JP2021042542A - Reinforcement construction method of masonry retaining wall - Google Patents

Abstract

To provide a reinforcement construction method of a masonry retaining wall which can advantageously improve the strength of a masonry retaining wall, by constituting so as to perform connection of the masonry retaining wall firmly with respect to an inclined bedrock, while effectively forming a hardening layer of a urethane foam in a gap of a backing cobble stone layer.SOLUTION: In a masonry retaining wall 2 in which wedge stones 4 are piled up so as to be adjacent to each other on a front surface of an inclined bedrock 10 via backing cobble stones 6, a drilling rock bolt 20 is drilled from a bottom part of a head part storage recessed place formed in a joint part 8 between the wedge stones 4 and 4 to a predetermined depth reaching the inclined bedrock 10, and a hardening layer of a urethane foam 34 is formed around the drilling, and then, a head part portion of the drilling rock bolt 20 is fixed to the masonry retaining wall 2. Thereby, the connection between the masonry retaining wall 2 and the inclined bedrock 10 can be achieved.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for reinforcing a masonry retaining wall, and in particular, a masonry having a structure in which a backfill stone layer is provided between a sloping ground and a machi stone formed by stacking stone materials so as to be adjacent to each other. It is related to the reinforcement method of the retaining wall.

Traditionally, masonry retaining walls have been widely adopted as a structure for preventing the slope of a sloping ground from collapsing. However, in the masonry retaining wall that has a backfill stone layer on the back of Machiishi, the backfill stone that is filled moves due to shaking due to an earthquake or erosion by rainwater, etc., and a cavity is formed. The upper stones may sink and the lower stones may be pushed forward, causing deformation such as the wall surface protruding. Then, when the condition became worse, the strength of the entire masonry retaining wall was lowered, which could lead to a situation such as collapse.

Therefore, as one of the reinforcement methods for preventing such collapse of the masonry retaining wall, in Japanese Patent No. 4316940, a hole is drilled in the joint portion where the masonry stones are in contact with each other with respect to the existing masonry retaining wall. By injecting a grout material into the backfilling stone layer through this drilling, a solidified part is provided in the backfilling stone layer, and a stone wall different from the drilled part is further provided. A short reinforcing material is driven into the joints where they come into contact with each other, and a grout material is filled around the joint. By fixing the reinforcing material to the backfilling stone layer, the stones are pushed outward. , A method of reinforcing a masonry wall has been proposed in which deformation of the wall surface is suppressed by mutually restraining the Machi stones.

By the way, in the method of reinforcing the masonry wall as described above, when the grout material is filled in the backfill stone layer, the grout material to be injected is injected so that the grout material sufficiently spreads in the gap of the backfill stone layer. , It is necessary to have a certain degree of high liquidity. However, in such a highly fluid grout material, after injection, it does not stay in the backfill stone layer but hangs down due to its own weight, and as a result, the solidified part around the drilled hole is biased. There is an inherent problem that a sufficient reinforcing effect cannot be expected. On the other hand, in order to prevent the grout material from dripping, even if the flowability of the injected grout material is reduced, the grout material having low fluidity is used as a gap between the backfilling stone layers around the drilling. It was difficult to fully invade the retaining wall, and the solidified part made of grout material was limited in a narrow range, and there was no hope of improving the strength to the extent that the structural strength of the retaining wall was increased. For this reason, with the conventional reinforcement method using grout material, it is not possible to properly fill the gaps in the backfill grit stone layer with grout material, and if an earthquake larger than initially expected occurs, earth pressure There was an inherent problem of being unable to maintain the slope against the earthquake.

Japanese Patent No. 4316940

Here, the present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved thereof is to effectively form a cured layer of urethane foam in the gaps between the backfill stone layers. At the same time, it provides a method for reinforcing the masonry retaining wall so that the strength of the masonry retaining wall can be advantageously improved by constructing the masonry retaining wall so that it can be firmly connected to the sloped ground. ..

Then, in order to solve the above-mentioned problems, the present invention can be preferably carried out in various aspects as listed below, and each aspect described below can be carried out in any combination. It can be adopted. It should be noted that the aspects or technical features of the present invention are not limited to those described below, and are understood based on the invention idea grasped from the description of the entire specification and the drawings. , Should be considered.

Therefore, in the present invention, first, in order to solve the above-mentioned problems, a masonry retaining wall is reinforced by stacking Machi stones on the front surface of a sloping ground via a backfilling grit stone layer so as to be adjacent to each other. According to the construction method, (a) a head having a diameter larger than the diameter of the perforation provided so as to reach the sloping ground from the masonry retaining wall with respect to the joint portion formed between the masonry stones in the masonry retaining wall. A step of forming a retaining wall at a predetermined depth, and (b) a long bolt body having a hollow structure in which an appropriate number of through holes are formed from the inside of the hollow to reach the outer surface and open. A step of forming a perforation lock bolt having a perforation bit attached to the tip to a predetermined depth reaching the inclined ground from the bottom of the head storage recess, and (c) the perforation lock bolt. A ring-shaped rubber cone is externally fitted to the outer peripheral portion of the portion located on the head housing recess side, and the gap between the formed perforation and the perforation lock bolt is closed by the rubber cone. The step and (d) a two-component urethane foam raw material is injected into the hollow portion of the bolt body of the drilling lock bolt, and the inside of the drilling through the tip opening of the bolt body or the through hole of the retaining wall lock bolt. By invading the backfilling gritty stone layer of the masonry retaining wall around the perforation, and foam-curing the urethane foam raw material, a cured layer of urethane foam is formed around the perforation lock bolt. And (e) the head portion of the perforated lock bolt located in the head accommodating recess is fixed to the masonry retaining wall in which the head accommodating recess is formed. The gist is a method for reinforcing a masonry retaining wall, which is characterized by including a step of connecting the retaining wall and the sloping ground.

According to one of the preferred embodiments of the masonry retaining wall reinforcement method according to the present invention, the perforation enters the inclined ground at a length of at least 1 times or more the thickness of the masonry retaining wall. , Is formed.

Further, according to a more preferable aspect of the method for reinforcing the masonry retaining wall according to the present invention, the head accommodating recess is formed straddling the adjacent masonry stones.

Furthermore, according to another preferred embodiment of the masonry retaining wall reinforcement method according to the present invention, the head accommodating recess is formed at a depth of 20 to 70 mm.

Furthermore, according to one of the desirable embodiments of the masonry retaining wall reinforcement method according to the present invention, the perforated lock bolt is located on the head accommodating recess side prior to the injection of the two-component urethane foam raw material. A static mixer is charged and arranged in the hollow portion of the portion to be formed, and the two-component urethane foam raw material injected into the hollow portion of the drilling lock bolt is configured to be mixed by the static mixer. ..

Then, in the method for reinforcing the masonry retaining wall according to the present invention, it is advantageous to have a spherical female washer portion having a spherical concave portion on the seat surface, which is arranged so as to enter the head accommodating recess. , A washer member having a plate portion integrally provided on the outer peripheral portion of the spherical female washer portion and brought into contact with the surface of the masonry retaining wall, and a nut screwed onto the head of the perforated lock bolt. Using a nut member having a spherical male washer portion that is integrally formed at the lower portion of the portion and is seated on the seat surface of the spherical female washer portion, the nut member is formed into the perforated lock bolt via the washer member. The perforated lock bolt was secured to the masonry washer wall by screwing it onto the head of the washer.

In addition, in the method of reinforcing the masonry retaining wall according to the present invention, the cover member is attached under the arrangement state of the washer member and the nut member with respect to the head accommodating recess, and the washer member and the nut are attached. In a form in which the member is housed inside, the upper part of the head housing recess is configured to be partitioned from the outside.

As described above, according to the method for reinforcing the masonry retaining wall according to the present invention, a perforated lock bolt that reaches a predetermined depth of the sloping ground is driven from the masonry retaining wall and passed through the hollow portion of the bolt body of the perforated lock bolt. By injecting a two-component urethane foam raw material and discharging it into the perforation formed by the perforation lock bolt, the urethane foam layer and the ground around the perforation are invaded and injected. By foaming and curing the urethane foam raw material at a desired speed, a cured layer of urethane foam is effectively formed around the perforated lock bolt. As a result, the urethane foam material penetrates into the gaps between the backfilling stone layers around the drilling lock bolt without dripping in the backfilling stone layer, and is rapidly cured, thereby causing the drilling lock bolt. And the backfill stone layer around it, and even the Machi stone can be integrated advantageously, preventing the backfill stone layer from sinking, and effectively preventing the lower part of the masonry retaining wall from protruding or collapsing. It is possible to suppress it, and thus a reinforcing structure of the masonry retaining wall with further improved stability can be advantageously realized.

Further, in the method for reinforcing the masonry retaining wall according to the present invention, the perforated lock bolt is at least 1 times or more the thickness of the masonry retaining wall composed of the machi stone and the backfill stone layer, which is advantageous. By allowing the stone wall to penetrate the sloping ground at a length of 5 times or more, especially 2 to 3 times, the connection between the masonry retaining wall and the sloping ground is further strengthened. , It is possible to effectively suppress the displacement of the masonry retaining wall integrated by the urethane foam, and it is possible to exhibit the feature that it can contribute to the further reinforcement of the masonry retaining wall.

Then, in the method for reinforcing the masonry retaining wall according to the present invention, the diameter of the joint formed between the adjacent masonry stones is larger than the diameter of the perforation provided so as to reach the sloping ground from the masonry retaining wall. A head containing recess is formed at a predetermined depth, and the head portion of the perforated lock bolt is fixed to the masonry retaining wall at a position subducted from the surface of the masonry retaining wall. By allowing the cover member to be attached so as to cover the place, the multiple stone walls of the masonry retaining wall integrated by the urethane foam can be firmly connected to the sloping ground, and the perforated lock bolt can be firmly connected. By reducing the large protrusion of the head joint, damage to the head joint due to falling rocks and pedestrians passing around the masonry retaining wall may be injured by contact with the perforated retaining wall. It will be possible to prevent problems, and in addition, it will be possible to provide a scenic reinforcement structure without degrading the natural appearance of the masonry retaining wall.

It is explanatory drawing which shows an example of the masonry retaining wall to which the reinforcement method according to this invention was applied, (a) is the front explanatory view which shows the masonry retaining wall in the state of completion of construction, (b) is (a). It is a cross-sectional explanatory view of AA in the above. It is a process explanatory drawing which shows an example of the reinforcement construction method of the masonry retaining wall according to this invention, and (a) forms the head accommodating recess with respect to the joint part formed between the masonry stones in the masonry retaining wall. It is a cross-sectional explanatory view which shows the state which is made, (b) shows the state which formed the punch of a predetermined depth to reach the inclined ground by using the punching lock bolt, (c) is (b). The state in which a member for injecting a two-component urethane foam raw material is arranged in the perforation formed in (d) is shown in the perforation lock bolt after the step (c). A form is shown in which a urethane foam raw material is injected into the hollow portion of the hole to form a hardened layer of urethane foam around the perforated lock bolt, and (e) is the head of the perforated lock bolt located in the head accommodating recess. A form for fixing the portion and the machi stone is shown, and (f) shows a state in which a cover member is attached after the step (e). It is a partially enlarged explanatory view of the masonry retaining wall reinforcing portion by a perforated lock bolt in the cross-sectional explanatory view of the masonry retaining wall shown in FIG. 1 (b). It is a side view of the perforated lock bolt used in the reinforcement method according to this invention. It is a partial cross-sectional enlarged explanatory view which shows the fixing structure of the Machi stone and the perforation lock bolt in FIG.

Hereinafter, in order to clarify the present invention more concretely, a typical embodiment of the method for reinforcing a masonry retaining wall according to the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 (a) and 1 (b) show an example of a reinforcing structure of a masonry retaining wall obtained by applying a construction method according to the present invention, respectively, in the form of a front view and a cross-sectional view, respectively. .. There, the masonry retaining wall 2 is configured in a form in which the masonry stones 4 are piled up on the front surface (sloping surface) of the sloping ground 10 via the backfill stone layer 6 so as to be adjacent to each other. There is. Then, at a plurality of positions separated from each other with a predetermined interval with respect to the joint portion 8 formed between the stone walls 4 and 4 on the wall surface of such a masonry retaining wall 2, for example, FIG. 1 (a) shows. A drilling operation with a drilling lock bolt 20 has a diameter slightly larger than that of the drilling lock bolt 20 so as to penetrate the masonry retaining wall 2 and penetrate the sloping ground 10 sufficiently deeply at the staggered portion. A hole) 14 is formed, and a hole lock bolt 20 is inserted and arranged as it is in the hole 14. Further, the urethane foam 34 formed by foaming and curing the injected two-component urethane foam raw material is placed in the perforated lock bolt 20 around the perforated lock bolt 20 inserted in the inclined ground 10, or in the perforated lock bolt. The gaps in the backfill stone layer 6 around 20 are filled to form a hardened and integrated columnar reinforcing portion extending from the masonry retaining wall 2 to the sloping ground 10. As will be described later, a nut member (42) is screwed into the head portion 20a of the perforated lock bolt 20 via a washer member (40), whereby the perforated lock bolt 20 is screwed together. It is fixed to the masonry retaining wall 2 so that a strong connection between the masonry retaining wall 2 and the sloped ground 10 is realized.

Then, in the present invention, in order to obtain such a reinforcing structure of the masonry retaining wall 2, the reinforcing work is carried out as shown in FIGS. 2 (a) to 2 (f). .. Specifically, first, as shown in FIG. 2A, with respect to the joint portion 8 formed between the masonry stones 4 and 4 on the wall surface of the masonry retaining wall 2, the masonry retaining wall 2 to the inclined ground 10 A head accommodating recess 12 having a diameter larger than the diameter of the perforation 14 provided so as to reach, for example, a diameter of about 80 mm is formed at a predetermined depth. The depth of such a head accommodating recess 12: d is such that a washer member (40) and a nut member (42), which will be described later, can be arranged in the head accommodating recess 12. The depth is preferably adopted, and the head accommodating recess 12 is generally formed at a depth of about 20 to 70 mm. Further, there, as shown in the drawing, the head accommodating recess 12 is preferably formed so as to straddle the adjacent stones 4 and 4. As a result, by arranging the washer member (40) and the nut member (42) with respect to the head accommodating recess 12, the perforated lock bolt 20 can be effectively connected to the adjacent stones 4 and 4 and firmly. It is possible to advantageously suppress the positions of the Machi stones 4 from being integrated and being individually displaced or moved.

Next, as shown in FIG. 2B, by performing the drilling operation as known using the drilling lock bolt 20, a drilling 14 having a predetermined depth (D + L) reaching the inclined ground 10 is formed. Further, the perforated lock bolt 20 used here has, for example, a hollow tubular structure as shown in FIGS. 4 and 5, and a continuous screw structure is formed on the outer surface of the tubular wall portion. An appropriate number of through holes 24 that reach the outer surface from the inside of the hollow and open are formed in the cylinder wall portion. Further, a known drilling bit 22 having an outer diameter slightly larger than the outer diameter of the drilling lock bolt 20 is attached to the tip of the drilling lock bolt 20 in a screw connection structure. Then, using the drilling lock bolt 20, the base end portion (head) of the drilling lock bolt 20 is connected to a rock drilling machine such as an anchor drill machine, and the drilling operation is performed in the same manner as before. , A perforation 14 having a depth sufficient to reach the inclined ground 10 is formed from the bottom of the head accommodating recess 12 formed in FIG. 2 (a).

The length of the perforation 14 formed by the perforation work from the masonry retaining wall 2 to the sloped ground 10 is appropriately selected according to the thickness of the masonry retaining wall 2: D, but the sloped ground. The length of the perforated 14 portion in the ridge 10: L is usually formed at least at least 1 times the thickness: D, preferably 1.5 times or more, especially 2-3 times the length. Become. As described above, by forming the perforation 14 in the inclined ground 10 at the above length, the connection between the perforated lock bolt 20 and the inclined ground 10 is strengthened, and as a result, it is hardened as described later. The connection between the masonry retaining wall 2 integrated by the urethane foam (34) and the inclined ground 10 via the perforated lock bolt 20 becomes even stronger, and thus the masonry retaining wall 2 is entangled. Retaining and collapse can be suppressed in an advantageous manner.

By the way, the drilling lock bolt 20 used in the above-mentioned drilling work is filled with the backfilling stone while pushing away the backfilling stone filled behind the Machi stone by the rotation and impact by the rock drill. It penetrates the area and is driven into the sloping ground 10 located on the back surface of the masonry retaining wall 2. Then, by perforating while sending compressed air into the hollow portion 20b of the perforated lock bolt 20 having a hollow structure, a plurality of through holes 24 provided in the perforated lock bolt 20 and the tip opening of the perforating bit 22 are used. , Air is sent into the perforation 14, which prevents the perforation 14 and the through hole 24 provided in the perforation lock bolt 20 from being clogged with earth and sand, and thus fills the two-component urethane foam material described later. The work can be done in an advantageous manner.

Further, in the present invention, as shown in FIGS. 4 and 5, the perforated lock bolt 20 has a hollow structure and has an outer surface that has a good adhesion and bond with the urethane foam 34 that has been foam-hardened. Although perforated lock bolts having various known structures can be used, it is particularly preferable to use perforated lock bolts having a hollow structure and having continuous threads formed on the outer surface. Further, the perforated lock bolt 20 is generally connected by a joint 20c so as to have a required length and is used.

Further, FIG. 2C shows the preparation state of the filling work of the two-component urethane foam raw material after the drilling work by the drilling lock bolt 20 is completed. There, a gap between the formed perforation 14 and the perforation lock bolt 20 is formed by externally fitting the ring-shaped rubber cone 26 to the portion of the perforation lock bolt 20 located on the head accommodating recess 12 side. Leakage during pressure injection of the urethane foam raw material, which will be described later, can be suppressed or prevented by closing the block. On the other hand, a static mixer 28 is charged in the head portion 20a of the perforated lock bolt 20, and an injection adapter 30 for pressurizing and injecting a urethane foam raw material is further provided in the head portion 20a of the perforated lock bolt 20. Once connected, the preparation for injecting the two-component urethane foam raw material consisting of the first liquid and the second liquid is completed.

Here, the urethane foam raw material that is injected into the hollow portion 20b of the perforated lock bolt 20 and is foam-hardened is used to firmly bond the perforated lock bolt 20 and the backfill stone layer 6. After injecting such a urethane foam raw material into the stone layer 6, not only the gap in the backfilled stone layer 6 around the perforated lock bolt 20 is sufficiently spread, but also the foam is immediately cured without dripping. There is a need. Therefore, the urethane foaming raw material used here is a two-component type composed of a first liquid and a second liquid, which is foam-cured by mixing, has a controllable reaction rate and a high reaction rate. A urethane foaming raw material will be used, and due to the speed of the foaming and curing reaction, a static mixer 28 is charged into the head portion 20a of the perforated lock bolt 20 so as to be mixed immediately before injection into the masonry retaining wall 2. It is desirable to attach and mix the two injected liquids so that the foam curing reaction can proceed rapidly.

Further, as the static mixer 28 used there, various known static mixers 28 are known as long as the first liquid and the second liquid constituting the two-component urethane foaming raw material can be mixed and discharged in a short time. A static mixer (static mixer) can be used. For example, a two-component urethane foam raw material in which a plurality of torsion blade-shaped elements are arranged in a fixed position inside a cylindrical member and can be circulated inside the cylindrical member. A mixture of (1st liquid + 2nd liquid) is used, and these two-component urethane foam raw materials injected into the mixer 28 are effectively mixed and inside the perforated lock bolt 20. Will be introduced in.

Then, as shown in FIG. 2D, the two-component urethane foam raw material is pressurized and injected into the drilling 14 through the hollow portion 20b of the drilling lock bolt 20. Specifically, the injection hoses 32 and 32 that separately supply the first liquid and the second liquid constituting the two-component urethane foaming raw material are connected via the injection adapter 30 prepared in the previous step. .. As the two-component urethane foaming raw material, known materials are appropriately used. For example, a first solution mainly composed of a polyol compound and a second solution mainly composed of a polyisocyanate compound are used to perform the perforation. It is pressurized and injected into the hollow portion 20b of the lock bolt 20. Then, these urethane foam raw materials are mixed by the static mixer 28 and then perforated through the hollow portion 20b of the perforation lock bolt 20 and from the tip opening of the perforation bit 22 and the through hole 24 of the perforation lock bolt 20. It is discharged into the 14 and is allowed to invade the backfilling gritty layer 6 and the inclined ground 10 around the perforation 14, and further, these two-component urethane foaming raw materials (first liquid + second liquid) are foamed and hardened. As a result, the cured layer of the urethane foam 34 is integrally formed around the perforated lock bolt 20. Thus, the injected two-component urethane foam raw material spreads in the gaps of the backfilling stone layer 6 around the drilling lock bolt 20 without dripping at the backfilling stone layer 6, and the drilling lock bolt 20 and its The surrounding backfill stone layer 6 and even the Machi stone 4 can be effectively integrated.

As the above-mentioned two-component urethane foaming raw material, the curing time (time from mixing to curing) when the urethane foaming raw materials are mixed is generally within 150 seconds, preferably within 120 seconds, more preferably. Those within 100 seconds are preferably used. For example, if the time from injecting the urethane foam raw material to curing becomes long, the urethane foam raw material cannot stay in the gap of the backfill stone layer 6 and hangs down, so that the perforated lock bolt 20 and its surroundings are used. This is because the backfill stone layer 6 located in the above cannot be sufficiently integrated via the urethane foam 34, and the effective reinforcing strength of the masonry retaining wall 2 may not be obtained. .. Therefore, it is desirable to mix the two-component urethane foam raw material in the vicinity of the head portion 20a of the drilling lock bolt 20 and immediately discharge it into the drilling 14 to quickly perform reaction curing.

Here, the polyol compound which is the main component of the first liquid of the two liquids constituting the urethane foaming raw material used above is not particularly limited, and is, for example, a known polyether polyol or polyester polyol. And so on. The polyether polyol is produced by using a compound such as a polyhydric alcohol, an amine or an alkanolamine having at least two or more active hydrogen groups as an initiator, and adding an alkylene oxide to the compound as an initiator. Is. Examples of the polyester polyol include a polycarboxylic acid-based polyester polyol obtained by reacting a polyhydric alcohol with a polycarboxylic acid, a lactone-based polyester polyol obtained by ring-opening polymerization of a lactone or the like, and the like. ..

On the other hand, the polyisocyanate compound as an essential component of the second liquid, which is one of the other constituents of the two-component urethane foaming raw material, is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule. For example, aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (Crude MDI), tolylene diisocyanate, polytolylen polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and fats such as hexamethylene diisocyanate. In addition to alicyclic polyisocyanates such as group polyisocyanates and isophorone diisocyanates, urethane prepolymers having an isocyanate group at the molecular terminal, isocyanurate-modified polyisocyanates, and carbodiimide-modified products can be mentioned.

In addition, the first liquid and the second liquid constituting the two-component type urethane foaming raw material will contain the same additive components as before, if necessary. Here, examples of such an additive component include a catalyst for promoting the reaction between the polyol compound and the polyisocyanate compound, as well as a foaming agent, a defoaming agent, a thickening agent, a flame retardant, and the like. The component is added to and contained in either one or both of the first liquid and the second liquid according to the same criteria as the conventional two-component urethane foaming raw material.

Then, the two-component urethane foam raw material as described above is injected to complete the foam hardening, so that the perforated lock bolt 20 and the masonry retaining wall 2 are effective as shown in FIG. 2 (e). Further, the integrated structure of the perforated lock bolt 20 and the hardened layer of the urethane foam 34 around the perforated lock bolt 20 can achieve an integral connection between the masonry retaining wall 2 and the inclined ground 10. It will be. After that, the cover member 44 is attached so as to cover the head accommodating recess 12, and the desired reinforcing structure is completed in the form shown in FIG. 2 (f).

Specifically, as shown in FIG. 5, the washer member 40 arranged so as to enter the head accommodating recess 12 has a structure including a spherical female washer portion 40a and a plate portion 40b. It is said that. Therefore, the spherical female washer portion 40a has a spherical recessed portion on the seat surface, has an insertion hole large enough to be inserted into the head of the perforated lock bolt 20, and a cover member described later is screwed on the upper outer circumference. A screw part for dressing is provided. Further, the plate portion 40b is integrally provided on the outer peripheral portion of the spherical female washer portion 40a, and is brought into contact with the surfaces of the masonry retaining walls 2 and the masonry stones 4 and 4, respectively. It is structured so as to have a sufficient size (area) to fulfill the holding function. As a result, the stability of the connection between the masonry retaining wall 2 integrated by the urethane foam 34 and the inclined ground 10 can be effectively improved.

On the other hand, the nut member 42 has a size used in the spherical female washer portion 40a, and the spherical female washer portion 40a is located below the nut portion 42a screwed into the head portion 20a of the drilling lock bolt 20. It has a structure in which a spherical male washer portion 42b to be seated on the seating surface of the is integrally provided. Then, by screwing the perforated lock bolt 20 to the head portion 20a of the perforated lock bolt 20 via the washer member 40 using the nut member 42, the perforated lock bolt 20 can be fixed to the masonry retaining wall 2. -ing By using these spherical washer portions 40a and 42b, the washer member 40 can be accurately attached and a stable fixing force can be obtained even if the attachment angle between the washer member 40 and the drilling lock bolt 20 is different. It will be possible.

Then, in the present embodiment, under the arrangement state of the washer member 40 and the nut member 42 with respect to the head accommodating recess 12, the mounting screw portion has a flattened container (arc cross section) shape and is provided on the lower inner peripheral surface. In a form in which the provided cover member 44 is screwed into the washer member 40 and the washer member 40 and the nut member 42 are accommodated inside, the upper portion of the head accommodating recess 12 is partitioned from the outside. It is covered with. As a result, in addition to improving the rust preventive performance for the perforated lock bolt 20, the problem that the head of the perforated lock bolt 20 is projected and exposed is solved, and thus the head joint is damaged or masonry due to falling rocks or the like. Pedestrians and the like passing around the retaining wall will not be injured by contacting the reinforcing member of the masonry retaining wall 2, and the scenery will be excellent.

Although one of the typical embodiments of the present invention has been described in detail above, it is merely an example, and the present invention is described in a specific manner according to such an embodiment. It should be understood that it is not to be interpreted in a limited way.

For example, in the above-described embodiment, in the static mixer 28, the static mixer 28 is charged into the head portion 20a of the drilling lock bolt 20, and then the injection adapter 30 for pressure-injecting the urethane foam raw material is drilled. It is attached in a form connected to the head portion 20a of the lock bolt 20, but instead of this, a first liquid constituting a two-component urethane foam raw material on the upstream side of the perforated lock bolt 20. Injection configured by incorporating the static mixer (28) on the flow path downstream from the mixing point of the second liquid and, for example, inside the injection adapter (30) connected to the head portion 20a of the drilling lock bolt 20. It is also possible to use the adapter (30).

Further, even in the structure of the illustrated rubber cone 26, any structure can be adopted as long as it has a shape capable of closing the gap between the perforation 14 and the perforation lock bolt 20. For example, in order to improve handleability or workability, the ring-shaped rubber cone 26 is provided with a notch (slit) for cutting the ring shape, and the notch is opened to open the tubular wall portion of the perforated lock bolt 20. A structure in which the above is fitted will also be advantageously adopted.

Further, in the exemplary embodiment, in order to fix the perforated lock bolt 20 to the masonry retaining wall 2, the spherical female washer portion 40a having a shape that enters into the head accommodating recess 12 and the surface of the masonry retaining wall 2 are hit. A washer member 40 having a plate portion 40b in contact with the plate portion 40b is used, but the washer member 40 is not always required and is suitable as long as the perforated lock bolt 20 and the masonry retaining wall 2 can be fixed. There is also a form in which the perforated lock bolt 20 is fixed to the masonry retaining wall 2 simply by screwing a nut member into the head of the perforated lock bolt 20 and pressing it against the bottom surface of the head accommodating recess 12. It can be adopted, and even in its fixed form, various conventionally known forms can be adopted.

In addition, in the above-described embodiment, the cover member 44 is fixed by screwing the male screw portion provided on the cover member 44 to the female screw portion provided on the upper portion of the washer member 40. Although it is attached, the attachment structure is not limited to the screwing structure as shown in the example, and even if it is a fitting structure, there is no problem, and the head accommodating recess 12 is used. Known structures that allow them to be detachably attached to each other, such as structures that are directly fitted together, can be appropriately adopted.

In addition, although not listed one by one, the present invention can be implemented in embodiments with various modifications, modifications, improvements, etc., based on the knowledge of those skilled in the art, and such embodiments are: It goes without saying that all of them belong to the category of the present invention as long as they do not deviate from the gist of the present invention.

2 Masonry retaining wall 4 Machi stone 6 Backfill stone layer 8 Joint part 10 Inclined ground 12 Head accommodation recess 14 Perforation 20 Perforation lock bolt 20a Head part 20b Hollow part 22 Perforation bit 24 Through hole 26 Rubber cone 28 Static Mixer 30 Injection adapter 32 Injection hose 34 Urethane foam 40 Washer member 40a Spherical female washer part 40b Plate part 42 Nut member 42a Nut part 42b Spherical male washer part 44 Cover member

Claims (7)

In front of the sloping ground, a masonry retaining wall reinforcement method is used in which Machi stones are piled up so as to be adjacent to each other via a backfill stone layer.
With respect to the joint portion formed between the masonry stones in the masonry retaining wall, a head accommodating recess having a diameter larger than the diameter of the perforation provided so as to reach the inclined ground from the masonry retaining wall is defined. The process of forming at depth and
Using a drilling lock bolt having a long bolt body of a hollow structure formed with an appropriate number of through holes that reach the outer surface from the inside of the hollow and a drilling bit attached to the tip thereof, A step of forming a perforation having a predetermined depth from the bottom of the head housing recess to the sloping ground, and
A ring-shaped rubber cone is fitted onto the outer peripheral portion of the portion of the perforated lock bolt located on the side of the head housing recess, and the perforated lock bolt is used between the formed perforation and the perforated lock bolt. The process of closing the gap and
A two-component urethane foam raw material is injected into the hollow portion of the bolt body of the perforated lock bolt and discharged into the perforated portion from the tip opening of the bolt body or the through hole of the perforated lock bolt. A step of forming a hardened layer of urethane foam around the perforated lock bolt by invading the backfilling stone layer of the masonry retaining wall around the perforation while foaming and hardening the urethane foam raw material.
By fixing the head portion of the perforated lock bolt located in the head accommodating recess to the masonry retaining wall in which the head accommodating recess is formed, the masonry retaining wall is connected to the sloped ground. And the process of planning
A method of reinforcing a masonry retaining wall, which is characterized by including. The method for reinforcing a masonry retaining wall according to claim 1, wherein the perforation is formed so as to enter the sloped ground at a length of at least one time or more the thickness of the masonry retaining wall. The method for reinforcing a masonry retaining wall according to claim 1 or 2, wherein the head accommodating recess is formed straddling adjacent stones. The method for reinforcing a masonry retaining wall according to any one of claims 1 to 3, wherein the head accommodating recess is formed at a depth of 20 to 70 mm. Prior to the injection of the two-component urethane foam raw material, a static mixer is charged and placed in the hollow portion of the portion of the perforated lock bolt located on the head accommodating recess side, and the perforated lock bolt is hollow. The method for reinforcing a masonry retaining wall according to any one of claims 1 to 4, wherein the two-component urethane foam raw material injected into the portion is mixed by the static mixer. A spherical female washer portion having a spherical recessed portion on the seat surface, which is arranged so as to enter the head housing recess, and an outer peripheral portion of the spherical female washer portion are integrally provided to support the masonry. A washer member having a plate portion that is brought into contact with the surface of the wall, and a lower portion of a nut portion that is screwed onto the head of the perforated lock bolt are integrally formed on the seat surface of the spherical female washer portion. By using a nut member having a spherical male washer portion to be seated and screwing the nut member onto the head of the perforated lock bolt via the washer member, the perforated lock bolt is attached to the masonry retaining wall. The method for reinforcing a masonry washer wall according to any one of claims 1 to 5, wherein the stone is fixed. The head accommodating recess is in a form in which a cover member is attached and the washer member and the nut member are internally accommodated under the arrangement state of the washer member and the nut member with respect to the head accommodating recess. The method for reinforcing a masonry retaining wall according to claim 6, wherein the upper part of the stone wall is partitioned from the outside.

Images