JPS58210205A - Controlling dam for debris flow - Google Patents

Abstract

PURPOSE:To suppress the impaction acting on a dam body by a method in which the upstream side of the lattice formed dam is inclined upwards toward the downstream side of the dam in such a way as to permit huge rocks in debris flow to ride on it. CONSTITUTION:A dam 1 is constituted of wings 2 made of concrete and a steel lattice-work 3 provided between the wings 2, and the steel lattice-work 3 is inclined 9 upwards toward the downstream side of the dam 1. Thus, the debris flow is directed downwards through an opening 8 and huge sizes of rocks are ridden on the upwardly inclined part 9 by their potential energy E1. Therefore, impaction acting on the dam body is reduced by as much as P1 or the potential energy, the sliding and turning movements of huge sizes of rocks are suppressed, and the falling moment is also greatly limited.

Description

[Detailed description of the invention] The present invention relates to a debris flow control tom.

In recent years, there has been a desire to control the flow of sediment through water systems, and erosion control dams with positive sediment control effects have come to be expected. In addition, the so-called phantom 1-upstream is gradually becoming clearer, and the percentage nature of debris flows is being effectively utilized.

In this way, new types of dams are being researched and developed to replace conventional gravity concrete dams.

These dams removed the powerful destructive power of debris waves by changing the quality of debris flows into bedrock, and in history, they aimed at the organic O 2 function of rivers. It is. Here, a drastic change in a debris flow is a change in the debris flow into a bed-sweeping flow due to changes in the moisture content of the debris flow, reduction of the dense layer, finer grains of the constituent gravel, etc.

When the water content of a debris flow becomes extremely high, it enters a sweep state, and when the water content a#: is extremely low, it becomes a mass of gravel and comes to a halt.

Debris flows generally have a high density force, so their movement is naturally large. Therefore, in order to reduce the movement cap, that is, the destructive force, it is sufficient to create a low-density sweep state. For this reason, the idea is to either add water or remove the boulders present in the fluid, but the former is extremely difficult. Therefore, the latter method of removing the boulders in the raw material, the so-called method of sieving the transported gravel and leaving the boulders in the fertile bed, is effective.

From this point of view, slit-type sabo dams, wire rope net-type dams, and beam-type dams have been proposed.

In other words, a slit-type dam has a deep slit in the part that allows water to pass through compared to a conventional gravity-type concrete dam. The slits in a concrete slit dam, such as X 3, are made from steel pipes.

In addition, the wire rope net type dam takes advantage of the elasticity of wire rope (1) to alleviate the strong impact force of a debris flow, blocking only one debris, and allowing small debris and mudflow to flow downstream. The idea is to reduce the kinetic energy of the debris flow and help it stop.

Furthermore, a screen type dam is constructed by using steel pipes or shaped steel for the beams of a beam type dam, which is effective against earth and sand flowing out during normal times and is being constructed in large numbers.

However, debris flows have T1-like properties.

(A) It is not transported individually, but in the form of pension transport.

(B) Most of the debris includes slag, driftwood, etc., and single gravels gather at the top to form a raised top, and beyond this, water debris and lahar continue to flow down.

(C) At the leading end, a large amount of gravel rotates or slides down while flowing down, and therefore has a large destructive force and impact force.

(D) The erosive force is extremely large, and when it occurs, small-scale particles grow and flow down the stream while taking in streambed sediments, causing deep erosion of streambeds and banks.

It has the following properties.

Therefore, when using a slit type dam or a wire rope net type like the conventional type described above, it is not possible to take into account all the predisposition properties of a debris flow, leading to disasters.

Also, although the beam type is advantageous in terms of workability, it is more susceptible to damage from debris flows.

In particular, the conventional beam type (concrete dam with an opening in the center and array of Parken dams, concrete gravity type for the oil part and grid-like water passage part, dam made of steel truss, water A slit is made with a steel pipe in the passage part,
A dam with a lattice-shaped driftwood stopper on the front) is used when the upstream side of the dam is on a plane perpendicular to the direction of impact of the debris flow.
fc, h+ 5 If it receives the impact of a huge debris flow, it will become l-4r, and the overturning moment will be large, and the debris will accumulate on the front, making it easy to slide.

Therefore, the present invention aims to reduce the overturning moment and reduce the overturning moment by constructing a structure in a shape that prevents the sliding of single debris accumulated on the dam, while the huge debris flow uses the potential energy of riding up on the upstream side of the dam. The purpose of this project is to provide a debris flow control dam with complete measures against debris flow.
In the present invention, the part that regulates the debris flow is a lattice-type dam, and the upstream side of the lattice-type dam is sloped upward toward the downstream side of the dam, where one debris from the debris flow can be loaded onto the dam. It is expressed as a percentage.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a front view of the regulation dam ill according to the present invention, and FIG.
Although the figure shows a plan view, the dam fi+ is mainly composed of a concrete oil section (2+ + 21) and a steel lattice-shaped section (3) between the oil sections (21). river,
In particular, the vertical structure is constructed on the mountain stream bed (4).

Floor 16 Steel lattice type part (31 is a steel pipe (6) with a hollow cross section, for example, a circular shape, which is joined vertically and horizontally with bone a L- by means of joints, etc., and the joining part (6) is an anchor plate, an anchor It is embedded in the foundation concrete (7) and fixed to the bedrock with bolts or the like.

The lattice-shaped part (3), which is made up of steel pipes (BL) vertically and horizontally, has a number of water passages of 1, iB i8+, and itself functions as a stop for driftwood, etc.

The oil section (2) is constructed as a gravity concrete dam as shown in Figure 4, and the upstream plane of the lattice section (3) is covered with debris from the debris flow, as shown in Figure 3. It is said that the 4th tom is upwardly oriented toward the downstream.

To explain more specifically, the direction of action of the debris flow (1()・
In the embodiment, the angle θ is approximately 45°.

Therefore, if the velocity of the debris flow is τ and its Jjk amount is 4, its kinetic energy E will be E-Save〃Lv2,
Since it is tilted upward, the potential energy key E1 becomes E in Figure 3 and becomes 'tttv 2, and eventually E-
Saving m v2 = El 0 PI, and here, the impact force P will act on the skeleton, that is, the lattice type part (3), but the kinetic energy acting on the skeleton will be smaller by the potential energy E1. be.

Comparing this with the conventional example, in the conventional case v, 1 dam F flow side is the direction of action ill! Therefore, the kinetic energy E is acting on the skeleton, and the impact force is quite large.

In addition, the overturning moment is large, and boulders accumulate at the front, causing the building to slide and scrape off the foundation concrete.

On the other hand, in the embodiment of the present invention, the crushed water, etc. of
Of these, the boulders tilt upward (9) due to potential energy E1.
The impact force that is placed on top and acts integrally here can be reduced by Pl, that is, the potential energy.
This prevents the gravel from sliding and rotating while being carried on board, and also reduces the overturning moment.

From this point of view, the lattice type part (31 T' H, 1111 (
II.t'' This may be configured to be perpendicular to the direction of action (10), and the material L11' used here or its superimposition may be approximately the same as the conventional one. In addition, the sedimentary soil will also work on the stable side.

Additionally, in FIG. 3, 021 indicates a sub-dam.

Note that in the present invention, it should be understood that the lattice-shaped portion (3) can be made of shaped steel in addition to the steel pipe (5).

According to the present invention, since the upstream side of the lattice-shaped part, which is the regulating part of the dam, is inclined upward toward the downstream with respect to the acting direction of the debris flow, a part of the acting force of the debris flow is converted into potential energy. However, not only could the boulders be mounted on top of them to prevent them from sliding and rotating, but also the impact force acting on the structure could be suppressed. The practicality of the present invention is remarkable as it has succeeded in taking complete disaster prevention measures by taking into consideration the characteristics.

[Brief explanation of drawings]

The drawings show examples of implementation of the invention, the first being a front view and the second being a front view.
The figure is a plan view, Figure 3 is an arrow diagram of No. 1 1654131,
4 is the same as the arrow 4-4 in FIG. 1. (1)...Dam, (2)...Shaft part, (3)...Lattice type part, (6...Steel pipe, (9)...Upward slope part. Patent application People Kobe Steel Co., Ltd. 81st generation
Attorney Patent Attorney Yasu 1) Toshio 1: i□・□;
1・1

Claims (1)

[Claims] 1. For dams with a lattice-type part that regulates debris flow, the special requirement is that the upstream side of the lattice-type dam be sloped upward toward the downstream of the dam, where boulders from the debris flow can be carried. dam.