JPH0663233B2 - Yamadome method - Google Patents

Description

The present invention relates to a mountain retaining method for stabilizing an excavated ground surface, and in particular, a mountain retaining method for stabilizing a long excavated ground. It is about.

[Prior art and its problems]

When carrying out the mountain retention of a tall and long natural ground, the method of excavating from the upper part to the lower part at a stretch, and then installing the mountain retaining structure along the excavated ground surface is adopted.

However, after excavating a large excavated surface, the excavated ground was in an unstable state until the fixing of the retaining structure was completed, and working under this ground surface was extremely dangerous.

In addition, if the structure is to support all the pressure applied to the back surface of the structure when the excavated ground is about to collapse, the structure must have high strength.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a mountain retaining method that enables safe construction and does not necessarily require a large strength for an earth retaining structure. To do.

[Means for Solving the Problems]

The mountain retaining method according to the present invention is for temporarily temporarily fixing the ground as it is excavated.

When digging up a long excavation surface, excavation is performed in multiple stages from top to bottom. In other words, the excavation is carried out sequentially at a predetermined height, and temporary fastening is performed for each excavation.

First, an anchor is placed from the ground level at each stage. A vertical beam arranged along the ground surface is fixed to this anchor, and the vertical beam prevents collapse of the ground surface. A concrete columnar body is conceivable as the vertical beam, and a ready-made column may be used, or a concrete frame may be assembled on site to construct concrete.

In the temporary fastening state with the vertical beams, the downward excavation and the temporary fastening are repeated to excavate the long mountain surface.

After completion of excavation, earth retaining structures such as existing concrete panels are erected along the excavation surface. This earth retaining structure is fixed to the anchor described above. A space may be provided between the earth retaining structure and the ground and filled with earth and sand or crushed stone.

The earth retaining structure is further piled up on the earth retaining structure and fixed to the anchor, and the earth retaining of the whole excavated ground is completed.

〔Example〕

The present invention will be described in detail below based on an embodiment shown in the drawings.

First, the ground is excavated along the planned line in a plurality of stages at predetermined heights from above. For each excavation, the anchor 2 is driven from the excavated ground surface 1 toward the natural ground. Various types of anchors can be used as the anchor 2, but a ground anchor is used in which a stranded steel wire is inserted into a drilled hole and fixed by a hardening material.

The vertical beam 3 is fixed to the anchor 2. The vertical beams 3 are laid out along the natural ground surface to form a formwork, and shot concrete is placed. The vertical beam 3 is formed in a columnar body in the embodiment. The protruding portion of the anchor 2 from the natural ground is passed through the vertical beam 3 and fixed by a nut 4 or the like.
(Fig. 2) Keep the protruding part of the anchor 2 from the ground sufficiently long.

In this way, the upper excavated ground surface is temporarily fastened with the vertical beams 3 to prevent collapse, and further excavated downward. (FIG. 3) The excavated ground is also temporarily fixed by the vertical beam 3 in the same manner as described above. (4th
(Fig.) After that, excavation and temporary fastening are repeated to excavate the entire ground as planned. (Figs. 5 and 6) A ready-made earth retaining panel 5, which is an earth retaining structure, is erected along the excavated ground surface 1. The anchor 2 is fixed to the earth retaining panel 5 with a nut 6 or the like through the protruding portion of the anchor 2 from the natural ground. As the soil retaining panel 5, in the embodiment, the soil retaining panel 5 having an arcuate arch portion 7 and a shelf-like reinforcing portion 8 on its front surface is used. The anchor 2 is passed through both ends of the soil retaining panel 5 to be fixed.

Between the soil retaining panel 5 and the excavated ground surface 1, crushed stones 9 for draining water from the ground are packed. (FIG. 7) The soil retaining panels 5 are sequentially stacked on the soil retaining panels 5, fixed to the anchors 2, and crushed stones 9 are packed. (FIG. 8) The above work is repeated to cover the entire surface of the excavated ground 1 with the soil retaining panel 5.

The earth retaining structure is not limited to the earth retaining panel 5 having the above-mentioned shape, but various other materials such as a flat panel can be used.

〔The invention's effect〕

The present invention can obtain the following effects by the above configuration.

B. The ground is excavated in multiple stages from top to bottom, and the vertical beam can be used to temporarily secure the excavated ground surface at each stage, reducing the risk of ground collapse during construction. You can work safely.

(B) If the vertical beam is designed as a permanent structure, the back pressure that acts on the soil retaining structure is small, and the strength of the soil retaining structure itself does not need to be too large, and a lightweight structure can be used, and the cost is lower. Can act. In addition, the vertical beams can share a load close to all of the earth retention loads, and there is a design correspondence range, and the earth retention method is ideal because it can be optimally designed according to the site conditions.

By installing a vertical beam, the unevenness of the excavated surface can be leveled and this vertical beam can be used as a foundation beam that is a pillow for installing earth retaining structures. Therefore, the earth retaining structure can be installed accurately and easily.

(D) Due to the above effects, it becomes possible to extremely safely and easily carry out the earth retaining of the vertical ground, which was conventionally extremely difficult.

(E) In this earth retaining work, which has not been established by this construction method, for retaining large ground, it is a reverse construction method that excavates from the top in order and stabilizes, then excavates to the bottom, and then piles up soil retention structures from the bottom. It is possible to construct concretely.

[Brief description of drawings]

1 to 8 are sectional views showing the order of construction of one embodiment of the present invention, FIG. 9 is a transverse sectional view after completion of mountain fastening, and FIG. 10 is a perspective view showing a construction state. 1 ... excavated ground surface, 2 ... anchor, 3 ... vertical beam, 4 ... nut, 5 ... earth retaining panel, 6 ... nut, 7 ... arch part, 8
… Reinforcement part, 9… Crushed stone.

Claims (2)

[Claims] 1. An excavation of a rock from a top to a bottom in a plurality of steps, an anchor is placed from a rock excavation surface at each step, and a vertical beam arranged along the excavation surface is used as an anchor. To prevent the ground from collapsing, excavate to the lower end, and then stand up the soil retaining structure from below in order along the excavation surface, fix it to the anchor, and stack the soil retaining structure along the excavation surface. Yamadome method. 2. The mountain retaining method according to claim 1, wherein the vertical beam is a columnar body made of concrete.