JPS5996313A - Sand protecting and breakwater dam - Google Patents

Abstract

PURPOSE:To completely prevent the scattering of sand and force of tidal wave on the coastal line or at the position of the dam by forming a curved line permitting the utilization of its dynamical characteristics on the seaside wall of a dam. CONSTITUTION:The seaside edge line 4 of the vertical cross section of a dam 1 is shaped into a curved form such that a gentle rise from the horizontal face is changed to vertical form toward the inland direction and the vertical form is curved with gradually reducing radius and ended before heading for the lower part of the vertical section. By such a curved line, the force of tidal waves is raised along a smooth curve according to the water level and energy, changed into potential energy, and then dropped. Since the falling sea water serves as forces in the opposite and right-angled directions to the following tidal waves, the tidal wave force is damped by itself and the reach of the tidal waves onto road can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dam having a sand control and wave barrier effect, and more specifically, the present invention relates to a dam having a sand prevention and wave barrier effect, and more specifically, a dam whose ocean side wall surface is a logarithmic curved surface, a parabolic surface, a catenary curved surface, and other curved surfaces that can take advantage of their mechanical characteristics. This invention relates to a dam that has a characteristic structure that uses its curved surface to reverse the force of flying sand and waves that the dam receives, and attenuates the force of flying sand and waves that continue to push in.

In coastal areas, especially on sandy beaches, large amounts of seawater spray and flying sand wash over inland urban areas, roads, forests, farmlands, etc. on rough days, necessitating large areas of sand protection forests and buffer zones. In addition, dams are constructed to prevent flooding during typhoons, but because most of these walls have vertical ocean walls, the waves crashing against the dams are blown up vertically, and the force of the wind is added to inland areas. There were many cases in which roads were flooded due to repeated patterns of falling onto the roads, making traffic impossible.

The present invention prevents the above-mentioned damage by almost completely suppressing the force of flying sand and waves at the coastline, that is, at the location of the dam, and also makes it possible to collect sea sand carried by the waves, and use it as construction material. It provides a dam that can be used. In other words, the waves hitting the ocean side wall of the dam of the present invention rise up the curved surface of the dam, and because the curved surface is a corresponding logarithmic curve, theoretically, the waves reach the upper end of the curved surface with almost no kinetic energy consumed. , it acts as a force in the opposite direction or at right angles to the succeeding waves, falls against them, and cancels out the force of the succeeding waves.

According to the present invention, damage caused by flying sand that flies up and reaches the hinterland is almost completely prevented, and a fixed sand pool is temporarily formed. This accumulated sand must be removed intermittently to maintain the effectiveness of the dam, but this accumulated sand itself can be reused as an effective resource. Furthermore, according to the dam of the present invention, there is a net that prevents flying sand, which cannot be called aesthetically pleasing, and a dam that is distorted.
It is possible to convert polluted sand protection forests into environmentally friendly plantings and enhance the beauty of the surrounding area.

Hereinafter, the present invention will be described in detail by way of examples with reference to the drawings.

FIG. 1 is a perspective view showing a vertical cross section of the dam of the present invention. 1
is the dam, 2 is the crown, 3 is the ocean side wall surface, and 4 is the edge line on the ocean side of the vertical section. In the present invention, the shape of this edge line 4 is important; it is a continuous curve that gradually rises from horizontal toward the inland direction, changes to vertical, then curves while gradually decreasing the radius, and ends before heading vertically downward. It requires something. In the case of Figure 1, the formula r=me (however, m > Q, 8
=2.718..., r and θ are polar coordinates. ) of the logarithmic spiral curve, from point Q, where it begins to rise from the horizontal, to point P, where this curve curves into a spiral shape and begins to descend. That is, the curve from point Q to point P satisfies the above conditions of the present invention. Other desirable curves include parabolas, catenary curves, and logarithmic curves.

When such a curved surface is used, waves rise up the smooth curved surface according to their water level and energy, are replaced by potential energy, and then fall. At this time, the falling seawater acts as a force in the opposite or perpendicular direction to the following waves, resulting in the waves being reduced by the force of the waves themselves. In addition, the ocean side wall surface of the dam itself is not only a curved surface that satisfies the above conditions, but also a smooth surface, so even on a rough day it receives almost no additional physical pressure from waves and follows the above curved surface. It only needs to be strong enough to withstand the centrifugal force of the waves, and has the advantage of suppressing the energy of the waves and maintaining the dam.

Furthermore, if the top of the dam is sufficiently strong, it can be used as a promenade, road, or parking lot.

The height of the dam needs to be higher than the expected highest tide level and wave height.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view showing a vertical cross section of a dam, and FIG. 2 is an example of a curve used for the ocean side wall surface. In the drawing, 1 is the dam, 2 is the crown, 3 is the ocean side wall, and 4 is the edge line. Patent Applicant Yukio Mori Tomo Attorney Patent Attorney Sada Suzuki (Written Amendment Form) March 15, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of Case Patent Application No. 202163 1988 , Title of the invention Sand control/breakwater dam 3, Relationship to the case of the person making the amendment Patent applicant address 3-61 Higashi Minami 5-chome, Chigasaki, Kanagawa Name Yukio Moritomo 4, Agent ■150 Telephone 03-463- No. 5046 No. 5, Date of amendment order: February 2, 1980 Date of dispatch: February 22, 1982 6, Subject of amendment Application and specification

Claims (1)

[Claims] It has a smooth curved surface in which the ocean side edge line of the vertical cross section gently rises from horizontal toward the inland direction, changes to vertical, and then curves while gradually decreasing the radius, ending before heading vertically downward. A sand control/breakwater dam that forms the ocean side wall.