preferably 3 or 4, rather than the 2-axis assembly as shown in FIG. 1, as in the 3-axis assembly shown in FIG. 2 or the 4-axis assembly shown in FIG.

  As the fiber constituting the multi-axial assembly fabric, a fiber having high strength and high elastic modulus and low creep and high durability is preferable. For example, it is selected from one or more of glass fiber, carbon fiber, aramid fiber, wholly aromatic polyester fiber, PBO fiber, vinylon, and metal fiber. One or more of these fibers may be used in combination with nylon, polyester fiber, acrylic fiber, cotton, or the like. Particularly in railway tunnels and the like, alkali-resistant glass fibers that are non-conductive and are not subject to deterioration due to alkali components from concrete are preferable.

  The tensile strength at break of the multiaxial fabric is important from the viewpoint of supporting the fallen fallen objects. It is preferable that the breaking strength per one yarn bundle impregnated with the resin in each axial direction is 500 N or more. In the case of glass fibers and carbon fibers, the breaking strength is not exhibited unless the yarn bundles constituting the multiaxial fabric are impregnated with an appropriate amount of an appropriate resin. Therefore, in the case of glass fiber and carbon fiber, an appropriate resin and impregnation amount are important.

  Intersection breaking strength of resin-impregnated multiaxial assembly is also important. The force that supports the exfoliation depends on the fixing force between the multi-axis assembly fabric impregnated with the resin and the structure. It is necessary to disperse the load of the stripped object at the fixing points by a plurality of jigs existing nearby. The intersection of the resin-impregnated multiaxial assembly fabric is not physically fixed, but is bonded with the impregnating resin. In order to disperse the load, the intersecting point breaking strength of the resin-impregnated multiaxial woven braid is important. In the intersecting point breaking strength test shown in FIGS. is necessary. If the intersection breaking strength is lower than this, the sag distance from the structure increases. For example, in the case of a tunnel, if it falls below the building limit (for example, 20 cm or more), there is a risk of hitting a train or a car. Further, if the load is not distributed to a plurality of fixing points present in the vicinity, the yarn bundle may be broken or a specific fixing point may be broken.

  Note that FIG. 4 shows the creation of a test piece used for the intersection breaking strength test, taking a biaxial assembly as an example. The intersection is measured by the test while cutting out the assembly as shown in the left diagram of FIG. In the vicinity of the lower side, a cut is made in the yarn bundle, and a test piece as shown in the perspective view of the right view of FIG. 4 is prepared. Next, a test piece as shown in FIG. 5 is fixed with a fixing jig, and the intersection breaking strength is measured. The left figure of FIG. 5 is a metal plate for fixing the lower side of the test piece, and the right figure of FIG. 5 shows a state in which the upper and lower parts of the test piece are gripped by the respective fixing jigs (grippers). By applying a load so as to separate the upper and lower fixing jigs, the breaking strength at the intersection point of interest is measured. In FIG. 5, the distance between the intersection to be measured and the upper fixing jig is set to 75 mm, and the upper fixing jig is raised at 1 mm per minute, but the present invention is not limited to this.

  In the resin-impregnated multiaxial assembly fabric, the mesh opening is also important. In general, when the yarn bundle constituting the multi-axis assembly fabric is thickened or multi-axial, the mesh opening is reduced. The mesh opening is an important factor in adjusting the flexibility and rigidity of the braid as will be described later. Furthermore, when anchor pins are used when fixing the braid to the structure, the mesh opening If it is small, there is a risk of damaging the multi-axis assembly. Considering these comprehensively, the opening ratio is preferably 50 to 80%, and more preferably a resin-impregnated multiaxial assembly fabric having an opening through which a round bar of 6 to 13 mm can pass. By using an anchor bolt having an outer diameter of 6 to 13 mm, a sufficient holding force can be exerted by the anchor even on a fallen fallen piece from a structure made of concrete or the like.

  In construction on site, the softness (flexibility) of the resin-impregnated multiaxial assembly fabric is also important. It is difficult to specify the length of the resin-impregnated multiaxial assembly fabric in advance when performing fall prevention work on site. Therefore, the wound resin-impregnated multiaxial assembly fabric is carried into the construction site, the situation at the construction site is judged, and the assembly fabric is cut and attached with scissors or the like. For that purpose, it is convenient if it can be wound around a core tube having a diameter of 7.5 to 20 cm.

  On the other hand, the hardness (rigidity) of the resin-impregnated multiaxial assembly fabric is also important in the actual attaching operation. If it is too hard, it becomes difficult to follow the irregularities when the surface of the structure has irregularities. On the other hand, if the hardness is too low, the resin-impregnated multiaxial assembly fabric hangs down due to its own weight during the pasting operation, and the efficiency of the pasting work is reduced. For this reason, it is preferable that the hanging distance when the resin-impregnated multiaxial assembly fabric is horizontally extended by 1 m is 20 to 40 cm.

  As the resin to be applied to the multiaxial assembly fabric, a resin having a high yarn bundle strength expression rate, a high intersection breaking strength, and suitable flexibility can be used. Specifically, it is selected from at least one of vinyl chloride resin, polyurethane resin, polycarbonate resin, epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin and the like.

  In particular, when flame resistance is required for resin-impregnated braids, such as in closed spaces such as in tunnels or construction of building structures, flame retardant resins may be applied. A flame retardant may be added to impart flame retardancy. Moreover, when electrical insulation is required, it is preferable to apply an insulating fiber and resin. The content of the resin is preferably in the range of 10 to 40% with respect to the weight of the entire resin-impregnated braid. If it is 10% or less, the breaking strength of the yarn bundle constituting the braid becomes low, and the intersection strength of the resin-impregnated multiaxial braid decreases, so that the ability to prevent the fallen object from falling falls. On the other hand, even if it is 40% or more, the breaking strength and the intersection strength do not increase any more, but the weight simply increases, the braid becomes stiff, and winding, carrying in, and construction become difficult.

  The sheet to be overlapped with the resin-impregnated multiaxial assembly fabric is preferably a transparent waterproof sheet that allows easy observation of the deterioration state of the structural body and discovery of a peeled piece. In addition, since the surface of the target structure often has irregularities, a sheet that can fix the resin-impregnated multiaxial assembly fabric with an anchor bolt is preferable. The thickness of the sheet is preferably 0.5 to 3.0 mm. Furthermore, in particular, in the case of a closed space such as a tunnel, it is preferable to have flame retardancy or nonflammability that can secure a time for the user to evacuate. The sheet is selected from vinyl chloride, nylon, polyester, urethane, polyethylene, polypropylene resin, and the like. A sheet reinforced with short fibers or continuous fibers is also effective. Thus, by laminating a resin sheet (which can be fiber reinforced as necessary), it is possible to disperse the load applied to the braid from the peeled piece and increase the load that can be retained. Visible surface water can be achieved.

  Any fixing jig may be used as long as the resin-impregnated braid can be stably fixed to the structure. Specifically, a metal expansion type anchor, an adhesion type chemical anchor or a combination type of various anchor bolts may be mentioned. In the case of an anchor bolt, the thickness is preferably 6 to 13 mm and the length is preferably 30 to 200 mm. When the thickness is 6 mm or less, the breaking strength of the anchor bolt is insufficient. If it is 13 mm or more, it is necessary to increase the mesh opening of the multiaxial assembly fabric, which is disadvantageous because the breaking strength of the resin-impregnated assembly fabric is lowered. Further, when the anchor bolt is embedded in a length of 30 mm or less, the fixing force to the structure of the resin-impregnated braid is insufficient, and when it is 200 mm or more, the fall-off fall prevention range assumed for the resin-impregnated braid is overspec. Moreover, although the space | interval which arrange | positions an anchor is not specifically limited, It is desirable to fix at the space | interval of 35-50 cm like the below-mentioned Example.

  A washer is used together to relieve stress concentration near the anchor bolt. The diameter of the washer preferably has an area capable of suppressing about 3 to 5 adjacent intersections of the resin-impregnated braid. More preferably, a construction method is adopted in which a curable resin is applied between the braid and the washer and cured to fix the multiaxial resin-impregnated braid into the structure more firmly.

  Furthermore, a resin packing larger than the diameter of the washer having the above area may be installed between the washer and the resin-impregnated braid to firmly fix the resin-impregnated braid on the structure having unevenness. it can. In the case of a railway tunnel, the repeated load received by the resin-impregnated braid due to a change in atmospheric pressure accompanying the passage of the train can be buffered to prevent fatigue failure due to aging. In this case, the diameter of the resin packing is preferably equal to or greater than the washer diameter (Lmm) + 2 × washer thickness (Tmm).

Examples according to the present invention will be described below.
(Manufacture of resin-impregnated braid)
Manufactured by Nippon Electric Glass Co., Ltd., manufactured by using an alkali-resistant glass fiber (trade name: ARG: 2170 tex), a 25-mm pitch in the vertical direction and a 25-mm pitch in the horizontal direction and a 100-cm width biaxial assembly fabric (see FIG. 1) with a diameter of 76 mm It was wound up on a paper tube.

  Further, a triaxial assembly fabric (see FIG. 2) having a width of 100 cm and a pitch of 17.2 mm in the vertical direction and a pitch of 15 mm in the ± 45 degrees direction was manufactured using the same glass fiber and wound around a paper tube having a diameter of 76 mm.

  In addition, a 4-axis braided fabric (see Fig. 3) with a width of 100 cm and a pitch of 38.1 mm in the vertical and horizontal directions and a pitch of 26.9 mm at ± 45 degrees is manufactured from the same glass fiber, and wound around a paper tube with a diameter of 76 mm. It was.

  The three types of wound fabrics were unwound and continuously impregnated with a vinyl chloride resin solution dissolved in a solvent. As shown in Table 1, the resin impregnation amount was changed, the fabric was impregnated, applied and dried, and fabrics having different resin impregnation amounts were wound around a paper tube having a diameter of 76 mm.

(Intersection break strength test of resin impregnated braid)
A yarn bundle test piece having the shape shown in FIG. 4 was cut out from the resin-impregnated braided fabric (biaxial braided fabric), fixed with an iron plate jig as shown in FIG. 5, and the intersection breaking strength was measured. The results are shown in Table 1. Since it is clear that the breaking strength of the triaxial assembly fabric and the 4-axial assembly fabric is larger than that of the biaxial assembly fabric, the biaxial assembly fabric is shown here.

(Flexibility and rigidity test of resin impregnated braid)
The resin-impregnated braided fabric (triaxial braided fabric) obtained above was unwound by 100 cm, the curl was removed, and then the hang-up was measured from the horizontal table and shown in Table 1.

(Pullout test related to fallen fall prevention method from structure)
A pull-out test was performed on the fallen fall prevention method from the structure of the present invention. The pull-out test was conducted based on the “Pull-out test method (draft) of the net method” described in the “FRP tunnel lining peeling countermeasure manual” (Tunnel Safety Measure Method Study Group).
The above-mentioned biaxial assembly fabric (assembly fabric 1), 3-axis assembly fabric (assembly fabric 2), and 4-axis assembly fabric (assembly fabric 3) impregnated with 20% resin are cut into 600 mm squares, as shown in FIG. A 160 mm square steel plate (drawing steel plate) connected with a tension metal fitting was temporarily fixed at the center of a concrete plate for groove lid having a width of 600 mm, a width of 600 mm, and a thickness of 70 mm. Further, a resin-impregnated braid was placed, and fixed with four M10 anchor bolts using a washer having a diameter of 60 mm and a resin packing (same diameter as the washer) to obtain a test specimen.

  As shown in FIGS. 7 and 8, the concrete plate was fixed to a Tensilon tester, a displacement meter was attached, and a pull-out test was performed in which the relationship between stress and displacement was measured by pulling it up through a load cell. The measurement speed was 30 mm / min. 7 and 8 are schematic cross-sectional views of the pull-out test of FIG. 6. FIG. 7 uses only a resin-impregnated braid and FIG. 8 uses a resin-impregnated braid and a (fiber reinforced) transparent sheet. An example is shown.

  FIG. 9 shows the measurement results of only the resin-impregnated braid of FIG. As the number of axes of the braid increases, the stress-displacement relationship becomes linear and the maximum peel strength increases. When the biaxial resin-impregnated braid is subjected to a load, the square lattice is deformed into a parallelogram or rhombus, and the amount of displacement increases, and it has been found that the biaxial resin-impregnated fabric does not meet the purpose of this time.

  The pull-out test result of the 4-axis resin-impregnated braid alone showed that when the anchors were installed at intervals of 350 mm, the numerical value at a displacement of 50 mm was 130 kgf (1274 N). Next, when the anchors are installed at intervals of 500 mm, the numerical value at the displacement amount of 50 mm indicates 35 kgf (343 N), and the numerical value at the displacement amount of 100 mm indicates 155 kgf (1519 N). The displacement was 190 kgf (1862 N) at a displacement of 140 mm.

Here, when the resin-impregnated braid alone or the resin-impregnated braid and a transparent sheet were laminated, the load applied to the fall prevention net by the peeled piece of the structure was estimated as follows.
The distance between anchor bolts (L (cm)), the thickness (T (cm)) assuming peeling, the specific gravity of the structure (C (kgf / cm ³ )), and the safety factor (SF = 3).
(1) L = 35 cm × 35 cm, T = 10 cm, C = 2.3, SF = 3 35 × 35 × 10 × 2.3 × 3 = 84.5 kg
(2) L = 35 cm × 35 cm, T = 5 cm, C = 2.3, SF = 3 35 × 35 × 5 × 2.3 × 3 = 42.3 kg
(3) L = 50 cm × 50 cm, T = 10 cm, C = 2.3, SF = 3 50 × 50 × 10 × 2.3 × 3 = 172.5 kg
(4) L = 50 cm × 50 cm, T = 5 cm, C = 2.3, SF = 3 50 × 50 × 5 × 2.3 × 3 = 86.25 kg

With reference to the load of the peeling piece and the pull-out test result of FIG. 9, the selection of the multi-axis assembly and the distance between the anchor bolts can be appropriately selected. For example, the anchor spacing required to prevent the brick layer (T = 10 cm) in the schematic diagram shown in FIG. is there. Assuming that the building limit is 150 mm, in the case of only the 4-axis resin-impregnated braid, it is possible to increase the anchor interval to 50 cm and reduce the number of anchors to be driven per 1 m ² .

  In addition, as shown in FIG. 8, when a 2 mm thick vinyl chloride sheet was used as the transparent sheet, even when the anchor interval was 50 cm, the displacement was the same as in the case where the anchor interval was 35 cm with only the resin-impregnated braid. However, it has been confirmed by experiments that it can withstand higher loads. In this way, by fixing the resin-impregnated multiaxial assembly fabric to the structure through the resin sheet, the durability against the falling load of the peeled piece can be further increased compared to the case of only the assembly fabric, and surface water conduction can be performed. It is also possible to do this.

  According to the present invention, the surface treatment work on the surface of the target structure can be reduced, and even if the surface of the structure is wet or the working environment is low temperature, the fixing force with the surface of the structure can be maintained over a long period of time. It is possible to provide a method for preventing fallen objects from falling off the structure, which can be secured stably and can further reduce the work time.

  In addition, the progress of deterioration of the structure can be observed, and if a stripped piece hangs on the fabric, for example, the fabric of that part is cut, the stripped piece is removed, and the cross section of the stripped portion is repaired. After performing the above, it is possible to provide a fallen fall prevention method from a structure that can be easily repaired, such as attaching a braided fabric in a patchwork manner.

  Furthermore, even if there is no water leakage during construction, it is possible to conduct water in the rainy season, or even in areas where it is difficult to conduct or stop water due to leakage in the surface of a brick lining tunnel. It is possible to provide a fallen fall prevention method from the structure.

It is a figure which shows a biaxial assembly fabric. It is a figure which shows a triaxial assembly fabric. It is a figure which shows 4 axis | shaft assembly fabric. It is a figure which shows the yarn bundle test piece for an intersection breaking strength test. It is a figure which shows the mode of mounting | wearing of the fixing jig which concerns on an intersection breaking strength test, and this fixing jig. It is a top view of the test body attachment state which concerns on a pull-out test. It is a sectional side view which shows the measurement condition of the drawing test only by a braid. It is a sectional side view which shows the measurement condition of the drawing test by a braid and a resin sheet. It is a graph which shows the measurement result of a drawing test. It is a schematic diagram of the brick lining.

Claims (3)

A resin sheet is disposed on the structure, and an opening ratio obtained by impregnating the resin into a multiaxial assembly fabric in which fiber bundles are arranged in three or more axes on the resin sheet and drying is 50 to 80%. A method for preventing fallen objects from falling off a structure, comprising arranging a resin-impregnated multiaxial assembly fabric and fixing the resin-impregnated multiaxial assembly fabric to a structure via a resin sheet with an anchor.   2. A method for preventing fallen objects from falling off from a structure according to claim 1, wherein the opening of the resin-impregnated multiaxial assembly is formed so that a 6 to 13 mm round bar can pass therethrough. Method to prevent falling objects from falling.   3. A method for preventing fallen objects from falling off from a structure according to claim 1 or 2, wherein the anchor fixes the resin-impregnated multiaxial assembly fabric to the structure through a resin packing. Method to prevent falling objects from falling.

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