Method of Coastal Erosion Control Using Massive Sea Block System

1. Field of the Invention

The present invention relates to coastal erosion control and more particularly relates to a method and apparatus of coastal erosion control wherein an array of hollow reinforced concrete blocks are positioned along vunerable coastline areas, filled with sand, water, mud, shell, or heavy refuse such as broken concrete or rip-rap, then sealed after the refuse is added so that the wave action of heavy seas cannot scatter the refuse, and wave action is dissipated.

2. General Background

Stabilization of coastal shorelines has become a major problem in many coastal areas of the country, such as, for example, the Louisiana Gulf Coast area, where many thousands of acres of wetlands are disappearing each year. The shorelines are eroding or disappearing because of a number of reasons, at least one reason being excessive wave action that eats away at the shoreline. Loss of wetlands causes a decrease in habitat for numerous marine species, such as shrimp, crabs, and fish.

Numerous devices have been patented which have attempted to solve the problem of coastal stabilization. The following are examples of U.S. Pat. Nos. that have been granted for structures that can be placed in a coastal zone or in shallow water for the purpose of stabilizing the shoreline:

Many of these prior art systems use blocks or structures that are relatively small and that are stacked or placed side-by-side for the purpose of dissipating wave energy. The problem with such small structures is that they are only used where the water interfaces with the shoreline and thus, are of little value in deeper water to break the wave action which pounds at beaches and shorelines. Many of these smaller structures can be moved by very heavy wave action that occurs, for example, during storms such as hurricanes. It is known that hurricanes can greatly erode a shoreline in a matter of a few days when huge wave surges pound at the shoreline and when water levels rise several feet in what is commonly called a tidal surge.

The present invention solves the problem of coastal erosion by providing a very effective barrier to wave action so that waves can be dissipated even during storms, such as hurricanes, where wave action becomes intense. The present invention provides a method of coastal erosion control that includes the steps of transporting a plurality of massive hollow yet transportable reinforced concrete blocks to a coastal site where erosion is to be controlled. The massive blocks are arranged in an array that extends along the erosion site so that the blocks can dissipate wave action. The hollow blocks are filled with refuse material until each block has a massive weight of at least 25 tons. The blocks are then sealed after the fill material refuse is added so that wave action cannot scatter the fill during heavy seas.

Typically the fill material will be sand, water, mud, clay, reef shell or discarded chunks of concrete, large blocks of stone, and/or gravel. In the preferred embodiment, the blocks are generally rectangular having upper and lower flattened surface areas so that the blocks can be stacked. In one embodiment, the block array can be stacked vertically and can extend horizontally so that the array can be used to form jetties in deeper water.

In the preferred embodiment, the blocks are spaced apart a distance so that some water flow can pass between the blocks.

The massive reinforced concrete blocks are preferably hollow having exemplary dimensions of fourteen feet (14') long, eight feet (8') wide, and minimal six feet (6') tall, with a concrete wall thickness of approximately twelve inches (12") minimum. The walls are preferably reinforced with number four (No. 4) diameter steel reinforcing rods spaced twelve inches (12") on center in both directions, and each block is fitted with a plurality of lifting eyes so that the massive blocks can be transported from barges, for example, to the particular site where erosion is to be controlled.

The sea block solution is to place the sea blocks at strategic locations where erosion is taking place. These blocks are arranged in shallow or deep water and arranged in rows or stacked in order to barricade the action of the sea against the shore.

Inside the block, the hollow interior can be sealed using a plastic liner, having a thickness, for example, of twelve mils (12 m) so that any compacted fill material could be sealed within the plastic liner. It should be understood, that the refuse or waste material would normally be material that would be suitable from an environmental standpoint so that there would be no danger to the surrounding environment if one of the blocks should crack allowing sea water to communicate with the interior of the sea block.

The blocks could be manufactured at a construction facility located near the coastline where erosion is a problem, or they could be transported long distances by barge and set in place using a crane at its position upon the barge. Crane barges or derrick barges are commonly used by a number of offshore construction companies and are known in the art.

Each block would be formed and poured, allowed to cure, lined if desired, and then filled with the refuse material. The material could be compacted, if desired, and then each block sealed by pouring concrete over the top of the material. The sealing of the material could be accomplished at the erosion site or at the construction facility depending upon lifting capabilities for movement of the blocks.

The method thus provides a means to readily form a break water or barrier to wave action in any geometric configuration that would be particularly useful in a given situation. The blocks are massive and of structural load carrying reinforced concrete, and because they can be filled with heavy refuse material, they have a potential of weighing massive amounts, and thus little or no susceptibility to movement during storms such as hurricanes.

A better understanding of the invention can be had when the detailed description of a preferred embodiment set forth below is considered in conjunction with the drawings, in which:

FIG. 1 is a top plan schematic view of the preferred embodiment of the apparatus of the present invention showing placement of the sea blocks along a coastal erosion zone;

FIG. 1A is a schematic side elevational view illustrating placement of a sea block at a coastal erosion zone;

FIG. 2 is a perspective view of the sea block system of the present invention shown in a construction of a jetty in deeper water;

FIG. 3 is an elevational view of the preferred embodiment of the apparatus of the present invention;

FIG. 4 is a top view of the preferred embodiment of the apparatus of the present invention;

FIG. 5 is an end view of the preferred embodiment of the apparatus of the present invention;

FIG. 6 is a perspective view of the preferred embodiment of the apparatus of the present invention; and

FIG. 7 is a perspective cut-away view of the preferred embodiment of the apparatus of the present invention.

FIGS. 1, 1A and 2 show generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral 10 with a plurality of sea blocks 15 being shown in various geometric configurations. It should be understood that the present invention provides a wave control break water or coastal stabilization system that comprises a plurality of erosion control massive blocks which can be arranged in any number of geometric patterns. The top plan view of FIG. 1 is exemplary of an elongated array of blocks 15 including five blocks 15 which are positioned end-to-end with spaces 30 therebetween and seven blocks positioned side-by-side with spaces 30 therebetween to provide a much more substantial barrier to wind and wave action.

In FIG. 1, the land zone area is designated by the numeral 12, while the sea is designated generally by the numeral 13. In FIG. 1A, a side view illustrates placement of a single block 15 in water upon the sea bed 14 and spaced a distance from the land 12. In this manner, blocks 15 could be arranged in a break water or erosion control array several hundred feet from the seashore in water, for example, five-eight feet (5'-8') deep. Then sediment material, such as sand, could be added in that space shown in FIG. 1A between land mass 12 and the blocks 15. Because the blocks are readily transportable using a derrick barge, crane barge or the like, they could then be moved outwardly and more sand or sediment material added between the blocks and the land zone.

Thus, the present invention provides a very flexible versatile method and apparatus for controlling erosion in that the blocks 15 can be formed into a variety of designs for different environments and for different erosion control problems. Because the blocks are readily transportable and structurally very strong and massive, they could be reused indefinitely if constructed properly at different sites and locations over a long period of time.

In FIG. 2 a perspective view illustrates a jetty formed of a plurality of blocks 15. Notice that the underlying layer of blocks extends along the sea bed five blocks wide and three blocks deep. A second layer of blocks 15 is stacked upon the first layer and includes an array of blocks three blocks wide and three blocks deep, while the uppermost layer includes three blocks stacked end-to-end, as shown in the drawing. Thus, the blocks are stackable so that they can be used even in deeper water, that is, water that is deeper than the height of a particular block. Because the blocks are flat on top and bottom surfaces and can be stacked, the present invention would have utility in the construction of very long jetties and piers, in that persons could walk on the top surface of blocks 15 forming the jetties, and in some installations, automobiles could drive on the top of the blocks if they were arranged on a tightly packed jetty construction and then covered with a road surface, such as bituminous materials such as asphalt, concrete or the like.

FIGS. 3-7 show more particularly the construction of the preferred embodiment of the apparatus of the present invention. In FIGS. 3-7, each block 15 is shown as comprising a plurality of concrete side walls 17-20 defining in combination with bottom 21 an interior space 16. Reinforcing steel would be included within all of the walls 17-21. In FIG. 7, reinforcing steel is designated generally by the numeral 25. A plurality of lifting eyes 27 are provided, preferably four, each lifting eye 27 being recessed within recess 26 so that the lifting eye 27 does not interfere with stacking of a number of blocks upon one another. An uppermost lid 29 would be used to seal the blocks, as shown in FIG. 7, or alternatively, the blocks would be sealed with liquid concrete and then the liquid concrete cover would be allowed to cure before use of the blocks.

In the preferred embodiment, the reinforcing rods 25 would include half inch (1/2") diameter steel rods spaced 12 inches (12") on center both ways.

The foregoing description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.