JPH0333320A - Landslide protection wall technique - Google Patents

Abstract

PURPOSE:To enable execution safely by driving an anchor from an excavating face at every stage excavated to a bedrock, fixing longitudinal beams disposed along the excavating face to the anchor, erecting a sheathing structure along the excavating face and fastening the sheathing structure to the anchor. CONSTITUTION:A bedrock is excavated in a plurality of stages at every fixed height from an upper section along a design line, and anchors 2 are driven toward the bedrock from an excavating bedrock face 1 at every stage. Longitudinal beams 3 are fixed to the anchors 2, and the longitudinal beams 3 are penetrated into protruding sections from the bedrock of the anchors 2 and the protruding sections are fastened by nuts 4. A lower section is excavated and fixed temporarily by the longitudinal beams 3, and excavation and temporary fixation are repeated and the whole surface of the bedrock is excavated. Sheathing panels 5 are erected along the excavating bedrock face 1, and the protruding sections from the bedrock of the anchors 2 are passed through the panels 5 and the panels 5 are fastened by nuts 6. Sections among the panels 5 and the bedrock face 1 are filled with crushed stone 9.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a retaining method for stabilizing the surface of an excavated ground, and in particular, a retaining method for stabilizing a long excavated ground. It is related to.

[Prior art and its issues]

When retaining a long and high ground, the method used is to excavate from the top to the bottom all at once, and then install retaining structures along the surface of the excavated ground.

However, after excavating a large excavation surface, the excavated ground remains unstable until the earth retaining structure is fixed, and it is extremely dangerous to work under this ground surface.

In addition, if the structure is to support all the pressure exerted on the back of the structure when the excavated ground is about to collapse, the structure must have great strength.

This invention was made in order to solve the above-mentioned problems, and the purpose is to provide a mountain retaining method that allows safe construction and does not necessarily require large strength of the earth retaining structure. do.

[Means to solve the problem]

The mountain retaining method according to the present invention is one in which temporary retaining is performed sequentially as the ground is excavated.

When retaining a long excavated surface, the excavation is done in multiple stages from the top to the bottom. In other words, the tunnel is excavated one after another to a predetermined height, and temporary fixing is performed after each excavation.

First, anchors are driven from the ground surface at each stage. A vertical beam placed along the ground surface is fixed to this anchor, and the vertical beam prevents the ground surface from collapsing. Concrete columnar bodies can be considered as the vertical beams, and ready-made ones may be used, or they may be constructed by assembling formwork and pouring concrete on site.

With this vertical beam temporarily secured, a long mountain face is excavated by repeatedly excavating downward and temporarily securing.

After excavation is complete, earth retaining structures such as existing concrete panels will be erected along the excavation surface. This earth retaining structure is fixed to the above-mentioned anchor. A gap may be provided between the earth retaining structure and the ground and filled with earth and sand or crushed stone.

Further earth retaining structures are stacked on top of the earth retaining structures and fixed to anchors to complete the retaining of the entire excavated ground.

〔Example〕

Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

First, the ground is excavated from above along a planned line in multiple stages at predetermined heights. For each excavation, the anchor 2 is driven toward the ground from the excavated ground surface l. Although various configurations can be adopted for the anchor 2, a ground anchor is used in which a steel strand is inserted into the tag and fixed with a hardened material.

The '#1 beam 3 is fixed to this anchor 2. The vertical beams 3 are constructed by arranging reinforcement along the ground surface, constructing a formwork, and pouring concrete. In the embodiment, the vertical beam 3 is formed into a columnar body. The protruding portion of the anchor 2 from the ground passes through the vertical beam 3 and is fixed with a nut 4 or the like. (Figure 2) The part of the anchor 2 that protrudes from the ground should be long enough.

In this way, the upper excavated ground surface is temporarily fixed with the vertical beams 3 to prevent collapse, and the lower part is further excavated. (Fig. 3) This excavated ground is also temporarily secured with vertical beams 3 in the same manner as described above. (4th
Figure) After that, excavation and temporary fixing are repeated to excavate the entire surface of the ground as planned. (Fig. 5.6) A ready-made earth retaining panel 5, which is an earth retaining structure, is erected along the excavated earth surface 1. The protruding portion of the anchor 2 from the ground is passed through the soil retaining panel 5 and fixed with a nut 6 or the like. As the retaining panel 5, in the embodiment, a retaining panel 5 having an arcuate arch portion 7 and a shelf-like reinforcing portion 8 on the front surface thereof is used. The anchors 2 are passed through both ends of the retaining panel 5 and fixed.

Crushed stone 9 for draining water from the earth is packed between the earth retaining panel 5 and the excavated earth surface l. (FIG. 7) The earth retaining panels 5 are stacked one after another on top of the earth retaining panels 5, fixed to the anchors 2, and crushed stones 9 are filled.

(Fig. 8) By repeating the above operations, the entire surface of the excavated ground 1 is covered with the retaining panels 5.

The earth retaining structure is not limited to the earth retaining panel 5 having the shape described above, but various types such as flat panels can be used.

〔Effect of the invention〕

With the above configuration, the present invention can obtain the following effects.

■ The ground can be excavated in multiple stages from top to bottom, and the surface of the excavated ground can be temporarily secured using vertical beams at each stage, reducing the risk of the ground collapsing during construction. , can work safely.

@ If the vertical beam is designed as a permanent structure, the back pressure acting on the earth retaining structure will be smaller, and there will be no need to increase the strength of the earth retaining structure itself, allowing the use of lighter structures and lower costs. It can work. In addition, it is possible to have the longitudinal beams share almost all of the earth retaining load, and there is a wide range of design flexibility, making it ideal as an earth retaining method as it allows for optimal design according to site conditions.

■ By installing vertical beams, unevenness on the ground excavation surface can be smoothed out, and these vertical beams can be used as foundation beams that serve as pillows for installing earth retaining structures. Therefore, the earth retaining structure can be installed accurately and easily.

■ Due to the above-mentioned effects, it is now possible to secure vertical ground, which was previously considered extremely difficult, extremely safely and easily.

■ This construction method is used to hold back a long ground that has not been previously established, and involves excavating from the top to the bottom while stabilizing it, and then stacking earth retaining structures from the bottom. Construction method-based construction becomes possible.

[Brief explanation of drawings]

1 to 8 are sectional views in the construction sequence of an embodiment of the present invention, FIG. 9 is a cross sectional view when the heaping is completed, and FIG. 1O is a perspective view of the construction state. 1... Excavation 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) Excavate the ground in multiple stages from above to below, and drive anchors from the ground excavation surface at each stage.
Vertical beams placed along the excavation surface are fixed to these anchors to prevent the ground from collapsing, and after excavation to the bottom end, earth retaining structures are erected sequentially from below along the excavation surface and fixed to the anchors. , a mountain retaining method in which earth retaining structures are piled up along the excavation surface. (2) The mountain retaining method according to claim (1), wherein the vertical beam is a columnar body made of concrete.