JP7306637B2 - Masonry retaining wall reinforcement method - Google Patents

Description

The present invention relates to a method for reinforcing a masonry retaining wall, and in particular, a masonry structure in which a backfilling stone layer is provided between a sloping ground and masonry stone, which is made by stacking stones so as to be adjacent to each other. This paper relates to the improvement of retaining wall reinforcement method.

Conventionally, masonry retaining walls have been widely used as a structure for preventing the collapse of the slope of a sloping ground. However, masonry retaining walls with a backfilling stone layer on the back of the masonry stone are eroded by shaking due to earthquakes and rainwater, etc., and the backfilling stones move and form cavities. When the piled stones at the top subside and the piled stones at the bottom are pushed forward, deformation such as protrusion of the wall surface may occur. If the condition worsens further, the strength of the entire masonry retaining wall is reduced, and there is a possibility that it may collapse.

For this reason, in Japanese Patent No. 4316940, as one of the reinforcement methods for preventing the collapse of such a masonry retaining wall, a hole is drilled in the joint part where the interlocking stones are in contact with each other in the existing masonry retaining wall. is formed, and grout material is injected into the backfilling grout stone layer through the drilling to provide a solidified portion in the backfilling grout stone layer, and further, a grout separate from the drilled portion A short reinforcing material is driven into the joint where the joints are in contact with each other, and grout material is filled around it to fix the reinforcing material to the backfilling grout layer, thereby pushing the interlocking stones outward. A method of reinforcing a masonry wall has been proposed in which deformation of the wall surface is suppressed by mutually restraining interlocking stones.

By the way, in the method of reinforcing a masonry wall as described above, when filling the grout material into the backfilling grout stone layer, the grout material to be injected has , it is necessary to maintain a certain level of liquidity. However, such a highly fluid grout material does not stay in the backfilling grout layer after injection and drips down due to its own weight. There is an inherent problem that arises and a sufficient reinforcing effect cannot be expected. On the other hand, even if the fluidity of the grout material to be injected is reduced in order to prevent the grout material from dripping, the grout material with low fluidity is placed in the gap of the backfilling grout layer around the drilled hole. It was difficult to penetrate the wall sufficiently, and the solidified portion of the grout material was limited to a narrow range, and it was not possible to hope for an improvement in strength that would increase the structural strength of the retaining wall. For this reason, in the conventional reinforcement method using grout material, it is not possible to properly fill the gaps in the backfilling grout layer with grout material. It was inherent in the problem that it would not be possible to maintain the law against the law.

In addition, in the method of reinforcing masonry walls disclosed in the above-mentioned patent publications, the reinforcing material driven into the joints of the masonry walls, as shown in FIG. 5 and FIG. A portion is protruded, and a nut is screwed onto the protruding portion via a wide plate, thereby abutting on the sprocket and fixing it. Similarly, in the seismic reinforcement method for masonry walls disclosed in Japanese Unexamined Patent Application Publication No. 2007-70980, as shown in FIGS. After being inserted into a grout material injection hole provided in a masonry wall, the grout is driven through a striking cap screwed onto a head protruding from the wall surface of the masonry wall. In this document, the head of the hollow perforated pipe body and the head cap screwed together protrude a predetermined length from the wall surface of the masonry wall. It is considered to be in the form of However, in such a form in which the reinforcing member or the head of the reinforcing member for masonry wall protrudes from the wall surface of the masonry wall, a large number of reinforcing members are arranged at predetermined intervals with respect to the masonry wall. From a certain point, it significantly damages the appearance of the masonry wall, and there is a problem that the head of the protruding reinforcing member is damaged by falling rocks, etc., and furthermore, such a protruding head hinders work on the masonry wall. There was also the inherent problem of injuries to people involved in the accident, such as pedestrians and passers-by.

Therefore, in Japanese Patent Application Laid-Open No. 2000-178969, the head of a rock bolt as an anchor is positioned in a large-diameter hole portion of a concrete bearing pressure plate provided on the surface of the ground, and buried with grout material. The structure is clarified, in which a cap is attached to cover the large-diameter hole of the bearing plate, and the cap protrudes from the ground surface. In addition, it was not sufficient to improve the landscape as mentioned above. Of course, in FIG. 6, a structure is also proposed in which a step portion having a hole diameter larger than that of the large diameter hole portion is provided, and the cap 12 is inserted into the step portion so as not to protrude from the surface of the bearing plate. However, the formation of such a large-diameter stepped portion, which is exposed on the surface of the bearing plate, is unattractive and is still not desirable in terms of scenery. Moreover, since a concrete bearing plate is constructed on the surface of the ground to cover the surface, the natural landscape of the ground cannot be effectively exhibited.

Japanese Patent No. 4316940 Japanese Unexamined Patent Application Publication No. 2007-70980 Japanese Patent Application Laid-Open No. 2000-178969

Here, the present invention has been made against the background of the circumstances as described above, and the problem to be solved is to effectively form a hardened layer of urethane foam in the gaps between the back-filling grout layers. At the same time, by constructing the masonry retaining wall so that it can be firmly connected to the sloping ground, the strength of the masonry retaining wall can be advantageously improved and a masonry retaining wall with excellent scenery can be provided. Another object of the present invention is to provide a method for reinforcing a wall, and to prevent the head of a drilled rock bolt from being damaged by falling rocks or the like without using a special cap or the like, and to provide a masonry retaining wall. To provide a reinforcement construction method for a masonry retaining wall, the surface of which can effectively exhibit a natural landscape.

In order to solve the above-described problems, the present invention can be suitably implemented in various aspects as listed below. Adoptable. It should be noted that the aspects and technical features of the present invention are not limited to those described below, and can be understood based on the inventive idea grasped from the descriptions of the entire specification and the drawings. , should be considered.

Therefore, first, in order to solve the above-mentioned problems, the present invention first reinforces a masonry retaining wall by piling up interlocking stones adjacent to each other on the front surface of a sloping ground through a backfilling stone layer. In terms of the construction method, (a) the diameter of a hole provided so as to reach the sloped ground from the masonry retaining wall so as to be positioned at a predetermined location selected for reinforcement of the masonry retaining wall (b) forming a large-diameter head-accommodating recess at a predetermined depth; A drilling lock bolt having a bolt body and a drilling bit attached to its tip is used to form a drilling hole of a predetermined depth from the bottom of the head accommodation recess to the sloped ground, and the drilling lock (c) allowing the drilled lock bolt to remain in the drilled hole in a form in which the head of the bolt does not protrude from the head accommodating recess; (d) a two-liquid type A urethane foam raw material is injected into the hollow portion of the bolt body of the perforated lock bolt, discharged into the perforation from the tip opening of the bolt body of the perforated lock bolt and the through hole, and further filled around the perforation. (e) a step of forming a hardened layer of urethane foam around the perforated rock bolt by intruding into the backfilling stone layer of the masonry retaining wall and foaming and hardening the urethane foam raw material; By filling the head accommodating recess with a caulking agent to form a caulking portion in the head accommodating recess, the head portion of the drilled lock bolt is buried in the caulking portion to accommodate the head. A method of reinforcing a masonry retaining wall, comprising the step of fixing the retaining wall to a masonry retaining wall in which a recess is formed, and connecting the masonry retaining wall to the sloped ground. is.

According to one of the preferred embodiments of the method for reinforcing a masonry retaining wall according to the present invention, the head of the perforated rock bolt positioned in the head accommodation recess is extrapolated to the head accommodation recess. and a nut member screwed onto the head of the drilled lock bolt. The drilled rock bolts are secured to the masonry retaining wall by screwing together, and the heads of the drilled rock bolts, the washer members and the nut members located in the head receiving recesses are inserted into the caulking portion. It is formed so that it can be buried.

Further, according to a further preferred embodiment of the method for reinforcing a masonry retaining wall according to the present invention, the perforations are formed so as to enter the sloped ground over a length of at least one time or more the thickness of the masonry retaining wall. , is formed.

Furthermore, according to another preferred embodiment of the method for reinforcing a masonry retaining wall according to the present invention, the perforation is formed so as to penetrate the sloped ground over a length of at least one time or more the thickness of the masonry retaining wall. is configured to

Furthermore, according to one of the desirable aspects of the method for reinforcing a masonry retaining wall according to the present invention, the head accommodation recess is formed at a depth of 20 to 70 mm.

In a preferred embodiment of the masonry retaining wall reinforcement method according to the present invention, the caulking portion fills the head accommodating recess to a level flush with the masonry retaining wall, It constitutes part of the wall surface of the retaining wall.

In addition, in the masonry retaining wall reinforcement construction method according to the present invention, while the head accommodation recess is formed for the interlock stone, the opening of the head accommodation recess is advantageously formed with A thin stone plate processed to a corresponding size is placed on the caulking portion formed in the head housing recess, and the surface of the thin stone plate is flush with the surface of the stone. It is formed so as to be fixed in such a way that

According to another preferred embodiment of the method for reinforcing a masonry retaining wall according to the present invention, the head-receiving recess corresponding to the head-receiving recess extracted from the head-receiving recess by the formation operation of the head-receiving recess is It is configured such that the surface layer portion of Manichi stone is separated from the stone portion and this surface layer portion of Manji stone is used as the thin plate of Manji stone.

Further, according to another preferred aspect of the method for reinforcing a masonry retaining wall according to the present invention, the head accommodation recess is provided in a joint portion formed between masonry stones in the masonry retaining wall. configured to be

Further, according to another preferred aspect of the method for reinforcing a masonry retaining wall according to the present invention, the head accommodation recess is formed across adjacent Machiji stones.

Further, according to a further preferred embodiment of the method for reinforcing a masonry retaining wall according to the present invention, the joints of a size corresponding to the adjoining joints excised by the formation operation of the head accommodating recess are formed. A stone piece is placed on the caulking portion formed in the head housing recess, and fixed so that the surface of the stone piece is flush with the adjacent stone piece. I am forced.

In addition, in the method for reinforcing a masonry retaining wall according to the present invention, preferably, prior to the injection of the two-component urethane foam raw material, the portion of the perforated rock bolt located on the head accommodation recess side is removed. A static mixer is charged and arranged in the hollow portion of the perforated rock bolt so that the two-component urethane foam raw material injected into the hollow portion of the perforated rock bolt is mixed in the static mixer.

As described above, according to the method for reinforcing a masonry retaining wall according to the present invention, after driving a perforated rock bolt reaching a predetermined depth from the masonry retaining wall to a predetermined depth of the slope ground, the bolt is passed through the hollow portion of the bolt body of the perforated rock bolt. , by injecting a two-liquid type urethane foam raw material and discharging it into a hole formed by such a drilled rock bolt, causing it to penetrate into the backfilling rock layer and ground around the hole, and the injection By foaming and hardening the obtained urethane foam raw material at a desired speed, a hardened layer of urethane foam is effectively formed around the perforated rock bolt. As a result, the urethane foam raw material penetrates into the gaps of the back-filling griststone layer around the perforated rock bolt without dripping down, and hardens quickly, thereby making the perforated rock bolt and the surrounding backfilling stone layer, and even the interstitial stone can be advantageously integrated, preventing subsidence of the backfilling stone layer and effectively preventing protrusion and collapse of the lower part of the masonry retaining wall. Therefore, it is possible to advantageously realize a reinforcing structure of a masonry retaining wall with further improved stability.

In the method for reinforcing a masonry retaining wall according to the present invention, the thickness of the perforated rock bolts is at least 1 times or more the thickness of the masonry retaining wall composed of the interstitial stone and the backfilling stone layer, preferably 1.5 times. By penetrating into 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 becomes even stronger. Therefore, it is possible to effectively suppress the displacement of the masonry retaining wall integrated with the urethane foam, and it is possible to exhibit the characteristics of being able to contribute advantageously to the further reinforcement of the masonry retaining wall.

Moreover, in the method for reinforcing a masonry retaining wall according to the present invention, the head-receiving recess having a diameter larger than the diameter of the bore hole provided so as to reach the sloping ground from the masonry retaining wall is Formed at a predetermined depth, the head portion of the perforated rock bolt is sunk below the surface of the masonry retaining wall, and is embedded in the caulking portion formed by the caulking agent filled in the accommodation recess. The head of the perforated rock bolt is prevented from protruding outside from the surface of the masonry retaining wall by fixing the perforated rock bolt head with a slab, thereby avoiding the head of the perforated rock bolt from being damaged by falling rocks or the like, and In addition to effectively avoiding injury to persons involved such as retaining wall workers and pedestrians, such a protruding head advantageously enhances the natural appearance of the masonry retaining wall. We were able to provide a reinforcement construction method that can effectively improve the appearance of the masonry retaining wall while securing it.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory view showing an example of a masonry retaining wall to which a reinforcement method according to the present invention is applied, wherein (a) is a front explanatory view showing a masonry retaining wall in a completed construction state, and (b) is (a); It is an explanatory view of the AA cross section in . FIG. 4A is a process explanatory drawing showing an example of a reinforcement method for a masonry retaining wall according to the present invention, in which (a) forms a head accommodation recess for a joint formed between masonry stones in a masonry retaining wall; It is a cross-sectional explanatory view showing a state formed, (b) shows a state formed by forming a hole of a predetermined depth reaching the slope ground using a drilling rock bolt, (c), (b) (d) shows a state in which a member for injecting a two-component urethane foaming raw material is placed in the hole formed in (d) after the step (c). (e) shows a configuration in which a urethane foam raw material is injected into the hollow portion of the drilled rock bolt to form a hardened layer of urethane foam around the drilled rock bolt. Fig. 10(f) shows a state in which the caulking agent is filled in the head accommodating recess after the step (e). FIG. 2 is a partially enlarged explanatory view of a reinforcement portion of a masonry retaining wall by a perforated rock bolt in the cross-sectional explanatory view of the masonry retaining wall shown in FIG. 1(b); It is side explanatory drawing of the drilling rock bolt used in the reinforcement construction method according to this invention. FIG. 4 is an enlarged partial cross-sectional explanatory view showing a fixing structure between the interlocking stone and the drilled rock bolt in FIG. 3 ; After forming a head-accommodating recess in the joint portion formed between the interlocking stones, a caulking agent is filled to form a caulking portion, and further interlocking stone pieces are placed and fixed. It is partial explanatory drawing which expands the surface of a masonry retaining wall and shows a process. Masonry corresponding to FIG. 3 showing a configuration in which a recess for accommodating the head is provided in the stone that constitutes the masonry retaining wall, and a hole is formed by a perforated rock bolt so as to penetrate the stone. It is cross-sectional explanatory drawing of a retaining wall. To form the reinforcing structure shown in FIG. 7, after the head-receiving recess is formed in the interlocking stone, a caulk is formed in the head-receiving recess and the interlocking stone is formed over the caulk. FIG. 4 is a partially enlarged explanatory view of the surface of the masonry retaining wall showing a form in which thin plates are placed and fixed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a mixer for mixing urethane foaming raw materials supplied into a perforated rock bolt, wherein (a) is an overall explanatory diagram of the mixer, and (b) is a mixer inserted into the perforated rock bolt; It is a cross-sectional explanatory view showing a form in which it is housed in and an adapter is attached. FIG. 10 is an explanatory view showing a configuration in which a static mixer is inserted into the hollow portion of the head of the drilled rock bolt remaining in the drilled hole, and an adapter for supplying urethane foam raw material is assembled.

Hereinafter, in order to clarify the present invention more specifically, representative embodiments 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 for a masonry retaining wall obtained by applying the construction method according to the present invention in the form of a front view and a sectional view, respectively. . Therein, the masonry retaining wall 2 is constructed in a form in which the intermediate stones 4 are piled up so as to be adjacent to each other on the front surface (sloping surface) of the sloping ground 10 via the 6 layers of backfilling stone. there is In the wall surface of such a masonry retaining wall 2, the joint portion 8 formed between the interlocking stones 4, 4 is filled with mortar or the like as required, and the interlocking stones are filled in the same manner as in the conventional art. Mutual connection between 4 and 4 is intended, but here, with respect to such a joint portion 8, a plurality of positions spaced apart from each other by a predetermined distance, for example, in FIG. At the sites positioned in a zigzag pattern, perforations having diameters slightly larger than those of the perforation rock bolts 20 are drilled (drilled) by the perforation rock bolts 20 so as to penetrate the masonry retaining wall 2 and enter the slope ground 10 sufficiently deeply. A hole 14 is formed, and a drilled lock bolt 20 is inserted and arranged in the drilled hole 14 as it is. In addition, the urethane foam 34 formed by foaming and hardening of the injected two-liquid urethane foam raw material is placed in the perforated rock bolt 20 inserted into the inclined ground 10 and in the perforated rock bolt 20. The gaps between the 6 layers of backfilling stone around 20 are filled to form a hardened and integrated columnar reinforcement portion extending from the masonry retaining wall 2 to the slope ground 10 . As shown in FIG. 1(b), the masonry retaining wall 2 having such a structure is supported by foundation concrete 16 at its lower part, while its upper part is supported by the sloping ground 10. It is covered with shading concrete 18 of a predetermined thickness so as to reach the upper part of the structure so as to prevent intrusion of water. A nut member (42) is screwed onto the head portion 20a of the perforated lock bolt 20 via a washer member (40), as will be described later, so that the perforated lock bolt 20 is It is fixed to the masonry retaining wall 2, so that a strong connection between the masonry retaining wall 2 and the slope ground 10 is realized.

In the present invention, in order to obtain such a reinforcing structure for 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. A head-receiving recess 12 having a diameter larger than the diameter of the perforation 14 provided to reach the head, for example, a diameter of about 90 mm, is formed at a predetermined depth. The depth of the head housing recess 12: d is such that the head 20a of the drilled lock bolt 20 is sufficiently housed in the head housing recess 12, and the head 20a is attached to the head housing recess 12. In general, the depth of the head housing recess 12 is about 20 to 150 mm. will be formed. Further, in this case, a configuration in which the head accommodation recess 12 is formed so as to straddle the adjacent chin stones 4, 4 as shown in the drawing is advantageously adopted. Thus, by arranging the washer member (40) and the nut member (42) with respect to the head housing recess 12, the perforated lock bolt 20 can be effectively connected to the adjacent stones 4, 4, and firmly. , and it is possible to advantageously suppress the displacement and movement of the interlocking stones 4 individually.

Next, as shown in FIG. 2(b), a hole 14 of a predetermined depth (D+L) reaching the slope ground 10 is formed by drilling using a drilling rock bolt 20 in a known manner. ,It is formed. 4 and 5, the perforated lock bolt 20 used here has a hollow cylindrical structure, and a continuous threaded structure is formed on the outer surface of the cylindrical wall. A suitable number of through holes 24 are formed in the cylindrical wall portion to reach the outer peripheral surface from the hollow interior. Furthermore, 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 with a screw connection structure. Then, using such a drilling rock bolt 20, the base end portion (head portion 20a) of the drilling rock bolt 20 is connected to a rock drilling machine such as an anchor drill machine, and drilling work is performed in the same manner as in the conventional art. As a result, a borehole 14 having a depth sufficient to reach the slope ground 10 is formed from the bottom of the head accommodation recess 12 formed in FIG. 2(a).

The length of the perforations 14 extending from the masonry retaining wall 2 to the sloping ground 10 formed by such perforating work is appropriately selected according to the thickness of the masonry retaining wall 2: D. The length of the perforations 14 at the peak 10: L is usually at least 1 time or more, preferably 1.5 times or more, especially 2 to 3 times the thickness D. Become. Thus, by forming the borehole 14 with the above length in the slope ground 10, the connection between the drilled rock bolt 20 and the slope ground 10 is strengthened and, as described later, hardened. The connection between the masonry retaining wall 2 integrated by the urethane foam (34) and the sloping ground 10 via the perforated rock bolts 20 becomes even stronger. Demolition and collapse can be advantageously suppressed.

By the way, the drilling rock bolt 20 used in the above-described drilling work is rotated and struck by a rock drill to scrape and push away the back-filling grout 6 that is filled behind the interlocking stone 4, thereby pushing the back-filling rock bolt 20 away. It is driven into the sloped ground 10 located behind the masonry retaining wall 2 by penetrating the filling area of the masonry stone 6 . Then, by drilling while sending compressed air into the hollow portion 20b of the drilling lock bolt 20 having a hollow structure, a plurality of through holes 24 provided in the drilling lock bolt 20 and the tip opening of the drilling bit 22 can be drilled. As a result, air is fed into the perforations 14, and as a result, the perforations 14 and the through holes 24 provided in the perforated rock bolts 20 are not clogged with earth and sand, etc., and the two-liquid type urethane foam raw material described later can be filled. Work can proceed advantageously.

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 can be well adhered and bonded to the foam-cured urethane foam 34. Although perforated lock bolts of various known structures can be used, it is particularly preferable to use a perforated lock bolt having a hollow structure and a continuous thread formed on the outer surface. Also, the perforated lock bolt 20 is generally used by being connected to a required length by a joint 20c.

Furthermore, FIG. 2(c) shows a preparatory state for the filling operation of the two-liquid urethane foaming raw material after the drilling operation by the drilling lock bolt 20 is completed. A ring-shaped rubber cone 26 having a truncated conical outer peripheral surface is fitted to the portion of the perforated lock bolt 20 located on the side of the head housing recess 12, so that the rubber cone 26 functions as a rubber plug. , the clearance between the drilled hole 14 and the drilled lock bolt 20 is closed, so that leakage can be suppressed or prevented when the urethane foam raw material, which will be described later, is pressurized and injected. On the other hand, a static mixer 28 is inserted into the head portion 20a of the perforated lock bolt 20, and an injection adapter 30 for pressurizing and injecting the urethane foam raw material is attached to the head portion 20a of the perforated lock bolt 20. After connection, 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 rock bolt 20 and foamed and hardened is used to form a strong bond between the perforated rock bolt 20 and the backfilling grid 6 layers. After injecting such urethane foaming raw material into the stone 6 layer, it not only fully penetrates the gaps in the backfilling stone 6 layer around the perforated rock bolt 20, but also immediately foams and hardens without dripping. There is a need. Therefore, the urethane foam raw material used here is a two-liquid type consisting of a first liquid and a second liquid, which can be foamed and cured by mixing, can control the reaction rate and has a high reaction rate. A static mixer 28 is inserted into the head portion 20a of the perforated rock bolt 20 in order to mix just before injection into the masonry retaining wall 2 due to the speed of foaming and hardening reaction of urethane foam raw material. It is desirable to mix the two injected liquids by installing the device so that the foaming and curing reaction proceeds rapidly.

As the static mixer 28 used therein, any known type of static mixer can be used as long as it can mix and discharge the first liquid and the second liquid constituting the two-liquid type urethane foam raw material in a short time. A static mixer (stationary mixer) can be used, for example, a two-liquid type urethane foam raw material in which a plurality of torsion vane-like elements are fixedly arranged inside a cylindrical member and the inside of the cylindrical member is made to flow. (first liquid + second liquid) is used, and the two-component urethane foam raw materials injected into the mixer 28 are effectively mixed, and the perforated rock bolt 20 will be introduced into

Then, as shown in FIG. 2( d ), a two-liquid type urethane foam raw material is pressurized and injected into the perforations 14 through the hollow portions 20 b of the perforated rock bolts 20 . Specifically, injection hoses 32, 32 for separately supplying the first liquid and the second liquid constituting the two-component urethane foam raw material are connected via the injection adapter 30 prepared in the previous step. . As the two-liquid type urethane foaming raw material, a known one is appropriately used. It is pressurized and injected into the hollow portion 20b of the lock bolt 20. As shown in FIG. After being mixed in the static mixer 28, the urethane foam raw materials are passed through the hollow portion 20b of the drilling lock bolt 20, through the tip opening of the drilling bit 22 and the through hole 24 of the drilling lock bolt 20, and then drilled. 14 and penetrates into the 6 layers of backfilling grits around the perforations 14 and the sloped ground 10, and these two-liquid urethane foam raw materials (first liquid + second liquid) are foamed and hardened. As a result, a hardened layer of the urethane foam 34 is integrally formed around the perforated lock bolt 20 . Thus, the injected two-liquid type urethane foam raw material spreads in the gaps between the six layers of back-filling grits around the perforated rock bolt 20 without dripping down from the six layers of back-filling grits. Six layers of surrounding backfilling gris stones, and even 4 layers of interstitial stones can be effectively integrated.

As for the two-liquid type urethane foaming raw material, the curing time (time from mixing to curing) when mixed is generally within 150 seconds, preferably within 120 seconds, more preferably within 120 seconds. Those within 100 seconds are preferably used. For example, if the time from the injection of the urethane foam raw material to the time it hardens becomes longer, the urethane foam raw material cannot remain in the gaps between the six layers of back-filling grout, and drips down. This is because the 6 layers of back-filling stone located at 1 cannot be sufficiently integrated through the urethane foam 34, and there is a risk that effective reinforcement strength of the masonry retaining wall 2 cannot be obtained. . Therefore, it is desirable to mix the two-component urethane foam raw material near the head portion 20a of the perforated rock bolt 20 and immediately discharge it into the perforated hole 14 for rapid reaction hardening.

Here, the polyol compound, which is the main component of the first liquid of the two liquids constituting the urethane foam raw material used above, is not particularly limited, and examples thereof include known polyether polyols and polyester polyols. etc. can be mentioned. The polyether polyol is produced by adding an alkylene oxide to a compound such as polyhydric alcohols, amines, and alkanolamines having at least two active hydrogen groups as an initiator. is. Examples of polyester polyols include polycarboxylic acid-based polyester polyols obtained by reacting polyhydric alcohols and polycarboxylic acids, and lactone-based polyester polyols obtained by ring-opening polymerization of lactones and the like. .

On the other hand, the polyisocyanate compound as an essential component of the second liquid, which is another component of the two-component urethane foam raw material, is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule. and aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), tolylene diisocyanate, polytolylene polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and fatty polyisocyanates such as hexamethylene diisocyanate. In addition to alicyclic polyisocyanates such as group polyisocyanates and isophorone diisocyanates, urethane prepolymers having isocyanate groups at the molecular ends, isocyanurate-modified polyisocyanates, and carbodiimide-modified polyisocyanates can be used.

The first liquid and the second liquid constituting the two-liquid type urethane foam raw material may contain the same additive components as in the prior art, if necessary. Examples of such additive components include a catalyst for promoting the reaction between the polyol compound and the polyisocyanate compound, as well as foaming agents, foam stabilizers, viscosity reducing agents, flame retardants, and the like. The components are added to and contained in either or both of the first liquid and the second liquid according to the same criteria as for conventional two-liquid type urethane foam raw materials.

Then, the two-liquid type urethane foaming raw material as described above is injected, and the foaming and hardening is completed. Furthermore, the integral structure of the perforated rock bolt 20 and the hardened layer of the urethane foam 34 around it enables the integral connection between the masonry retaining wall 2 and the sloped ground 10. This is what happens. Further, after that, after the washer member 40 is externally inserted into the head portion 20a of the drilled lock bolt 20 located in the head accommodation recess 12, the nut member 42 is screwed to perform tightening. Become.

Specifically, as shown in FIG. 3, it enters into the head housing recess 12, is fitted over the head 20a of the drilled lock bolt 20, and hits the bottom surface of the head housing recess 12. In a form in which an annular disk-shaped washer member 40 is arranged so as to be in contact with and positioned, a nut member 42 is screwed onto the head portion (20a) of the drilled lock bolt 20, thereby performing such drilling. The rock bolt 20 is effectively fixed to the masonry retaining wall 2 . When the space of the perforation 14 is formed between the rubber cone 26 and the washer member 40 externally inserted into the perforated lock bolt 20 as described above, such a space is preferably formed by injecting a caulking agent. After filling, extrapolation of the washer member 40 will take place. Also, here, the washer member 40 is brought into contact with the adjacent interlocking stones 4, 4 that provide a part of the bottom surface of the head housing recess 12, thereby performing a pressing function for the interlocking stones 4, 4. As a result, the stability of the connection between the masonry retaining wall 2 integrated with the urethane foam raw material 34 and the slope ground 10 can be effectively improved.

Further, in the configuration in which the nut member 42 is screwed onto the head portion 20a of the drilled lock bolt 20 via the washer member 40, the space of the head accommodation recess 12 contains a known material such as mortar. is filled with the caulking agent, and the caulking portion 44 is formed so as to fill it. As a result, as shown in FIG. 2( f ), the head portion ( 20 a ) of the drilled rock bolt 20 is buried in the caulking portion 44 so that the masonry retaining wall 2 , specifically, the retaining wall 2 , is formed. , and are fixed to the interlocking stones 4, 4, so that the effect of connecting the masonry retaining wall 2 and the sloped ground 10 can be further enhanced through the perforated rock bolts 20.

In this manner, the head 20a of the perforated lock bolt 20 (therefore, the washer member 40 and the nut member 42 as well) is embedded in the caulking portion 44 formed in the head accommodation recess 12, and the external In addition, the head 20a of such a drilled rock bolt 20 does not protrude from the wall surface of the masonry retaining wall 2. The problem of damage to the head 20a of the drilled lock bolt 20 is not caused at all, and furthermore, workers working on the masonry retaining wall 2, passers-by, and other concerned parties can In addition to not being injured at all by the head 20a of the bolt 20, the caulking part 44 is flush with the interstitial stone 4 constituting the masonry retaining wall 2. By constructing in this way, it is possible to assimilate the surface of the masonry retaining wall 2 so as not to cause discomfort, so that the landscape of the natural masonry retaining wall 2 can be realized more advantageously. characteristics can be exhibited.

In the embodiment shown in FIG. 3, the caulking portion 44 formed by filling the caulking agent into the head accommodation recess 12 has a surface that is substantially flush with the interlocking stone 4. However, in order to further enhance the natural appearance of the masonry retaining wall 2, as shown in FIG. A piece of stone 46 corresponding to the size is placed on the caulking part 44 and fixed so that the surface of the piece 46 of stone is flush with the stone 4 adjacent to it. A form in which the

Specifically, as shown in FIG. 6, a predetermined head accommodating recess 12 is formed in a joint portion 8 formed between the interlocking stones 4, 4 in the masonry retaining wall 2. , the part located in the head accommodation recess 12 is cut from the adjacent kajishi stones 4, 4, and a kajishi stone piece 46 of a size corresponding to such a cut part is cut. , is placed on the caulking portion 44 formed in the head housing recess 12, and the adjacent stones 4, 4 are configured to exhibit the external shape of the original size, respectively. As a result, the surface appearance of the masonry retaining wall 2 exhibits the natural masonry form of the interlith 4, and the appearance of the masonry retaining wall 2 can be further improved. . In addition, here, the pieces 46 of the interlocking stones to be placed on the cut portions of the interlocking stones 4 are newly cut out from the interlocking stones. It is possible to use the portion excised from the interstitial stone 4 as it is, or to use it after partially processing it.

Further, in the present invention, in addition to the case where the head accommodation recess 12 and the perforation 14 are provided for the joint portion 8 as in the above example, as shown in FIG. It is also possible to provide That is, there, a head-receiving recess 12 is formed directly in the interstitial stone 4 and, through its bottom, a drilling 14 in the perforated rock bolt 20 so as to pass through the interstitial stone 4 . The perforations 14 are formed so as to penetrate into the sloping ground 10 at a predetermined depth. And here, on the caulking portion 44 formed in the head-receiving recess 12, a size substantially corresponding to the opening of the head-receiving recess 12, preferably slightly smaller than such opening. A thin plate 48 of small size stone is placed and fixed so that the surface of the thin plate 48 is substantially flush with the outer surface of the stone 4, It is adapted to block the head accommodation recess 12 .

Specifically, as shown in FIG. 8, first, a head accommodation recess 12 is formed in a predetermined interlocking stone 4 that constitutes the masonry retaining wall 2, and then the bottom of the recess is penetrated, A borehole 14 is formed that penetrates the slope ground 10 at a predetermined depth. Then, the rubber cone 26 is fitted onto the perforated lock bolt 20, the urethane foam raw material is injected, foamed, and cured to form a hardened layer of the urethane foam 34. A caulking portion 44 is formed in the head receiving recess 12 so that the head 20a is buried. On the other hand, by forming the head-receiving recess 12 for the head-receiving recess 12 for the head-receiving recess 4, the surface layer portion of the head-receiving recess-corresponding recess-receiving recess 4a is separated by a predetermined thickness to form a circular recess. A stone slab 48 will be formed. Then, the thin plate 48 of Kanchi stone is placed on the caulking portion 44 formed in the head housing recess 12 and fixed so as to block the head housing recess 12, thereby forming the Kachi stone. The surface of the stone 4 is formed in a state in which the stone 4 and the thin plate 48 of the stone 48 are substantially flush with each other, thereby making it difficult to feel the presence of the head housing recess 12 and improving the appearance of the stone. can be achieved. In addition, here, the interlocking stone thin plate 48 is formed by processing the interlocking stone portion 4a corresponding to the head accommodation recess which is taken out by the operation of forming the head accommodation recess 12 in the interlocking stone 4. However, it goes without saying that, instead of this, it is also possible to use a thin stone plate 48 formed by using a stone material similar to the stone material of the stone 4 and processing it. .

Furthermore, FIG. 9 shows an example of a static mixer preferably used in the above embodiment and an example of an injection adapter combined therewith. 9(a), the static mixer 28 is configured by combining a plurality of (for example, two or three) helical filaments 28a, and has an annular plate at its end. A shaped base 28b is fixed by welding or the like, and an annular rubber packing 28c is fixed to the outer surface of the base 28b. As shown in FIG. 9B, the static mixer 28 is inserted into the hollow portion of the drilled lock bolt 20, and the injection adapter 30 is screwed to the end of the drilled lock bolt 20. As a result, the mouthpiece 28b and the rubber packing 28c of the static mixer 28 are attached by being pressed between the end surface of the drilled lock bolt 20 and the stepped portion provided on the inner surface of the injection adapter 30. ing.

One form of attachment of the static mixer 28 and injection adapter 30 is shown in FIG. There, after the static mixer 28 is inserted into the opening of the head 20a present in the head receiving recess 12 of the drilled lock bolt 20 remaining in the drilled hole 14, the outer circumference of the head 20a is Then, the infusion adapter 30 is screwed together so that it is attached in the form shown in FIG. 9(b). To the injection adapter 30, as shown in FIG. 2(d), injection hoses 32, 32 for separately supplying the first liquid and the second liquid constituting the two-component urethane foam raw material are connected. , these urethane foam raw materials will be supplied.

Although the representative embodiments of the present invention have been described in detail above, they are merely examples, and the present invention is not limited in any way by specific descriptions of such embodiments. It should be understood that it should not be construed as

For example, in the above-described embodiment, the static mixer 28 is inserted into the head portion 20a of the perforated lock bolt 20, and then the injection adapter 30 for pressurizing and injecting the urethane foam raw material is inserted into the perforated hole. Although it is attached in the form of being connected to the head portion 20a of the lock bolt 20, instead of this, the first liquid constituting the two-component urethane foam raw material is upstream of the perforated lock bolt 20. and the second liquid on the flow path downstream of the mixing point, for example, inside the injection adapter (30) connected to the head portion 20a of the drilled rock bolt 20, a static mixer (28) is incorporated into the injection It is also possible to use an adapter (30).

Moreover, even in the structure of the rubber cone 26 illustrated in the example, any structure can be adopted as long as it has a shape that can close the gap between the drilled hole 14 and the drilled lock bolt 20. For example, in order to improve handling 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 cylindrical wall portion of the drilled lock bolt 20. A structure having a structure in which the .

Furthermore, it is also effective to attach an air venting pipe so as to axially penetrate the thick wall portion of the illustrated rubber cone 26. Through such an air venting pipe, when the urethane foam raw material is injected, a hole is formed. It is also preferable to make the air inside 14 be released to the outside.

In addition, FIG. 5 shows a state in which the caulking portion 44 also extends around the perforation 14 located between the washer member 40 and the rubber cone 26. After injecting the caulking agent so as to fill the gap, the washer member 40 is fitted onto the head portion 20a of the drilled lock bolt 20, and the nut member 42 is screwed together to connect the drilled lock bolt 20 and the interlock stone 4, After connecting with the masonry retaining wall 2, a caulking agent is injected into the head accommodation recess 12 to form the desired caulking portion 44.例文帳に追加

In addition, although not listed individually, the present invention can be implemented in aspects with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art. It goes without saying that all of them belong to the scope of the present invention as long as they do not deviate from the gist of the present invention.

2 Masonry Retaining Wall 4 Intermediate Stone 4a Intermediate Stone Portion 6 Backfill Guri Stone 8 Joint Part 10 Slope Ground 12 Head Recess 14 Drilling Hole 16 Foundation Concrete 18 Shedding Concrete 20 Drilling Rock Bolt 20a Head 20b Hollow Part 22 Drilling bit 24 through hole 26 rubber cone 28 static 28a mixer helical filament 28b mouthpiece 28c rubber packing 30 injection adapter 32 injection hose 34 urethane foam 40 washer member 42 nut member 44 caulking part 46 interlocking stone piece 48 interlocking stone thin plate

Claims (11)

Reinforcement method for masonry retaining wall, in which intercalary stones are piled up adjacent to each other on the front surface of the sloping ground through the backfilling stone layer,
A head accommodation having a larger diameter than the diameter of a borehole provided from the masonry retaining wall to reach the sloped ground so as to be positioned at a predetermined location selected for reinforcement of the masonry retaining wall. forming a recess at a predetermined depth;
Using a drilling lock bolt having a longitudinal bolt body with a hollow structure in which a suitable number of through holes are formed to reach the outer peripheral surface from the hollow interior and a drilling bit attached to the tip of the bolt body, The drilled lock bolt has a configuration in which a drilled hole of a predetermined depth is formed from the bottom of the head accommodation recess to reach the slope ground, and the head of the drilled lock bolt does not protrude outside from the head accommodation recess. remaining within the perforations; and
A ring-shaped rubber cone is fitted around the outer circumference of the portion of the drilled lock bolt located on the side of the head housing recess, and the rubber cone provides a gap between the drilled hole and the drilled lock bolt. closing the gap;
A two-liquid type urethane foam raw material is injected into the hollow portion of the bolt body of the perforated lock bolt, and discharged into the perforation from the tip opening of the bolt body of the perforated lock bolt and the through hole, and further a step of forming a hardened layer of urethane foam around the perforated rock bolt by infiltrating into the backfilling stone layer of the masonry retaining wall around the perforation while foaming and hardening the urethane foam raw material;
By filling the head accommodating recess with a caulking agent to form a caulking portion in the head accommodating recess, the head portion of the drilled lock bolt is buried in the caulking portion and the head is formed. a step of fixing to a masonry retaining wall in which an accommodation recess is formed, and connecting the masonry retaining wall and the sloped ground;
A reinforcement method for a masonry retaining wall, comprising: a washer member inserted over the head of the drilled lock bolt positioned in the head accommodating recess and abutted and positioned on the bottom surface of the head accommodating recess; A mating nut member is used to fix the perforated rock bolt to the masonry retaining wall by screwing the nut member onto the head of the perforated rock bolt through the washer member. 2. Reinforcement of masonry retaining wall according to claim 1, characterized in that the head of the drilled rock bolt, the washer member and the nut member located in the head accommodating recess are buried in the caulking portion. Construction method. 3. The method for reinforcing a masonry retaining wall according to claim 1, wherein the perforations are formed so as to penetrate into the sloped ground over a length of at least one times the thickness of the masonry retaining wall. The method for reinforcing a masonry retaining wall according to any one of claims 1 to 3, wherein the head accommodation recess is formed at a depth of 20 to 150 mm. 5. The caulking portion is filled in the head accommodating recess to a level flush with the masonry retaining wall, and constitutes a part of the wall surface of the masonry retaining wall. A reinforcement construction method for a masonry retaining wall according to any one of items 1 and 2. While the head-accommodating recess is formed with respect to the head-accommodating recess, a thin stone plate processed to a size corresponding to the opening of the head-accommodating recess is placed in the head-accommodating recess. Claims 1 to 4, characterized in that it is placed on the formed caulking part and fixed so that the surface of the thin sheet of magpie stone is flush with the surface of the magpie stone. The method for reinforcing a masonry retaining wall according to any one of 1. From the head-accommodating recess-corresponding Kaji-seki taken out from the Kaji-seki by the operation of forming the head-accommodating cavity, the Kachi-seki surface layer is separated from the Kachi-seki surface-layer part. 7. The method for reinforcing a masonry retaining wall according to claim 6, wherein the stone is used as a thin stone plate. 6. The method for reinforcing a masonry retaining wall according to any one of claims 1 to 5, wherein the head accommodating recess is provided for a joint portion formed between the masonry stones in the masonry retaining wall. 9. The method for reinforcing a masonry retaining wall according to claim 8, wherein the head-accommodating recess is formed across adjacent masonry stones. A piece of Kajime stone having a size corresponding to the adjacent Kajime stone portion excised by the forming operation of the head accommodation recess is placed on the caulking portion formed in the head accommodation recess. 10. The method for reinforcing a masonry retaining wall according to claim 9, wherein the surfaces of the pieces of masonry stone are fixed so as to be level with the adjacent pieces of masonry stone. Prior to the injection of the two-liquid type urethane foam raw material, a static mixer is charged and placed in the hollow portion of the perforated lock bolt located on the side of the head housing recess, and the hollow portion of the perforated lock bolt is filled with a static mixer. 11. A method for reinforcing a masonry retaining wall according to any one of claims 1 to 10, wherein said two-liquid type urethane foam raw material injected into said part is mixed by said static mixer.

Images