JP5771824B2 - Precast flexible box culvert and its construction method - Google Patents

Description

  The present invention relates to a precast flexible box culvert and its construction method, and to a structure such as a newly supported or existing rigid support structure such as a pipe for intake and drainage installed across a river embankment and supported by a pile foundation or the like. It is connected or added, and it is in a raised state that assumes the amount of settlement in advance, so that the cross-sectional area of the channel can be secured even if uneven settlement occurs, so that the reaction force at the time of raising can be reduced It is a thing.

For intake and drainage using the river, a pipe for intake and drainage is installed across the river embankment. This soot pipe is configured by continuously connecting box culverts made of, for example, PC concrete.

When installing such dredgers across the embankment, the dredgers under the embankment are usually supported by a pile foundation, etc., and the ground adjacent to the embankment is It is often soft ground.
When the soot pipe sinks unevenly on such soft ground, one of the two connected box culverts that make up the soot pipe sinks with respect to the other, and the flow path is effective between the two. A difference in cross-sectional area may occur, and it may not be possible to secure a necessary flow rate of water.

Therefore, unequal subsidence can be prevented by preliminarily raising the pipes installed on the soft ground to be connected to or added to the new or existing rigid support structure pipes for water intake and drainage. Even if it occurs, it has been proposed to reduce the difference in effective cross-sectional area of the flow path between the two (see Patent Document 1).
In this precast flexible box culvert 1, as shown in FIGS. 5 and 6, the precast flexible box culvert 1 is brought into a raised state by the following steps (a) to (u). In the figure, the left side is the raising side (sinking side).
(A) The ceiling plate 2a of the first precast box culvert 2 having a rigid support structure is thicker than the ceiling plate 3a of the second precast box culvert 3 on the sinking side installed on the soft ground by a predetermined thickness. On the contrary, the floor plates 2b and 3b are made thicker by a predetermined thickness than the floor plate 2b of the first precast box culvert 2 of the first precast box culvert 2 on the rigid support structure side. Keep it like that.
(Ii) The first and second precast box culverts 2 and 3 are disposed adjacent to each other so that the inner peripheral surfaces 2c and 3c form the same plane, and the adjacent precast box culverts 2 and 3 are flexibly fixed. Connect with water joint 4.
(Iii) The second precast box culvert 3 on the sinking side is lifted so that the upper surface and the lower surfaces 2d and 3d of the first and second precast box culverts 2 and 3 form the same plane. The first and second precast box culverts 2 and 3 are fixed to each other by fixing members 5 on both sides.
By installing the precast box culvert 3 on the subsidence side on the soft ground in a raised state and removing the fixing member 5, even if unequal subsidence occurs, a large difference occurs in the effective cross-sectional area of the flow path. It becomes possible to prevent this.

JP 2004-76451 A

In such a precast flexible box culvert 1, after attaching the flexible waterproof joint 4 to the inner peripheral surfaces 2 c and 3 c which are the same plane between the adjacent precast box culverts 2 and 3, When raised, the expansion / contraction part 4a of the flexible water-stop joint 4 is displaced corresponding to the raised amount and swells greatly inward, so as shown in FIG. The swell preventive cloth 6 in which the attachment holes are formed in accordance with is attached to the upper and lower sides and both sides of the inner circumference of the precast box culverts 2 and 3, respectively.
However, as shown in FIG. 7 (b), the deformation of the flexible waterproof joint 4 is suppressed by the swell prevention cloth 6, and the deformation reaction force is large. When one precast box culvert 3 is lifted, the other There is a problem that it is difficult or impossible to secure a predetermined raised amount, for example, the precast box culvert 2 is lifted and needs to be loaded on the other precast box culvert 2 each time.
In particular, when a large-sized precast box culvert that requires a lifting work after being transported to a construction site is used, the problem becomes even greater.

  The present invention has been made in view of the above-mentioned problems of the prior art. A precast flexible box culvert capable of reducing a reaction force during raising and easily securing a predetermined raising amount and its construction. It is intended to provide a law.

The precast flexible box culvert according to claim 1 of the present invention that solves the above-described problems of the prior art is a precast flexible box culvert that is connected to a short cylindrical flexible waterproof joint between adjacent precast box culverts, and is one of the precasts that becomes the sinking side. In the precast flexible box culvert in which the box culvert is raised and held in advance, the first bulge prevention presser member for pressing the bulge of the flexible water-proof joint on the side wall portion between the adjacent precast box culverts is While forming a strip shape with a bolt hole that matches the arrangement of a pair of anchor bolts between adjacent precast box culverts, the first bulge-preventing pressing member is attached with an interval between adjacent anchor bolts, One of the adjacent precast box culverts is raised. A second bulge prevention presser member having a plurality of pairs of bolt holes in accordance with the arrangement of the anchor bolts on the side wall is formed in a substantially parallelogram shape, and the second bulge prevention presser member is raised after the raising. The first bulge prevention pressing member is attached to an anchor bolt in an overlapping manner, and the first and second bulging prevention pressing members are separately attached before and after raising .

  A precast flexible box culvert according to a second aspect of the present invention is the precast flexible box culvert according to the second aspect of the present invention. Thickness corresponding to the sinking amount than the ceiling part of the culvert, and the floor part of the precast box culvert on the sinking side is thicker than the floor part of the precast box culvert on the non-sinking side only by the thickness corresponding to the sinking amount. In addition to being thick, the upper and lower surfaces of the adjacent precast box culverts are arranged so as to form the same plane in the raised state.

The construction method of the precast flexible box culvert according to claim 3 of the present invention is such that a short cylindrical flexible waterproof joint is connected between joint portions of adjacent precast box culverts, and one of the precast box culverts on the subsidence side is connected. In the construction method of the precast flexible box culvert that holds the pre-lifted state in advance, the first bulge prevention presser member that presses the bulge of the flexible waterproof joint on the side wall portion between the adjacent precast box culvert joints. The first bulge-preventing presser member is formed between the adjacent anchor bolts by forming a strip shape with a bolt hole that matches the arrangement of the pair of anchor bolts between adjacent precast box culverts before raising. Install with a gap between the adjacent precast box culverts. After the second bulge prevention pressing member having a plurality of pairs of bolt holes matched to the arrangement of the anchor bolts on the side wall portion in a state of being in a substantially parallelogram shape and being raised, the second attached to the anchor bolt overlapping the prevention pressing member bulge in the first bulge preventing the pressing member, and the mounting so that divides the first and second bulge-preventing pressing member after raising before and the additional It is characterized by this.

  According to a fourth aspect of the present invention, the precast flexible box culvert is constructed in addition to the structure of the third aspect, wherein one end edge portion of the second bulge-preventing presser member is connected to the first bulge-preventive presser. After being overlapped and attached to one end edge of the member, it is raised, and then the other end edge of the second bulge prevention press member is overlapped with the first bulge prevention press member and attached to the anchor bolt. It is characterized by that.

  The construction method of the precast flexible box culvert according to claim 5 of the present invention, in addition to the configuration according to claim 3 or 4, in addition, between the joint portions of the adjacent precast box culverts, on the end face of one precast box culvert. While the joint material is bonded, the end surface of the joint material on the anti-adhesion side is coated with biodegradable grease, and then the short tubular flexible water-stop joint is connected. To do.

The construction method of the precast flexible box culvert according to claim 6 of the present invention is the ceiling according to any one of claims 3 to 5, in addition to the precast box culvert on the non-sinking side among the adjacent precast box culverts. The portion is thicker than the ceiling portion of the precast box culvert on the subsidence side by a thickness corresponding to the amount of subsidence, and the floor portion of the precast box culvert on the subsidence side is lower than the floor portion of the precast box culvert on the non-sink side Also, the thickness corresponding to the subsidence amount is formed thick, and the ceiling and floor between adjacent precast box culverts are arranged so that they form the same plane, and then between the joints of these precast box culverts. The flexible waterproof joint is connected, and then the adjacent precast box Upper and lower surfaces of Albert is raised so as to form a same plane, it is characterized in that it has to be fixed and held by a fixing metal fitting raised state.
In addition, raising is not limited to the case where one of the adjacent precast box culverts is lifted, but includes both cases where one of the adjacent precast box culverts is relatively lifted by lowering the other.

According to the precast flexible box culvert of the first aspect of the present invention, a short cylindrical flexible waterproof joint is connected between adjacent precast box culverts, and one of the precast box culverts on the sinking side is raised beforehand. In the precast flexible box culvert held by the first pre-press box culvert between the adjacent pre-cast box culverts, the first bulge prevention press member for pressing the bulge of the flexible waterproof joint on the side wall between the adjacent pre-cast box culverts The first pre-press box culvert is formed in a strip shape having a bolt hole corresponding to the arrangement of the pair of anchor bolts, and the first bulge-preventing pressing member is attached with a space between adjacent anchor bolts. The anchor bolt on the side wall in a state in which one side is raised The second bulge prevention presser member having a plurality of bolt holes matched to the arrangement of the bolts is formed in a substantially parallelogram shape, and the second bulge prevention presser member is raised after the first bulge prevention. Since the first and second bulge-preventing pressing members are mounted separately before and after raising, a pair of bolt holes are provided before raising. By attaching the strip-shaped first bulge-preventing presser members at intervals such as every other anchor bolt, the reaction force accompanying the increase in height can be reduced, and at the same time, the bulge of the flexible waterproof joint can be suppressed. weight to, after raising the substantially parallelogram shaped second bulge preventing pressing member bolt holes and a plurality of pairs formed to match the sequence of the anchor bolt raised state preventing the pressing member first bulge By so attaching Te, it is possible to suppress the bulge of the subsequent flexible sealing member, such as after construction.
As a result, the first and second bulge-preventing presser members can be attached separately before raising and after raising so that the attachment can be simplified and the raising reaction force can be reduced. This makes it easy to apply to a large precast box culvert.

  According to the precast flexible box culvert according to claim 2 of the present invention, the ceiling portion of the precast box culvert on the non-sinking side among the adjacent precast box culverts sinks more than the ceiling portion of the precast box culvert on the sinking side. The thickness of the precast box culvert on the subsidence side is made thicker than the floor of the precast box culvert on the non-sink side, and the thickness corresponding to the subsidence amount is increased. In the state, the upper and lower surfaces of the adjacent precast box culverts are arranged so as to form the same plane. Therefore, the thickness of the ceiling portion and the floor portion of the adjacent precast box culverts is changed according to the amount of settlement. Secure the effective cross-sectional area of the channel more reliably even if it sinks from the state It is possible, can be easily raised.

According to the construction method of the precast flexible box culvert according to claim 3 of the present invention, the short cylindrical flexible waterproof joint is connected between the joint portions of the adjacent precast box culverts, and the one precast which becomes the subsidence side In the construction method of the precast flexible box culvert that holds the box culvert in a previously raised state, a first bulge prevention presser that holds the bulge of the flexible waterproof joint on the side wall between the adjacent precast box culvert joints. The member is formed in a strip shape having a bolt hole that matches the arrangement of a pair of anchor bolts between adjacent precast box culverts before being raised, and the first bulge-preventing pressing member is positioned between adjacent anchor bolts. And attach one side between the adjacent precast box culverts. The second bulge-preventing pressing member having a plurality of pairs of bolt holes that match the arrangement of the anchor bolts on the side wall portion in the raised state is formed in a substantially parallelogram shape, attached to the anchor bolt 2 the bulge preventing pressing member superimposed on said first bulge preventing the pressing member, the mounting so that divides the first and second bulge-preventing pressing member after raising before and the additional Therefore, before raising, by forming a strip-shaped first bulge prevention presser member with a pair of bolt holes and attaching every other anchor bolt, etc. In addition, it is possible to reduce the reaction force associated with the increase in height and to suppress the bulge of the flexible waterproof joint, and after the increase in height, a plurality of bolt holes that match the arrangement of the raised anchor bolts are formed in a substantially flat shape. By forming a second quadrilateral-shaped second bulge-preventing presser member and attaching it to the first bulge-preventive presser member, the subsequent bulge of the flexible water-proof member, such as after construction, can be suppressed. Will be able to.
As a result, the first and second bulge-preventing presser members can be attached separately before raising and after raising so that the attachment can be simplified and the raising reaction force can be reduced. This makes it easy to apply to a large precast box culvert.

  According to the construction method of the precast flexible box culvert of the fourth aspect of the present invention, the one end edge of the second bulge prevention press member is connected to the one end edge of the first bulge prevention press member. After being attached in piles, it is raised, and then the other end edge of the second bulge prevention press member is attached to the anchor bolt so as to overlap the first bulge prevention press member. When attaching the bulge prevention presser member, attach one end edge of the second bulge prevention presser member and attach it to the anchor bolt. Can be reduced.

  According to the construction method of the precast flexible box culvert according to claim 5 of the present invention, the joint material is adhered to the end face of one precast box culvert between the joint portions of the adjacent precast box culverts, while being anti-adhesive. Since the biodegradable grease is applied to the end surface of the joint material on the side, the short cylindrical flexible water-stopping joint is connected to the end surface of the joint material. In addition to the reduction by using the first and second bulge prevention pressing members, the raising reaction force can be further reduced.

  According to the construction method of the precast flexible box culvert according to claim 6 of the present invention, the ceiling portion of the precast box culvert on the non-sink side among the adjacent precast box culverts is the ceiling portion of the precast box culvert on the sink side. The floor portion of the precast box culvert on the sinking side is made thicker than the floor portion of the precast box culvert on the non-sinking side by a thickness corresponding to the sinking amount. In addition, after arranging the ceiling and floor between adjacent precast box culverts to form the same plane, the flexible waterproof joint is connected between joints of these precast box culverts, The upper and lower surfaces of adjacent precast box culverts are flush Since the raised state is raised and the raised state is fixed and held by the fixing bracket, the thickness of the ceiling and floor of the adjacent precast box culvert is changed according to the amount of subsidence, so that it sinks from the raised state. Even in this case, the effective cross-sectional area of the flow path can be secured more reliably, and the raised state can be easily maintained by connecting and fixing with the fixing bracket.

1A is a front view and a plan view of a first bulge-preventing presser member, and FIG. 2B is a second bulge-preventing presser. It is the front view and top view of a member. 1A is a front view of a mounting state of a first bulge prevention pressing member, and FIG. 2B is an enlarged front view of a state after raising. FIG. According to one embodiment of the precast flexible box culvert and its construction method of the present invention, (a) is a cross-sectional view of the mounting state of the second bulge-preventing pressing member in the floor (or ceiling) (b). FIG. 3 is a cross-sectional view of the state after raising. It is an enlarged front view of the attachment state of the 2nd bulge prevention press member concerning one embodiment of the precast flexible box culvert of this invention and its construction method. It is a fragmentary sectional view of the state before the raising concerning one embodiment of the precast flexible box culvert of this invention and its construction method. It is a fragmentary sectional view of the state after the raising concerning one embodiment of the precast flexible box culvert of this invention and its construction method. It is applied to a conventional precast flexible box culvert, (a) is a front view and a plan view of a bulge-preventing cloth, (b) is a cross-sectional view of the state after raising.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
This precast flexible box culvert 10 is used when adding to an existing box culvert that constitutes a dredging pipe under a dike having a rigid support structure such as a pile foundation, and one precast box culvert to be added. 2 is supported by a rigid structure such as a pile foundation, and the precast box culvert 3 adjacent to the precast box culvert 2 is connected to the precast box culvert 2 via a flexible waterproof joint 4 and is installed on the soft ground. Therefore, the precast box culvert 3 is the sinking side and the raising side.

In the first precast box culvert 2, as shown in FIG. 5, the thickness of the ceiling portion 2a corresponds to a predetermined thickness, for example, an assumed subsidence amount, than the ceiling portion 3a of the second precast box culvert 3. It is formed thick by a thickness Δh.
In addition, the floor portion 3b of the second precast box culvert 3 is formed thicker than the floor portion 2b of the first precast box culvert 2 by a predetermined thickness, for example, a thickness Δh corresponding to the assumed subsidence amount. It is.
Therefore, in the adjacent first and second precast box culverts 2 and 3, when the upper surface and the lower surfaces 2d and 3d, which are outer peripheral surfaces, are arranged so as to form the same plane, as shown in FIG. The ceiling part 3a and the floor part 3b of the second precast box culvert 3 are higher than the ceiling part 2a and the floor surface 2b of the first precast box culvert 2 by, for example, a thickness Δh corresponding to the amount of settlement.
On the other hand, in the adjacent first and second precast box culverts 2 and 3, when the inner peripheral surfaces 2c and 3c are arranged so as to form the same plane, as shown in FIG. The upper surface and the lower surface 3d, which are the outer peripheral surfaces of the box culvert 3, are lower than the upper surface and the lower surface 2d, which are the outer peripheral surfaces of the first precast box culvert 2, for example, by a thickness Δh corresponding to the amount of settlement.

Therefore, in this precast flexible box culvert 10, the inner peripheral surfaces 2c, 2c, 3c are arranged so that the inner peripheral surfaces 2c, 3c of the adjacent first and second precast box culverts 2, 3 form the same plane. The flexible waterproof joint 4 is connected to 3c, and then the second precast box culvert 3 on the sinking side is raised so that the upper and lower surfaces 2d and 3d as outer peripheral surfaces form the same plane. Then, this raised state is applied in a state where the fixing material 5 as a fixing metal fitting is attached and held.
Then, when the fixing material 5 is removed after construction, the second precast box culvert 3 sinks at a relatively early stage due to the soft ground, and the first and second precast box culverts 2 adjacent to each other due to the sinking. , 3 have a tendency to form the same plane, and the cross-sectional area of the flow path can be effectively secured when the estimated amount of settlement is reached.

A flexible waterproof joint 4 used in such a precast flexible box culvert 10 is formed into a short cylindrical shape made of a flexible material such as rubber or synthetic resin, as shown in FIG. A stretchable portion 4a is formed at the center portion on the inner side in the direction, and attachment portions 4b and 4c are formed at both ends thereof.
The flexible waterproof joint 4 is pressed against the anchor bolt 7 embedded in the stepped portions 2e and 3e formed at the inner peripheral ends of the first and second precast box culverts 2 and 3 adjacent to each other. It is attached by a washer and nut 9 through a plate 8.

When the flexible waterproof joint 4 is attached, a swell prevention pressing member is attached to suppress the bulging inward of the stretchable portion 4a.
Up to now, as the pressing member for preventing swelling, a swelling preventing cloth 6 in which a plurality of pairs of attachment holes are formed in advance according to the pitch of the anchor bolt as shown in FIG. When the flexible waterproof joint 4 is attached to the anchor bolt 7 on each of the upper and lower sides and both sides of the inner circumference of the inner periphery of the inner periphery of the presser plate, the flexible waterproof joint 4 is attached between the presser plates 8. However, with this bulge-preventing cloth 6, when the precast box culvert 3 is lifted and raised relative to the precast box culvert 2, or conversely, the precast box culvert 3 is relatively lifted by lowering the precast box culvert 2. When raising to a state, the raising reaction force is increased, and it may be difficult to ensure a predetermined amount of raising.

In this precast flexible box culvert 10, as a bulge-preventing pressing member, the side walls of the adjacent first and second precast box culverts 2 and 3 are different before and after raising the precast box culvert. A bulge prevention presser member is used, the bulge prevention presser member before being raised is a first bulge prevention presser member 11, and the bulge prevention presser member after being raised is a second bulge prevention presser member 2. Prepare the type.
In addition, for the ceiling portions 2a and 3a and the floor portions 2b and 3b of the adjacent first and second precast box culverts 2 and 3, a sheet-like bulge prevention cloth is used as a bulge prevention press member as before. 6 is used.

As shown in FIG. 1 (a), the first bulge prevention presser member 11 is made of, for example, synthetic fiber, and the inner peripheral surfaces 2c and 3c of the adjacent first and second precast box culverts 2 and 3 are formed. A strip shape (rectangular shape) formed at both ends with bolt holes 11a aligned with a pair of anchor bolts of the first and second precast box culverts 2 and 3 in a state where the flexible waterproof joint 4 is connected on the same plane. ).
The first bulge-preventing pressing member 11 is, for example, a two-ply synthetic resin fiber cloth. If the expansion / contraction part 4a of the flexible waterproof joint 4 can be prevented from excessively bulging inward, It is also possible that the strength is further increased as 3 plies or more, or the material is different.

As shown in FIGS. 1 (b) and 3 (a) (b), the second bulge prevention pressing member 12 is made of, for example, a synthetic fiber, and adjacent first and second precast box culverts 2, Matching the arrangement of multiple pairs of anchor bolts of the first and second precast box culverts 2 and 3 with the flexible water-stopping joint 4 connected so that the outer peripheral surfaces 2d and 3d of 3 are in the same plane. Bolt holes 12a are formed in a sheet shape formed at both ends, and approximately one Ω-shaped folded portion 12b is formed at the central portion in the width direction so as to straddle the folded portion 12b. A patch 12c is attached with an adhesive or the like.
The size of the second bulge-preventing pressing member 12 is such that the side walls of the adjacent first and second precast box culverts 2 and 3 can be handled by a single sheet, or is applied to a large precast box culvert. In some cases, a plurality of sheets may be used.

Next, a construction method of the precast flexible box culvert 10 using the first and second bulge-preventing pressing members 11 and 12 will be described.
The precast flexible box culvert 10 is constructed by attaching and connecting a flexible waterproof joint 4 between the adjacent first and second precast box culverts 2 and 3, and then attaching the second precast box culvert 3. It is construction until it keeps as a raised state, and the precast flexible box culvert 10 made into the raised state is installed similarly to the past.

(A) In the construction method of the precast flexible box culvert 10, the joint material 13 made of an annular foam rubber or the like is interposed on the opposing end surfaces (joint portions) of the adjacent first and second precast box culverts 2 and 3. Here, the joint material 13 is fixed to the end face of the second precast box culvert 3 with a rubber adhesive, and the biodegradable grease 14 is attached to the end face of the joint material 13 facing the end face of the first precast box culvert 2. Is applied.

(Ii) Thereafter, the first and second precast box culverts 2 and 3 face each other and are mounted on the fixed base and the lifting base, and the inner peripheral surface 2c of the adjacent first and second precast box culverts 2 and 3 , 3c are arranged so as to form the same plane.

(Iii) The flexible water-stop joint 4 on the inner peripheral surfaces 2c and 3c in a state where the inner peripheral surfaces 2c and 3c of the adjacent first and second precast box culverts 2 and 3 form the same plane. Are connected to the entire circumference, and the ceiling bolts 2a, 3a and the floors 2b, 3b are provided with the anti-swelling cloth 6 so far on the anchor bolt 7 so as to straddle the mounting portions 4b, 4c of the flexible waterproof joint 4. The clamp plate 8 is sandwiched and attached with a washer and a nut 9.
On the other hand, in the side wall portion where the inner peripheral surfaces 2c and 3c of the adjacent first and second precast box culverts 2 and 3 are coplanar, as shown in FIGS. At the same time that the attachment portions 4b and 4c of the anti-skid water joint 4 are attached to the anchor bolts 7 and 7, for example, the first bulge prevention presser member 11 is applied to every other pitch of the anchor bolts 7, and the presser plate is placed thereon. Apply 8 and tighten with washer and nut 9.

(E) Thereafter, the second precast box culvert 3 on the sinking side is raised so that the upper and lower surfaces 2d and 3d, which are outer peripheral surfaces thereof, form the same plane.
In this raising, the second precast box culvert 3 on the subsidence side is raised by lifting it with a jack or heavy equipment, or conversely, the weight or loading of the first precast box culvert 2 on the rigid support side is raised. For example, it is relatively raised by lowering it.
When the second precast box culvert 3 on the sinking side is lifted so as to be lifted, it is raised to the ceiling portions 2a, 3a and floor portions 2b, 3b of the adjacent first and second precast box culverts 2, 3. Although the corresponding level difference arises and the flexible waterproof joint 4 is deformed so as to be sheared, the first bulge prevention presser member 11 is formed in a strip shape, and every other pitch of the anchor bolt 7 is changed. Since it is attached, as shown in an enlarged view in FIG. 2B, each of the first bulge-preventing pressing members 11 is inclined so that no large reaction force is generated, and the reaction force accompanying the increase in height is reduced. As shown in FIG. 3 (b), the bulge of the flexible waterproof joint 4 that accompanies the first bulge prevention presser member 11 can be easily raised with a small force. It can be effectively suppressed.
Further, since the biodegradable grease 14 is applied between the joint material 13 and the first precast box culvert 2, the frictional resistance between them can be reduced, and the bulk can be raised with a smaller force.

(O) After the first and second precast box culverts 2 and 3 adjacent to each other are raised, the raised state is set to the first and second precast box culverts 2 and 2 adjacent to the fixing member 5 as a fixing bracket. 3 is attached to and held on the outer wall.

(Or) In parallel with this, the attachment portion 4b on one side of the flexible water blocking member 4 is fixed on the side wall portions of the inner peripheral surfaces 2c, 3c of the adjacent first and second precast box culverts 2, 3. The washer and nut 9 are loosened, the presser plate 8 is removed, the second bulge prevention presser member 12 is applied to the first bulge prevention presser member 11, and the first and second bulge prevention presser members 11 are placed. , 12, and the presser plate 8 is applied again and tightened with a washer and a nut 9, and the second bulge prevention presser member 12 is overlapped with the first bulge prevention presser member 11 on the opposite side in the same manner. Install (see FIG. 4).
Since such a second bulge-preventing pressing member 12 has a sheet shape in which bolt holes 12a are formed in accordance with the pitch of the anchor bolts 7 in the raised state, it can be easily attached as it is.
As a result, the precast flexible box culvert 10 in the raised state can be pressed by the second bulge-preventing pressing member 12 so as to press the bulge of the expansion / contraction part 4a of the flexible waterproof joint 4 as before. Can do.

  In the above-described embodiment, the first bulge prevention presser member 11 is attached before raising, and the second bulge prevention presser member 12 is attached after being raised. Only one side of the second bulge prevention presser member 12 is attached so as to overlap the bulge prevention presser member 11 and the opposite side of the second bulge prevention presser member 12 is raised to the first bulge prevention presser member. 11 can also be attached in a superposed manner, and the number of washer and nut 9 removals can be reduced, enabling efficient construction.

According to such a precast flexible box culvert 10 and its construction method, since the biodegradable grease 14 is applied to the end face of the joint material 13, the first precast box culvert 2 and the joint material 13 at the time of raising deformation are used. The dynamic friction generated on the contact surface can be reduced. For example, the amount of friction can be reduced to about ¼ compared to the conventional case, and the influence on the environment can be suppressed as much as possible.
In addition, by using the first bulge prevention presser member 11 before raising the height, when the side walls of the precast box culverts 2 and 3 are raised (shear deformation), the deformation resistance is reduced and the flexible waterproof joint 4 is used. Twisting and bulging can be minimized, and by providing a slack amount that does not interfere (restrain) the deformation of the flexible waterproof joint 4, The displacement reaction force can be reduced.
Further, after the raising (shearing) deformation is finished, the use of the second bulge-preventing pressing member 12 in which the pitch of the bolt holes 12a is shifted allows the precast box culverts 2 and 3 to be attached to the side walls. Later, the surface is not twisted and can be easily performed.
In addition, by reducing the displacement reaction force when raising the height, it is not necessary to install large-scale equipment, and even a precast box culvert with a large cross section can be transported alone to the construction site, and then the flexible waterproof joint 4 can be installed and raised on site. It is possible to work, and can handle large-scale properties.

The flexible water-stop joint 4 is not limited to the shape shown in the figure, and for example, various other shapes such as a configuration in which three substantially U-shaped and substantially U-shaped expansion / contraction portions are alternately arranged are used. can do.
Further, the precast flexible box culvert and its construction method according to the present invention are not limited to the addition of an existing box culvert such as an existing pipe installed across the embankment, and other existing and new boxes in soft ground Can be widely applied for culvert connection.

1, 10 Precast flexible box culvert 2 Precast box culvert 3 Precast box culvert 2a, 3a Ceiling 2b, 3b Floor 2c, 3c Inner peripheral surface 2d, 3d Upper and lower surfaces 2e, 3e Stepped portion 4 Flexible waterstop joint 4a Expansion / contraction Part 4b, 4c Mounting part 5 Fixing material (fixing bracket)
6 Bulge Prevention Cloth 7 Anchor Bolt 8 Presser Plate 9 Washer, Nut 11 First Bulge Prevention Presser Member 11a Bolt Hole 12 Second Bulge Prevention Presser Member 12a Bolt Hole 12b Folding Portion 12c Batter Cloth 13 Joint Material 14 Biodegradation Grease

Claims (6)

In the precast flexible box culvert in which a short cylindrical flexible waterproof joint is connected between adjacent precast box culverts and one of the precast box culverts on the sinking side is raised and held in advance.
The first bulge-preventing presser member that presses the bulge of the flexible waterproof joint on the side wall portion between the adjacent precast box culverts is aligned with the arrangement of a pair of anchor bolts between the adjacent precast box culverts before being raised. While forming in the shape of a strip with a bolt hole and attaching the first bulge prevention presser member with an interval between adjacent anchor bolts,
Forming a second bulge-preventing pressing member having a plurality of bolt holes in accordance with the arrangement of the anchor bolts on the side wall in a state where one of the adjacent precast box culverts is raised, in a substantially parallelogram shape ; The second bulge prevention presser member is overlaid on the first bulge prevention presser member after being raised and attached to an anchor bolt .
A precast flexible box culvert, wherein the first and second bulge-preventing pressing members are attached separately before and after raising .   Of the adjacent precast box culverts, the ceiling portion of the non-sinking precast box culvert is made thicker than the ceiling portion of the sinking side precast box culvert by a thickness corresponding to the sinking amount. The floor portion of the culvert is made thicker than the floor portion of the non-sinking precast box culvert by a thickness corresponding to the sinking amount, and the upper and lower surfaces of the adjacent precast box culverts are flush with each other in the raised state. The precast flexible box culvert according to claim 1, wherein the precast flexible box culvert is arranged. In the construction method of a precast flexible box culvert that connects a short cylindrical flexible waterproof joint between joints of adjacent precast box culverts and keeps one precast box culvert on the sinking side in a pre-lifted state,
Before Symbol the first bulge preventing pressing member for pressing the bulge of the flexible waterproofing joint of the side wall portions between adjacent precast box culverts joints, raising the previous arrangement of a pair of anchor bolts between adjacent precast box culverts Formed into a strip shape with bolt holes matched to
The first bulge prevention presser member is attached with an interval between adjacent anchor bolts,
Forming a second bulge-preventing pressing member having a plurality of pairs of bolt holes in accordance with the arrangement of the anchor bolts on the side wall in a state where one of the adjacent precast box culverts is raised in a substantially parallelogram shape ; Every
After the raised state, the second bulge prevention press member is overlaid on the first bulge prevention press member and attached to the anchor bolt ,
Construction methods of precast flexible box culvert being characterized in that the attachment so that divides the first and second bulge-preventing pressing member after raising before and raised.   The one end edge portion of the second bulge prevention press member is overlapped with and attached to the one end edge portion of the first bulge prevention press member, and then raised, and then the second bulge prevention press member. The construction method of the precast flexible box culvert according to claim 3, wherein the other end edge portion is attached to the anchor bolt while being overlapped with the first bulge prevention pressing member.   Between the joint portions of the adjacent precast box culverts, a joint material is adhered to the end surface of one precast box culvert, while biodegradable grease is applied to the end surface of the joint material on the anti-adhesion side. The construction method of the precast flexible box culvert according to claim 3 or 4, characterized in that the short cylindrical flexible waterproof joint is connected. Among the adjacent precast box culverts, the ceiling portion of the precast box culvert on the non-sinking side is thicker than the ceiling portion of the precast box culvert on the sinking side by a thickness corresponding to the sinking amount. The floor portion of the culvert is formed thicker than the floor portion of the non-sinking precast box culvert by the thickness corresponding to the sinking amount.
After arranging the ceiling part and floor part between adjacent precast box culverts to form the same plane, the flexible waterproof joint is connected between the joint parts of these precast box culverts,
Next, the upper surface and the lower surface of adjacent precast box culverts are raised so as to form the same plane, and the raised state is fixed and held by a fixing bracket. Precast flexible box culvert construction method.

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