JP3099039B2 - Embankment culvert - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underfill embankment culvert when a road is constructed by embankment in a mountain valley or the like.

[0002]

2. Description of the Related Art For example, it is difficult to secure a road construction site only in a flat area such as a plain in a mountainous country and in a place where the land is narrow as in Japan. , And the road will penetrate the mountains across the valleys.

When building a road in such a valley,
As shown in FIG. 5, since the road 1 is constructed through the hillside 3 of the mountain 2, it is necessary to form the embankment 5 in the valley portion 4, but the drainage water flows under the embankment 5. It is necessary to secure a waterway 6, which is a small river, and a road 7 such as a farm road which has existed and is used.

In order to secure the waterway 6 and the road 7, a culvert 8 under the embankment having a width of, for example, 10 m, a height of 5 to 10 m, and a length of 100 to 200 m is constructed as a tunnel, and the culvert 8 under the embankment is conventionally constructed. Are used as the waterway 6 and the road 7. Conventionally, as a construction method of the culvert 8 under the embankment,
For example, arches were constructed from cast-in-place reinforced concrete, but recently the construction period can be shortened and the construction cost can be made relatively inexpensive. The embankment using cement stabilized soil (reinforced soil or artificial soft rock) ring There is a lower culvert.

As shown in FIG. 6, the underfill embankment culvert 8 rolls out a mixed material (soil cement) of cement and aggregate while sufficiently rolling the mixture into a portion to be an artificial soft rock ring (reinforced soil ring) 9. In addition, general soil (excavation of a tunnel, which is soil generated in the field) 20 is sufficiently rolled into the inside of the artificial soft rock ring 9 while being rolled out, and the soil cement and the general soil 20 are brought to a predetermined height. When the height is raised to (the height of the road surface), the general soil 20 surrounded by the artificial soft rock ring 9 is excavated to construct a tunnel, and the waterway 6 and the road 7 are constructed. In the figure, reference numeral 10 denotes general soil generated locally on the outside of the artificial soft rock ring 9.

After excavating the general earth and sand 20, in the same manner as in the case of constructing a general tunnel, as shown in FIG. 7, a concrete 21 is sprayed on the inner surface of the tunnel, and a secondary lining is formed on the inner surface. The lining concrete 22 is constructed.

However, the culvert 8 under the embankment constructed by such a method cannot be used as a tunnel until the construction of the lining concrete 22 for the secondary lining is completed. The road 7 as a farm road is also unstoppable because it cannot be used, which is very inconvenient for local residents, and at the same time, the construction cost increases because the inner surface of the tunnel is separately covered.

Further, since the artificial soft rock ring 9 is constructed only of soil cement, the quality, especially the strength, of the artificial soft rock ring 9 is often largely influenced by the mixing condition of the cement and the aggregate, and the strength is stable. It was difficult to secure the artificial soft rock ring 9.

Further, after the work of unmixing the mixed material and the general earth and sand and performing the compaction work, the general earth and sand 20 in the artificial soft rock ring 9 are excavated and penetrated through the tunnel. Construction becomes large-scale.

In order to solve such a problem, to stabilize the strength and to further shorten the construction period, a half PC board formed by projecting a reinforcing reinforcing bar on one side is installed in an arch shape, and a soil PC is provided outside the half PC board. An underfill culvert is proposed in which cement is integrated with a half-PC board and the outside of this soil cement is filled with general earth and sand, and in this culvert, internal excavation and secondary lining of a tunnel are omitted.

[0011]

SUMMARY OF THE INVENTION The above-mentioned half P
In the method using the C plate, since the artificial soft rock and the half PC plate are integrated, the half PC plate receives stress such as earth pressure of the artificial soft rock until the artificial soft rock ring is constructed circularly at the top of the tunnel. Therefore, it is necessary to make the half PC plate thick enough to prevent the occurrence of cracks inside the tunnel, which increases the cost.

An object of the present invention is to solve the inconvenience of the conventional example and to form an inner wall of a tunnel corresponding to a conventional half PC board by separately providing a member that absorbs and deforms the earth pressure from the artificial soft rock ring side. It is an object of the present invention to provide an embankment under embankment which can be constructed easily, inexpensively in a short period of time, and which is reliable in terms of strength, without having to increase the thickness of the member to be formed.

[0013]

According to the present invention, in order to achieve the above object, a precast (PC) plate is installed in an arch shape, and an artificial soft rock ring made of cement stabilized soil is constructed outside the precast (PC) plate. And a material for absorbing earth pressure from an artificial soft rock ring such as styrofoam between the precast (PC) plate and the artificial soft rock ring, further comprising an embankment for embedding general earth and sand outside the artificial soft rock ring. The gist is to intervene.

According to the first aspect of the present invention, by installing a PC board in advance at a location located on the inner surface of a tunnel constructed under an embankment, the work of compacting and excavating general earth and sand inside the tunnel can be performed. It is also possible to omit spraying of concrete on the inner peripheral surface of the tunnel and construction of secondary lining concrete.

By interposing a material such as styrofoam which absorbs the earth pressure from the artificial soft rock ring between the PC board and the artificial soft rock ring, the stress applied to the PC board from the side of the artificial soft rock ring is released. In addition, the PC board can be made slim and lighter.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional front view showing an embodiment of an embankment culvert according to the present invention, and the same components as those of the conventional example shown in FIG. 6 are denoted by the same reference numerals. In the figure, reference numeral 11 denotes an arch-shaped precast (PC) plate installed at a construction site of a tunnel constructed in the valley 4 or the like, and the earth pressure from the artificial soft rock ring 9 is absorbed outside the precast (PC) plate 11. For example, a polystyrene foam 12 or the like is interposed as a material to be removed, and a mixed material of cement and aggregate (soil cement) is rolled out to the portion to be an artificial soft rock ring (reinforced soil ring) 9 while being sufficiently rolled out,
Further, a general soil 10 generated locally is put on the outside.

A method for constructing a tunnel, which is a culvert 8 under embankment, using such a precast (PC) plate 11, styrofoam 12, and general earth and sand 10 will be described first. For example, a concrete foundation 14 is cast on a base 13 as a foundation for a precast (PC) plate 11 to a width of 6 m and a height of 0.5 m over 200 m) (see FIG. 2). In this case, the installation portion of the precast (PC) plate 11 is formed without a box. This is based on the road 7 in the tunnel
13 For installation on fixed and level setting.

Then, a precast (PC) plate 11 manufactured and processed in a factory in advance is placed on the concrete foundation 14. The precast (PC) plate 11 is, for example, a quarter-circle shape suspended from both sides by a wrecker or the like, and a plurality of pieces are sequentially assembled in the length direction of the tunnel by a top fitting method, and a resin is injected into a joint portion. And stop the water.

On the other hand, when the artificial soft rock ring 8 is to be constructed under the road 7 in the tunnel, the lower part of the precast (PC) plate 11 is directly embedded in the artificial soft rock ring 8 as shown in FIG.

Next, a styrofoam 12 is disposed outside the precast (PC) plate 11, and a mixed material (soil cement) of cement and aggregate is further provided on the outside thereof to form a reinforced soil ring (artificial soft rock ring) 9. And the outside is filled with general soil 10 generated locally.

The filling of the soil cement requires a form because the material itself is fluidized at the time of construction. However, as shown in FIG.
C) The embankment made of the plate 11 and the outside general earth and sand 10 is used as a formwork, and is also carried out using a concrete pump or a chute, and is carried out simultaneously in parallel from both sides of the tunnel toward the vertex.

The soil cement to be used is manufactured at a manufacturing plant installed on site, and its characteristics are shown in Table 1 below.

[0023]

[Table 1]

[0024]

As described above, the culvert under the embankment of the present invention can reduce the compaction of general earth and sand inside the tunnel by installing a PC board in advance at a location located on the inner surface of the tunnel constructed under the embankment. Excavation work can be omitted, and concrete spraying on the inner surface of the tunnel and construction of secondary lining concrete can be omitted.

Further, when the construction of the tunnel space by the PC board is completed, the tunnel space can be used for a while.
At this time, the traffic stop of the agricultural roads existing in the valley can be released, and the traffic stop period can be shortened.

By interposing a material such as styrofoam for absorbing the earth pressure from the artificial soft rock ring between the PC board and the artificial soft rock ring, the stress applied to the PC board from the side of the artificial soft rock ring is reduced by the styrofoam. The PC board is released by being deformed and deformed, so that the PC board can be made slim, light, and inexpensive.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of an underfill embankment of the present invention.

FIG. 2 is a vertical cross-sectional front view showing an example of an installation portion of a PC board showing an embodiment of a submerged culvert according to the present invention.

FIG. 3 is a vertical sectional front view showing another example of the installation portion of the PC board showing the embodiment of the underfill embankment of the present invention.

FIG. 4 is a perspective view showing a construction state of an underfill embankment of the present invention.

FIG. 5 is a partially cutaway perspective view showing a construction example of an underfill embankment of the present invention.

FIG. 6 is a longitudinal sectional front view showing a conventional buried culvert.

FIG. 7 is a vertical sectional front view of a main part of a conventional underfill culvert.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Road 2 ... Mountains 3 ... Hillside 4 ... Valley 5 ... Embankment 6 ... Waterway 7 ... Road 8 ... Culvert under embankment 9 ... Artificial soft rock ring 10 ... General earth and sand 11 ... Precast (PC) plate 12 ... Styrofoam 13 ... Base 14 ... Concrete foundation 20 ... General earth and sand 21 ... Shotcrete 22 ... Lining concrete

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-150898 (JP, A) JP-A-59-85099 (JP, A) JP-A-55-129595 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) E02D 29/05

Claims (1)

(57) [Claims] 1. A precast (PC) plate is installed in an arch shape, an artificial soft rock ring made of cement stabilized soil is constructed outside the precast (PC) plate, and general earth and sand is poured outside the artificial soft rock ring. An underfill embankment culvert, wherein a material that absorbs earth pressure from an artificial soft rock ring such as styrene foam is interposed between the precast (PC) plate and the artificial soft rock ring.