JPH0692641B2 - Road widening method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a road constructed by excavating an inclined surface stepwise like a hillside road, a road constructed on a raised embankment, and the like.
The present invention relates to a method for widening a road in which the road under the shoulder is an inclined surface.

(Prior Art) In recent years, along with the increase in traffic volume, it has become necessary to expand the width of roads from the old roads and to attach sidewalks or motorways. It is no exception on roads where the other side faces the valley and the road shoulders have a steep slope.

When widening a road such as a hillside road, the method of expanding the mountain side of the road is to excavate the slope on the mountain side and fix the frame or sprayed concrete to the excavated surface with an underground anchor or use a gravity-type concrete. There is a construction method that prevents collapse of the slope by stacking blocks to construct a retaining wall. On the other hand, the fifth method is to widen the valley side of the road.
As shown in the figure, a foundation 2 is constructed at an appropriate position below the slope of the existing road 1 and a gravity type block 3 is piled up on the foundation to construct a retaining wall 4, and the block 3 is appropriately constructed. Fix with tie rods 5 at intervals, fill the tie rods 5 and fill the space between the slope 6 and the retaining wall 4 with earth and sand, and use the top surface as a road, or a tip on an existing road as shown in Fig. 6. A precast concrete structural material 7 in the air on the valley side is installed over the entire width of the road 1, a road surface is formed on the structural material 7, and an underground anchor 8 is constructed under the road 1 to form the base of the structural material 7. There is a construction method in which it is fixed on the end side and counteracts the moment due to vertical load applied to the tip side.

(Problems to be Solved by the Invention) Among the conventional methods described above, the method of excavating the slope on the mountain side of a road can excavate when the slope on the mountain side is gentle, but the slope is steep. In such a case, there is a problem that it is difficult to prevent the collapse of the area after the excavation because it is difficult to prevent the collapse.

Moreover, as shown in FIG. 5, a retaining wall is erected on the slope on the valley side,
Even in the method of burying earth and sand, it is difficult to widen a wide area when it is a steep slope, and there is a problem that a small widening becomes uneconomical.

Furthermore, as shown in FIG. 6, by fixing the structural material on the existing road and projecting the tip into the air, when constructing it,
Since it is necessary to use the entire width of the existing road, there is a problem that the road must be closed.

In view of the problems of the conventional construction method as described above, the present invention is a road widening method that can be constructed without closing an existing road and can be economically constructed even if the slope of the slope on the valley side of the road is steep. It is intended to be provided.

(Means for Solving the Problem) 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 road is located below the road surface below the road surface. A slope protection retaining wall that covers the slope is formed by cast-in-place concrete while being supported by the molded underground anchor, and a support column is formed on the front surface of the slope protection retaining wall. A precast concrete slab is laid between the upper ends of the installed columns and the upper surface of the slope protection retaining wall to form a widened floor slab, and the widened floor slab is paved to form a road surface.

(Operation) According to this method, it is only necessary to excavate to the depth required to construct the slope protection retaining wall, and it is possible to work within the excavation part, and there is no need to construct scaffolding even on steep slopes. Is.

The slope protection retaining wall supports horizontal earth pressure, and the underground anchor is used to counter the rotational moment generated by the lower end of the retaining wall as the axis of rotation.

Further, the vertical load applied to the widened floor slab is received by the upper end of the retaining wall and the support pillar, and the load applied to the support pillar is received by the support pillar portion on the front surface of the retaining wall.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS.

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 in the horizontal direction at a constant interval substantially perpendicular to the excavation surface 11. It is preferable that each of the anchor holes 12 has a depth to reach a stable rock mass in the ground. Next, while injecting cement milk into the anchor hole 12, inserting the anchor tension material 14 and placing the anchor concrete 15 in the anchor hole 12 and at the same time embedding the anchor tension material 14 therein, the anchor tension material 14 is rock bed. Fix it on.

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

When constructing this retaining wall 16, the upper part of the retaining wall 16 is made thin to integrally form a horizontal step portion 17 on the front surface, and support posts 18 are opened at regular intervals on the upper surface of the support portion 17 to support the support pillar. The support portion 19 is formed. An anchor steel material 20 is projected on the top surface of the retaining wall 16.

After constructing the retaining wall 16 in this way, after solidifying the concrete and making necessary backfilling, the anchor tension member 14 is tensioned from the retaining wall surface side, and the end portion is fixed to the retaining wall 16 by the fixing metal fitting 21. Fix it.

Next, as shown in FIG. 3, each strut receiving hole 18 of the strut support 19
A column 22 made of precast concrete is fitted into the above to make it self-supporting, and a beam 23 made of precast concrete is spanned over the top end and the top surface of the retaining wall of the column 22 and fixed by an anchor steel material 20.

In this way, the precast concrete slab 24 is spanned between the beams 23 spanned at regular intervals to form the widened floor slab 25.

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

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

(Effects of the Invention) As described above, the road widening method of the present invention constructs the retaining wall on the slope below the road shoulder with cast-in-place concrete, and the underground anchor is used to counteract the earth pressure. By supporting the widened floor slab on the upper end of the wall and widening the road by this, the excavation of the slope only requires the depth for constructing the retaining wall, and the amount of excavation is reduced. There is little destruction of the road part, and construction can be performed with the stable roadbed left as it is, and the stability of the road surface after construction will be high.

In addition, one end of the widened floor 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 surface of the retaining wall. A widened portion with a high degree can be obtained.

In addition, half of the road can be passed during construction, avoiding complete closure of the road. In addition, since the pre-cass member is used without performing large-scale excavation or embankment, there is an effect that the construction period is short and the widening work can be economically performed at low cost.

[Brief description of drawings]

1 to 3 are sectional views showing construction steps of an embodiment of the present invention, FIG. 4 is a front view after completion, and FIGS. 5 and 6 are sectional views of a conventional example. 10 …… Road, 11 …… Excavation surface, 12 …… Anchor hole, 14 …… Anchor tension material, 15 …… Anchor concrete,
16 …… Retaining wall, 17 …… Step, 18 …… Support hole, 19… Support support, 20… Anchor steel material, 21… Fixing bracket, 22… Support, 23
…… Beam, 24 …… Precast concrete slab, 25 …… Widening floor slab, 26
...... Sidewalk.

Claims (1)

[Claims] 1. A slope protection retaining wall that covers the slope is supported by a ground anchor formed in the ground below the road from the slope below the road shoulder, and is molded by cast-in-place concrete. A strut support is formed on the front surface of the wall, and a precast concrete slab is laid between the upper end of the strut erected on the strut support and the upper end surface of the slope protection retaining wall to form a widened floor slab, Widening method A road widening method characterized by paving the floor slab to form a road surface.