JPH03279501A - Widening of road - Google Patents

Abstract

PURPOSE:To ease road-widening work even in a sharply tilted slope-face by fixing a slope-face protection retaining wall with an anchor member buried in the ground, and placing a precast concrete plate on the protection retaining wall to form a road-widening floor bed. CONSTITUTION:A widen road 26 is composed by forming a road-widening floor bed 25 with a beam 23 and a precast concrete plate 24 overhung above the upper surface of a slope-face retaining wall 16 to pave the upper side of the widen road 26. The retaining wall 16 is fixed to the ground with anchor concrete 15, an anchor tension material 14 buried in the ground and a fixing fitting 21. Moreover a step part 17 is integratedly formed with the retaining wall 15 and a supporting hole 18 is provided on the upper surface of the step part 17 to standingly provide a column 22, and anchor steel members 20 are buried in the uppermost part at regular intervals. Then the precast concrete plate 24 is placed and the road-widening floor bed 25 is formed to make up a sidewalk 25. This permits the construction of a stable roadbed even in a sharp slope-face.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to roads constructed by excavating slopes in stages like mountainside roads, roads constructed on raised embankments, etc.
This invention relates to a method for widening a road where the bottom of the road shoulder is a slope.

(Prior art) In recent years, with the increase in traffic volume, there has been a demand for widening the width of traditional roads and installing sidewalks or motorways. Roads that face a valley on the other side and have a steep slope below the shoulder are no exception.

When widening a road such as a mountainside road, the method of widening the mountainside road is to excavate the slope of the mountain side, and fix the slope frame or sprayed concrete to the excavated surface with underground anchors, or use gravity There is a construction method that prevents slopes from collapsing by stacking concrete blocks to form retaining walls. On the other hand, as a construction method for widening the valley side of the road, as shown in Figure 5, a foundation 2 is constructed at an appropriate position at the bottom of the slope below the shoulder of the existing road 1, and a gravity block 3 is placed on the foundation.
Build a retaining wall 4 by piling up the blocks 3, fix the blocks 3 with tie rods 5 at appropriate intervals, embed the tie rods 5 and fill the space between the slope 6 and the retaining wall 4 with earth and sand, and use the upper surface as a road. As shown in Fig. 6, a precast concrete structural material 7 with its tip protruding into the air on the valley side is installed over the entire width of the road 1 on the existing road 1.
There is a construction method in which a road surface is formed above, and an underground anchor 8 is constructed under the road 1 and anchored to the proximal end of the structural member 7 to counteract the moment due to the vertical load applied to the distal end.

(Problems to be Solved by the Invention) Among the conventional methods described above, the method of excavating the slope on the mountain side of the road is possible when the slope on the mountain side is gentle; If the excavation is sudden, there is a problem in that it becomes difficult to prevent the slope from collapsing after excavation, making construction impossible.

In addition, as shown in Figure 5, a retaining wall was erected on the slope facing the valley side.
Even in the method of filling with earth and sand, there is a problem that it is difficult to widen the slope significantly if the slope is steep, and furthermore, it becomes uneconomical to widen the slope to a small extent.

Furthermore, as shown in Figure 6, the method of fixing structural members on the existing road and extending the tips into the air requires the use of the entire width of the existing road during construction, which requires the road to be closed. There is a problem.

The present invention has been developed as described above.In view of the problems of conventional construction methods, the present invention is a road widening method that can be constructed without closing the existing road and that can be constructed economically even if the slope on the valley side of the road is steep. The purpose is to provide

(Means for Solving the Problems) A feature of the road widening method of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose is that the method of widening the road from the slope under the shoulder to the ground under the road A slope protection retaining wall that covers the slope is formed using cast-in-place concrete, supported by formed underground anchors, a pillar support is formed in front of the slope protection retaining wall, and a pillar support is formed on the pillar support. A precast concrete material is stretched between the upper end of the provided pillar and the upper end face of the slope protection retaining wall to form a widened floor slab, and the widened floor slab is paved to form a road surface.

(Function) According to this method, it is only necessary to excavate to the depth required to construct the slope protection retaining wall, and work can be done within the excavated area, so there is no need to construct scaffolding even on steep slopes. It is.

The slope protection retaining wall supports horizontal earth pressure, and the rotational moment generated by this with the lower end of the retaining wall as the axis of rotation is countered by underground anchors.

Further, the vertical load applied to the widening floor slab is received by the upper end of the retaining wall and the pillars, and the load applied to the pillars is received by the pillar support portion in front of the retaining wall.

(Example) Next, an example of the implementation of the present invention will be described with reference to FIGS. 1 to 4.

First, as shown in FIG. 1, the slope below the shoulder of the existing road 10 is excavated by the amount necessary for constructing the retaining wall.

Anchor holes 12 are formed substantially perpendicularly to the excavated surface 11 at regular intervals in the horizontal direction. Each of these anchor holes 12 preferably has a depth that reaches the stable bedrock of the ground 6 Next, cement milk is injected into the anchor holes 12 , anchor tensile material 14 is inserted, and anchor concrete 15 is poured into the anchor holes 12 . At the same time, the anchor tension material 14 is buried in this, and the anchor tension material 14 is fixed to the rock.

Next, as shown in FIG. 2, a slope protection retaining wall 16 is constructed using cast-in-place concrete along the excavated surface 11, and the anchor tension member 14 is passed through this.

When constructing this retaining wall 16, the thickness of its upper part is reduced, a horizontal step 17 is integrally molded on the front surface, and support support holes 18 are opened at regular intervals on the upper surface of the step 17 to support the support. A support portion 19 is formed. Furthermore, an anchor steel material 20 is made to protrude from the top surface of the retaining wall 16.

After constructing the retaining wall 16 in this way, and after the concrete has hardened and the necessary backfilling has been performed, the anchor tension member 14 is tensioned from the surface side of the retaining wall, and the end portion is attached to the retaining wall 1 with the fixing metal fittings 21.
Fix 6.

Next, as shown in FIG. 3, precast concrete columns 22 are fitted into each column receiving hole 18 of the column support part 19 to stand on their own, and are straddled over the top of the column 22 and the top surface of the retaining wall. A precast concrete beam 23 is spanned over and fixed with anchor steel 20.

In this way, the precast concrete slabs 24 are stretched between the beams 23 stretched at regular intervals, and the widened floor slabs 25 are
Nasu.

In this way, the widened floor slab 25 is extended to the side of the road 10, coarse-grained material for a sidewalk is laid on its upper surface, and the upper surface is paved with asphalt to form a sidewalk 26.

In addition to the sidewalk, continuous pavement may be provided to the surface pavement of the road 10 to form a roadway.

(Effects of the Invention) As described above, in the road widening method of the present invention, the retaining wall on the slope under the road shoulder is constructed using cast-in-place concrete, and is opposed to the tonosho using underground anchors. By supporting the widening slab at the upper end and widening the road, the slope only needs to be excavated to the depth required for constructing the retaining wall, reducing the amount of excavation and thus reducing the need for existing construction. There is less destruction of road sections, construction can be done with a stable roadbed left intact, and the stability of the road surface after construction is increased.

In addition, one end of the widening slab is fixed to the top surface of the retaining wall, and the other end is supported by a column whose lower end is fixed to the front of the retaining wall, so it has a stable structure and is safe. A widened portion with a high degree of width can be obtained.

Additionally, half of the road will be open to traffic during construction, avoiding or avoiding complete road closure. In addition, since large-scale excavation and earth mounding are not required, and precast members are used, the construction period is short and widening work can be carried out economically at low cost.

[Brief explanation of drawings]

1 to 3 are cross-sectional views showing the construction process of an embodiment of the present invention, FIG. 4 is a front view after completion, and FIG. FIG. 6 is a sectional view of a conventional example. 10...road, 11...excavation surface, 12
...Anchor hole, 14...Anchor tensile material, 15...Anchor concrete, 16.
...Retaining wall, 17...Step, 18...
・・Strut receiving hole, 19・・・Stroll support part, 20・・
...Anchor steel material, 21...Fixing metal fitting, 2
2... Support, 23... Beam, 24...
...Precast concrete slab, 25... Widening floor slab, 26... Sidewalk. Patent applicant Kurosawa Construction Co., Ltd. 1 Figure 2 Figure 4 Flow A Figure 3 Figure 6 Figure 5

Claims (1)

[Claims] A slope protection retaining wall covering the slope is formed using cast-in-place concrete, supported by underground anchors formed in the ground under the road from the slope below the road shoulder, and supports are installed in front of the slope protection retaining wall. A support section is formed, and a precast concrete material is stretched between the upper end of the column erected at the column support section and the upper end surface of the slope protection retaining wall to form a widened floor plate, and a widened floor plate is formed on the widened floor plate. A road widening method characterized by paving the road surface.