JP3877370B2 - Reinforcement method for reinforced concrete piers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reinforcing method for a reinforced concrete pier in which a wall surface of an existing wall-type reinforced concrete pier is covered with a steel plate and integrated with a rod-shaped member.
[0002]
[Prior art]
Existing wall-type reinforced concrete piers that are seismically designed only in accordance with the allowable stress design based on the seismic intensity method generally have a larger concrete cross-section and a smaller axial rebar ratio than column-type piers such as circular or rectangular cross-sections. In many cases, the bending strength is relatively small.
[0003]
Further, in a wide cross section such as a wall-type pier, due to its shape, the restraining effect by the band reinforcement on the side surface in the direction perpendicular to the bridge axis is reduced.
[0004]
Therefore, it is desirable to reinforce the wall-type reinforced concrete pier to improve both the bending strength and toughness. The wall-type pier here is a reinforced concrete pier with a wide rectangular cross section or an oval cross section in which the ratio a / b of the cross-sectional dimension a in the direction perpendicular to the bridge axis to the cross-sectional dimension b in the bridge axis direction exceeds 3. is there.
[0005]
Conventionally, as a method of reinforcing a wall-type reinforced concrete pier, a steel plate combined reinforced concrete winding method has been constructed. As shown in FIG. 27, this construction method winds up the pier housing 2 with reinforced concrete (winded reinforced concrete portion C), sandwiches both wall surfaces on the long side of the pier base B with the steel plate 3, and these are rod-shaped members, That is, it is a structure integrated by a cross-sectional penetration type PC steel rod (hereinafter referred to as an intermediate penetration PC steel rod) 4.
[0006]
In this construction method, every two axial rebars K1 and K2 of the wound reinforced concrete portion C are fixed to the footing F. In addition, the code | symbol K3 has shown the band reinforcement. And, the steel plate 3 and the intermediate through PC steel bar 4 with both ends fastened with nuts are used together to constrain the concrete cross section, and a gap of about 5 to 10 cm is provided between the lower end of the steel plate and the upper surface of the footing F. The lower end of the steel plate and the upper surface of the footing F are in contact with each other to prevent an unexpected force from acting on the steel plate 3.
[0007]
In addition, it is standard that the installation range H of the steel plate 3 is a range from the cross-section base to a height corresponding to the width in the bridge axis direction after reinforcement. Moreover, the code | symbol p1 is below the wall thickness after reinforcement with the insertion pitch of the bridge | cross-axis perpendicular | vertical direction of the PC steel bar 4, and the code | symbol p2 is 30 cm or less with the pitch in the pier axis direction.
[0008]
In the pier reinforcement method using the steel plate combined reinforced concrete hoisting method described above, it is necessary to drill in order to pass the intermediate penetration PC steel rod through the pier frame, but this hole is drilled avoiding the reinforcing bar in the pier frame. There is a need. Conventionally, this perforation is performed by, for example, rotary percussion.
[0009]
However, in general, it is difficult to accurately predict the position of the reinforcing bar in the housing. And if it hits a reinforcing bar while drilling by rotary percussion, it is necessary to refill the drilled hole and start drilling again. Here, if the re-drilling is performed, the number of steps increases, resulting in an increase in cost.
[0010]
In addition, if the rebar is accidentally cut during drilling by rotary percussion, the strength of the pier will be adversely affected.
[0011]
On the other hand, a method of drilling using a drifter is known. 28 to 31 show a method for driving a lock bolt by a self-drilling method using a drifter (for example, a drilling machine manufactured by Mitsubishi Heavy Industries, Ltd .: trade name “MRD150”).
[0012]
In FIG. 28, the drilling machine 10 holding the lock bolt 15 is installed at the lock bolt driving position. The lock bolt 15 is a hollow shaft having a lost bit 16 at the tip, and high-pressure water is supplied through a water swivel 17 provided at the rear end. The lock bolt 15 is held by a drifter 12 provided on the guide cell 11 so as to be able to move back and forth in the drilling direction through a gripping device 13, and is given a blow in the direction D and rotation R to be propelled. The ground is drilled while flushing from the hollow hole of the bolt 15.
[0013]
As shown in FIG. 29, when the drifter 12 propels only by the stroke S and reaches the stroke end, the gripping device 13 is loosened and moved backward. Then, as shown in FIG. 30, the lock bolt 15 is again gripped from the retracted position and drilled. This is repeated, and when the hole is drilled to a predetermined depth as shown in FIG. 31, a fixing material is injected from the hollow hole to fix the lock bolt 15.
[0014]
Although such a drilling method is an effective technique, the wall of the existing reinforced concrete pier is covered with a steel plate, and when reinforcing a reinforced concrete pier that is integrated with a rod-shaped member, It is not used when drilling through holes.
[0015]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-mentioned problems of the prior art, and even if a reinforcing bar is arranged in the pier frame, a reinforced concrete pier that can easily drill the insertion hole of the rod-shaped member. The purpose is to provide a reinforcement method.
[0016]
[Means for Solving the Problems]
According to the present invention, in the reinforcing method of a reinforced concrete pier in which the wall surface of an existing wall-type reinforced concrete pier is covered with a steel plate and a rod-shaped member is inserted into the pier housing and integrated with the steel plate, the rod is attached to the pier housing. When piercing the insertion hole of the cylindrical member, a hollow rod with a water jet attached to the tip of a drilling machine drilled by rotary percussion is held, and the part including the reinforcing bar of the pier frame is waterjetted by the drilling machine. Drill the part that does not contain the reinforcing bar with rotary percussion, and when the insertion hole of the rod-shaped member penetrates the pier housing, insert the hollow rod through it and inject the filler around it, both ends of the hollow rod Is engaged with the fastening member to integrate the pier housing and the steel plate.
[0017]
According to the present invention having such a configuration, a portion including a reinforcing bar is perforated by a water jet. Here, the water jet is also used in so-called “hanger” work, and removes the concrete without damaging the reinforcing bars. Here, even if it hits the reinforcing bar when drilling, the reinforcing bar may be exposed as long as the monitor or the rod-shaped member can pass therethrough.
Therefore, even if the reinforcing bars are exposed, there is no need to refill all the holes that have been drilled and start drilling again. For this reason, the number of cases where re-drilling is necessary is drastically reduced, and the cost spent for re-drilling is greatly reduced. Furthermore, since the water jet does not damage the reinforcing bars, the possibility of adversely affecting the strength of the pier is reduced.
[0019]
Further, according to the present invention, in the reinforcing method of a reinforced concrete pier in which the wall surface of an existing wall-type reinforced concrete pier is covered with a steel plate and a rod-shaped member is inserted into the pier housing and integrated with the steel plate, When the insertion hole of the rod-shaped member is drilled, a hollow rod with a water jet monitor attached to the tip of the drilling machine drilled by rotary percussion is gripped, and the portion including the reinforcing bar of the pier frame is watered by the drilling machine. Drilling with a jet, drilling the part that does not contain the reinforcing bar with rotary percussion, and drilling the insertion hole of the rod-shaped member to a predetermined depth of the pier housing, insert the hollow rod and inject filler around it, The end of the hollow rod that is not inserted into the insertion hole is engaged with the fastening member so that the pier frame and the steel plate are integrated. It is.
[0020]
Furthermore, in the reinforcing method for a reinforced concrete bridge pier according to the present invention, the insertion hole of the rod-shaped member is penetrated by connecting holes drilled from both sides of the pier frame.
[0021]
In addition, the reinforcing method of the reinforced concrete bridge pier according to the present invention is such that the insertion hole of the rod-like member drilled from both sides of the pier frame has a diameter of the hole drilled from one side of the pier frame. The hole is drilled in a state where the diameter is larger than the diameter of the hole drilled.
Here, when the hole drilled from one side of the pier frame and the hole drilled from the other side are misaligned, the rod is inserted from the side opposite to the side where the rod-shaped member is inserted. It is preferable that a rod-shaped member is inserted through the guide member.
By configuring in this way, due to the arrangement of reinforcing bars, etc., it is necessary to offset the hole drilled from one side of the pier housing and the hole drilled from the other side. If there is, you can deal with it.
[0022]
Here, the reinforcing method for a reinforced concrete pier of the present invention described above includes a step of winding the pier frame with reinforced concrete prior to covering the wall surface of the pier frame of the existing wall-type reinforced concrete pier with a steel plate. Is preferred.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0024]
In FIG. 1, a drilling machine 10 is installed at a drilling position of an insertion hole 8 for an intermediate penetrating PC steel bar of the pier housing 2. The drilling machine 10 is a drilling machine that can perform drilling by water jet and drilling by rotary percussion. For example, the above-mentioned drilling machine MRD150 manufactured by Mitsubishi Heavy Industries, Ltd. is preferable. That is, the drilling machine 10 is provided with a drifter 12 capable of moving back and forth in the drilling direction (left-right direction in the figure) on the guide cell 11, and the drifter 12 is provided with a hollow shaft and a screw on the outer periphery. The held rod 5 is gripped. The rod 5 is provided with a monitor 6 for ejecting a water jet J at the front end and a water swivel 16 for supplying pressurized water at the rear end, and the impact D and rotation R are transmitted by the drifter 12. ing.
[0025]
Next, the construction mode will be described with reference to FIGS.
As shown in FIG. 2, in the portion A1 of the pier housing 2 where the reinforcing bars are present, the water jet J is ejected from the monitor 6 at the tip while the rod 5 is rotated R, and drilled. And if it penetrates the part A1 with a reinforcing bar (FIG. 3), the monitor 6 will be removed and it will perforate with percussion D (FIG. 4). When it reaches the part A2 where the opposing reinforcing bar is present, it is perforated again with the water jet J (FIG. 5) and penetrates.
[0026]
After the penetration, the rod 5 is left as an intermediate penetration PC steel rod, one end of the insertion hole 8 is closed with a packer 9, an injection nozzle N is inserted from the other end (FIG. 6), and a filler Z is injected (FIG. 7). ), The rod 5 is fixed (FIG. 8), the steel plates 3 and 3 are brought into contact with both sides of the housing 2, and fastened with nuts 7 and 7 (FIG. 9).
[0027]
10 to 13 show an embodiment that does not penetrate the hole. A hole 8A is drilled from one side of the pier housing 2 with a water jet J (and percussion) (FIG. 10), and after drilling to a predetermined depth, a filler Z is injected from the hollow hole of the rod 5 (FIG. 11). When the rod 5 is fixed (FIG. 12), the steel plate 3 is brought into contact and fastened with the nut 7 (FIG. 13). In place of injecting the filler Z from the rod 5 as shown in FIG. 11, the rod 5 may be withdrawn once, a new PS rod is inserted, and the filler Z may be injected from the PS rod. .
[0028]
FIGS. 14 to 18 show an embodiment in which drilling is performed from both sides of the pier housing 2. In FIG. 14, after drilling from one end of the housing 2 with a water jet J to a predetermined depth (indicated by reference numeral “8A”) (FIG. 15), from the other end facing the center, the diameter of the drilling is taken into consideration. Hole 8B is drilled with water jet J to a large diameter (FIG. 16). After the penetration, the rod 5 is passed (FIG. 17), the filler Z is injected, the steel plates 3, 3 are brought into contact with both sides, and fastened with nuts 7, 7 (FIG. 18).
[0029]
The embodiment shown in FIGS. 19 to 26 is also perforated from both sides. As shown in FIG. 19, a hole 8A is drilled from one end with a water jet J, and the diameter of the hole 8B is increased in the middle to drill a hole 8B to a predetermined depth (FIG. 20). (FIG. 21), and penetrates the enlarged diameter portion 8B (FIG. 22). Here, in order to allow the rod 5 to be inserted even if there is a misalignment, a tool T having a shape such as “樋” is inserted (FIG. 23), and the tool T (樋) is used for guidance. The rod 5 is inserted as a guide (FIG. 24). When the rod 5 is inserted (FIG. 25), the filler Z is injected, the steel plates 3 and 3 are brought into contact with both sides, and fastened with nuts 7 and 7 (FIG. 26).
[0030]
【The invention's effect】
As described above, according to the present invention, the part of the pier frame with the reinforcing bars is perforated by the water jet, so that it does not cause damage even if it hits the reinforcing bars, and the part without the reinforcing bars can be quickly removed by rotary percussion. It can be easily drilled. Therefore, there is no need to search for the position where the reinforcing bar is located or hit back the reinforcing bar as in the prior art.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an outline of an apparatus for constructing the present invention.
FIG. 2 is an explanatory view of perforation of a portion having a reinforcing bar by a water jet.
FIG. 3 is an explanatory view showing a state in which a part having a reinforcing bar is penetrated.
FIG. 4 is an explanatory diagram of a perforated state by rotary percussion.
FIG. 5 is an explanatory diagram of a state in which a portion having a reinforcing bar on the opposite side is perforated.
FIG. 6 is an explanatory diagram of the inserted state of the rod after penetration.
FIG. 7 is an explanatory diagram of a filling material injection state.
FIG. 8 is an explanatory diagram after injection of a filler.
FIG. 9 is an explanatory diagram of a state in which a steel plate is fastened with a nut.
FIG. 10 is an explanatory diagram of a perforated state according to another embodiment.
FIG. 11 is an explanatory diagram of a state where a filler is being injected.
FIG. 12 is an explanatory diagram of a state after the filling material is injected.
FIG. 13 is an explanatory diagram of a state in which a steel plate is fastened with a nut.
FIG. 14 is an explanatory diagram of a drilling start state of an embodiment in which drilling is performed from both sides.
FIG. 15 is an explanatory diagram of a state in which drilling is completed by a water jet.
FIG. 16 is an explanatory diagram of a state in which perforation is performed from the other side.
FIG. 17 is an explanatory view of a state where the rod is inserted through the rod.
FIG. 18 is an explanatory diagram of a state in which a steel plate is fastened.
FIG. 19 is an explanatory diagram of a drilling start state of another embodiment in which drilling is performed from both sides.
FIG. 20 is an explanatory diagram of a state where the diameter is expanded and perforated.
FIG. 21 is an explanatory diagram of a state in which perforation is performed from the other side.
FIG. 22 is an explanatory diagram of a penetrating state.
FIG. 23 is an explanatory diagram of a state in which fishing is performed.
FIG. 24 is an explanatory diagram of a state in which a rod is inserted.
FIG. 25 is an explanatory diagram of a state where a rod is inserted.
FIG. 26 is an explanatory diagram of a state in which a steel plate is fastened.
FIG. 27 is a perspective view showing a conventional pier reinforcement method using steel plate combined reinforced concrete winding.
FIG. 28 is an explanatory diagram of a drilling method for placing a lock bolt using a drifter.
FIG. 29 is an explanatory diagram of a state where the drifter has advanced to the stroke end.
FIG. 30 is an explanatory diagram of a state where the drifter has retracted and drilling has started again.
FIG. 31 is an explanatory diagram of a state where a hole is drilled to a predetermined depth.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pier 2 ... Housing 3 ... Steel plate 4 ... Intermediate penetration PC steel bar 5 ... Rod 6 ... Monitor 7 ... Nut 8 ... Hole 9 ... Packer 10 ... Punching machine 11 ... Guide cell 12 ... Drifter 13 ... Gripping device 15 ... Lock bolt 16 ... Lost bit 17 ... Water swivel J ... Water jet

Claims (6)

  In the reinforcing method of a reinforced concrete pier that covers the wall of the pier housing of the existing wall-type reinforced concrete pier with a steel plate and inserts the rod-shaped member into the pier housing so as to be integrated with the steel plate, the insertion hole of the rod-shaped member is provided in the pier housing. When drilling, hold a hollow rod with a water jet monitor attached at the tip of the drilling machine drilled with rotary percussion, and drill the part of the pier frame containing the reinforcing bar with the water jet. The perforated part is drilled with rotary percussion, and when the insertion hole of the rod-shaped member penetrates the pier housing, the hollow rod is inserted and filler is injected around it, and both ends of the hollow rod are engaged with the fastening member. The reinforced concrete pier reinforcement method is characterized by integrating the pier frame and steel plate.   In the reinforcing method of a reinforced concrete pier that covers the wall of the pier housing of the existing wall-type reinforced concrete pier with a steel plate and inserts the rod-shaped member into the pier housing so as to be integrated with the steel plate, the insertion hole of the rod-shaped member is provided in the pier housing. When drilling, hold a hollow rod with a water jet monitor attached at the tip of the drilling machine drilled with rotary percussion, and drill the part of the pier frame containing the reinforcing bar with the water jet. The perforated part is drilled with rotary percussion, and when the insertion hole of the rod-shaped member is drilled to the predetermined depth of the abutment frame, the hollow rod is inserted, the filler is injected around it, and the hole is inserted into the insertion hole of the hollow rod. An iron characterized in that an end portion on a non-side is engaged with a fastening member to integrate a pier frame and a steel plate Retrofit for concrete piers.   The reinforcing method for a reinforced concrete pier according to claim 1, wherein the insertion hole of the rod-shaped member is penetrated by connecting holes drilled from both sides of the pier housing.   The insertion hole of the rod-like member drilled from both sides of the pier housing is in a state where the diameter of the hole drilled from one side of the pier housing is larger than the diameter of the hole drilled from the other side. The reinforcing method for a reinforced concrete bridge pier according to claim 3, which is perforated.   When the hole drilled from one side of the pier housing and the hole drilled from the other side are misaligned, the hook-shaped guide member is inserted from the side opposite to the side where the rod-shaped member is inserted. The reinforcing method for a reinforced concrete bridge pier according to claim 4, wherein the rod-shaped member is inserted by the guide member.   The reinforcing method for a reinforced concrete pier according to any one of claims 1 to 5, comprising a step of winding the pier frame with reinforced concrete prior to covering the wall surface of the pier frame of the existing wall-type reinforced concrete pier with a steel plate.

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