JP5731928B2 - Injection stiffening member for maintenance repair of mortar spray - Google Patents

Description

  The present invention relates to an injection stiffening member used when maintaining and repairing an aging mortar spray.

  In order to prevent the slopes of natural ground from collapsing due to wind and rain, etc., mortar is sprayed on the surface to reinforce, but in recent years, the mortar spray has become obsolete, and due to runoff of earth and sand, etc. There is a case where a cavity is generated between the mortar spray and the natural ground. Then, maintenance repairs are performed on such aging mortar sprays and grounds. For example, a hole is formed in the mortar sprays and grounds. There is a method of filling a grout in a drilling hole or a cavity by inserting an anchor and press-fitting the grout through the anchor (see, for example, Patent Document 1). In addition, after that, the head of the lock bolt is fixed by a fixing means such as a nut, and new mortar may be sprayed from above the aging mortar spray.

Japanese Patent Publication No. 5-22775

  However, in such a conventional repair method for aging mortar spraying, grout is press-fitted into the hole through the anchor, so that it is possible to completely fill the grout in the hole or cavity. When fine cracks (cracks) have occurred on the inner walls of the holes, it is difficult to completely fill the grout into the cracks.

  Therefore, although the present applicant has not yet disclosed at the time of filing the present application, the present applicant uses an injection stiffening member in which a pressure plate for pressing the grout material injected into the drilling hole is provided at the distal end of the tubular body. "Reinforcing structure used in maintenance repair method for chemical mortar sprayed surface and method thereof" (Japanese Patent Application No. 2011-027620, patent application date February 10, 2011). According to this invention, further pressure is applied to the grout press-fitted into the hole (primary injection) by pushing the injection stiffening member into the hole, and the grout is further pressed in the pressurized state. By performing (secondary injection), the grout can be reliably filled up to the inside of the crack described above.

  However, the injection stiffening member described in this unpublished application is provided with a large gap between the outer peripheral edge of the pressure plate and the inner peripheral surface of the drilled hole, so that the grout is discharged from the gap. As for the pressure plate, the area becomes small as much as there is a gap, and the force to press the grout is weak. In addition, on the outer peripheral edge of the pressure plate, a rubber elastic spacer is provided in the circumferential direction in order to maintain straightness when the injection stiffening member is pushed into the hole and to be positioned at the center of the hole. An example in which parts are provided at equiangular intervals is also disclosed. However, since this injection stiffening member also has a lock bolt reinforcement function and a rust prevention effect, it is not pulled out from the ground or the like after the maintenance and repair work. Therefore, the elastic spacer made of rubber is buried in the drilling hole, and may be treated as a foreign substance due to the structure. As for the size of the pressure plate, in terms of pressure efficiency, etc., it is best to set the outer diameter to be approximately the same as the diameter of the drilling hole. When pushing the stiffening member into the hole, it becomes difficult to discharge the excess grout material to the outside. In addition, there is a situation where a part of hard rock protrudes from the inner wall of the drilling hole, and there is a possibility that the pushing operation of the injection stiffening member may be hindered. May be deformed. About this point, since the pressurization plate is formed with one steel plate, the deformation reaches the whole pressurization plate, and it is assumed that pressurization efficiency falls.

  Therefore, the present invention has been made paying attention to such a problem, and has a large applied pressure and excellent linearity of the injection stiffening member, and a spacer for positioning at the center of the drilling hole. In addition, the entire pressure plate will not be deformed even if it hits the rock protruding from the inner wall of the drilling hole, and there is no structural problem even if it is not pulled out from the ground. An object is to provide a member.

  In order to achieve the above object, an injection stiffening member for maintaining and repairing mortar spray according to the invention of claim 1 is provided with a substantially annular pressure plate made of steel at the tip of a tubular body, Maintaining mortar spraying in which grout is injected into the drilling hole with a lock bolt inserted into the drilling hole formed in the mountain and pressed into the drilling hole by pressing the grout with a pressure plate An injection stiffening member for repair, wherein the pressure plate has an outer diameter substantially the same as the inner diameter of the hole, and a plurality of slits extending from the outer peripheral portion to the outer peripheral surface of the tubular body are formed at appropriate intervals in the circumferential direction. And a notch is formed at the intersection between the outer periphery and the slit. As a result, the pressing force is large, the straightness of the injection stiffening member is excellent, it also functions as a spacer for positioning at the center of the drilling hole, and even when it hits rocks protruding from the inner wall of the drilling hole Even if the entire pressure plate is not deformed and is not pulled out from a natural ground or the like, there is no problem in structure.

  The pressure plate has an outer diameter that is almost the same as the inner diameter of the hole, so that the maximum pressure efficiency can be achieved, and the injection stiffening tube member can be inserted straight along the center of the hole. The workability is improved. In addition, since a plurality of slits extending from the outer peripheral portion of the pressure plate to the outer peripheral surface of the tubular body are formed at appropriate intervals in the circumferential direction, the rigidity is lower than that of a conventional steel pressure plate and the insertability is improved. . Even if a part of the pressure plate is deformed by rocks protruding from the inner wall of the drilling hole, the transmission of the deformation is blocked by the slit and does not reach the entire pressure plate, so the reduction in pressure efficiency is minimized. Can do. Furthermore, since the notch is formed at the intersection of the outer periphery and the slit, it is easy to avoid even if there is a rock protruding from the inner wall of the drilling hole, and the grout is formed via the slit and the notch. It can be reliably discharged outside. Further, since it is not necessary to provide a rubber elastic spacer on the pressure plate, it is possible to prevent foreign matter from being buried in the hole.

It is a figure which shows embodiment of an injection | pouring stiffening member. It is a figure which shows the construction procedure of the maintenance repair work which uses this injection stiffening member. It is a figure which shows the modification of a pressurization board. It is a figure which shows the other modification of a pressurization board. It is a figure which shows the other example of attachment of the pressurization board to a tubular body.

  Next, an embodiment of the injection stiffening member according to the present invention will be described.

  1A and 1B are views showing the entire injection stiffening member 1 according to the present invention. FIG. 1A is a front view thereof, and FIG. 1B is a left side view thereof. This injection stiffening member 1 is composed of a hollow long tubular body 11 and a substantially annular pressure plate 12 provided at the tip of the tubular body 11, and a grout injected from the tubular body 11 into a drilling hole. Is pressed by the pressure plate 12. The pressure plate 12 has substantially the same size as the inner diameter of the drilling hole, that is, the outer diameter of the drill bit. As a result, the gap provided between the inner peripheral surface of the hole is minimized, so that the injection stiffening member 1 can be inserted straight along the center of the hole and the workability is improved. Furthermore, since the surface area of the pressure plate 12 is maximized, the pressing force is also improved.

  In addition, a plurality of slits 122 extending radially in the radial direction from the outer peripheral portion 121 to the outer peripheral surface of the tubular body 11 are provided in the pressurizing plate 12 at equiangular intervals in the circumferential direction (here, for example, 45 degrees). (Here, for example, 8 pieces are formed.) Therefore, the rigidity is lower than that of a conventional steel pressure plate not provided with the slit 122 and the flexibility is provided, so that the insertability of the injection stiffening member 1 into the hole is improved. Further, even if the pressure plate 12 is deformed by the rock protruding from the inner wall of the drilling hole, the deformation is blocked by the slit 122 and does not reach the entire pressure plate 12. Can be minimized.

  Further, a notch 123 having an opening wider than the width of the slit 122 is formed at the intersection of the outer peripheral portion 121 and the slit 122. Therefore, the grout can be reliably discharged into the drilling hole behind the pressure plate 12 through the notch 123 in combination with the slit 122. Therefore, even if the pressure plate 12 is set to an outer diameter that is substantially the same as the hole diameter or the bit diameter, there is no problem in grout discharge. Each notch 123 has an inverted isosceles triangle shape in which the apex of the triangle faces the injection stiffening tube 11 side and the base is the outer peripheral part 121 side as shown in an enlarged view in FIG. There is no. Therefore, since the width of the opening becomes larger toward the outer peripheral portion 121 side, the grout can be easily discharged, and even if there is a rock protruding from the inner wall of the drilling hole, the workability can be improved. The shape of each notch 123 is not limited to an inverted isosceles triangle, but may be a semicircular shape or a sector shape, a quadrangular shape, a pentagonal shape, or the like. It is desirable to have a shape in which the width of the opening increases toward the side, because it is possible to avoid grout discharge and rocks protruding from the inner wall of the drilling hole. The tubular body 11 is made of iron, but the pressure plate 12 is preferably made of stainless steel. This is because stainless steel can be made thinner while maintaining strength than iron, and by reducing the thickness of the pressure plate 12, insertability into the hole is improved. However, if the thickness of the pressure plate 12 does not matter so much, it may be made of iron. The pressurizing plate 12 is provided with a short joining auxiliary tube 12 a having an outer diameter corresponding to the inner diameter of the tubular body 11 on the back surface side thereof, that is, on the tubular body 11 side. The pressure plate 12 is fixed to the tubular body 11 by bonding the outer peripheral surface of the joining auxiliary pipe 12 a to the inner peripheral surface of the tubular body 11.

  Next, the construction procedure of the maintenance repair work using the injection stiffening member 1 of the present invention will be described with reference to the drawings.

  2A to 2D are diagrams showing the construction procedure. First, the mortar spray 3 reinforced by spraying mortar on the surface of the natural ground 2 is a structure in which a cavity 4 is formed between the surface of the natural ground 2 and the back surface of the mortar spray 3 due to secular change or earthquake. On the other hand, as shown in FIG. 2A, a hole 5 is formed by a hole member (not shown) having a drill bit attached to the tip, and a lock bolt 6 is inserted into the hole 5. Although not shown, a spacer is provided on the distal end side (hole bottom side) of the lock bolt 6 in order to position the lock bolt 6 at the center of the drilling hole. Next, as shown in FIG. 2 (b), after setting the grout injection tool 13 at the rear end of the injection stiffening member 1 of the present invention, the pressure plate 12 at the tip of the tubular body 11 was formed on the mortar spray 3. After matching with the opening 31 of the drilling hole, the lock bolt 6 is inserted from the head of the lock bolt 6, and the lock bolt 6 is inserted into the tubular body 11. And when the front-end | tip of the tubular body 11 enters the back surface of the mortar spraying 3, ie, the cavity part 4, the insertion operation | work of the injection stiffening member 1 is interrupted temporarily, the injection tool 13 is operated, and grout is inject | poured. The grout passes through the tubular body 11 and is injected from the center of the pressure plate 12 into the cavity 4 and the hole 5. This is called primary injection.

  Next, after the grout is filled into the cavity 4 or the hole 5, the insertion of the injection stiffening member 1 is resumed and further pushed into the hole 5 as shown in FIG. Thereby, since the pressure plate 12 at the tip of the tubular body 11 pressurizes the grout in the hole 5, the grout is pressed into the crack (crack) 51 generated from the inner wall of the hole 5 toward the inside. Can do. In particular, the pressure plate 12 has substantially the same outer diameter as the inner diameter of the hole 5, so that the maximum pressure efficiency can be exhibited and the outer peripheral portion 121 also functions as a spacer. From this, it becomes possible to insert the injection stiffening member 1 straight along the center of the hole 5, and the conventional technique in which a large gap is provided between the outer peripheral edge of the pressure plate and the inner peripheral surface of the hole. Also improves workability.

  Then, as shown in FIG. 2 (d), after the entire injection stiffening member 1 is embedded in the hole 5, the grout is injected into the hole 5 by applying a certain pressure with the grout injection tool 13. . This is the secondary injection of grout. Thereby, not only the drilling hole 5 but also the crack (crack) 51 continuing to the drilling hole 5 can be filled reliably. Then, after the secondary injection of grout is completed, the grout injection tool 13 is removed from the injection stiffening member 1, but the injection stiffening member 1 is fixed in a state of being embedded in the hole 5. After that, as with the prior art, after fixing the head of the lock bolt with a fixing means such as a nut, a new mortar is sprayed over the aging mortar spray to complete the maintenance repair work. From the above, the injection stiffening member 1 of the present invention is solidified by the grout injected through it reaching the entire cavity 4 and the entire drill hole 5 and further to the crack 51 continuing to the drill hole 5. Therefore, the natural ground can be reinforced strongly.

  In the description of the embodiment of the present invention described above, the width of the slit 122 is not particularly limited. However, when it is desired to increase the grout discharge performance by the slit 122, as shown in FIG. The width W may be increased. In addition, when it is desired to improve the grout dischargeability at the notch 123, the notch 123 can be provided at a location where the slit 122 is not formed on the outer periphery 121 as shown in FIG. Furthermore, the attachment of the pressure plate 12 to the distal end portion of the tubular body 11 is not limited to the above-described method, and as shown in FIGS. 5A and 5B, the tubular body is provided on the back surface side or the front surface side of the pressure plate 12. Alternatively, a short joining auxiliary pipe 12b having an inner diameter corresponding to the outer diameter of 11 may be provided, and the inner peripheral surface of the joining auxiliary pipe 12b may be fixed to the outer peripheral face of the tubular body 11 by bonding or the like. Further, the pressure plate 12 may be directly fixed to the distal end surface of the tubular body 11 by welding or the like, as shown in FIG.

  The injection stiffening member for maintaining and repairing the mortar spray according to the present invention has a large pressure applied to the grout, is excellent in the straightness of the injection stiffening member, and further, even if it hits a rock protruding from the inner wall of the drilling hole There is no structural problem even if it is not pulled out from the natural ground, etc., so that not only the maintenance repair method for the aging mortar spraying, but also the newly constructed slope reinforcement soil and rock bolt There is also industrial applicability in technical fields such as engineering.

  DESCRIPTION OF SYMBOLS 1 ... Injection stiffening member, 11 ... Tubular body, 12 ... Pressure plate, 121 ... Outer peripheral part, 122 ... Slit, 123 ... Notch part, 2 ... Ground, 3 ... Mortar spray surface, 4 ... Cavity part, 5 ... Cutting Hole, 6 ... Rock bolt.

Claims (1)

  A substantially annular pressure plate made of steel is provided at the tip of the tubular body, and grout is inserted into the drilled hole with a mortar sprayed and a lock bolt inserted into the drilled hole formed in the ground. Injecting and stiffening member for maintaining and repairing mortar sprayed by pressing the grout with a pressure plate by injecting into the hole, and the pressure plate has an outer diameter substantially the same as the inner diameter of the hole. A plurality of slits extending from the outer peripheral portion to the outer peripheral surface of the tubular body are formed at appropriate intervals in the circumferential direction, and notches are formed at the intersections of the outer peripheral portion and the slit. Injection stiffening member for maintenance repair of mortar spray.

Images