JPH05272167A - Reinforcing structure of existing cave path - Google Patents

Abstract

PURPOSE:To reinforce a cave path from the inside without cutting and opening the deteriorated cave path. CONSTITUTION:In a reinforcing structure of an existing cave path for reinforcing an existing cave path 3 which has been deteriorated to be in the pin- connected state, a tubular involute body 4 is constructed close to the inner wall surface of the existing cave path. The involute body is divided in the circumferential direction into plural parts, and the divided parts are connected to each other at the divided areas 6a, 7a, 8a, 9a. The divided areas are disposed in positions separated in the circumferential direction from the pin-connected areas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an existing cave installed in the ground such as a common ditch, an electric power cave, a sewer cave, and an existing cave that has deteriorated due to secular change. Reinforcement structure of existing cave that reinforces from inside the road.

[0002]

2. Description of the Related Art Some of the cave roads currently in use were constructed in or before the Showa 30's, and some of them have deteriorated due to aging. Recently, the concept of scrap-and-build (demolition and rebuilding) has been the mainstream for structures that have deteriorated after their useful lives have passed. Often built in.

[0003]

However, since the caverns are often installed under important trunk roads, it is extremely difficult to carry out new construction work that involves excavation.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a reinforcing structure for an existing cavern that can reinforce a deteriorated cavern from the inside of the cavern without excavating. To do.

[0005]

The reinforcing structure for an existing cave according to the present invention is a reinforcing structure for an existing cave that reinforces a deteriorated and pin-connected existing cave, and is close to the inner wall surface of the existing cave. Then, a cylindrical inner winding body is constructed, and the inner winding body is divided into a plurality of pieces in the circumferential direction and is connected to each other at this dividing portion, and the dividing portion is formed from the pinned portion in the circumferential direction. It is characterized in that it is arranged at a position away from.

[0006]

[Operation] The existing cavern that is deteriorated and pinned is an unstable structure. Further, the inner winding body, which is divided into a plurality of pieces in the circumferential direction and is connected by the dividing portion, is also an unstable structure.

Here, in the present invention, since the divided portions are arranged at positions circumferentially separated from the pinned portions of the existing cave, the divided portions are located between the pinned portions ( It will be located in a healthy state), and the existing cavern and inner winding will complement each other to form a stable structure.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a reinforced concrete box culvert (existing cavern) 3 having a cavernous space 2 having a rectangular cross section is buried in the ground 1. A cylindrical inner winding body 4 made of precast concrete is arranged on the inner wall surface of the box culvert 3, and a grout material 5 is filled in a gap between the inner winding body 4 and the inner wall surface of the box culvert 3.

The inner winding body 4 is composed of four pieces of a top plate 6, a bottom plate 7 and two side plates 8 and 9, and each piece is a joint end face (split portion) along the axial direction of the sinusoidal space 2. ) 6a, 7a, 8
a and 9a are arranged in contact with each other, and are connected to each other by a joint portion 15. The joint part 15 is as follows. That is, the joining end surfaces 6a, 7 of each piece
As shown in FIGS. 2 and 3, a joint box 10 connected to the anchor streak 11 is attached to a, 8a, 9a, and a bolt 12 is inserted between the joint boxes 10 facing each other and tightened with a nut 13. Each piece is connected. The joint box 10 that has been bolted is filled with non-shrink mortar.

The top plate 6 and the bottom plate 7 have a cave space 2
Has a through hole penetrating in the axial direction, and as shown in FIG. 1, by inserting a bolt 14 into the through hole,
The pieces arranged in the axial direction of the sinus space 2 are connected to each other.

Here, when the height of the sinusoidal space 2 is set to 3 m, the positions of the joint end surfaces 6a, 7a, 8a, 9a are set to be 30 cm to 50 cm from the corners of the sinusoidal space 2. There is. The thickness of each piece is 15 cm
And its width (the axial dimension of the sinus space 2) is 50c.
It has become m. Since each piece is dimensioned as described above, all the pieces can be loaded through the manhole (about 75 cm in diameter).

Next, the operation of this embodiment will be described.

As a typical example of the deterioration state of the box culvert 3, a case where the corrosion of the reinforcing bar provided in the box culvert 3 progresses due to the action of salt in the box culvert 3 constructed near the coast will be described. Normally, the bar arrangement of the box culvert 3 is set for the design bending moment as shown in FIG. However, several decades after the construction, the diameter of the reinforcing bar decreases as the reinforcing bar corrodes, and the bending strength of the reinforcing bar decreases. It becomes a pin coupling model as shown in. In this state, the structure is no longer stable and does not hold as a structure.
However, the portion between the pinned portions is in a sound state with sufficient strength as a member.

The case where the inner winding body 4 is provided on the inner wall of the box culvert 3 as in the above embodiment is modeled as shown in FIG. That is, the inner winding body 4 is superposed on the inner wall of the box culvert 3 in a layered structure so that the joint portion 15 is arranged in a portion of the box culvert 3 in a sound state, and the generated stress level of the box culvert 3 is an allowable value. The part 16 beyond the end and the joint part 15 of the inner winding body 4
Is regarded as a pin connection, and the box culvert 3 and the inner winding 4
It is considered that the and are connected by a coupling spring that transmits only the compressive force. An image of the coupling spring is shown in FIG. In order to transmit only the compression force to the coupling spring, specifically, the coupling spring with the increased displacement (which transmits the tension force) is repeatedly deleted from the model, and all couplings are performed. The final calculation model is the one in which the spring arrangement reduces the displacement of the spring.

As in this embodiment, the box culvert 3
Since the inner wrapping body 4 made of precast concrete is superposed on the inner surface of the box wrapping structure and the joint portion 15 of the inner wrapping body 4 is arranged in a sound state part of the box culvert 3, Together with the body 4, it forms a stable structure. That is, the box culvert 3 alone and the inner wrapping 4 alone each have a large number of pin couplings, which are unstable structures. However, in this embodiment, the joint portion 15 of the inner wrapping 4 and the box culvert 3 are unstable. The position at which the generated stress degree of 1 exceeds the allowable value is displaced, and the box culvert 3 and the inner winding body 4 complement each other and can oppose the external force, resulting in a stable structure.

In the embodiment, the precast concrete inner winding body 4 is joined to the inner wall of the box culvert 3 by the joint portion 15, so that the box culvert 3 and the inner winding body 4 constructed. It suffices to fill the gap between and with grout, and there is no need to connect a new member to the box culvert 3 with a dowel or an anchor as in the composite structure, and the construction period can be shortened. It should be noted that FIG. 8 shows a comparison between the reinforcing method as a synthetic member and the reinforcing method as a laminated member.

[0018]

As described above, according to the present invention, in a reinforcing structure for an existing cavern that reinforces an existing cavern that has deteriorated and has been pinned, a structure close to the inner wall surface of the existing cavern is provided. A cylindrical inner winding body is constructed, and the inner winding body is divided into a plurality of pieces in the circumferential direction and connected to each other at this dividing portion, and the dividing portion is separated from the pinned portion in the circumferential direction. Since it is placed in a different position, the split part will be located in the part located between the pinned parts (part in a healthy state), and the existing cavern and the inner winding body will complement each other. And stable structure.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a reinforcing structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a joint portion in a reinforcing structure according to an embodiment of the present invention.

FIG. 3 is a view of the joint portion in the reinforcing structure according to the embodiment of the present invention as viewed from the inside of the sinus space.

FIG. 4 is a diagram showing a distribution of design bending moments acting on a box culvert.

FIG. 5 is a diagram showing a box culvert model in a state where deterioration has progressed.

FIG. 6 is a diagram showing a design model of a reinforcing structure according to an embodiment of the present invention.

7 is a diagram showing an image of a coupling spring in the model of FIG.

FIG. 8 is a diagram showing a comparison between a reinforcing method as a composite member and a reinforcing method as a stack member.

[Explanation of symbols]

3 Box culvert (existing cave) 4 Inner roll 6,7,8,9 Piece 6a, 7a, 8a, 9a Joint end face (split part) 10 Joint box 12 Bolt 13 Nut 15 Joint part 16 Generated stress is allowable value Part beyond (pinned part)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Ito 2-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Toden Design Co., Ltd. 2nd Civil Engineering Headquarters (72) Inventor Yoshiya Tsuburaya 2-chome, Uchisaiwaicho, Chiyoda-ku, Tokyo No. 1-1 Toden Engineering Co., Ltd., Second Civil Engineering Headquarters (72) Inventor Mitsuo Saito 2-6-21 Yaesu, Chuo-ku, Tokyo Rose Bay Yaesu Building Ishikawajima Kenzai Kogyo Co., Ltd. In-house (72) Inventor Mitsuhisa Maehama Shimizuura 1-3-2, Minato-ku, Tokyo Shimizu Construction Co., Ltd.

Claims (1)

[Claims] 1. A reinforcing structure for an existing cave that reinforces a deteriorated and pin-jointed existing cave, wherein a cylindrical inner winding body is constructed adjacent to an inner wall surface of the existing cave, and the inner winding is formed. The body is divided into a plurality of parts in the circumferential direction and is connected to each other at the dividing parts, and the dividing parts are arranged at positions distant from the pinned part in the circumferential direction. Reinforcement structure of the cave.