JPH0226008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for laying transport pipes in a bridge over a river or the like, and more particularly to a structure for laying a transport pipe in a bridge that has a structure capable of absorbing deformation due to thermal stress.

In river bridges where transport pipes buried underground are exposed above ground, if thermal stress is generated in the transport pipes due to fluid flowing inside the pipes, unlike underground pipes, deformation due to the thermal stress may occur. Since it is not restricted,
Damage occurs to the transport pipe due to deformation. In order to prevent such damage, transport pipes installed on bridges have a structure that absorbs deformation due to thermal stress.

FIG. 1 is a bottom view showing the construction of transport pipes in such a bridge. In Figure 1, 1
1 is a platform (abutment) on which the bridge 2 is installed, 3 is a bridge pier, and 4 is a main body (hereinafter referred to as the bridge main body) consisting of the steel frame of the bridge 2. Concrete is laid on top of the bridge main body 4. The transport pipe 5 has a bracket (not shown)
It is attached to the lower part of the bridge body 4 by
A telescopic pipe joint 6 interposed in the middle of the transport pipe 5
This allows the deformation of the transport pipe 5 due to thermal stress to be absorbed.

However, in this structure, since a thin-walled pipe that is thinner than the transport pipe 5 is used for the pipe joint 6, there are problems in terms of strength and safety, and usage restrictions due to laws and regulations.
Furthermore, there is a drawback that maintenance of the pipe joint 6 is required.

Therefore, in order to eliminate such drawbacks, as shown in FIG. By the bent pipe 7, the transport pipe 5
Laying structures have also been adopted that absorb deformation due to thermal stress caused by. The transport pipe 5 is attached to the lower part of the bridge body 4 using a bracket (not shown) so that it can be freely displaced in the direction of the pipe axis, and its both ends are fixed to the installation base 1 with mortar or the like. There is.

According to this structure, problems such as strength will not occur in the bent pipe 7, but since the installation space for the bent pipe 7 is limited, the bent pipe 7 must be made small and have poor ability to absorb deformation due to thermal stress. Therefore, there is a disadvantage that a large number of bent pipes 7 must be installed.

On the other hand, as shown in FIG. 3, a bent pipe 8 made of the same pipe as the transport pipe 5 is connected to
Instead, there is also known an installation structure in which the pipe is interposed in a transport pipe section 5' buried underground in front of the installation stand.
In this structure, the installation space for the bent pipe 8 is not limited, so the bent pipe 8 can be made large enough to absorb the deformation of the transport pipe 5 due to thermal stress. alone,
Since the bent pipe 8 is restrained by the surrounding soil and does not deform, it is difficult for the bent pipe 8 to absorb the deformation of the transport pipe 5 due to thermal stress. For this purpose, the bent pipe 8 is housed in a sheath pipe 9 as shown in FIG. 4a, or in a culvert box 10 as shown in FIG. It is necessary to provide the bending pipe 8 so that it can be deformed. In addition, the transport pipe 5' is fixed so that the part exposed underground from the sheath pipe 9 or the culvert box 10 is not displaced by mortar, etc., and the transport pipe 5 is so arranged that it can be freely displaced in the pipe axial direction. It is attached to the lower part of the bridge body 4 by a bracket.

However, such a structure has the disadvantage of being too complex.

In view of the above-mentioned current situation, this invention provides a structure for laying transport pipes in bridges that has a simple structure, can absorb deformation due to thermal stress, has excellent strength, and is inexpensive to install. A transport pipe consisting of at least one pipe curved with a predetermined curvature,
The pipe is displaceably supported on the steel frame of the bridge via a bracket and laid on the bridge. It is distinctive in that it is connected to the ends located near both ends of the bridge.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 5 is a bottom view showing the construction of a transport pipe in a bridge according to the present invention. In Fig. 5, 11 is the installation platform (abutment) of the bridge 12, 13 is the bridge pier,
14 is a bridge body made of a steel frame, and a transport pipe 15 is laid horizontally under the bridge body 14. The transport pipe 15 is composed of curved pipes 15a and 15b which are curved in opposite directions at a predetermined curvature in the horizontal direction, and the curved pipes 15a and 15b are connected by welding or the like. The bent pipes 15a and 15b are arranged so that they can be freely displaced in the pipe axis direction and the curved direction by the brackets 16 at multiple locations between the installation base 11 and the pier 13, and at locations on the pier 13 (the bent pipe 15a). and 15b) is attached to the lower part of the bridge body 14 by a bracket 17 so as to be freely displaceable in the tube axis direction.
The bent pipes 15a and 15b are connected to the installation base 11.
The location of the mounting base 11 is fixed with mortar etc. 18.
Transport pipe section 19 fixed to etc. and buried underground
is connected to ends located near both ends of the bridge 12.

FIG. 6 is a plan view showing an example of the structure of the attachment portion of the curved pipes 15a and 15b to the bridge body;
The figure is a sectional view thereof. As shown in FIGS. 6 and 7, the bridge body 14 is made of a steel frame.
A bracket 16 is fixed to the bracket 16.
A sliding material 20 made of, for example, tetrafluoroethylene resin is attached on the surface of the slider. Bent pipe 15
A support 21 having a horizontal bottom surface 21a is attached to the portions a and 15b that contact the bracket 16, and the bottom surface 21a of the support 21 is as follows.
It is slidably abutted on the sliding member 20 of the bracket 16. Thus, the bent pipes 15a and 15b are supported via the brackets 16 on the bridge body 14 made of a steel frame so as to be freely displaceable, as shown by broken lines in FIG.

Therefore, according to such a laying structure, when the transport pipe 15 expands due to a rise in temperature due to the fluid flowing inside, the bent pipes 15a and 15b are further curved and deformed, and conversely, the temperature When the curved pipes 15a and 15b are lowered and contracted, the curved pipes 15a and 15b are deformed in the direction of straightening, so that the deformation caused by thermal stress is easily absorbed.

In the above example, the transport pipe 15 was formed by connecting the curved pipes 15a and 15b curved in opposite directions, but depending on the length of the bridge 12, the installation space in the width direction of the bridge where the transport pipe 15 is provided, etc. Therefore, the transport pipe 15 may be formed by one curved pipe, or may be formed by connecting three or more pipes. Further, the curvature of these curved pipes 15a, 15b, etc. is appropriately determined depending on the strength of the curved pipe, the degree of deformation of the curved pipe due to heat of the fluid, etc., the installation space, etc. Further, although the curved pipes 15a and 15b are curved horizontally, they may be curved in any direction such as vertically.

Since the present invention is configured as described above, when the transport pipe expands and contracts due to the fluid flowing inside the transport pipe, the transport pipe can easily deform and absorb the deformation caused by thermal stress. It has a large absorption capacity and a simple structure. Moreover, it is strong in terms of strength because it is possible to use the same pipe as the transport pipe part buried underground, without using a thin-walled pipe like a flexible pipe joint. Moreover, since the structure is simple, the installation cost is also low.

[Brief explanation of drawings]

Figures 1 to 3 are bottom views showing the construction of a conventional transport pipe; Figure 4a is a sectional view of a sheath pipe used in the transport pipe of Figure 3; Figure 4b is a culvert. 5 is a bottom view showing the installation structure of the transport pipe of the present invention; FIG. 6 is a plan view showing an example of the structure of the part where the curved pipe is attached to the bridge body; and FIG. FIG. In the drawing, 11... Installation stand, 12... Bridge, 13... Pier, 14... Bridge body, 15...
Transport pipe, 15a, 15b... Bent pipe, 16, 17...
... Bracket, 18 ... Mortar, 19 ... Transport pipe, 20 ... Sliding material, 21 ... Support.

Claims (1)

[Claims] 1. A transport pipe consisting of at least one pipe curved at a predetermined curvature in the horizontal direction is supported on the steel frame of the bridge via a bracket so as to be freely displaceable,
The transport pipe is installed on the bridge, and both ends of the transport pipe thus installed on the bridge are connected to ends of a transport pipe buried underground that are located near both ends of the bridge. , Laying structure of transport pipes in bridges.