US78793A - Improved subaqueous foundation - Google Patents

Description

panying drawings, and to the letters of reference marked thereon.

JAMES B..EADS, OF ST.*LOUIS, MISSOURI..

Letters-Patent No. 78,793, dated June 9, 1868.

IMrnovsD SUBAQUEOUS FOUNDATIQN, i

@In rlgaul rifatta tu in g'te trttas man ma mutxigfpzvt at tip aina.

To ALL WHoM 1r MAY coNcEaNQ l Be it known that I, JAMES B. EADS,of the city of St. Louis,in the county of St. Louis, and State 'of i Missouri, have made certain new and useful Improvements in LConstructingSubaqueous Foundations; ,andjI do hereby declare that the following 'is a full and clear description thereof, reference being had to the m- Itis well known that in the construction of bridge-piers, dams, breakwaters, and similar structuresthe foundations are made yupon the firm subaqueousv strata of rock or hard soil. Toconstruct said structures `firmly 4 upon the proper substrato., various general methods have been devised. In the method used by Brunel at the Saltash bridge, and by Keller at the Kehl-Rhine bridge, a strong box was employed', the said box being open" at the bottom, and sustaining the masonry on its top, when supported by chains. The masonry was laid abo-vc water, the foundation-box being lowered asthe masonry was raisedr When the box reached the watcrbed, it became necessary to excavate the sand or other subsoil to permit the box to descend and reachV the iirrnsubstratum intended to support the structure. To enable workmen to perform the work of excavation under said box, compressed air was lforced into the same, thus forcing out the water therein, and supplying a medium` for respiration for the laborers.4 It will be seen that in said method the supply of compressed air, and its retention,

necessitate various and 4complex devices, which, at the same time, are modified by the necessities for passage of workmen and material from the platform above to-tlie work-site below. And-it isfurther apparent thattheV progress of said work must be slow, because ofthe limited space a'orded to apply the powers of laborers, and the circumstantial operations which must be performed to achieve limited results. The advantage possessed by said general method is in the possibility of laying all masonry above water, but the disadvantage in said method is in the delay and expense caused by the manner of excavating the subaqueous passage for lthe descent ofv the foundation-boxer crib. To retain the general: advantage of said method, and to evade its said defects, the nature of my improved method ofconstructing subaqueous foundations is in the prior formation of thc' passage in which the Apier or other structure descends as it is constructed, and for said purposethc nature of'` my invention is in the application of an openfended tube or caisson, which shall rstbe sunk surrounding the pier-site, and from within which the sand or light subsoil shall have been excavated, thereby forming-within said caisson a clear site containing no other obstruction but water to 'ithe'dcscent of the inner structure. "There-' upon the masonry is constructed in a suitable caisson, sectional or otherwise in its detail constructiomor Vsaid i masonry inlay be built upon a simple platform, and the said caisson or platform and superinrcumbent 'masonry being sustained either by the water-displacement or by screws and chains, and being guided properly in its' descent as the masonry is built up.

To enable those skilled herein to use my said improvement, I will now describe the same in its generalv detail constructions and operations, referring herein tothe accompanying Figure lqas a horizontal sectional plan, and to Y Figure 2 as a vertical sectional elevation. a V In said iignres similar letters of reference are used-to indicate similar parts.

I- construct the enclosing caisson A of wood or iron, and sink the same ,to reach the iirm substratum, asl

indicated in iig. 2. To facilitate the descent of said caisson, the lower edge a iscurved outwardly,and may be' sharpened or shod. In lowering the caisson A, the weight thereof, with any added ballast thatmay he needed,

-will be aided by the excavation of the sand, gravel, or light subsoil` within the caisson; said sand, gravehor,

subsoil being `excavated by dredges or sand-pumps, or similar devices. By said processes the space within the' caisson A willbe cleared of all obstructions except water, and, as the water-levels withii and without the -sme are or may be properly adjusted, the compressionupon the caisson itselfwill be so slight that a light andinia-X#V pensive construction thereof is admissible.

I construct, furthermore, a platform, B, to sustain thc masonry, andguide said platform B bythe guide-v posts B arranged on the inner surface of the caisson A.' In case the weight of themasonry built on B cannot beprolperly balanced by the upward pressure of the water' in A, suitable valves may be arranged to add a bal.

last o'n Water on B, as required. Around the platform B, I arrange the caisson Gf' enclosing the masonry.l Inv the construction of C, it is advisableto arrange the same in sections Cl CZ C3, the said sections being added successively as the building of the masonry 'within progresses, and the platform B and caisson C descend.V

It will be seen that, byl the caisson C, the water may be excluded from the masonry until the same is set,

'and that the sides of `*said caisson maybe braced by proper braces acting against the masonry within the same,

and thus the caisson be relieved to a great extent of the p'rcssureof the surrounding water, thereby permitting a light and inexpensive construction ofsaid caisson. Y, V

j When the platform B has been lowered to the subsoil prepared by blasting, or by layers of beton to receive the same properly, it willvbe easyto remove the enclosing sectional caisson C by disconnectin` the same or'its separate sections from each other nndfrom the platform B. The outer caisson A may then be removed, and the removal hereof will be facilitated by a construction thereof in sect-ions similarly to the caisson C.

Having thus fully described myinvention, what I claim is i Thecombination and arrangement of the outer caisson, its ribs or posts B B', with the internal caisson, C, in th'e'manner and for thepurpose substantially as herein set forth.

'JA's B. EAbs. s Witnesses:

Gro. P. HERTHEL, Jr., GEO. W. HERBERT.

Images