JP2813607B2 - L-shaped retaining wall block and method of constructing L-shaped retaining wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to an L-shaped retaining wall block used when constructing a retaining wall for preventing a stepped portion of a land from collapsing, and a retaining wall using the block. It concerns the construction method.

<< Conventional Technology >> A retaining wall is constructed to prevent a collapse of a stepped portion of a land having a height difference. A retaining wall using an L-shaped retaining wall block (referred to as an L-shaped retaining wall) is used. It has an excellent feature that the land area required for installation of a retaining wall can be minimized as compared with a retaining wall using a building block or the like.

In the conventional L-shaped retaining wall block, as shown in FIG. 7, the lower surface of the bottom plate 3 is horizontal. The L-shaped retaining wall is constructed by laying crushed stones or the like at a position lower than the ground surface of the lower land 17 to form a foundation 10 having a horizontal upper surface, and laying a mortar 13 thereon to stand the L-shaped retaining wall block 1. It is constructed by burying earth and sand 14 on it.

<< Problems to be Solved by the Invention >> In the conventional L-shaped retaining wall block, since the lower surface of the bottom plate 3 is horizontal or nearly horizontal, the soil on the higher land 18 where the block is to be moved forward is to be moved. The resistance force against the horizontal component of the pressure depends on the frictional force between the lower surface of the bottom slab and the upper surface of the foundation 10, and has a magnitude obtained by multiplying the friction coefficient between the two by the vertical force applied to the bottom slab 3. However, since the lower surface of the bottom slab 3 and the upper surface of the foundation 10 are smooth concrete surfaces or surfaces similar thereto, the coefficient of friction cannot be increased so much that the resistance against the forward movement of the block is weak. There was a problem.

To remedy this problem, the bottom plate 3 of the L-shaped retaining wall block was used.
Although the projections are provided on the lower surface of the slab and the width of the bottom plate 3 is widened, there are problems such as difficulty in construction, large blocks and loss of L-shaped retaining walls.

<< Means for Solving the Problems >> In the present invention, a front inclined surface 5 and a rear inclined surface 6 which are inclined in directions opposite to each other with respect to a horizontal plane are provided on a lower surface of a bottom plate 3 of an L-shaped retaining wall block, and the bottom plate as a whole is provided. The lower surface of 3 is formed with a concave groove having a cross section. Small windows 8 penetrating the bottom plate 3 up and down are provided at the top portions of the concave grooves in the direction along the longitudinal direction of the retaining wall at intervals at which there is no risk of lowering the strength of the bottom plate 3.

At the time of construction, a base 10 having a flat upper surface is formed with a split stone or the like in the same manner as before, and then, a split stone having a smaller particle size is preferably formed thereon to form the lower surface of the bottom plate 3 of the L-shaped retaining wall block. A ridge 12 having a U-shaped cross section corresponding to the cross section is constructed, and a slightly fluid and viscous material such as mortar is laid on the ridge 12. Then, the lower surface of the bottom plate 3 of the L-shaped retaining wall block is placed on the mortar layer 13 so as to be in close contact therewith, and after checking the state of close contact between the mortar layer 13 and the lower surface of the bottom plate 3 through the small window 8,
Earth and sand are backfilled on the bottom slab 3 to form an L-shaped retaining wall.

It is preferable that the lower surface of the bottom plate 3 has a front end and a rear end in an edge shape, and does not have a horizontal surface which substantially supports a vertical force. A horizontal plane that does not substantially bear the vertical force, such as a narrow horizontal plane provided due to the need for forming the block or to prevent breakage of the block, does not hinder the properties of the block in the preferred form.

<< Operation >> According to the above configuration, the force for pushing the block forward is to be taken up by the shear resistance between the foundation 10 and the ridge 12, but the foundation 10 and the ridge 12 Due to the intricate state of the granular crushed stones that are the constituent materials, they have a friction coefficient much higher than the friction coefficient between the conventional horizontal concrete surface and mortar surface. Block 1 is the friction resistance of the value multiplied by the normal force
Movement of the block can be completely prevented from moving the block in the horizontal direction due to earth pressure.

The state of adhesion between the mortar layer 13 and the lower surface of the L-shaped retaining wall block at the time of construction can be monitored from the small window 8, and there is no structure in which a horizontal surface for supporting a vertical load is provided on the lower surface of the L-shaped retaining wall block. For example, it is possible to prevent the block 1 from being supported by the horizontal planes at the front and rear ends of the inclined surfaces 5 and 6 and to form a gap between the mortar layer 13 and the lower surface of the bottom plate 3.
A shaped retaining wall can be built.

Further, by burying the earth and sand on the bottom plate 3 of the block before the mortar layer 13 has not yet set, a load is applied to the bottom plate 3 of the block at an early stage, and the adhesion between the mortar layer 13 and the bottom plate 3 of the block is more completely achieved. This will also contribute to the early completion of the construction.

Furthermore, when there is a possibility that sufficient horizontal resistance may not be obtained even with the above structure, or when safety is particularly ensured, the pile 15 is driven into the ground through the small window 8 and the block 15 is moved horizontally by the pile 15. Can be prevented more completely. Since the pile is driven into a space where nothing is obstructed above the bottom slab, the workability is good by both the hammering and the vibrating driving, and the pile is piled up to a sufficient depth if necessary. It is possible to type.

<< Embodiment >> FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a perspective view of an L-shaped retaining wall block, and FIG. 2 is a sectional side view showing a construction state. is there. In the drawing, 1 is an L-shaped retaining wall block, 2 is its wall plate, 3 is its bottom plate, 4 is the bottom surface of the bottom plate, 5 is its front inclined surface, 6 is its inclined surface thereafter, 7 is the top horizontal surface, and 8 is a small window It is. The lower surface 4 of the block is formed in a U-shaped cross section by a front inclined surface 5 and a rear inclined surface 6, and a small window 8 penetrating through the bottom plate 3 at a predetermined interval along the longitudinal direction of the block 1 is opened at the top. ing.

In FIG. 2, reference numeral 10 denotes a foundation formed of split stones 11 and 12 denotes ridges formed by laminating relatively small-diameter split stones on the base 10 and forming a cross-sectional shape. To the shape of. Reference numeral 13 denotes a mortar layer raised on the surface of the ridge 12, on which the bottom plate of the block 1 is placed so that no gap is formed between the lower surface 4 and the mortar layer 13. The above-mentioned gap can be visually confirmed through the small window 8, and if the mortar 13 is constructed without gaps, the earth and sand 14 are backfilled before the mortar 13 is completely solidified, and the bottom plate 3 and the mortar 13 are further adhered. The mortar 13 is solidified in this state.

In FIG. 2, reference numeral 15 denotes a stake that has been driven into the ground 16 through the small window 8 and the ridge 12 and the foundation 10, and if necessary, such a stake is used to drive the block 1 into place. Horizontal movement can be more firmly blocked,
Generally, such driving of the pile 15 is not necessary.

3 to 6 show other cross-sectional shapes of the L-shaped retaining wall block of the present invention, and FIG.
The top ridge is provided on the back side of the bottom plate, and FIG. 4 is provided near the front side. As shown in these figures, the shape of the letter on the lower surface of the bottom plate of the block is It can be changed as appropriate according to the earth pressure applied to the requested or constructed retaining wall or the state of the ground.

FIG. 5 shows two lower grooves provided on the lower surface of the block, and FIG. 6 shows a horizontal surface 19 at the front end of the lower surface of the block, which bears a vertical force. FIGS. 5 and 6 are provided to show that the function and effect of the present invention can be achieved to some extent even with such a shape.

<< Effects of the Invention >> According to the present invention described above, the drawback of the L-shaped retaining wall block that there is a danger of the block being moved by the horizontal earth pressure is completely eliminated, and a stronger and more reliable L-shaped retaining wall block is provided. There is an effect that a retaining wall can be constructed.

[Brief description of the drawings]

1 and 2 show a first embodiment of the present invention. FIG. 1 is a perspective view of an L-shaped retaining wall block, and FIG. 2 is a sectional side view showing a construction state. 3 to 6 are side views illustrating other examples of the cross-sectional shape of the L-shaped retaining wall block of the present invention. FIG. 7 is a sectional side view showing a construction state of a conventional L-shaped retaining wall block. In the figure, 3: bottom plate, 5: front slope 6: rear slope, 8: small window 10: foundation, 11: split stone 12: ridge, 13: mortar layer

Claims (3)

(57) [Claims] 1. A bottom surface of a bottom plate (3) is formed in a U-shaped cross section having a front inclined surface (5) and a rear inclined surface (6), and is arranged on the upper surface of the bottom plate (3) at predetermined intervals along its top ridge. An L-shaped retaining wall block comprising a small window (8) penetrating therethrough. 2. The L-shaped retaining wall block according to claim 1, wherein the lower surface of the bottom slab (3) is not provided with a horizontal portion which bears a substantially vertical load. 3. A ridge (12) having a cross-section in the shape of a cross section made of relatively small-diameter split stone is formed on a horizontal foundation (10) on which a split stone (11) is laid, and a mortar (13) is placed thereon. Excitement, Claim 1
After placing the lower surface of the bottom plate (3) of the described L-shaped retaining wall block in close contact with the mortar (13), and confirming the close contact state from the small window (8) provided in the bottom plate, the mortar (13) is removed. A method for constructing an L-shaped retaining wall, comprising backfilling earth and sand on the bottom plate (3) before completely solidifying.