Hydraulic and earth engineering – Foundation – Columnar structure
Reexamination Certificate
2000-01-27
2002-06-25
Hartmann, Gary S. (Department: 3673)
Hydraulic and earth engineering
Foundation
Columnar structure
C405S231000, C052S223400, C052S749100, C052S749100
Reexamination Certificate
active
06409433
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to foundation piles and similar load carrying structural elements.
A pile and/or load carrying similar structural element design advancing the present art is required to address all the following engineering characteristics:
a) Components that don't rust, corrode, or decompose when exposed to fresh water and/or sea water and/or sewage and/or water-borne creatures, plants, bugs or other things that like to eat,
b) Does not require getting ready-mix concrete to the job-site,
c) Ease of transport to job-site,
d) Ease of handling and rigging, in marine and other similar applications, structural element sections, such as, but not limited to, piles, should float,
e) Requires no new expensive handling and/or pile driving equipment,
f) Quick field jointing of structural element sections, such as, but not limited to, piles,
g) Structural element sections, such as, but not limited to, piles, design and construction by components certified and in use by state agencies and approved for use by Federal Agencies,
h) Allows the use of existing engineering design codes, addresses pertinent engineering design consensus standards and specifications,
i) provides a high “coefficient of skin-friction”,
j) the pile designer should be able to tailor the pile's “coefficient of skin-friction” to the expected soil matrix the pile is to be placed in,
k) the structural element sections, such as, but not limited to, piles, should be fire resistant, through application of a “wearing surface”
l) the structural element sections, such as, but not limited to, piles, should resist impact damage, the pile design should allow for expected impact loads associated with transport, placement, installation and intended use, plus safety factor, through application of a “wearing surface”.
m) the structural element sections, such as, but not limited to, piles, design should allow for inspection in-situ.
The present art of marine pile design has been limited to that constructed of steel, wood, or metal reinforcement concrete due to economic and engineering reasons. Maintenance costs due to corrosion of metal components and attack of boring marine animals on wood component have resulted in numerous attempts to address the shortcomings of the present art of marine pile design.
Grosse & Fehr U.S. Pat. No. 3,939,665 (Feb. 24, 1976) describe “. . . the application of a coating of a corrosion resistant covering consisting of an outer shield of stiff plastic . . . ” protecting an existing, already-in-place, metal H-pile. The Grosse & Fehr U.S. Pat. No. 3,939,665 “. . . relates to the protection of metal piles from corrosion in underwater and semi-underwater environments.” Grosse & Fehr U.S. 3,939,665 references Fox, U.S. Pat. No. 1,013,758 (Jan, 2, 1912), and Drusbel et al., U.S. Pat. No. 2,874,548 (Feb. 24, 1959), and Liddell, U.S. Pat. No. 3,321,924 (May 30, 1967) and finally Wiswell, U.S. Pat. No. 3,370,998 and states “(S)uch prior disclosures and practices, while effective to various extents to apply corrosion resisting coatings to piling in general, have not been notably successfully in applying corrosion resistant coatings to H or I-type metal piling or other irregularly shaped piling. It has in particular proven very difficult, and in many cases substantially impossible to obtain a good interfit which is effective to exclude moisture between the inside of the outer plastic coating and the outside of the H or I-pile due to the inconvenient shape of such piling.” Grosse & Fehr U.S. Pat. No. 3,939,665 does describe why use of metal piling is not good design. Quoting from Grosse & Fehr U.S. Pat. No. 3,939,665, “Iron, as is well known, is not stable when subjected to the usual surface atmospheric conditions. Under such conditions, unprocted iron will oxidize to produce various oxides of iron which are more stable under surface conditions than the uncombined metal. Such oxidation or corrosioin, as is known, is accelerated beneath the surface of bodies of water, especially sea water. Corrosion of metal surfaces is particularly severe in the so-called ‘splash zone.’ The splash zone is the zone near the surface of the bodies of water, which is alternately exposed to water and air due both to changing level of tides and the like, the breaking of waves, the spray from waves and various other turblences coming in contact with metallic structures.”
Grosse & Fehr U.S. Pat. No. 3,939,665 does not address, given all the problems associated, why H-piles or I-beam piles are used for piling. Grosse & Fehr U.S. Pat. No. 3,939,665, state that “(U)nfortunately H-beam and I-beam type piling, while strong and rigid for its weight, has large surface areas which, being made of metal, and usually iron, are subject to oxidation and other corrosive attack when exposed to corrosive environment.” The reason why H and I-beam piles are frequently used, in spite of corrosion problems, si because of their “. . . large surface areas . . . ” Piles are “driven” into a soil matrix. The act of “driving” the pile causes friction to develop between the soil matrix and the surface of the pile. This is commonly referred to as a pile's skin-fraction. Pile skin-friction frequently accounts for most or all the physical support the soil-matrix provides. In piling applications where skin-friction is the dominate support mechanism, the “surface area-to-cross-sectional area ratio” becomes an important economic issue for a number of reasons. Some of those reasons, but not limited to, are A) transport costs of the pile sections to the installation site. This is a function of how much “surface-area” can be transported at a time. That is, in the case where friction is an important design factor, the more friction developed per length of structural element the lower the overall cost of transportation, and obviously other associated costs, will be. As such, a “round” cross-section is less efficient than a “square” which is less efficient than a “triangle” and so on. The more efficient shape for the present invention, in specific applications, would be as a “corrugated” “sheet” pile. B) pile driving operations are functions of how long it takes for the pile being “pushed” into the soil-matrix to develop the amount of friction to resist the design-loads demanded. The greater the “surface area-to-cross-sectional area ratio” the shorter the required length of pile that needs to be placed into the soil-matrix for the required development of friction. C) in extremely “weak” soil-matrix conditions, the “dead-load” weight of the pile itself, as a ratio to the unit length of surface area, becomes a design factor. That is, pile-foundations must be designed to carry all design loads including the weight of the pile itself. Increasing the total surface-area available for friction load between pile and soil-matrix while reducing the weight of the pile in question allows for a more overall economic use of materials for the structure intended to be supported by the pile-foundation in question. D) freuqently, a site's macro-soil-matrix includes layers of “strong-soils” interlaced with layers of “weak-soils”. Shorter piles which allow full development of design loads without penetrating deeper “weak-soil” layers which could lead to foundation instability after installation of a pile foundation. For example, if a pile foundation is driven thru a “weak-soil” strata or a series of “weak-soil” strata resulting in a “puncture” of a previously water-tight strata, the result may be a “de-watering” of the strata in question which could result in a reducing of load-bearing capacity of said strata. Grosse & Fehr U.S. Pat. No. 3,939,665 would have the pile installer use “. . . a heavy grease or other petroleum products, applied to the inner surface . . . ” to a pile in -situ. While the state of the art at the time of the Grosse & Fehr U.S. Pat. No. 3,939,665 patent. 1976, may have allowed this practice, present U.S. Environmental Protection Agency regulations make use of such practices more expensive today.
Fox 4,019,301 (Oct. 2
Hubbell David A.
Owen Alfred W.
Hartmann Gary S.
Zborovsky I.
LandOfFree
Foundation piles or similar load carrying elements does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Foundation piles or similar load carrying elements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Foundation piles or similar load carrying elements will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2981339