Modular dike for shore protection

Abstract

The invention relates to a modular dike which is intended for shore protection. The inventive dike is based on a reduced number of different prismatic, tubular modules including one quadrangular-section module, two triangular-section modules and a straight trapezoidal-section module. The aforementioned modules are equipped with tongue-and-groove coupling means for the stacking thereof and lateral fixing means such that it is possible to produce a dike of any width, height and section. Moreover, the modules have a thickness of the order of 2.5 metres, a similar height and a length of between 6 and 12 metres. In this way, the dimensions of the modules are suitable for the standard containers that are used to transport goods by road and, more specifically, the constituent modules of the dike can be transported by road on the standard transport network used for the containers. Furthermore, the modules are provided with large lightening holes and, following installation, the modules can be stabilised using, among other means, sand-filled geotextile bags which are disposed therein.

Description

OBJECT OF THE INVENTION [0001] The invention relates to the field of shoreline maritime works, dikes and groynes for shore protection, designed to reduce shoreline wave energy so as to improve beach stability or to reduce overflow and improve conditions of coastal flooding due to storms. The precise object of the invention is the definition of modular units which afford construction, within a very short period of time, of shoreline maritime works, dikes or groynes of varying shapes and sizes, easy to dismantle, and with a reduced impact on the environment. The invention is especially recommended for shore protection works in situations of emergency following major storms, where the coast requires protection against waves and the construction of a conventional structure, effective and reliable from an environmental standpoint, is not an option, due to lack of habitual time and information. ANTECEDENTS OF THE INVENTION [0002] Storms cause erosion, flooding and damage of different desc...

AI Technical Summary

Benefits of technology

[0009] The fundamental advantage of the invention is the ability to industrialise the construction of a large part of the dike and to optimise the logistical aspects of dike construction on land or sea. By being able to construct a large variety of dikes with a few basic modules, it is possible to optimise and industrialise the module manufacturing process in places suitably prepared for the purpose (pre-manufacturing plants), avoiding the environmental impact and cost increments involved in on-site and / or tailored to the site construction. The dismantling of a modular dike allows the modules to be reutilised in the construction of other dikes, reutilising and avoiding the production of residues, with the ensuing economic and long-term environmental advantage. Furthermore, as the basic modules have certain standardised weights and dimensions similar to or compatible with those of the containers (section of 8×8 feet and lengths of 20 and 40 feet) and can be transported by the intermodal container transport network, it is possible to efficiently manage large centralised stores of basic modules, to be transported in a short space of time, with a large degree of flexibility and at little cost, to the place on the shoreline requiring the construction of a groyne or protection dike. In this way, reductions are achieved in environmental impacts, prefabrication costs, installation and dike operability times. In addition, the elements resulting from the dismantling may be reutilised, minimising the impact on the global environment.

[0010] The invention permits change in the manner in which shoreline protection is currently managed. The ability to construct different types and sizes of dike for shoreline protection using few basic elements makes large-scale industrialised production of basic modules possible, to be stored in determined deposits prior to distribution. Industrial production, transport and storage would be very efficient processes from an economic and environmental stance, since it would be a matter of executing scheduled, repetitive tasks, continuous over time, and unconstrained by space. Once the need for rapid intervention has been established (for example, following a large storm), a construction project would be swiftly drawn up, adapted to the site (floor type, depth and maritime climate), the necessary modules would then be transported from the distribution deposits. The on-site construction would be simple, and at a later stage, the structure could be easily modified or dismantled, and the basic elements reutilised. The logistical, economic and environmental advantages of the invention are evident.

[0011] In addition to the clear logical, economic and environmental advantages (if mass produced), the invention affords flexible shoreline management, reduced global environmental risks and shorter intervention times for shoreline protection. Furthermore, modular dikes permit a total separation, in time and space, of the prefabrication and installation processes; accumulated reserve modules may be used in situations of crisis (large storms simultaneously affecting extensive areas of shoreline). And furthermore, shoreline intervention times are clearly reduced, as the only requirements are for modules to be transported from the deposits to the dike site using the efficient intermodal container network and for maritime equipment to be available for the mounting and stabilisation of the dike. Lastly, the dike, made up of reutilisable basic modules of reinforced concrete, in addition to being easy to dismantle, has a residual value which underpins the economic interest in dismantling and reversing the end works; this means the environmental impact would be small, and a guarantee thereof would be offered, which does not accompany non-modular prefabrications.

[0012] The invention permits the construction of emerged or submerged modular dikes, with numerous gaps, to be used in all likelihood by abundant marine species, as occurs in artificial reefs. These modular dikes will generally be installed within the breaker zone (up to 7 metres deep) to support beaches or diminish waves reaching the shores. In their wave-reducing function, these dikes may be used to signal the limit of the bathing area, utilising the danger signals for boats to protect bathers. In this breaker zone, the gaps, with different levels of light as defined by the modular dike, allow different marine species to settle and shelter, and therefore to benefit from the new ecological space. Thus, in addition to contributing to beach and shoreline protection, these dikes may serve to heighten the productivity and stability of marine ecosystems.

[0013] More concretely, the invention advances the construction of dikes based on a series of basic modules, which are essentially prismatic and have varying sections. For illustrative purposes, four prisms of different sections have been defined, namely, a quadrangular prism, a rectangular triangular prism with little difference between catheti, a straight trapezoidal rectangular prism with considerable difference between catheti and a straight trapezoidal prism. All these modules have a width comparable to that of a conventional container (8 feet), and a direct or combined height roughly similar to that of a conventional container, for transport by semi-trailer, free from clearance issues. The length of the modules may vary, but would ideally be as long as the most usual conventional container length, to facilitate transport by the usual means for such containers.

[0014] For easy dock crane manipulation, the weight of the basic module must not exceed 30 tons. Using these basic modules, modular dikes can be constructed from 4 up to 24 feet high with inclined vertical batters from 1 / 1 to 2 / 1, which covers the bulk of requirements of works for shoreline protection.

Problems solved by technology

Storms cause erosion, flooding and damage of different descriptions to large swathes of coastal areas.

In particular, enduring erosive processes and beach erosion due to storms frequently provoke significant social, economic and environmental damage.

The effects of beach erosion, overflows, coastal flooding and other damage due to storms tend to worsen over time, since the looming climate change and intense urban development of coastal areas heighten foreseeable risks and damage in large swathes of coastal areas.

Beaches and low-lying coastal areas are especially vulnerable in terms of rises in average sea level and storm intensification.

Indeed, the critical factor of production of the tourist industry is the beach, and erosion, albeit temporary, could potentially devastate local economies.

Nevertheless, each year, it is becoming increasingly difficult to use rockfill and loose materials in shoreline maritime works, owing to issues which relate, firstly, to the environmental impact of such structures during the construction phase and secondly, to their dismantling, in the long-run, as loose residual materials are left scattered about the submerged beach.

From a social, economic and environmental viewpoint, the coastline has many vulnerable spaces, where each year it is proving evermore costly to assume environmental impacts from construction and operation of quarries, transport of loose materials, dumping of material into the sea, and so forth.

The use of traditional rockfill and loose material-based typologies is being gradually hampered by these two sets of circumstances, and other typologies, easier to dismantle and with a lower environmental impact during construction, must progressively replace them.

The effectiveness of these dikes depends to a large extent on the depth of the crest or freeboard, as a simple settling of the structure can drastically affect functioning and effectiveness; adaptation to unforeseen situation changes is very costly and reutilisation in different conditions is by no means easy.

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