Hydraulic and earth engineering – Bank – shore – or bed protection – Wave or flow dissipation
Patent
1995-11-15
1997-04-15
Taylor, Dennis L.
Hydraulic and earth engineering
Bank, shore, or bed protection
Wave or flow dissipation
405 16, E02B 304
Patent
active
056202806
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a concrete armor unit for protecting coastal and hydraulic structures and shorelines. In particular, the invention relates to randomly placed modules of a multiple slender-legged shape, to provide a stable interlocking assembly which resists the action of waves and water currents without exceeding the structural capacity of any single component of the assembly. In general, the modules are supported by an underlying layer of stone and are held in place by gravity and by the interlocking forces between adjacent modules.
BRIEF DESCRIPTION OF THE PRIOR ART
Interlocking concrete armor units or erosion prevention modules are well-known in the patented prior art as evidenced by the Kaneko et al. U.S. Pat. No. No. 3,614,866 and Chevallier U.S. Pat. No. 4,347,017.
The Kaneko et al. patent discloses a polypod block comprised of at least three integral pillar-shaped parts joined in an alternately crossed relationship. Hence, the block has at least six appendages which interlock with other blocks so that a large number of blocks can be arranged to form tightly assembled combinations. A primary drawback of the Kaneko et al. design is that the pillar-shaped members are joined together with a minimum amount of shared surface area. This provides tremendous stress concentrations at these areas. Owing to these excessive stress concentrations, the blocks possess a higher probability for breaking, potentially leading to a massive failure of an entire arrangement or assembly of blocks. Another drawback of the Kaneko et al. block is that the appendages do not stay together in an assembled fashion. This is due to the fact that the pillar-shaped members have a square cross-section which provides a limited area of frictional engagement with neighboring blocks. Yet another drawback derives from the regular arrangement of modules, whereby catastrophic failure of the entire protective structure can result from the failure of a relatively few armor blocks. Also, the regularly placed blocks produce an armor layer with very low porosity, providing little wave energy dissipation and therefore little contribution to reduction in wave energy for the protected area in the lee of the structure.
The Chevallier patent discloses a barrier block for protecting riverside structures and shorelines. The block comprises a cubic central core having top and bottom surfaces provided with anvil-shaped legs and opposed front and rear legs in the form of four-sided truncated pyramids. A major drawback of the hydraulic stability characteristics of the Chevallier block is that the anvil-shaped legs are not slender and thus produce minimal unit-to-unit wedging which reduces interlocking stability. The blocks rely primarily on gravity forces from overlying units to enhance individual block stability and must therefore be placed on steep slopes to assure stability. However, steep-sloped structures have a tendency to fail catastrophically and have proven to have a high probability of failure and risk when used. Placed on slope, the Chevallier unit exhibits the characteristics of a low-porosity armor layer, which provides less reduction in wave energy than found in an armor layer composed of more slender armor units. Further, the Chevallier blocks require exact placement in order to develop enhanced hydraulic stability.
Practical difficulties result in the manufacture, storage and transport of armor units. For example, some armor units have shapes which are not easily cast or formed. Some armor units do not allow for nested placement in yard areas or in shipping barges, and consequently are difficult to store and ship efficiently. Also, some structures are not repairable by simple addition of replacement armor units, but must be partially disassembled.
There is thus a need for a durable interlocking module capable of random placement resulting in a structure which has strong individual modules and which structure is stable. The module shape should have slender appendages to provide improved stabili
REFERENCES:
patent: D277609 (1985-02-01), Deimen
patent: D300863 (1989-04-01), McNeely
patent: 2909037 (1959-10-01), Palmer
patent: 3176468 (1965-04-01), Nagai
patent: 3456446 (1969-07-01), Kusatake
patent: 3614866 (1971-10-01), Kaneko et al.
patent: 3759043 (1973-09-01), Tokunaga
patent: 4347017 (1982-08-01), Chevallier
patent: 4594023 (1986-06-01), O'Neill
patent: 4594206 (1986-06-01), Grafton
patent: 4633639 (1987-01-01), Deimen
patent: 5122015 (1992-06-01), Shen
patent: 5190403 (1993-03-01), Atkinson
patent: 5441362 (1995-08-01), Melby et al.
Permanent International Association of Navigation Congresses Bulletin, A..C.N.-P.I.A.N.C 1994--No. 82, pp. 3-17.
Breakwater Choices, George Vincent, Civil Engineering, pp. 64-66, Jul. 1989.
Stability of Accropode(R) and Comparison with dolosse, A.H. Holtzhausen et al., Coastal Engineering, 15 (1991) 59-86.
Melby Jeffrey A.
Turk George F.
Marsh Luther A.
Taylor Dennis L.
U.S. Army Corps of Engineers as Represented by the Secretary of
LandOfFree
Concrete armor unit to protect coastal and hydraulic structures does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Concrete armor unit to protect coastal and hydraulic structures , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Concrete armor unit to protect coastal and hydraulic structures will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-356052