US3429129A - Method for producing foundations for columns and the like - Google Patents

Description

Feb. 25, 1969 J. E. JOHANSSON E L 3,429,129

METHOD FOR PRODUCING FOUNDATIONS FOR COLUMNS AND THE LIKE Filed July 6, 1967 United States Patent Oflice 3,429,129 Patented Feb. 25, 1969 3,429,129 METHOD FOR PRODUCING FOUNDATIONS FOR COLUMNS AND THE LIKE Jan Erik Johansson, Slattervagen 1C, Luud, Sweden, and Karl-Erik Nyman, Vastra Kanalgatan 5, Malmo, Sweden Filed July 6, 1967, Ser. No. 651,431 Claims priority, application Sweden, July 15, 1966,

9,697/ 66 US. Cl. 61-50 Int. Cl. E02d 5/22, 5/54, 27/12 4 Claims ABSTRACT OF THE DISCLOSURE lThlS invention relates to a method of producing foundations for columns and the like.

A foundation of known design may consist exclusively of a concrete footing cast into the ground and having an amply dimensioned bottom area to keep the load per unit area below the permissible maximum. Alternatively, piles driven into the ground may be used as column foundation. Usually, it is not enough to have a single pile underneath a column. Although a single pile may suffice to support the vertical loadprovided the pile rests on bedrock or it is sufiiciently long and the soil is of suitable consistency this single pile usually will not be sufficiently stable in lateral direction and must be enlarged into a group of piles driven obliquely into the ground so as to be inclined towards one another and together to support the column.

[The invention relates to a method for producing a novel foundation which is a combination of pile and footing and which according to computations and test results is economically more advantageous than both the footing and the pile group, with-out any sacrifice of load-bearing capacity or lateral stability.

The invention thus relates to a method for producing a foundation which is characterised in that it consists of a pile driven into the ground and a concrete footing cast around the pile at and at least partly below ground level.

Under favourable conditions, the pile of this construction can alone carry the vertical load or at least the greater part thereof, and the footing can then be made considerably smaller than a footing which has no such base pile because it need be dimensioned only to give the required lateral stability.

'T he invention more particularly relates to a method of making the above construction, which comprises drilling or digging a footing hole into the ground, filling the footing hole partly with concrete grout, driving a pile through the concrete grout and the bottom of the footing hole to such depth that its upper part projects above the bottom of the footing hole, possibly above the ground level, and then filling the hole with concrete up to the desired level.

The method is illustrated schematically in the accompany-ing drawing, in which:

FIG. 1 illustrates in vertical section an intermediary stage during the construction of a column foundation;

FIGS. 2 and 3 each show a finished foundation with column.

In FIG. 1, a hole 1 is dug or drilled into the ground to the required depth beneath the ground level 2. The diameter of the hole is wide enough to impart to a concrete footing cast into the hole adequate lateral stability as a column foundation. FIG. 1 also shows a quantity of concrete grout 3 poured into the hole to fill but a part thereof. This concrete grout serves to stabilise the bottom and wall of the footing hole during the subsequent driving of a pile into the bottom of the hole, and also to resist wandering of the pile laterally during the initial part of the pile driving.

FIG. 2 shows how a pile 4 which may be of concrete or steel has been driven into the bottom of the hole 1, although only so far that its upper part projects up into the hole, and how there has then been cast into the hole around the pile end a concrete footing 5 which supports a column 6.

FIG. 3 shows a footing 7 cast around a pile 8 which is so long that its upper part rises out of the ground and forms a column. If this pile-column is made of concrete, it should preferably be cast with a special reinforcement to withstand computed bending moments on the upper side of the footing, and with supports for girders and the like.

To enable t-rue positioning of the column and with a drilling machine available, a small hole 9 could also be drilled into the bottom of the footing hole 1 to guide the pile during the driving operation, but with a quantity of concrete grout in the footing hole during the setting-down of the pile such pilot hole is usually unnecessary.

What we claim and desire to secure by Letters P-atcut is:

1. A method for producing a foundation or footing for a column or the like with concrete surrounding the column in that portion below a support surface, characterized by forming a hole in a support surface;

pouring concrete into the hole and partially filling the hole;

driving a pile through the unset concrete and int-o the surface therebelow and permitting a portion of the pile to project above the unset concrete; and

pouring concrete into the hole above the first-poured concrete and about the portion of the pile projecting thereabove.

2. The method as claimedin claim 1 including the step of forming a pilot hole at the base of the hole prior to making the first pour of concrete for substantially guiding the pile as it is driven through the first-poured, unset concrete.

3. The method as claimed in claim 1, including driving said pile into the hole and first-poured concrete so that the upper terminal end thereof is below the support surface in which the hole is formed, and inserting a column into the second-poured concrete.

4. The method as claimed in claim 1, including forming said pile of such a length so that the portion thereof projecting above said first-poured concrete project-s out of the hole and above the support surface in which the hole is formed.

References Cited UNITED STATES PATENTS 794,971 7/ 1 905 Ericsson 6150 2,3 73,276 4/ l 945 T hornley 6l50 FOREIGN PATENTS 715,3 14 12/1941 Germany. 263,997 1/1927 Great Britain.

IACO'B SHA P'IRO, Primary Examiner.

US. Cl. X.'R.

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