US3606716A - Timber piling construction - Google Patents

Abstract

A TIMBER PILING CONSTRUCTION INCLUDING AN UPRIGHT TIMBER PILE AND A CONCRETE SLAB SUPPORTED ON THE UPPER END OF THE PILE. A PAIR OF CONNECTOR PLATES ARE RIGIDLY SECURED ON OPPOSITE SIDES OF THE PILE, THE CONNECTOR PLATES ARE IN THE SHAPE OF AN ANGLE WITH ONE LEG HAVING A PLURALITY OF NAIL HOLES FOR RECEIVING NAILS DRIVEN INTO THE WOOD PILE. THE OTHER LEG OF THE CONNECTOR PROJECTS OUTWARDLY AT THE UPPER END OF THE PILE. CONCRETE IS CAST OVER THE CONNECTOR AND THE UPPER END OF THE PILE TO FORM A UNITARY STRUCTURE.

Description

Sept. 21, 1971 NORCROSS ET AL 3,606,716

TIMBER FILING CONSTRUCTION Filed July 31, 1969 2 Sheets-Sheet 1 INVENTOR5 ATTORNEYS Sept. 21, 1971 R, NORCRQSS ET AL 3,606,716

TIMBER FILING CONSTRUCTION Filed July 31, 1969 2 Sheets-Sheet 2 E 0 do 0 0 n n n h 0 0 :19 0 n n n 0 0 D INVENTORS any/o A. #0909055, #055797 75000413,

BY ZN, ,DM, W, julh-m ATTORNEY United States Patent O1 ice 3,606,716 Patented Sept. 21, 1971 3,606,716 TIMBER PILING CONSTRUCTION David R. Norcross, Washington, D.C., and Hubert T.

Dudley, Arlington, Va., assignors to Timber Engineering Company, Washington, DC.

Filed July 31, 1969, Ser. No. 846,510 Int. Cl. E04c 3/34; E02d /54 US. Cl. 52-301 5 Claims ABSTRACT OF THE DISCLOSURE A timber piling construction including an upright timber pile and a concrete slab supported on the upper end of the pile. A pair of connector plates are rigidly secured on opposite sides of the pile. The connector plates are in the shape of an angle with one leg having a plurality of nail holes for receiving nails driven into the wood pile. The other leg of the connector projects outwardly at the upper end of the pile. Concrete is cast over the connector and the upper end of the pile to form a unitary structure.

BACKGROUND OF THE INVENTION This invention relates to timber pile construction and, more particularly, to means for securing concrete slabs or caps to timber piling.

Timber piles are used to provide a foundation for buildings, bridges, piers, wharves, and other structures over water or soft ground. The piles are long lengths of timber having an average diameter of about one foot and are driven endwise into the ground to such a depth that they are rigidly supported in an upright position.

In order to provide a firm foundation, it is desirable to apply a concrete slab or cap to the top of each pile. The weight of the concrete cap is imposed directly on the upper end of the pile and if there is any lateral movement between the pile and the cap, such as by seismic action, there is a danger that the cap will be displaced from the center of the pile, and as a result, will overturn.

Another problem with timber piling construction is that strong winds under the slab may tend to lift the slab off the top of the pile. Also, uneven distribution of load on the slab may cause the slab to overturn.

Timber piles are usually made of tree trunks cut to the desired length. These tree trunks may be rough turned and treated. The diameter of these piles varies considerably, and pile connectors that are not readily adjustable over a wide range of sizes are not practical.

Various attempts have been made to anchor concrete caps or slabs to wood piles, but generally these have been unsuccessful. It has been estimated that the overturning moment of the cap exerts a tensile force at the outer surface of the timber pile of the order of 40,000 lbs. or more. Of course, the force depends upon the dimensions of the particular means that is used for joining the pile to the cap, but it is apparent that an extremely large tensile force is imposed on the connecting means.

Accordingly, it is an object of this invention to provide a timber piling construction including a concrete cap that effectively resists overturning moment under seismic loading, or other external forces.

It is a further object of this invention to provide a means for connecting a concrete cap or slab with a timber pile that is readily installed.

Another object of this invention is to provide timber piling construction that permits a variation in width and depth of the concrete cap or slab.

SUMMARY OF THE INVENTION These objects are accomplished in accordance with a preferred embodiment of the invention by a timber pile having individual connector plates applied on opposite sides adjacent the load bearing end of the pile. Each connector plate is in the shape of an angle and one leg of the angle has a plurality of openings arranged in transverse rows for receiving nails driven through the openings into the timber pile. The other leg of the angle is positioned approximately at the level of the top end of the pile and projects outwardly at approximately right angles to the length of the pile. Concrete is then cast around the upper end of the pile enclosing the connector plates and forming a unitary structure. The nail openings are preferably elongated in the direction of tensile stress in the plates, in order to strengthen the connection between the plates and to provide a larger cross-sectional area for resisting tensile stresses.

DETAILED DESCRIPTION OF THE DRAWINGS This preferred embodiment of the invention is illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of the timber piling construction of this invention;

FIG. 2 is a cross-sectional view of the piling construction of FIG. 1;

FIG. 3 is an elevational view of the connector plate secured to the timber pile prior to pouring the concrete;

FIG. 4 is a perspective view of a nail for joining the connector plate to the timber pile; and

FIG. 5 is an enlarged cross-sectional view of a nail hole in the connector plate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a typical timber pile 2 has its lower end, not shown, embedded in the ground to a sufficient depth to maintain the pile rigidly in an upright position. The pile 2 may be a foot or more in diameter and may have a length of as much as 30 feet. The timber pile 2 may be either circular or square in cross section, or it may have an irregular shape. The upper end 4 of the pile is substantially flat and forms a bearing surface for the concrete slab or cap 6.

Connector plates 8 are secured on opposite sides of the pile 2. Each connector plate is in the shape of an angle with a base leg 10 positioned against the side of the pile 2 and a supporting leg 12 projecting outwardly from the pile at substantially right angles to the length of the pile. The supporting leg 12 is preferably aligned with the upper end 4 of the pile.

Referring to FIG. 3, the base leg 10 of the connector 8 has a plurality of nail holes 14 which are arranged in transverse rows 16. The holes 14 in one row are laterally offset from the holes in the adjacent rows to provide improved resistance to tensile stresses in a lengthwise direction with respect to the leg 10. As shown in FIG. 5, the holes 14 have opposed arcuate edges 18 and opposed straight edges 20, with the longitudinal extent of the opposed straight edges 20 exceeding the transverse extent of the opposed arcuate edges 18. The straight edges 20 are aligned with the lengthwise dimension of the leg 10 in order to provide the maximum cross-sectional area of metal between adjacent holes in each row 16.

The connector plates 8 are secured to the pile 2 by nails 22, one of which is shown in FIG. 4. The shank of the nails and the head of the nails have substantially the same shape as that of the holes 14. The head, however, is tapered outwardly so that the opposite surfaces 26 of the head 24 are substantially frustoconical. The driving surface of the head 24 is slightly longer than the distance separating the arcuate edges 18 of the holes 14. Thus, when the nail 22 is driven into the hole 14, the frustoconical surfaces 26 engage the curved surface edges 18 of the hole to hold the base 10 tightly against the outer surface of the. pile 2, as shown in FIG. 2. Preferably, a nail 22 is driven in each hole 14 in the base leg 10.

After the connector plates 8 have been secured on the pile 2, concrete forms are erected. Reinforcing bars may be placed in the forms in accordance with conventional practice and the concrete slab or cap 6 is cast around the upper end of the pile 2. Preferably, the slab v6 extends below the lower end of the base leg of each connector plate 8 and above the top of the pile 4. Thus, the concrete protects the metal connector plate 8 and the nails 22 from corrosion.

Although only one pair of connector plates is shown in FIG. 1, the connector plates may be applied in pairs or individually, according to the load requirements. For example, three connector plates 8 could be applied to the upper end of a piling with each plate spaced equally from the adjacent plates around the circumference of the pile 2. The plates would be applied in the same manner as described above and as illustrated in the drawings.

It has been found in actual tests that the timber piling construction of this invention is extremely strong. A pair of connector plates each having a thickness of inch and a width of 4 inches, with a total of 64 nails is capable of withstanding a load tending to lift the slab of greater than 20,000 lbs. with a concrete slab of 8 inches in thickness.

The timber pile construction is particularly advantageous because it is readily installed at the site without requiring special equipment. The connector plates can be nailed in place after the piles have been driven into the ground. The special nails form a wedge fit with the connector plate, thereby providing a rigid assembly with very little slip between the plate and the nail when longitudinal tension stresses are applied to the plate. Also, no

adjustment is required for timber piles of different diameters or thicknesses.

While this invention has been illustrated and described in a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.

We claim:

1. Timber piling construction comprising:

a timber pile, said pile having a longitudinal outer surface and an end surface, at least two connector plates on said longitudinal surface adjacent said end surface, said plates being spaced apart from each other,

each connector plate including a base leg and a supporting leg, means securing said base leg against the longitudinal surface of said pile, said securing means including a plurality of nail receiving openings in said base leg, said openings being arranged in a plurality of rows extending transversely across said plate, said rows being spaced apart longitudinally of said plate, said plate openings each having opposite straight sides spaced apart transversely of said plate and having opposite arcuate ends interconnecting said opposite sides of said openings, said openings of one row being laterally offset from openings of adjacent rows, said securing means also including nails extending through said openings and embedded in said pile, said supporting leg extending outwardly from said base leg, adjacent said end surface,

said nails having sufficient thickness to substantially fill said openings and said nails including heads having outwardly sloping surfaces engaging said opposite arcuate ends of said plate openings, and

a concrete mass, said end surface and said connector plates being embedded in said mass.

2. In combination with a timber pile and a solid monolithic mass of concrete, a connector element rigidly joining said pile and said concrete mass, said element comprising:

a metallic plate having a base leg and a supporting leg, said base leg being positioned against the surface of said pile and said supporting leg extending at substantially right angles to said base leg and outwardly "from said pile,

said base leg having a plurality of openings, said openings being arranged in a plurality of rows extending transversely of said base leg, and nails extending through said openings into said timber pile, said concrete mass substantially enclosing said supporting leg and the upper end of said pile, said nails including wedge means to provide in cooperation with said element a rigid connection to secure said element to said pile so that said element resists displacement of said concrete mass relative to said pile.

3. The combination according to claim 2 wherein the sides of said openings are spaced apart from each other a greater distance in the longitudinal direction than in the transverse direction with respect to said element, said nails having a greater thickness in one direction than in another, whereby the nails resist shearing relative to said pile without reducing the net cross sectional area of said base leg along said rows of openings.

4. The combination according to claim 3 wherein said openings have opposite straight sides and opposite arcuate ends interconnecting said sides, said straight sides of each opening extending longitudinally of said plate.

5. The combination according to claim 2 wherein said openings have opposite straight sides and opposite arcuate ends interconnecting said sides, said straight sides of each opening extending longitudinally of said plate, said opposite straight sides of said openings have a longitudinal extent exceeding the transverse extent of said opposite arcuate ends, said nails having a head and a shank,

said head having opposite tapered surfaces tapering outwardly until the distance across said head between said tapered surfaces is greater than said longitudinal extent, said nails forming a wedge fit with said connector plate and rigidly secure said connector plate to said pile and said connector plate resists displacement of said concrete mass relative to said pile.

References Cited UNITED STATES PATENTS 1,481,745 1/1924 Ruybal 52295 1,558,939 10/1925 Smith et al 6153X 3,295,332 l/1967 Dougherty 61- 53 3,377,808 4/1968 Dougherty 52-301X 3,490,185 1/1970' M00re et al 52301X PRICE C. FAW, 111., Primary Examiner US. Cl. X.R. 52--733; 61-53

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