US2086977A

US2086977A - Pile foundation construction

Info

Publication number: US2086977A
Application number: US37621A
Authority: US
Inventors: Chapman Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-08-24
Filing date: 1935-08-24
Publication date: 1937-07-13
Anticipated expiration: 1954-07-13

Description

July 13, 1937. P M N 2,086,977

FILE FOUNDATION CONSTRUCTION Filed Aug. 2 4, 1955 INVENTOR.

Patented July 13, 1937 UNlTED STATE PATENT OFFlCE PILE FOUNDATION CONSTRUCTION Paul Chapman, New York, N. Y.

Application August 24, 1935, Serial No. 37,621

4 Claims.

This invention in pile foundation construction provides economical means of building rigidly braced pile foundations in great depths of water without the using of diving apparatus.

Referring to the accompanying drawing, Fig. 1 is a perspective view showing the construction; Fig. 2, Fig. 3, and Fig. 4 are detail plan views showing the guides used for various types of piles; Figs; 5 and 6 are plan and elevational views respectively, showing a connection of a cross beam and bracing frame to a pile; Fig. '7 is an elevational view showing the connection between the carrying beams and the bracing beneath with the means for properly distributing the portions of the lcadscarried by each; Fig. 8 is a plan view and Fig. 9 an elevational view showing an adaptation wherein only the piles on one side of a pier are braced; and Fig. 10 is a plan view and Fig. 11 an elevational view showing an adaptation wherein pairs of piles on one side of a pier are braced with a single bracing frame.

Referring to Fig. 1, the water level is indicated approximately by aa and the supporting bed level by b -b. The column B rests upon the girder 2 which in turn rests upon the cross beams 3. The ends of the cross beams 3 are supported 'by piles l which are driven into the supporting bed to provide the desired carrying capacity. Lateral bracing frames 5 between pairs of piles 4 extend downward below the cross beams 3 as near to the supporting bed as desired. In addition to providing guides for driving the piles i, the bracing frames resist lateral distorsion of the pier and reduce the unsupported length of the piles acting as columns. The lateral bracing frames embrace diagonals 5a, bottom ties 5b, end verticals 5c, sub-diagonals 5d, and subties 5e. Attached to the bracing frames at the levels of the bottom ties 5b and the sub-ties 5e, 'are guide members 6, through holes in which guides the piles d extend. The holes in the guides ii are made slightly larger than the piles so that the piles may be freely driven and at the same time be held in position in the horizontal plane. The end verticals 5c are connected to the piles 4 above the water level a-a, so that no connections need be made under water. When a lateral load is applied at the top of the pier, it is finally resisted by the supporting bed somewhat below the level 11-4) with resulting bending moments in the piles l at the level of the bottom ties 5b. The portion of the piles above this level acts as an anchor arm for these bending moments so that the sub-ties 56 have the effect of reducing the anchor arms with consequent decrease of lateral deflection. To brace the pier longitudinally, longitudinal brace frames 1 are provided for each line of piles, the frames consisting of diagonals la, bottom ties lb, and top ties 1c.

The bottom ties lb are connected to the guides 6 so that horizontal longitudinal forces are transferred from the frames 1 to the piles 4 thereby. The top ties 1c are connected to the frames 5 near their tops so that longitudinal forces are transferred to the piles in like manner at those locations. A longitudinal horizontal force applied at the top of the frame 1 causes an upward pressure on the near end and a downward pressure on the far end of the frame l, which pressures are transferred to the piles 4 through the frames 5 by means of the aforesaid connections to the frames i.

It is seen that if a unit consisting of the girder 2. the cross beams 3 and the bracing frames 5 and l with the guides 6, be held in position the piles 4 may be driven and connected to the cross beams and bracing frames without making any under Water connections.

The two lines of piles are shown to be vertical, but it is seen that the construction can be adapted. for inclined piles by shortening the sub-ties 5e and the cross beams 3 in proportion to their distance from the bottom tie 5b, and when the cross beams 3 are very short the diagonals 5a and the subdiagonals 5d are omitted.

Referring to Fig. 2, the pile 4 is shown to fit loosely in the hole in the guide 6 so that the pile may be driven readily and held in the desired position.

Referring to Figs. 1 and 3, the guide to is shown adapted for the use of cylindrical piles, the hole through which the pile la projects being slightly larger than the pile to permit driving.

Referring to Figs. 1 and 4, the construction is shown adapted for the use of rectangular wood piles 4b with the bottom tie 512a; being made of two timbers and the vertical brace member 5ca a single timber. The slot for driving the pile 4b and holding it in position is formed by the two timbers of the bottom brace, the vertical 50a, and a rectangular timber 6b of the same depth as the members 511a, all being bolted together by bolts 60.

Referring to Figs. 1, 5, and 6, it is evident that the desired carrying capacity for each of the piles 4 may be obtained at various levels so that the connection of the cross beam 3 and vertical 50 to each pile 4 cannot be accurately located on the the connection after the pile is driven, groups of equally spaced holes so are placed in the pile in order that the connection may be made at the desired level on the pile. A filler plate id through which the connection bolts 46 extend, is placed to keep the pile in the correct alignment.

Referring to Figs. 1 and '7, it is seen that the load from the girder 2 may be transferred to the piles i either by the crossbeam 3 or by the brace frame 5, the proportionate amount carried by each being inversely proportional to the deflections for a unity load applied to each. When the crossbeam 3 is required to carry more than its proportional share thus found, the filler 3a of required thickness inserted between the crossbeam 3 and the brace frame 5, is removed so that a portion of the load equal to that required to deflect the crossbeam the thickness of the filler 3a is carried by the crossbeam alone with the remainder aportioned as described.

Referring to Figs. 1, 8, and 9, the brace frame is adapted for use when only one half of the piles are required to resist the lateral loads. The piles 43 may be driven as shown and described for Fig. 1, the construction lifted vertically with the piles standing free in position, and the adaptation of the brace frame as shown in Fig. 9 with the cross beam 3 slipped over the piles and connected to them above water level by the bolts 46. In this adaptation a single diagonal 5a?) is used instead of the two diagonals 5a, and a short vertical brace member 50b replaces the longer member Ed on one side.

Referring to Figs. 1, i0, and 11, a single cross beam 8 and a single bracing frame 5 is used for two pairs of piles Go. In this adaptation the cross beam 3 is framed into a header beam 32) which is bolted to the piles to above water level. The cross frame 5 embraces a vertical member 55cc, a diagonal and a member similar to the vertical Ecb shown in Fig. 9, all being in the plane of the cross beam 3. A guide member 60 is connected to the brace frame 5 and has a hole at each end through which a pile 4g projects. As heretofore described for the adaptation shown in Figs. 8 and 9, the piles may be driven with the construction shown in Fig. 1, the construction removed leaving the piles freestanding, and the cross beams with brace frames and guides as shown in Fig. 11 slipped over pairs of piles and connected above the water level.

Where the depth of water is great, the construction may be adapted for more economy by inclining the piles driving them divergingly downward so that the cross beams 3 will be shortened and the distance between the two rows of piles at the bottom increased with increased stability of the pier. The construction may also be adapted for use with the outer pairs of piles driven divergingly downward longitudinally to obtain additional longitudinal stability.

I claim:

1. In a pile foundation construction, a plurality pile before it is driven and to avoid drilling for of rows of piles driven into an under water supporting bed, a plurality of cross beams, each connected at each end to a pile in adjacent rows of said piles, a plurality of lateral bracing frames below said cross beams and each connected at each end to a pile in adjacent rows of said piles, a plurality of longitudinal bracing frames, each extending along a row of said piles and connected at its top and bottom to said lateral bracing frames, guides attached to said lateral bracing frames below the water level, and each surrounding an adjacent pile, means connecting each cross beam and lateral bracing frame to an adjacent pile above the water level, said connecting means serving to transfer the vertical and horizontal forces to said piles above the water level, and said guides serving to transfer the horizontal forces to said piles below the water level.

2. In a pile foundation construction, a plurality of rows of piles driven into an under water sup- 5:.

porting bed, a plurality of cross frames, each connected at each end to a pile in adjacent rows of said piles, said cross frames each comprising a load carrying top member above the water level,

a guide below the water level, adapted to surround a pile in one of the rows of said piles, a vertical member adapted to extend along said pile and connecting said guide and top member, and a diagonal member extending diagonally upward to the other end of said top member and connected thereto.

3. In a pile foundation construction, a plurality of rows of piles driven into an under Water sup porting bed, a plurality of cross beams, each connected at each end to a pile in adjacent rows of said piles, a plurality of lateral bracing frames below said cross beams, and connected thereto, each frame being connected at each end to a pile in adjacent rows of said piles, said connection between the frames and adjacent piles including a plurality of equally uniformly spaced vertical rows ofholes, the rows of holes in the piles being longer than in the frames, whereby said piles may be driven to various depths and yet be connected to the rame, and bolts extending through adjacent holes in said frames and piles to secure them together.

4. In a pile foundation construction, a plurality of rows of piles driven into an under water supporting bed, a plurality of cross beams, each connected at each end to a pile in adjacent rows of said piles, a plurality of load-carrying lateral bracing frames, each connected at each end to a pile in adjacent rows of said piles, each of said cross beams being connected at its mid-point on its lower side to the adjacent bracing frame by a bolted connection, said bolted connection embracing removable fillers of predetermined thickness whereby the placing or removal of said fillers will serve to apportion the relative share of load carried by said cross beams and said loadcarrying lateral bracing frames.

PAUL CHAPMAN.

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