JP5339771B2 - Reinforcement method for columnar structures such as piers - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reinforcing a bridge pier or the like shortening a construction period and reducing a construction cost by securing a work yard around an aseismatic reinforcing bridge pier of a bridge pier in a river narrow in width and comparatively shallow in depth of water, lifting a reinforcing frame of an underground part above the bridge pier while open-cutting a base part of the bridge pier in a constantly stagnant state of water to achieve construction dispensing with spring water countermeasures, and dropping an underground frame into water after open-cutting and filling underwater unseparative mortar between the bridge pier and the underground frame after backfilling an open cut part. <P>SOLUTION: A reinforcing frame 13a made of steel plates are arranged surrounding the peripheral surface of a columnar structure 8 of the bridge pier or the like erected on a foundation 7 installed underground or underwater. A filler is filled between the columnar structure 8 and the reinforcing frame 13a. The work yard 25 is constructed around the base part of the columnar structure 8. Open-cutting is carried out from the periphery of the base part of the columnar structure 8 to the foundation 7 through the work yard 25. Open-cutting is executed with water 33 left stagnant in an excavated hole 32. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention is suitable for, for example, seismic reinforcement of a river pier with a narrow river width and a relatively shallow water depth. The work flow is secured around the pier by changing the flow of the river. Easily assembled and lifted above the pier, while the base of the pier is always excavated in a water-saturated state, realizing construction without any measures against springs regardless of geological conditions, and the slope of the excavation hole Stabilize and make the excavation space and work space compact.After excavation, the underground frame is dropped into the water, and after excavation is backfilled, an underwater non-separable mortar is placed between the pier and the underground frame. The present invention relates to a method for reinforcing a columnar structure such as a bridge pier, which can be filled and the mortar can be densely and reliably filled in water, and the use of temporary objects can be greatly reduced, thereby shortening the construction period and reducing the construction cost.

The damage situation such as the Great Hanshin Earthquake and the Niigata Chuetsu Earthquake has pointed out seismic reinforcement of piers, and urgent seismic reinforcement of piers is desired for ensuring vehicle safety and transportation safety.
Of these, seismic reinforcement for bridge piers in rivers involves underwater construction. For example, a temporary closing method using temporary earth retaining using a temporary pier or a seismic reinforcement by placing straight steel sheet piles. However, the temporary closing method requires a large amount of work, and the steel sheet pile placing method requires a large number of steel sheet piles, resulting in a problem that the construction cost is increased and the construction period is prolonged.

In particular, construction at the river head has many cobblestones with large diameters, and it becomes difficult to place temporary earth retaining or straight steel sheet piles as planned. In that case, combined use of agar becomes indispensable. , it increases the engineering costs, and since the construction of this kind is that there is a restriction of the dry season, can not be handled by the above-described method.

By the way, various reinforcement methods have been proposed for seismic reinforcement of bridge piers in deep rivers.
For example, a scaffold is constructed using a work table ship equipped with a crane on the water surface of a pier, and a steel pipe is formed by surrounding the circumferential surface of the pier by welding a plurality of steel plates using the scaffold. Reinforcing member provided with a root winding concrete by installing a reinforcing bar on the outer periphery of the lower end of the steel pipe, installing a mold on the outer periphery of the reinforcing bar, and placing a concrete between the steel pipe and the mold After the scaffold is removed once, the reinforcing member is suspended through a chain block provided above the pier, and is submerged in water and installed on the foundation.

  At that time, a guide roller is rotatably attached to the inside of the steel plate, and the roller is brought into contact with the peripheral surface of the pier to secure a gap between the steel plate and the surface of the pier, and then the scaffold is placed on the reinforcing member. There is a bridge pier reinforcement method in which a steel plate is welded using the scaffold, this is joined to a reinforcing member, and a non-shrink mortar is filled between the steel plate and the pier (see, for example, Patent Document 1) ).

  However, this reinforcement method requires a large work table ship instead of a temporary pier, and the work table ship constructs a scaffold and manufactures a steel pipe. -In the distance adjustment by the roller, the guide roller is only brought into contact with the peripheral surface of the pier, so there is a possibility that the placed concrete may intervene between the peripheral surface of the pier and the guide roller. There is a problem in that it is impossible to obtain a uniform interval and uniform adjustment.

  In addition, as another reinforcement method, via a joint to the pier peripheral surface above the water surface, a plurality of steel plate panels are connected in an annular shape to assemble an annular panel body, and this annular panel body is arranged up and down and connected, A part of the lower annular panel body is lowered into the water, the annular panel body is sequentially assembled on the upper part of the upper annular panel body, and the lower annular panel body is sequentially lowered into the water so that the entire circumference of the pier Is covered with an annular panel body, and then the earth and sand between the pier and the annular panel body are discharged, and underwater concrete is filled between them (for example, see Patent Document 2).

  However, this reinforcement method requires the construction of a temporary pier around the pier or the use of a work platform to provide a scaffold and a material storage area around the pier. Since the underwater concrete is filled in a narrow gap with the annular panel body, there is a problem in that the aggregate cannot inhibit the fluidity of the concrete and cannot be densely filled.

  Furthermore, as another reinforcing method, a press-fitting device is fixed to the peripheral surface of the pier, and a steel plate is placed around the pier, and the steel plate is connected with a bolt, and a rubber packing is connected to the joint. Inserted into a watertight assembly, the cut-off steel plate is pushed down by the press-fitting device, penetrated into the water bottom ground and watertightly cut off, and then the inside of the cut-off steel plate is drained to provide a scaffold, and the steel plate for reinforcement using the scaffold There is a construction method in which a block is suspended by a hoist, this is sequentially stacked on a peripheral surface of a bridge pier, and a joint portion is welded to be assembled (see, for example, Patent Document 3).

However, the above-mentioned reinforcing method requires a large and heavy dead steel plate, which requires a large amount of work and is assembled in a watertight manner by inserting a rubber packing at the joint. In addition to the time and effort required to assemble the steel plate for reinforcement after the watertight shut-off, there were problems such as a longer construction period and increased construction costs.
Thus, the pier seismic reinforcement in rivers with deep water has the above-mentioned problems, and it is difficult to apply this to seismic reinforcement of river piers with narrow river width and relatively shallow water depth.

Therefore, when solving the above-mentioned problem and constructing the earthquake proof reinforcement of the bridge pier in the river where the river width is narrow and the water depth is relatively shallow, the work yard is secured by replacing the river instead of the temporary pier, In addition, it is conceivable to employ an open-cut work with a backhoe that does not use temporary earth retaining.
In this case, the former can be realized by discussions between river managers, while the latter requires treatment of spring water generated in large quantities during underground excavation and prevention of collapse of the excavation slope.
Of these, the spring treatment can solve the problem if the spring can be excavated in a constantly stagnant state, but the reinforcement of the constantly stagnant state requires the assembly of an underground steel plate frame.

Therefore, the applicant changed the flow of the river instead of the temporary pier, created the periphery of the base of the pier to secure the work yard, assembled the steel plate frame in the ground with the work yard, After temporarily suspending it on the pier, the base of the pier was excavated in a constantly flooded state, and after excavation, the method of dropping the steel frame into the water was devised.
However, the method has problems of excavation and construction underwater, and adjustment of the distance between the steel plate frame dropped into the water and the pier, and the mortar in the narrow part between the steel plate frame dropped into the water and the pier. There were problems with the filling method and ensuring its quality.

JP-A-11-71718 JP 2001-107319 A Japanese Patent No. 3930345

The present invention solves such a problem, and is suitable for, for example, seismic reinforcement of a river pier with a narrow river width and a relatively shallow water depth, and by changing the flow of the river to secure a work yard around the pier, While the middle reinforcement frame can be easily assembled on the ground and lifted above the pier, the base of the pier is always excavated in a water-saturated state, realizing construction that eliminates spring measures regardless of geological conditions The slope of the excavation hole can be stabilized, the excavation space and the work space can be made compact, and after excavation, the underground frame can be dropped into the water. to be filled with water nondisjunction type mortar, with may dense and reliably fill the mortar in water, significantly reduces the use of temporary product, the columnar structure of the pier such that attained a reduced construction period shortened and construction cost The purpose is to provide a reinforcement method.

The invention according to claim 1 assembles the reinforcing frame of the underground part or the underwater part around the peripheral surface of a columnar structure such as a bridge pier standing on the foundation in the ground or the bottom of the ground , and the assembled reinforcing frame is columnar. When installing the reinforcing frame by suspending it above the structure, the pier is lowered and installed in the ground or underwater, and a pier is filled with a filler between the installed reinforcing frame and the columnar structure. In the method of reinforcing the columnar structure of the above, the work is constructed by embedding the periphery of the base of the columnar structure erected on the foundation in the spring ground or underwater ground, and creating a work yard capable of excavating the periphery of the base. Assemble the columnar structure on the yard and assemble the reinforcement frame in the ground part on the ground, move the assembled reinforcement frame above the columnar structure and suspend it, and then the base from the periphery of the base of the columnar structure drilled ground over and construction by retained the accumulated water in the wellbore with the drilling The reinforcement frame is lowered into the excavation hole and installed in the water, and after the installation of the reinforcement frame, the excavation hole is refilled, and a filler is filled between the reinforcement frame and the columnar structure, When reinforcing columnar structures erected on the foundation inside, conventional temporary earth retaining work and straight steel sheet pile placement are omitted, greatly reducing the labor and materials for temporary work and shortening the work period and FIG Rutotomoni reduction of construction costs, first work with fill the base periphery of the columnar structure ya - to construct a de, this task ya - easily after assembly the reinforcing frame of the ground portion on de ground, underground portion The reinforced frame is moved upward and suspended to excavate the ground spanning from the base of the columnar structure to the foundation, while retaining the accumulated water in the excavation hole and excavating using the accumulated water pressure. A stable excavation is realized by stabilizing the slope of the hole, and the underground reinforcement frame is suspended in the water of the excavation hole. After lowering and installing, the excavation hole is backfilled to stabilize the reinforcement frame, and the filler is filled between the reinforcement frame and the columnar structure to enhance the stability of the reinforcement frame. It is done safely and smoothly so that it can respond to the construction restrictions during the drought period of the river pier.

According to the second aspect of the present invention, the stagnant water is spring water from a river, sea or lake, and the stagnant water in the excavation hole can be obtained easily and inexpensively .
According to a third aspect of the present invention, the excavation hole has an inverted frustoconical shape, so that the working yard is made compact .
According to the invention of claim 4, excavation is carried out by a heavy machine installed on a work yard and a diver, and the excavation is rationally divided into heavy machine and human power, and there is a possibility of damage in the heavy machine. The site is excavated safely by human power to ensure excavation reliability .

In the invention of claim 5, the slope of the excavation hole has a steep slope with a ratio of horizontal distance to vertical distance of 1 to 2 to 1: 1, and the excavation hole is reduced in size and excavated sediment is reduced. In addition to speeding up the work and making the excavation work space compact, the work yards are made smaller .
Claim 6 The invention provides a corresponding position of the columnar structure in which through holes are formed at the upper and lower positions of each reinforcing frame in the underground, a nut is fixed to the inner edge of one through hole, and the other through hole is opposed. A concrete anchor having a screw hole is embedded, a first support bolt is inserted into the other through hole, a screw shaft of the bolt is screwed into a screw hole of the concrete anchor, and each reinforcing frame is attached to a columnar structure. The second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut so as to contact the peripheral surface of the columnar structure. The space between the objects is adjusted, the joint portions of the adjacent reinforcing frames are welded and assembled to form a filling space uniformly, and deformation of the reinforcing frame due to welding can be prevented .
The invention of claim 7, after welding, the first and second support bolt removed from the reinforcing frame, darken of reinforcing frame bottom up hanging moves upward of the columnar structures, the bottom up hanging time and water In addition to preventing scratching and damage to the columnar structure at the time, the excavation work of the excavation hole after hanging can be easily performed .

According to the eighth aspect of the present invention, after dropping the underground reinforcing frame into the accumulated water in the excavation hole, the second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut to surround the columnar structure. The space between each reinforcing frame and the columnar structure is adjusted so as to be in contact with the surface, so that a filling space of the underwater non-separable mortar is uniformly formed.
According to the ninth aspect of the present invention, the adjustment of the distance between the reinforcing frame and the columnar structure is performed by a diver in a stagnant excavation hole to correspond to reliable work in water.
The invention of claim 10, after adjusting the gap reinforcing frame and the columnar structures, backfill the wellbore, after returning Me該埋, while the water supply to clean fresh water between the reinforcing frame and the columnar structures, Supervising the state of contamination of the reflux water and adjusting the interval with the water supply pipe, cleaning the space between the reinforcement frame and the columnar structure in preparation for filling with the filler, and confirming the state of contamination of the reflux water. Thus, the presence / absence of excavated earth and sand and the timing of filling are judged, and the interval adjustment is supervised according to the insertion state of the water supply pipe to check whether or not the filling space is available.

The invention of claim 11, after backfill, the retention of water between the reinforcing frame and the columnar structures, filled with water nondisjunction type mortar positioned immediately above the bottom of the fill tube, backfill on the outside of the reinforcing frame The earth pressure of the earth and sand is applied to prevent stagnation of the reinforcing frame due to mortar filling and mortar leakage, and by filling with non-separable mortar, the separation of mortar in water is prevented. Filling and uniform mortar strength can be obtained, and the filling tube is positioned directly above the bottom, thereby improving the inseparability in water and reducing the variation in compressive strength compared to drop filling from above.
In the invention of claim 12, the underwater non-separable mortar is added with 1.0 to 2.0 kg / m 3 of the underwater non-separating agent so as to obtain good underwater non-separability and a large compressive strength.
In the invention of claim 13, after filling the mortar, on the solidified mortar and the backfilling member, the ground frame reinforcement frame is surrounded by the columnar structure and is assembled on the ground reinforcement frame protruding above the ground. The ground frame reinforcement frame can be assembled easily and rationally.

In the invention of claim 14 , a through hole is formed at the upper and lower positions of each reinforcing frame in the ground portion, a nut is fixed to the inner edge of one through hole, and the columnar structure facing the other through hole is supported. A concrete anchor having a screw hole at the position is embedded, a first support bolt is inserted into the other through hole, and the screw shaft is screwed into the screw hole of the concrete anchor, so that each reinforcing frame is attached to the columnar structure. The second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut so as to contact the peripheral surface of the columnar structure. Adjust the space between objects and weld and assemble the joint of the adjacent reinforcement frame and the joint of the adjacent ground frame to form a uniform filling space for the filler. Deformation can be prevented .
According to the fifteenth aspect of the present invention , the first and second support bolts are attached to the reinforcing frames of the ground portion, and the filling pipe is positioned between the reinforcing frame and the columnar structure so as to be directly above the bottom. The tightening force of the first support bolt prevents the squeezing of the reinforcing frame accompanying the filling of the filler and prevents the filler from leaking .

In the invention of claim 16, after the filling of the filler, the work yard is removed, the state before construction is restored, and environmental pollution of the river and change of the landscape are prevented .

The invention according to claim 1 is a method of embedding a periphery of a base of a columnar structure erected on a foundation in a spring ground or a submerged ground, creating a work yard capable of excavating the periphery of the base, Assemble the columnar structure on the door and assemble the reinforcing frame in the ground on the ground, move the assembled reinforcement frame above the columnar structure and hang it, and then extend from the periphery of the base of the columnar structure to the foundation excavating ground, as well as construction and allowed to stay the accumulated water in the wellbore, placed in water lowered the reinforcing frame to the wellbore after drilling, backfill wellbore after installation of the reinforcing frame, the reinforcing Since the filler is filled between the frame and the columnar structure, when reinforcing the columnar structure erected on the foundation in the spring ground or underwater ground, conventional temporary earth retaining works or straight steel sheet piles are hit. skip settings, greatly reduces the materials and labor for temporary Engineering, FIG Rutoto reduction shorten the construction period and construction cost First, a work yard capable of excavating the periphery of the base portion of the columnar structure and excavating the periphery of the base portion is constructed, and the reinforcing frame of the underground portion is easily assembled on the ground, and then the underground portion The reinforced frame is moved upward and suspended to excavate the ground spanning from the base of the columnar structure to the foundation, while retaining the accumulated water in the excavation hole and excavating using the accumulated water pressure. Stabilize the slope of the hole and realize safe excavation, hang the underground reinforcement frame in the water of the drilling hole and install it, then backfill the excavation hole to stabilize the reinforcement frame, Filling the space between the reinforcement frame and the columnar structure enhances the stability of the reinforcement frame, and a series of construction work is performed safely and smoothly. is there.

According to the second aspect of the present invention, since the accumulated water is spring water from a river, the sea or a lake, there is an effect that the accumulated water in the excavation hole can be obtained easily and inexpensively.
A third aspect of the present invention, wellbore is because an inverted truncated cone shape, the working Ya - compactness of the de may FIG Rukoto.
According to the invention of claim 4, since excavation is carried out by heavy machinery installed on the work yard and divers, excavation can be performed rationally by dividing it into heavy machinery and human power, and there is a risk of damage in heavy machinery. A certain part can be safely excavated by human power, and the excavation can be ensured .

In the invention of claim 5, since the slope of the excavation hole has a steep slope in which the ratio of the horizontal distance to the vertical distance is 1 to 2 to 1: 1, the downhole of the excavation hole and the reduction of the excavation sediment are reduced. The excavation work can be speeded up and the excavation work space can be made compact, and the work yard can be made smaller .
Claim 6 invention forms a through hole in the vertical position of the reinforcing frame of the earth middle, a nut is fixed to the inner brim of the one through hole, the corresponding positions of the columnar structures that face the other through hole A concrete anchor having a screw hole is embedded, a first support bolt is inserted into the other through hole, a screw shaft of the bolt is screwed into a screw hole of the concrete anchor, and each reinforcing frame is attached to a columnar structure. The second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut so as to contact the peripheral surface of the columnar structure. Since the interval between the objects is adjusted and the joint portions of the adjacent reinforcing frames are welded and assembled, the filling space of the filler can be formed uniformly and deformation of the reinforcing frame due to welding can be prevented .
The invention of claim 7, after welding, the first and second support bolt removed from the reinforcing frame, the reinforcing frame from above suspension under gel was moved to the columnar structure, the time of hanging down down and water In addition to preventing scratching and damage to the columnar structure when dropping, it is possible to easily perform excavation work of the excavation hole after hanging .

According to the eighth aspect of the present invention, after dropping the underground reinforcing frame into the accumulated water in the excavation hole, the second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut to surround the columnar structure. The space between the reinforcing frame and the columnar structure is adjusted in contact with the surface, so that the filling space of the underwater non-separable mortar can be formed uniformly.
According to the ninth aspect of the present invention, since the submarine performs the adjustment of the interval between the reinforcing frame and the columnar structure in the stagnant excavation hole, it can correspond to a reliable work in water.
The invention of claim 10, after adjusting the gap reinforcing frame and the columnar structures, backfill the wellbore, after returning Me該埋, while the water supply to clean fresh water between the reinforcing frame and the columnar structures, Supervising the state of contamination of the reflux water and adjusting the interval with the water supply pipe, cleaning the space between the reinforcement frame and the columnar structure in preparation for filling with the filler, and confirming the state of contamination of the reflux water. Thus, the presence / absence of excavated earth and sand and the timing of filling can be determined, and the interval adjustment can be managed according to the insertion state of the water supply pipe to check whether or not the filling space is available.

The invention of claim 11, after backfill, the retention of water between the reinforcing frame and the columnar structure, since positioned immediately above the bottom of the filling tube for filling the water nondisjunction type mortar fills the outside of the reinforcing frame The earth pressure of the returned earth and sand is applied to prevent stagnation of the reinforcing frame due to mortar filling and mortar leakage, and filling with non-separable mortar prevents the separation of mortar in the water. Can be obtained, and uniform mortar strength can be obtained. Further, by positioning the filling tube directly above the bottom, non-separability in water can be improved and variation in compressive strength can be suppressed small compared to drop filling from above.
According to the twelfth aspect of the present invention, since the underwater non-separable mortar adds 1.0 to 2.0 kg / m 3 of the underwater non-separation agent, it is possible to obtain good underwater non-separability and high compressive strength.
In the invention of claim 13, after filling the mortar, on the solidified mortar and the backfilling member, the reinforcing frame of the ground part is assembled on the reinforcing frame of the underground part projecting to the ground by surrounding the peripheral surface of the columnar structure. Thus, the reinforcing frame of the ground part can be assembled easily and rationally.

In the invention of claim 14 , a through hole is formed at the upper and lower positions of each reinforcing frame in the ground portion, a nut is fixed to the inner edge of one through hole, and the columnar structure facing the other through hole is supported. A concrete anchor having a screw hole at the position is embedded, a first support bolt is inserted into the other through hole, and the screw shaft is screwed into the screw hole of the concrete anchor, so that each reinforcing frame is attached to the columnar structure. Since the second support bolt is inserted into the one through hole and the screw shaft is screwed into the nut to come into contact with the peripheral surface of the columnar structure, each reinforcing frame and the columnar shape are fixed. Adjust the space between the structures and weld and assemble the joints of the adjacent reinforcement frames and the joints of the adjacent ground frame to form a uniform filling space for the filler, and welded reinforcement frames Can be prevented from being deformed .
According to the fifteenth aspect of the present invention , the first and second support bolts are attached to the reinforcing frames of the ground portion, and the filling pipe is positioned between the reinforcing frame and the columnar structure so as to be directly above the bottom. Therefore , the tightening force of the first support bolt can prevent stagnation of the reinforcing frame accompanying filling of the filler and leakage of the filler .

Since the invention of claim 16 removes the work yard after filling with the filler and restores the condition before construction, it can prevent environmental pollution of the river and changes in the landscape .

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, illustrated embodiments in which the present invention is applied to seismic reinforcement of a railway pier in a river having a relatively narrow river width and a relatively shallow water depth will be described. In FIGS. Is a relatively shallow river with embankments 2 and 3 projecting on both the left and right banks, and river streams 5 and 6 are formed separately on both sides of Nakashu 4.

  A footing 7 as a foundation is buried in the ground of the Nakasu 4, and a bridge pier 8, which is a columnar structure made of reinforced concrete, is erected on the footing 7. A floor slab 11 on which the track 10 can be laid is installed.

In the embodiment, the cross section of the pier 8 is formed in a substantially oval shape, and a reinforcing frame 13 made of a vertically long rectangular steel plate is attached to the peripheral surface of the pier 8 via an underwater non-separable mortar layer 12 as a filler. It has been.
The reinforcing frame 13 is formed into a flat or non-formed flat plate shape of the steel plate according to the construction position, the peripheral surface thereof is abutted against the adjacent reinforcing frame 13, and a joint (not shown) is formed on the back surface of the joint portion. ).

  The reinforcing frame 13 is divided into an underground frame 13a and a ground frame 13b depending on the construction position. Among these, the underground frame 13a is embedded in the natural ground 14 after the work yard removal described later, An upper end portion of the underground frame 13a is disposed so as to protrude above the ground, and a lower end portion of the lower ground frame 13b is disposed on the underground frame 13a so as to weld the joint portion.

  In the figure, reference numeral 15 denotes a concrete anchor which is driven into the peripheral surface of the pier 8 at a predetermined interval. A screw hole 16 is formed in the anchor anchor, and the screw hole 16 is a first from the outside of the reinforcing frames 13a and 13b. Support bolts 17 or screws are screwed.

Two through-holes 18 and 19 are formed at the upper and lower positions of the central portions of the reinforcing frames 13a and 13b. The first support bolt 17 can be inserted into one through-hole 18, and the screw shaft end portion is connected to the constriction end. -It can be screwed into the torque anchor 15 to prevent welding deformation during assembly of the reinforcing frames 13a, 13b.
The first support bolt 17 is removed from the underground reinforcing frame 13a after welding, and the through hole 18 on the reinforcing frame 13a side is filled with a seal material, which will be described later, and closed, and the ground reinforcing frame 13b. Maintains a screwed state and prevents deformation, that is, stagnation, when mortar is filled between the pier 8 after welding.

A nut 20 is welded to the inner opening edge of the other through hole 19, and second support bolts 21 and 23 for adjusting the distance are screwed into the nut 20.
Among these, one of the second support bolts 21 is a hexagonal bolt, and when the reinforcing frame 13a is assembled before welding, the screw shaft is screwed into the nut 20 to prevent deformation during welding, and after the screwing, the second support bolt 21 is removed and later described. Then, it is dropped into the water, and after dropping, it is screwed into the nut 20 by the diver.

Further, the other second support bolt 23 is formed in a rod shape, and a recess 23a capable of engaging with a hexagon wrench (not shown) is formed on the end surface thereof, and is screwed into the nut 20 at the time of assembly before welding the reinforcing frame 13b. The end of the screw shaft is brought into contact with the surface of the pier 8 so that the distance d between the reinforcing frame 13b and the pier 8 can be adjusted to be constant, and this screwed state is maintained between the reinforcing frame 13b and the pier 8. Filling material such as mortar is used.
In the figure, 24 is a seal material filled in the through holes 18 and 19 of the reinforcement frames 13a and 13b, the recess 23a of the second support bolt 23, and the recess 22 of the first support bolt 17 on the reinforcement frame 13b side.

The seismic reinforcement work by the reinforcing frame 13 of the bridge pier 8 is performed according to the procedure shown in FIG. 6. That is, the seismic reinforcement work is a process for creating the work yard 25 by changing the flow of one river flow 6. Replacement work / work yard work, underground reinforcement frame assembly work for assembling the reinforcement frame 13b to be placed on the ground and hanging on the pier 8, and then the base area of the pier 8 in the spring water An underwater excavator for excavation and an underground reinforcement frame dropping work for dropping the reinforcing frame 13b into the water staying in the excavated excavation hole are sequentially performed.

Next, a backfilling work for backfilling the excavated excavation hole and embedding the reinforcing frame 13b, a ground reinforcement frame mortar filling work for filling the mortar 21 between the bridge pier 8 and the reinforcing frame 13b, The ground part reinforcement frame assembly work for assembling the reinforcement frame 13a, and the detachment removal work for removing the scaffolding and the work yard 25, restoring the river flow 5, 6 and restoring the river 1 before construction. Do.

  The sewage work / working yard works by installing a large sandbag (not shown) on the upstream side of one river flow 6 to dam it up, and from the upstream side of the river flow 6 toward the river flow 5 A sandbag 26 having a shape is installed to change the flow of the river flow 6, and the river flow 6 is merged with the river flow 5 so that the river flow 6 is temporarily depleted.

Then, sediment is deposited on the depletion part on the downstream side of the river flow 6 and the inner side of one embankment 3 to create a slope-like river entrance path 27, and the sediment transport is performed using the river entrance path 27. A large automobile (not shown) is entered into the river 1 and the earth and sand loaded on the automobile are conveyed to the vicinity of the base of the pier 8 and are embanked to form the work yard 25.
At that time, the outer periphery of the work yard 25 facing the river flow 5 is protected by the sandbag 26. In this way, omission of the temporary pier is realized by the above-mentioned segregation and the approach path 27 in the river.

After the construction of the work yard 25, a scaffold 28 is assembled around the pier 8, and a plurality of lifting equipment 29 such as chain blocks are installed on the upper peripheral surface of the pier 8 using the scaffold 28. A plurality of concrete anchors 15 are attached to predetermined places on the peripheral surface of the ground part 8.
Then, the underground and ground reinforcement frames 13a and 13b and a heavy machine 30 such as a crane are carried into the work yard 25, and the heavy machine 30 first lifts the reinforcement frame 13a. It is arranged at a predetermined position and temporarily assembled, and an underground part reinforcing frame assembling work is performed to assemble the underground part reinforcing frame 13a.

When the underground reinforcing frame 13a is assembled, the first support bolt 17 is inserted into the through hole 18 from the outside of the reinforcing frame 13a, the screw shaft is screwed into the screw hole 16 of the concrete anchor 15, and its head 17a is engaged with the opening edge of the through hole 18.
Further, the second support bolt 21 is inserted into the through-hole 19 from the outside of the reinforcing frame 13 a, the screw shaft is screwed into the nut 20, and the screw shaft end is screwed in until it comes into contact with the peripheral surface of the bridge pier 8. The distance d between the reinforcing frames 13a is adjusted to be constant.
Thus, when all the reinforcing frames 13a are fixed to the peripheral surface of the pier 8, the joint portion of the reinforcing frame 13a is welded with a joint on the back surface to form a reinforcing frame tube having a substantially oval cross section. In the embodiment, the reinforcing frame 13a is formed in a tubular body stacked in two upper and lower stages.

After the reinforcement frame 13a is welded, the first support bolts 17 and 21 are removed, a locking bracket (not shown) is attached to the outer peripheral surface of the reinforcement frame 13a, and the chain block locking tool (not shown) is attached to the bracket. ), And is lifted and moved above the pier 8 and suspended.
Thereafter, the scaffold 28 is temporarily removed, the excavator 31 such as a backhoe is moved to the work yard 25, and the backhoe 31 is driven to construct an underwater excavator.

The underwater excavator excavates the work yard 25 around the base of the pier 8 and a part of Nakasu 4 by the backhoe 31, and forms a substantially inverted truncated cone-shaped excavation hole 32 from the pier 8 to the footing 7. Try to form.
The drilling is performed by moving the backhoe 31 along the opening edge of the opening diameter D ₂ of the wellbore 32, the opening diameter D ₂ is off - it is formed slightly larger than the outer diameter of the quenching 7, drilling The bottom diameter D ₁ of the hole 32 is smaller than the outer diameter of the footing 7 (D ₁ <D ₂ ).

The gradient of the slope face 32a of the wellbore 32, i.e. the ratio H / h of the horizontal distance H, the depth h of the wellbore 32 between the opening edge and the bottom diameter D ₁ of the drill hole 32 is approximately 1 in the embodiment formed in / 2-1 / 1, aims to steep for small diameter and Homen 32a of the opening diameter D ₂ of the wellbore 32, the work ya - so that achieving gasification - small space of de 25.
Thus, even if the slope 32a is steep, the slope 32a is stabilized by receiving the water pressure of the accumulated water 33 and is prevented from collapsing, so that it can be excavated stably.

Said bottom diameter D ₁ is off - located in the upper end surface of the quenching 7, the minimum space when said bottom diameter D ₁ is in standing water 33, such as spring water staying in the wellbore 32, and the divers 34 to work -It is set to a diameter corresponding to In the figure, reference numeral 35 denotes a large sandbag for preventing collapse which is installed on the slope 32a.
In this case, since the slope 32a is stable as described above, the sandbag 35 is not indispensable. However, when installing, the quantity is reduced by reducing the size of the digging hole 32 or shortening the length of the slope 32a. You can lose weight.

The underwater excavator is excavated by the backhoe 31 and excavated by the diver 34. The excavation by the diver 34 is difficult to excavate by the backhoe 31 and may be damaged. The periphery of the ching 7 is excavated by human power, and the fine sediment is processed by an air lift, and in particular, the sediment retained on the upper surface of the footing 7 is suction-excavated.
In the air lift or excavation, one end of a drain pipe (not shown) is immersed in the accumulated water 33, the other end is piped outside the excavation hole 32, compressed air is supplied into the drain pipe, and the one end is The residual sediment such as the pier 8 is sprayed and peeled off, and this fine sediment is discharged to the outside together with the staying water 33.

  As described above, since the underwater excavator excavates while stagnating the stagnant water 33 at all times, a conventional temporary member such as a steel sheet pile becomes unnecessary, and the slope 32 a is stabilized by the water pressure of the stagnant water 33. Therefore, the excavation work can be performed smoothly and stably, and the steep slope of the slope 32a can be realized to make the excavation space compact, so that the labor of the excavation work is reduced and the river width is narrow. It is suitable for construction and can be constructed regardless of the geological conditions at the site.

In this way, the underwater excavation work is completed, and the submerged member 34 brushes and cleans the peripheral surfaces of the pier 8 and the footing 7, and then the underground part reinforcement frame dropping work is performed.
In the underground reinforcement frame dropping work, the plurality of chain blocks are lowered stepwise, the suspended tubular reinforcement frame 13a is slowly lowered into the stagnant water 33, and the lower end of the reinforcement frame 13a is lowered. -It lands on the upper surface of the ching 7 and its upper end protrudes from the water surface of the staying water 33.
The work is performed by, for example, several operators boarding a simple work ship, and the workers sharing and operating the chain block.

After the reinforcement frame 13a is dropped , the second support bolt 21 is inserted into the through hole 19, the screw shaft is screwed into the nut 20, and this is used, for example, by using an air-impact wrench so that the screw shaft end portion is surrounded by the circumference of the pier 8. Abutting on the surface, the distance d between the reinforcing frame 13a and the pier 8 is adjusted to be constant.
Thus, after the reinforcing frame 13a is set up on the footing 7 so as to surround the bridge pier 8, a civil engineering sheet (not shown) is arranged over the upper surface of the footing 7 outside the lower end of the reinforcing frame 13a. Then, this is held by a sandbag (not shown) to close the gap between the lower end of the reinforcing frame 13a and the upper surface of the footing 7 and prepare for the next backfilling work.

In the backfilling work, the excavated earth and sand 36 is introduced into the excavation hole 32 using the backhoe 31 and the outer side of the reinforcing frame 13a is backfilled with the earth and sand 36.
In this case, stagnant water 33 remains between the reinforcing frame 13a and the pier 8 even after backfilling.
Even if the stagnant water 33 is pumped out by a pump (not shown), the spring water immediately stagnates and the same situation occurs. That is, it is impossible to make the space between the reinforcing frame 13a and the pier 8 dry. Based on this situation, a mortar filling work for the next underground reinforcing frame is performed.

  After the backfilling, the interior of the space between the reinforcing frame 13a and the pier 8 is internally cleaned, and the presence or absence of sediment in the interior and the possibility of the interval d are confirmed by the cleaning. That is, the accumulation of the earth and sand forms a deficient portion of the filled mortar, which has a significant effect on the support strength of the reinforcing frame 13a. The possibility of the interval is related to the thickness of the filled mortar, and the reinforcing frame 13a. By having a significant effect on the strength of support.

The internal cleaning is performed by supplying fresh water to the stagnant water 33 remaining between the reinforcing frame 13a and the pier 8 with an underwater pump (not shown), and depending on the turbid state of the reflux water, The presence or absence of accumulation is checked.
In addition, when supplying fresh water with the submersible pump, a long water supply pipe (outer diameter of about 3 cm) connected to the pump is inserted between the reinforcing frame 13a and the pier 8, and the interval depends on the insertion state. Whether or not d is possible is confirmed.

In the mortar filling work, the concrete mixer wheel 37 containing the underwater non-separable mortar 12 is moved back to the site and discharged between the reinforcing frame 13a and the pier 8 for filling. Yes.
Prior to filling the mortar, the inventor determined the mortar composition and the construction method. That is, as a filler for a narrow portion between the reinforcing frame 13a and the pier 8, a concrete containing a large aggregate is difficult to be densely filled, and a uniform strength cannot be obtained.

  For this reason, concrete is unsuitable as a filler, and mortar is suitable. However, since the stagnant water 33 is always stagnant in the gap, a non-separable mortar that does not separate into water is suitable. In that case, it is necessary to confirm the specific blending and its propriety.

Therefore, the composition of the underwater non-separable mortar was determined by conducting various tests shown in FIG. 7 for five types of samples that satisfy the following required quality.
As the required quality, the compressive strength is comparable to that of the pier 8, the ultimate strain is 3000 μm or more, the bleeding is not performed, the inseparability in water is good, The air strength ratio is 0.6 or more.

  The above five types of samples are based on mortar using high flow mortar admixture used for injection of narrow part of steel-rolled seismic reinforcement. A sticky agent was added. If the amount of the thickener is increased, the inseparability in water is improved, but there is a concern that the fluidity to the narrow portion is lowered and the expression of the compressive strength is insufficient.

  For this reason, the amount of thickener was tested in a five-part formulation, with appropriate water inseparability (confirmed by the degree of decrease in compressive strength in the air and water and visual material separation), and fluidity. A formulation that can ensure (confirm by flow value) was selected. As a result, it was determined that the second to fourth formulations shown in FIG. 7 can be applied to the construction method.

Next, regarding the construction method of the underwater non-separable mortar, that is, the filling method, the filling method was tested by a test of an actual mortar having a width of 50 mm. In the test, as shown in FIG. 8, a comparison between the tremi-tube type and the free drop casting, and confirmation of a decrease in strength between the direct fall casting and the horizontal mobility were performed.
As a result of the above test, it was confirmed that the tremi-tube type has improved water inseparability compared to free-fall filling and can suppress the variation in compressive strength, so the filling method is the tremi-tube type, that is, The method was a method in which the discharge port of the ejection pipe was immersed and filled in the mortar, and the insertion interval of the tremi pipe was determined in consideration of the reduction in the strength of the horizontal movement distance of the mortar.

In order to prevent stagnation of the steel sheet during mortar filling, filling was performed after backfilling the underground part to prevent leakage of the mortar. In the tremi-tube type casting, the pipe was fixed 50 mm above the bottom, and in the dropping, the pipe was fixed 400 mm above the bottom.
As a result of the test, it was found that tremi-tube casting was better in water inseparability and smaller compressive strength variation than drop casting, so the filling method of this construction was tremi-tube casting. .

That is, the filling of the mortar is performed by inserting a long casting pipe between the reinforcing frame 13a and the pier 8 and positioning the discharge port about 50 mm above the upper surface of the footing 7 so as to be inseparable in water. During the placement, the discharge port was immersed in the deposited mortar and filled.
In the embodiment, two placing pipes are used and arranged at symmetrical positions on the pier 8 so as to be filled with mortar. In this case, since the reinforcing plate 13a receives the earth pressure of the earth and sand 36, stagnation due to filling of the mortar 12 is prevented, and leakage of the mortar is prevented.

In this way, the mortar is filled, and after the mortar is hardened, an above-ground reinforcement frame assembly work is performed.
The ground part reinforcing frame assembling assembles the scaffold 28 on the backfilled earth and sand 36, lifts the ground part reinforcing frame 13b by the heavy machine 30, moves it to a predetermined position of the pier 8, and reinforces the reinforcing frame 13a. It is placed on the projecting end of the ground and temporarily assembled to assemble the ground portion reinforcing frame 13b.

When the reinforcing frame 13b is assembled, the first support bolt 17 is inserted into the through hole 18 from the outside of the reinforcing frame 13b, the screw shaft is screwed into the screw hole 16 of the concrete anchor 15, and the head portion 17a is passed through. Engage with the opening edge of the hole 18.
Further, the second support bolt 23 is inserted into the through-hole 19 from the outside of the reinforcing frame 13 a, the screw shaft is screwed into the nut 20, and the screw shaft end is screwed in until it comes into contact with the peripheral surface of the bridge pier 8. The distance d between the reinforcing frames 13a is adjusted to be constant.

  Thus, when all the reinforcing frames 13b are fixed to the peripheral surface of the bridge pier 8, the joint portion of the reinforcing frame 13b is welded with a joint on the back surface to form a reinforcing frame tube having a substantially oval cross section. In the embodiment, the reinforcing frame tube is formed in upper and lower 3.5 steps.

  Thereafter, with the first and second support bolts 17 and 21 attached, normal mortar is filled between the reinforcing frame 13b and the peripheral surface of the pier 8, and the reinforcing frame 13b is formed by equalizing and filling the mortar thickness. It is possible to prevent itching.

  In filling the mortar, the concrete mixer wheel 37 containing the mortar is moved, and the mortar is filled between the reinforcing frame 13b and the bridge pier 8 by the above-described tremi-tube method. Then, after the mortar is cured, the surface of the reinforcing frame 13b is painted, and a replacement removal work is performed.

  In the segregation removal work, the scaffold 28 is dismantled and removed, the work yard 25 is removed, the river entry path 27 is removed, and the large sandbag 26 damming the river stream 6 is The large sandbag 26 that formed the flow change is removed, the original flow of the river flow 6 is restored, and the situation before the construction of the river 1 is restored.

  The bridge construction method of the present invention constructed as described above is suitable for seismic reinforcement of a river pier with a relatively narrow river width and a shallow water depth as shown in FIG. Yard work, underground reinforcement frame assembly work, underwater excavation work, underground reinforcement frame dropping work, backfilling work, underground reinforcement frame mortar filling work, ground reinforcement frame assembly work, It consists of spare removal work, and the procedure is as shown in FIG.

  The changer / work yard works change the flow of one of the river streams 6 to create a work yard 25. The underground reinforcement frame assembler assembles the underground reinforcement frame 13a on the ground and piers. The underwater excavator excavates the vicinity of the base of the pier 8 in spring water, and the underground reinforcement frame dropping work drops the reinforcement frame 13a into the accumulated water 33 in the excavation hole 32.

  Further, the backfilling work fills the excavation hole 32 and embeds the reinforcing frame 13a, and the underground reinforcing frame mortar filling work fills the underwater non-separable mortar 12 between the pier 8 and the reinforcing frame 13a. The ground part reinforcement frame assembler assembles the ground part reinforcement frame 13b on the ground reinforcement frame 13a protruding above the ground, fills normal mortar between the bridge pier 8 and the reinforcement frame 13b, and removes the replacement. The worker removes the scaffold 28 and the work yard 25, restores the river flows 5 and 6, and restores the river 1 before construction.

  Of these, the sewage work / work yard works are installed with a large sandbag (not shown) on the upstream side of one river flow 6 to dam and flow through the large sandbag 26. The river flow 5 is merged to temporarily deplete the river flow 6, and the slope 27 is formed into the river entrance path 27 by embedding earth and sand inside a part of the depleted portion and one embankment 3.

Then, a large automobile (not shown) can enter the river 1 by the river entrance path 27, and the automobile is loaded with earth and sand and conveyed to the vicinity of the base of the bridge pier 8. Create. This situation is as shown in FIG.
In this way, the above-mentioned segregation and creation of the river access path 27 eliminates the conventional temporary pier, avoids the large-scale construction associated with the construction of the temporary pier, and prevents the construction period from increasing and the construction cost from increasing. obtain

Next, the underground reinforcement frame assembler assembles the scaffold 28 around the pier 8 after the work yard 25 is formed, and uses the scaffold 28 to form a chain block or the like on the upper peripheral surface of the pier 8. A plurality of lifting anchors 29 are installed, and a plurality of concrete anchors 15 are attached to predetermined locations on the circumferential surface of the pier 8.
Then, the underground and ground reinforcement frames 13a and 13b that are pre-formed and attached with the nut 20 are carried into the work yard 25 by a heavy machine 30 such as a crane, and among these, the reinforcement frame 13a is lifted, It is arranged at a predetermined position outside the pier 8 and temporarily assembled.

The underground reinforcing frame 13a is assembled by inserting the first support bolts 17 into the through holes 18 from the outside of the reinforcing frame 13a, screwing the screw shafts into the screw holes 16 of the concrete anchor 15, and the head 17a. Engage with the opening edge of the through hole 18.
Further, the second support bolt 21 is inserted into the through hole 19 from the outside of the reinforcing frame 13 a, the screw shaft is screwed into the nut 20, and the screw shaft end is screwed in until it comes into contact with the peripheral surface of the pier 8. The distance d between the reinforcing frame 13a and the reinforcing frame 13a is adjusted to be constant. This situation is as shown in FIG.

In this way, when all the reinforcing frames 13a are fixed to the peripheral surface of the pier 8, the joint portion of the reinforcing frame 13a is welded with a joint on the back surface to form a reinforcing frame tube having a substantially oval cross section. In the embodiment, the reinforcing frame 13a is formed in a tubular body stacked in two upper and lower stages. This situation is as shown in FIG.
In this case, since the reinforcing frame 13a is fixed at a fixed position outside the pier 8 by the first and second support bolts 17 and 21, deformation of the reinforcing frame 13a due to the welding is prevented.

After the reinforcement frame 13a is welded, the first and second support bolts 17 and 21 are removed, and one of the through holes 18 is filled with a seal material 24 and closed.
Then, a locking bracket (not shown) is attached to the outer peripheral surface of the reinforcing frame 13a, and the chain block locking tool (not shown) is hung on the bracket, lifted, and moved above the bridge pier 8. Hang and put. This situation is as shown in FIGS.
Thereafter, the scaffold 28 is temporarily removed, the excavator 31 such as a backhoe is moved to the work yard 25, and the backhoe 31 is driven to construct an underwater excavator.

The underwater excavator excavates the work yard 25 around the base of the pier 8 and a part of Nakasu 4 by the backhoe 31, and forms a substantially inverted truncated cone-shaped excavation hole 32 from the pier 8 to the footing 7. Form.
The excavation along the open opening edge of the aperture D ₂ of the wellbore 32, carried by moving the backhoe 31, the opening diameter D ₂ off - formed slightly larger than the outer diameter of the quenching 7, drilling The bottom diameter D ₁ of the hole 32 is formed to be smaller than the outer diameter of the footing 7 (D ₁ <D ₂ ). This situation is as shown in FIG.

Said bottom diameter D ₁ is off - located in the upper end surface of the quenching 7, said bottom diameter D ₁ is in standing water 33, such as spring water staying in the wellbore 32, and the minimum working space divers 34 - to scan Set to the corresponding diameter. In other words, the gradient of the slope face 32a of the wellbore 32 on the basis of the bottom diameter D _1, so that the opening diameter D ₂ is set.

Gradient of slope 32a of the wellbore 32, i.e. the horizontal distance H between the opening edge and a bottom diameter D ₁ of the wellbore 32, the ratio H / h between the depth h of the wellbore 32, approximately 1 in embodiment / 2-1 / 1 and formed, achieving steep or diameter of the opening diameter D ₂ of the wellbore 32 of slope face 32a, the working ya - working to facilitate the gasification and drilling - de 25 a small space ing.

Thus, even if the slope 32a is steep, the slope 32a is stabilized by the water pressure of the stagnant water 33 and can be prevented from collapsing. Can be made compact.
In this case, in the embodiment, the large sandbag 35 for preventing the collapse is provided on the slope 32a, but the slope 32a is stable as described above, so the sandbag 35 is not indispensable. Even when the sandbag 35 is installed, the quantity can be significantly reduced by downsizing the excavation hole 32 or shortening the length of the slope 32a.

  The underwater excavator is excavated by the backhoe 31 and manually excavated by the diver 34. The excavation by the diver 34 is difficult to be excavated by the backhoe 31 and may be damaged. -It is carried out by manually excavating around Ching 7, and the fine earth and sand at that time is sucked with an air lift.

  In the air lift or excavation, one end of a drain pipe (not shown) is immersed in the accumulated water 33, the other end is piped outside the excavation hole 32, compressed air is supplied into the drain pipe, and the one end is Blow off and peel off residual sediment such as piers 8 etc., and discharge this fine sediment together with stagnant water 33

  As described above, since the underwater excavator is excavated by the backhoe 31, a conventional temporary earth retaining work or temporary material using a steel sheet pile or the like is not required, and construction is possible regardless of the on-site geological conditions. Therefore, the construction can be facilitated, the construction period can be shortened, and the construction cost can be reduced.

  Moreover, since the excavation by the backhoe 31 is performed by constantly stagnating the accumulated water 33 by the spring water in the excavation hole 32, the slope 32a is stabilized by the water pressure of the retained water 33, and there is no fear of the slope 32a collapsing. Therefore, excavation work can be carried out smoothly and stably, and the slope of the slope 32a can be realized, the excavation space can be made compact and the excavation work can be shortened, and it is suitable for construction where the river width is narrow. It will be something.

Thus, the underwater excavation work is completed, and the diver 34 cleans the peripheral surfaces of the pier 8 and the footing 7 by brushing, and then the next underground reinforcement frame dropping work is performed.
In the underground reinforcement frame dropping work, the plurality of chain blocks are lowered stepwise, the suspended tubular reinforcement frame 13a is slowly lowered into the stagnant water 33, and the lower end of the reinforcement frame 13a is lowered. -Land on the upper surface of the ching 7 and project its upper end from the surface of the staying water 33. This situation is as shown in FIG.

  The work is performed by, for example, several operators boarding a simple work boat and the operators sharing and operating the chain block. At this time, since the first support bolts 17 and 21 are removed in advance, the reinforcing frame 13a is smoothly and stably lowered, and the peripheral surface of the pier 8 is not damaged.

  After dropping the reinforcing frame 13a into the stagnant water 33, the diver 34 dives and removes the second support bolt 21 that has been removed and inserted into the through hole 18, and the screw shaft is screwed into the nut 20, for example, air-impact. Using a wrench, the end of the screw shaft is brought into contact with the peripheral surface of the pier 8, and the distance d between the reinforcing frame 13a and the pier 8 is adjusted to be constant. This situation is as shown in FIGS.

  Thus, after the reinforcing frame 13a is set up on the footing 7 so as to surround the bridge pier 8, a civil engineering sheet (not shown) is arranged over the upper surface of the footing 7 outside the lower end of the reinforcing frame 13a. Then, this is held by a sandbag (not shown) to close the gap between the lower end of the reinforcing frame 13a and the upper surface of the footing 7 and prepare for the next backfilling work.

In the backfilling work, the excavated earth and sand 36 is put into the excavation hole 32 by the backhoe 31, and the outside of the reinforcing frame 13a is backfilled with the earth and sand 36. This situation is as shown in FIG. 5 (c) and FIG.
In this case, even after the backfilling, the stagnant water 33 remains between the reinforcing frame 13a and the pier 8, and even if the stagnant water 33 is pumped out by a pump (not shown), the spring water immediately becomes stagnant. And the same situation. That is, it is impossible to make the space between the reinforcing frame 13a and the pier 8 dry, and the next mortar filling work will be performed based on this situation.

After the backfilling, the inside of the space between the reinforcing frame 13a and the pier 8 is internally cleaned, and the presence / absence of sediment in the interior is confirmed by the cleaning, and at the same time, the possibility of the interval d is confirmed.
That is, the sedimentation of the earth and sand forms a deficient portion of the filling mortar, which has a significant effect on the support strength of the reinforcing frame 13a, and the possibility of the interval is related to the thickness of the filling mortar. By having a significant influence on the support strength of 13a.

The internal cleaning is performed by supplying fresh water to the stagnant water 33 remaining between the reinforcing frame 13a and the pier 8 with an underwater pump (not shown), and depending on the turbid state of the reflux water, Check for accumulation.
In addition, when supplying fresh water with the submersible pump, a long water supply pipe (outer diameter of about 3 cm) connected to the pump is inserted between the reinforcing frame 13a and the pier 8, and the interval depends on the insertion state. Confirm whether or not d is acceptable.

  In the mortar filling work, the concrete mixer truck 37 containing the underwater non-separable mortar 12 is moved back to the site, and the mortar 12 is discharged and filled between the reinforcing frame 13a and the pier 8. This situation is as shown in FIG.

  The underwater non-separable mortar 12 has the same compressive strength as that of the pier 8, has an ultimate strain of 3000 μm or more, does not bleed, and has good underwater inseparability. In addition, the sample was prepared by adjusting the addition amount of the thickener as an underwater non-separating material based on high flow mortar after satisfying quality conditions such as underwater strength ratio of 0.6 or more. Therefore, those having appropriate inseparability in water and fluidity were experimentally confirmed and adopted.

  That is, the thickener which is an underwater non-separating material based on the mortar using the high flow mortar admixture used as the non-separable underwater mortar 12 for the injection of the narrow portion of the steel-rolled seismic reinforcement From the sample in which the amount added was adjusted, the one with the composition of 3 in the table of FIG. 7 having the best balance between water inseparability and fluidity was used.

  The adopted underwater non-separable mortar 12 is guided from the concrete mixer wheel 37 to a long casting pipe, and the casting pipe is disposed at a symmetrical position on the bridge pier 8, and each of them is provided with a reinforcing frame. 13a and the bridge pier 8 are inserted, and the discharge port is placed approximately 50 mm above the upper surface of the footing 7 and is placed, and the discharge port is immersed in the deposited mortar for filling. To do.

In this way, the underwater non-separable mortar 12 is driven into the staying water 33 between the reinforcing frame 13 a and the pier 8 from the two placing pipes, and flows without being separated into the staying water 33. Wrap around and deposit and cure uniformly with a uniform width. At that time, the reinforcing frame 13a receives the earth pressure of the earth and sand 36 from the outside, so that the mortar 12 can be densely filled with a uniform thickness compared with the filling of the concrete, and the stagnation accompanying the filling is prevented. This situation is as shown in FIG.
Thus, the underwater non-separable mortar 12 is filled, and after the mortar 12 is cured, the ground part reinforcing frame assembly work is performed.

  The ground part reinforcing frame assembler assembles the scaffold 28 on the backfilled sand and sand 36, lifts the ground part reinforcing frame 13b by the heavy machine 30, moves it to a predetermined position of the pier 8, and It is placed on the protruding end of the reinforcing frame 13a and temporarily assembled.

When the reinforcing frame 13b is assembled, the first support bolt 17 is inserted into the through hole 18 from the outside of the reinforcing frame 13b, the screw shaft is screwed into the screw hole 16 of the concrete anchor 15, and the head portion 17a is passed through. Engage with the opening edge of the hole 18.
Further, the second support bolt 23 is inserted into the through-hole 19 from the outside of the reinforcing frame 13 a, the screw shaft is screwed into the nut 20, and the screw shaft end is screwed in until it comes into contact with the peripheral surface of the bridge pier 8. And the interval d between the reinforcing frames 13a is adjusted to be constant. This situation is as shown in FIG.

  In this way, when all the reinforcing frames 13b are fixed to the peripheral surface of the pier 8, the joint portion of the reinforcing frame 13b is welded with a joint on the back surface to form a reinforcing frame tube having a substantially oval cross section. In the embodiment, the reinforcing frame tube is formed in upper and lower 3.5 steps. This situation is as shown in FIG.

Thereafter, ordinary mortar is filled between the reinforcing frame 13b and the peripheral surface of the pier 8 with the first and second support bolts 17 and 23 screwed in.
At that time, the filling of the mortar is performed by moving the concrete mixer wheel 37 containing the mortar, inserting the placing pipe between the reinforcing frame 13b and the bridge pier 8 and placing it by the above-described tremi-pipe method.

In this case, the reinforcing frame 13b is connected to the pier 8 by the first support bolts 17, and the interval d is held by the second support bolts 23. Therefore, the mortar is more densely packed with a uniform thickness than the concrete filling. In addition, it is possible to prevent stagnation associated with filling.
Then, after the mortar is cured, the surface of the reinforcing frame 13b is painted, and a settling removal work is performed.

The segregation removal work dismantles and removes the scaffold 28, removes the work yard 25, removes the inflow path 27 in the river, and dams the river flow 6; The large sandbag 26 that formed the flow change is removed, the original flow of the river flow 6 is restored, and the state before construction of the river 1 is restored. This situation is as shown in FIG.
The pier 8 thus seismically reinforced is as shown in FIG. 1, and the reinforcing frames 13 a and 13 b are coated on the peripheral surfaces of the underground portion and the ground portion to counter the shear failure of the pier 8.

  As described above, the present invention adopts a settling or river approach path 27 in place of the temporary pier and the temporary earth retaining work, and the temporary construction is reduced by the continuous water cut-off work. The construction period of the temporary construction by the conventional temporary pier or temporary earth retaining is about ½, and the removal work in the present invention consists of the removal of the scaffold 28, the work yard 25, and the sandbag 26. Since it can be easily performed by the heavy machinery 31 and does not require removal of a large temporary object or equipment as in the conventional case, the construction period of the removal work can be reduced as compared with the conventional method. In addition, it seems that the construction period of the main body construction except the temporary construction and the removal construction is not so different from the conventional seismic reinforcement.

Therefore, it is estimated that it takes 2 months and a half for the present invention and 4 months for the conventional method, and the present invention is about a month and a half compared to the conventional method. It has been confirmed that the construction cost can be reduced.
Therefore, it has been confirmed that the present invention can be applied to the seismic reinforcement of the river pier with a narrow river width and a shallow water depth in accordance with the restriction due to the drought period construction.

  In addition, as a result of reducing the number of temporary structures by continuous water digging instead of the conventional construction of temporary earth retaining and auger combined use at the time of straight steel sheet pile placement, the present invention reduces the number of temporary structures per pier. A trial calculation of the seismic retrofitting cost has confirmed that the conventional cost can be considerably reduced.

In addition, although the above-mentioned embodiment is applied to the earthquake-proof reinforcement of the river pier 8 standing in the middle state 4, it is applicable also to the pier 8 standing in the river with comparatively shallow water depth.
In that case, after changing the flow of the river around the pier 8 and securing the work yard 25, the above-described construction method may be applied. Therefore, the present invention is not limited to rivers, and can also be applied to seismic reinforcement of bridge piers, columns, and columnar bodies erected on shallow coasts and lakes.

The method of reinforcing a columnar structure such as a pier of the present invention is to change the flow of a river to secure a working yard around the pier, and to easily assemble a reinforcement frame in the ground above the pier, While lifting, the base of the pier is always excavated in a water-spilled state to realize construction that eliminates spring water measures regardless of geological conditions, stabilizes the slope of the excavation hole, and excavation space and work space. -The size of the mortar can be reduced, and after excavation, the underground frame is dropped into the water, and after the excavation part is backfilled, an underwater non-separable mortar is filled between the bridge pier and the underground frame, and the mortar is dense in the water In addition to being able to be filled reliably, the use of temporary objects can be greatly reduced, the construction period can be shortened, and the construction cost can be reduced. For example, it is suitable for seismic reinforcement of a river pier with a narrow river width and a relatively shallow water depth.

It is a front view which shows the bridge pier which carried out earthquake-proof reinforcement by this invention. It is a side view of FIG. FIG. 1A is a cross-sectional view of FIG. FIG. 2B is an enlarged sectional view showing a part of FIG. Sectional drawing which expands and shows the principal part of the assembly condition of the underground part and ground part reinforcement frame applied to this invention, FIG. (A) shows the assembly condition of the reinforcement frame of an underground part, FIG. The assembly situation of the reinforcement frame of the part is shown.

It is sectional drawing which expands and shows the construction state of the underground part reinforcement frame applied to this invention, a figure (a) at the time of suspension, a figure (b) immediately after dropping in water, a figure (c) at the time of backfilling, a figure (D) has shown the condition at the time of the underwater non-separable mortar filling. It is a construction flow showing an embodiment of the present invention. It is a table | surface which shows the laboratory test result of five samples about the mixing | blending of the underwater non-separation type mortar applied to this invention.

It is a table | surface which shows the test result of two samples about the placement method of the underwater non-separation type mortar applied to this invention. It is a front view which shows the state of the construction step (0) of this invention, and has shown the condition of the river and pier before construction. It is a front view which shows the state of the construction step (1) of this invention, and has shown the condition of a change work and a work yard work.

It is a front view which shows the state of the construction step (2) of this invention, and has shown the condition of the underground part reinforcement frame assembly worker. It is the front view which shows the state of the construction step (3) of this invention, and has shown the condition of the underwater excavator. It is a front view which shows the state of the construction step (4) of this invention, and has shown the condition of underground part reinforcement frame dropping work.

The front view which shows the state of the construction step (5) of this invention has shown the condition of the backfilling. It is a front view which shows the state of the construction step (6) of this invention, and has shown the condition of the underground part reinforcement frame mortar filling construction. It is a front view which shows the state of the construction step (7) of this invention, and has shown the condition of the ground part reinforcement frame assembly worker. It is the front view which shows the state of the construction step (8) of this invention, and has shown the condition of seduction removal construction.

Explanation of symbols

1 River 7 Foundation (Footing)
8 Columnar structures (piers)
12 Filler (Unseparable underwater mortar)
13a Ground reinforcement frame 13b Ground reinforcement frame

17 First Support Bolt 21 Second Support Bolt 25 Work Yard 31 Heavy Equipment (Backhoe)
32 drilling hole 32a slope

33 Stagnant water 34 Diver

Claims (16)

Assemble the underground or underwater reinforcement frame around the circumference of the columnar structure such as a pier standing on the foundation in the ground or underwater ground, and suspend the assembled reinforcement frame above the columnar structure , when installing the reinforcing frame, the reinforcing construction method of the reinforcing frame lowered and placed in the ground or water, the columnar structure of pier or the like for filling a filler between the reinforcing frame and the columnar structures installed In this case, the periphery of the base portion of the columnar structure standing on the foundation in the spring ground or underwater ground is embanked, and a work yard capable of excavating the periphery of the base is created, and the columnar structure on the work yard is formed. Enclose the reinforcement frame in the ground by surrounding the object, move the assembled reinforcement frame above the columnar structure and hang it, then excavate the ground from the periphery of the base of the columnar structure to the foundation, while construction by retained the accumulated water in the wellbore, the complement to wellbore after drilling Placed in the water by lowering the frame, backfill wellbore after installation of the reinforcing frame, the reinforcing of the columnar structures pier etc., characterized by filling a filler between the reinforcing frame and the columnar structure Construction method. The method for reinforcing a columnar structure such as a bridge pier according to claim 1 , wherein the staying water is spring water from a river or the sea or a lake . The method for reinforcing a columnar structure such as a bridge pier according to claim 1 , wherein the excavation hole has an inverted truncated cone shape . The method of reinforcing a columnar structure such as a pier according to claim 1 , wherein the excavation is performed by a heavy machine installed on a work yard and a diver . The method for reinforcing a columnar structure such as a bridge pier according to claim 1 or 3, wherein the slope of the excavation hole has a steep slope with a ratio of a horizontal distance to a vertical distance of 1 to 2 to 1 to 1 . A through hole is formed in the vertical position of each reinforcing frame in the underground portion, a nut is fixed to the inner edge of one through hole, and a screw hole is provided at a corresponding position of the columnar structure facing the other through hole. A concrete anchor is embedded, the first support bolt is inserted into the other through hole, the screw shaft of the bolt is screwed into the screw hole of the concrete anchor, and each reinforcing frame is separated from the peripheral surface of the columnar structure. The second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut so as to come into contact with the peripheral surface of the columnar structure, thereby adjusting the interval between each reinforcing frame and the columnar structure. and, a reinforcing method of a columnar structure of the pier or the like of claim 1, wherein assembling by welding joint portions of the reinforcing frame adjacent. After the welding, the first and second support bolt removed from the reinforcing frame, the reinforcing method of the columnar structure such as a pier of the reinforcing frame columnar structure move and suspended under gel according to claim 6 upward. After dropping the reinforcing frame in the underground portion into the accumulated water in the excavation hole, the second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut to contact the peripheral surface of the columnar structure. The method for reinforcing a columnar structure such as a bridge pier according to claim 6 , wherein a distance between the reinforcing frame and the columnar structure is adjusted . The method for reinforcing a columnar structure such as a bridge pier according to claim 8 , wherein a diver adjusts the interval between the reinforcing frame and the columnar structure in a stagnant excavation hole . After adjusting the gap before Kiho strong frame and the columnar structures, backfill the wellbore, after returning Me該埋, while the water supply to clean fresh water between the reinforcing frame and the columnar structures of the reflux water The method for reinforcing a columnar structure such as a bridge pier according to claim 8, which supervises the confirmation of the contamination state and the adjustment of the interval by a water supply pipe. The method for reinforcing a columnar structure such as a bridge pier according to claim 10 , wherein after the backfilling, the submerged water between the reinforcing frame and the columnar structure is filled with an underwater non-separable mortar by positioning a filling pipe immediately above the bottom. . The method for reinforcing columnar structures such as bridge piers according to claim 11 , wherein 1.0 to 2.0 kg / m ³ of an underwater non-separating agent is added to the underwater non-separable mortar . 12. The pier according to claim 11 , wherein after the mortar filling, on the solidified mortar and the backfilling member, the ground frame reinforcing frame surrounds the peripheral surface of the columnar structure and is assembled on the ground reinforcing frame protruding above the ground. Reinforcement method for columnar structures such as A through hole is formed in the vertical position of each reinforcing frame of the ground portion, a nut is fixed to the inner edge of one through hole, and a screw hole is provided at a corresponding position of the columnar structure facing the other through hole. A concrete anchor is embedded, the first support bolt is inserted into the other through hole, the screw shaft is screwed into the screw hole of the concrete anchor, and each reinforcing frame is separated from the peripheral surface of the columnar structure. The second support bolt is inserted into the one through hole, and the screw shaft is screwed into the nut to come into contact with the peripheral surface of the columnar structure to adjust the interval between each reinforcing frame and the columnar structure. The method for reinforcing columnar structures such as bridge piers according to claim 1 or 13 , wherein the joint portions of adjacent reinforcing frames are assembled by welding . 2. The first and second support bolts are attached to the reinforcing frames of the ground portion, and a filler is filled between the reinforcing frame and the columnar structure with a filling pipe positioned immediately above the bottom. Method for reinforcing columnar structures such as bridge piers according to 4 . Retrofit for and removing the de columnar structures pier like according to claim 15 to recover the situation before installation - the rear filling charge Hamazai, the working Ya.

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