RU2524814C1 - Tsunami damper - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: tsunami damper comprises a block of channels 1 in the form of, for instance, packages of large-diameter pipes, installed on the sea bottom. At the side of the sea compressing deflectors 2 adjoin the end of the channels 1 block, and the upper deflector is strengthened with stiffening ribs 3, and the lower one rests onto the bottom base, which was previously profiled and reinforced against erosion, and is equipped with anchor joints. A reversible deflector 4 adjoins the other end of the block, at the shore side, having a channelled form and reinforced with support structures 5 with anchor joints. Tsunami waves are damped by impacting them with a strong opposite hydraulic flow, generated on their way with the proposed device, which reduces their destruction energy to the minimum.

EFFECT: using such tsunami dampers will make it possible to preserve natural conditions for ecosystems of coastal area and its natural landscape.

2 dwg

Description

The invention relates to hydraulic structures, in particular to devices for protection against the impact of destructive waves on the coast, and can be used to attenuate tsunami waves with an efficiency that is directly dependent on their intensity.

The tsunami is one of the most destructive natural phenomena: the scale of the calamities caused and the number of human casualties are not only terrible in themselves, but such phenomena with their potential danger create constant alarm among the population of very many coastal regions of the world, especially if other hazardous facilities are located in the danger zone , such as nuclear power plants.

The power of the most destructive tsunami waves is so great that in many very authoritative sources of information the impossibility of effective protection from them is stated. And this can be taken with understanding.

At the same time, taking into account, on the one hand, the due responsibility of the world community for the fate of the population of potentially dangerous territories, on the other hand, the great technical, economic and intellectual capabilities of modern civilization, it seems indisputable that all efforts should be made to search for and make the widest practical use of real technical solutions for the reliable protection of such territories from natural and man-made disasters. And such attempts are being made.

Known constructions of structures for attenuation of waves, including and tsunamis in the form of coastal and coastal dams, pneumatic breakwaters, coastal systems with deformable volumes in the form of objects made of porous materials or gas cylinders with elastic walls (RF patent No. 2147060, 2006), as well as complexes for damping wave energy from them reflection by front plates on triangular supporting structures (patents US 4818141 A, 1989 and the Russian Federation No. 2147641, 1998). All these devices are suitable for protection against ordinary wind waves and swell when their speed and impact force do not exceed certain critical values. For a tsunami with incomparable destructive power, the effectiveness of such protection is clearly not sufficient. Moreover, the integrity of the structures themselves under the influence of such waves is not guaranteed.

A device is known for reducing the destructive effect of a tsunami (RF patent No. 2310708, 2005), adopted as a prototype of the claimed invention.

This device includes a coastal structure in the form of embankments, in which tunnels are made with a c-shape, with inlet and outlet openings oriented perpendicular to the coastline, the length of the lower tunnels and their sections exceed the corresponding parameters of the upper parts, the lower part of the tunnels is located at sea, and the upper tower rises above it, while the curvature of the shape of the tunnel ensures a rotation of the velocity vector of the stream entering its lower part by 180 ° when the stream exits through the upper part unnelya.

It should be noted that the very key idea of using wave energy for their destruction is very valuable and probably the most fruitful in solving the problem under consideration: it, for example, is the basis for the design of a pneumohydraulic non-volatile breakwater (RF patent No. 2461681, 2012) an option would be a structure capable of changing the direction of the dangerous waves in the opposite direction, but this, of course, is not realistic, in any case for powerful tsunami waves.

Taken as a prototype device, however, has a number of disadvantages that impede its practical use.

Firstly, the placement of protective structures on the shore dramatically reduces the efficiency of their work when all the tsunami energy has already transferred to the energy of a surface wave, raising it to a height many times higher than the height of the structures themselves. At the same time, in order to provide the necessary advancing to the main wave extinguishing flow, the tunnels and embankments would have to be very large, which, in addition to the large costs, would require building up vast precious areas of sea coasts with them, permanently damaging their natural landscape.

Secondly, the ratio of the cross-sectional area of the tunnels and the size of the entire front of the protective structures does not provide the necessary relative magnitude of the damping flow and, therefore, the main shock power of the wave is preserved, and the latter is also capable of destroying the usual embankment with its naturally weak structure.

Thirdly, the presence of gaps between the embankments will allow the concentrated flows in them to fall into the protected objects with all their might, eroding the side surfaces of the embankments along the way, and the fragments of the protective structures demolished by the stream will strengthen the destructive potential of the tsunami.

The main objective of the invention is the creation of a reliable protective device against tsunami waves, in which the above disadvantages are absent.

In solving this problem, while maintaining the principle of damping waves by their own energy, new approaches have been used based on the specifics of tsunami wave propagation on the sea shelf. Taking into account the difference between their dynamics and the behavior of ordinary waves, adequate methods for their destruction were found, which made it possible to create an effective tsunami damper with channels for accelerating the quenching flow and a device for its reverse, characterized in that it is created according to the invention in underwater design and equipped with flow compressing deflectors , its channels are made with their dense arrangement, for example, in the form of packets of pipes of large diameter, and the reversing device is made in the form of an open deflector.

Placing the device on a deepened slope of the bottom, where dangerous tsunami waves begin to rise, allows you to select and use the energy of the “bottom” part of the shock wave concentrated in the water column of the shelf zone.

The presence of compressive deflectors increases the size of the trapped wave front and, due to the concentration of the flow, increases its speed and, consequently, its energy. The increased energy is supported by the very small frontal resistance of the ends of the channels and the obstacle created by their walls from scattering into the surrounding space, while a significant fraction of the energy of the rest of the shock wave is dissipated by the formation of vortices behind the deflectors and the rise of the surface wave.

An open reversing deflector forms behind the channels a common powerful flow, directing it towards a direct shock wave.

The device of the tsunami damper is illustrated by the drawings: Fig. 1 shows a longitudinal section thereof, Fig. 2 is a schematic view of a tsunami quenching zone.

A tsunami damper consists of a channel block 1 located on the seabed, and if it is implemented as a package of round pipes, both their internal and external - annular - channels are the channels. Compressing deflectors 2 are adjacent to the end of the channel block 1 from the sea side, the upper one is reinforced with stiffeners 3, the lower one rests on the bottom base, which is previously profiled with its hardening against erosion, the outer edge of this deflector has anchor fasteners. A reversing deflector 4, having a grooved shape and reinforced by supporting structures 5 with anchor fasteners, is adjacent to the other end of the block — from the shore side.

The operation of the tsunami damper is illustrated in a schematic view (figure 2).

The main tsunami energy, even in the deep water zone, is concentrated in the near-surface water column (see Kaftanov Yu.V. Special functions of mathematical physics, § 2. Mathematical model describing the behavior of tsunamis, p. 44, § 5. Model of tsunami wave propagation, s .107. Publisher: X. “New Word”, 2009). On approaching the shelf, all of it, with the exception of losses associated with the movement of water mass, is concentrated when passing over the shelf slope of the bottom and is transferred to the shallow water by a powerful front. Under ordinary natural conditions, it is here that a giant wave rises, rapidly rolling on the coast. And the shorter the path to the coast, the more force it falls upon it.

If the proposed tsunami damper is installed at the shallow water boundary, then the entire wave front, having reached it, will be cut into two zones: the lower one, additionally compressed by deflectors 2, will form an accelerated flow through channels 1, which will reach the reversing deflector 4 with the necessary advance and turn towards the flow the upper zone of the wave front. A huge water wall rises above the meeting point of these two streams of comparable power, which, however, having an insignificant horizontal speed, will immediately collapse, forming two secondary waves (they are indicated by a dash-dotted line): one of them will go towards the open sea, towards the tsunami waves, the second will go to the shore. But this will already be an ordinary surface wave with moderate dimensions and speed of movement in shallow water that are not comparable with the parameters of a tsunami wave. If necessary, on its way it is possible to provide for additional known wave breakers, for example, the above-mentioned pneumohydraulic ones (RF patent No. 2461681, 2012), which also reliably protect the coast from ordinary wave erosion.

It should be noted that with the above-described meeting of the fronts, the lower layer of the direct flow (shown in Fig. 2 by thickened arrows), without colliding with the quencher, which is provided with a more developed deflector 4 design, will reach the last one, will turn it in the opposite direction and through channels 1 will go towards the sea. This effect will additionally reduce the direct impact of the tsunami and even to some extent weaken the next wave.

Stiffeners 3 and supporting structures 5, which, based on the impact of a large impact force, are provided with deflectors 2 and 4 of the inventive device, will take on dangerous mechanical loads. If necessary, both compressive deflectors 2 can be reinforced with additional mutual connections. Surfaces in contact with the marine environment must be protected from corrosion and fouling.

The design of the tsunami damper, according to the author, is universal: for the convenience of designing such structures with reference to a specific area and their industrial production, they can be developed and presented in a certain size range.

The creation and installation of the proposed tsunami suppressors, of course, is associated with high costs, but the goal justifies these costs, which are hardly comparable to the potential damage from the impact of the tsunami, not to mention the possible human losses. And this goal is achievable, since such structures can minimize the danger of this almost unpredictable natural disaster, while preserving the natural landscape and conditions for coastal ecosystems.

Claims (1)

A tsunami-damper having channels for accelerating the quenching flow and a device for its reverse, characterized in that it, created in underwater design, is equipped with flow compressing deflectors, its channels are made with their dense arrangement in the form, for example, of large diameter pipe bundles, and the reversing device is made in the form of an open deflector.

Images