US1979670A - Method of preparing foundations - Google Patents

Description

NOV 6, 1934- s. o. BRUNE Er AL `1,979,670

METHOD OF-PREPARING FOUNDATIONS I Filed June 29, 1931 3 Sheets-Sheet l f f f NOV 6, 1934- s, o. BRUNE r AL.

METHOD OF PREPARING 'FOUNDATIONS Filed June 29, 1931 5 Sheets-Sheet 2 'NOW 6,1934. i s. Q BRUNE ET AL 1,979,670

METHOD F PREPARING FOUNDATIONS Filed June 29, 1951 s sheets-sheet s Ww,... 9' f-U 394i 1 f Patented Nov. 6, 1934 UNITED SATES METHOD 0F PREPASRING FOUDTIONS Samuel O. Brune and Oscar Peterson, Winnipeg,v Manitoba, Canada Application June 29, 1931, Serial No.` 547,504

In Canada July 28, 1930 1 Claim.

The invention relates tol improvements in means and method of underpinning walls and particularly existing walls which have sagged through faulty construction either of the building or of the walls forming part of the saine and an object of the invention is to provide an improved method for placing a supporting pier or piers under the foundationwall of the building and carried down to a hard permanent bottom and having their upper ends rmly supporting the foundation wall, the work being done without requiring excessive excavation or damage to the existing structure and permitting the workmen to work under desirable conditions.

A further object is to provide a method which permits of the effective reinforcement of the piers employed and of the underpinning of a part or of all of the foundation as occasion requires and which is also adaptable for use for underpinning the walls of the heavier types of houses,

apartments and such like dwellings.

A further object is to provide a method of preparing the foundations of walls for structures about to be erected.

A further object of the invention is to provide an improved type of auger for excavating the hole in which the pier is moulded, the auger construction permitting of the convenient boring of the hole in any location desired in respect to the foundation and also of the ready removal of the tooly from the -hole when working in the cellar.

With the above more important and other minor objects in View which will become more apparent as the description proceeds, the invention consists essentially in the arrangement and construction of parts hereinafter more particularly described, reference being had to the accompanying drawings, in whicht- I Fig, 1 is a vertical cross sectional view through a wall and showing the excavation made, a pier hole leading down from the excavation and the special auger used for boring the hole.

Fig. 2 is a perspective view of a portion of the tool.

Fig.A 3 is a vertical sectional view longitudinally and centrally through the wall and the reinforced concrete pier thereunder. 1

Fig. 4 is an enlarged detailed horizontal sectional view` at 4-4 Figure 3.

Fig.5 is an enlarged detailed horizontal sectional view at 5-5 Figure 3.

Fig. 6 is a longitudinal sectional view through a foundation and showing a number of piers supporting the same.

Fig. 7 is a vertical cross sectional View through (C1. (il- 51) a foundation and showing a modied method of' underpinning where parallel rows of piers are utilized to support the foundation wall, such type of construction being resorted to for walls in the heavier types of buildings.

Fig. 8 is a cross sectional view through the underpinning as it appears when two rows of piers are used.

Fig. 9 is a vertical sectional view at 9 9 Figure -8.

Fig. 10 is a horizontal sectional view at 10--10 Figure 8.

Fig. 1l is a perspective View showing the arrangement of piers.

In the drawings like characters of reference indicate corresponding parts in the several figures.

We will first describe the method and means of underpinning the foundation of a wall` where single piers are employed in a location centrally beneath the existing foundation wall of the building and then subsequently describe the modified type where two rows of piers are employed, such being resorted to where a wall of the heavier type is encountered.

We might initially explain that in some locations, trouble is found through walls slipping or sagging due to the building not having been properly underpinned at the time it was constructed. The practice amongst many builders has been to pla-ce a footing underneath the foundation wall of the building, the footing being considerably wider than the foundation wall and being reliedI upon to carry the imposed load. If the footing, however, is resting on unreliable strata, it will sink or slip and the building will sag or crack and subsequently has to be fixed and in so far as we are aware, such with existing methods, entails considerable excavation and expense and has proved unsatisfactory.

Where the wall or walls of a sagged foundation requires to be leveled and underpinned according to our method, we proceed as follows assuming primarily that the building is of the lighter type and only requires the single pier construction to support the same and that one or more piers are used in desired locations underneath the foundation.

In the case of buildings we find it preferable to work from the cellar as less excavating has to be done to get under the existing footing and the work can be carried on under more comfortable conditions for the workman. In cases, however, where it is not convenient to work in the basement or cellar, the operations can be carried on from the exterior of the building although more excavating will obviously have to be carried out. In Figures 1 to 7, we have shown in detail the manner in which the foundation footings are underpinned by reinforced concrete piles located centrally underneath the footing.

The wall foundation 1 is carried in the usual way by the footing 2 and the cellar or basement iioor is indicated by the reference numeral 3, this being customarily of cement. The method of putting several piers under a footing is just a duplication of putting a single pier under the footing.

Primarily a number of holes will be cut in the cement floor 3 in a location adjacent the cellar wall and then the earth will be dug out at these holes to provide an excavation Aunderneath the footing, the hole 4 leading down to the excavation 5 being of suflicient size to permit of the entrance of the workman. The excavation 5 will be made so that the earth forming the outer wall 6 thereof will be aring outwardly and downwardly from the outer lower corner of the footing and such that the earth forming the end walls of the excavation will flare upwardly and outwardly as shown at '7 and 8.

Having made a number of these excavations, one will insert in selected excavations the well known type of screw jacks and will operate the same to bring the sagged footing up to its proper level. The work can be then carried on in one or more of the unoccupied excavations to place supporting piers under the footing. A special auger or boring tool is provided, such tool comprising a number of lengths or sections of pipe 9 which have screw threaded ends to permit them to be readily connected together by the well known type of universal joint 10, the latter being shown in detail in Figure 2. The universal joints are screw threaded to the ends of the pipes so that as the work of boring proceeds, additional pipe sections can be added.

The boring tool 12 employed is of the conventional type and it is mounted on the lower end of the first pipe section used and ladjoining the upper end of such rst pipe section, we mount a guiding member 13 herein shown as a split wheel, the sections of which can be readily clamped around the pipe by bolting as indicated at 13.

` This guiding member has a diameter slightly less than the diameter of the hole A made by the tool, the arrangement being such that the guiding member will maintain the lowermost or leading tool section against wobbling in the hole. We have found that about four feet is a convenient length of the pipe sections.

When the work of boring is to be proceeded with, the tool handle 14 is screw threaded onto the upper screw threaded end of the leading pipe section, that is, the pipe section having the boring tool on the lower end thereof. The workman enters the unoccupied excavation and starts boring the hole A for the pier in a central location directly underneath the footing.

The tool will be lifted from time to time to raise out the bored earth as is customary practice and this earth will be passed out to the exterior. After the hole has been bored a depth approximately equal to the length of the first tool section, the handle 14 is removed from the leading section and one or more sections are connected to the leading section and to one another by universal joints and the handle is attached to the then upper section and in this connection,

" we might point out that it is desirable at such time to have the handle appearing in the cellar as it is much easier for the workman to work in such location.

The handle is then rotated to continue the boring and as the boring tool proceeds downwardly, the lower section of it is guided by the guiding member 13. As the boring work proceeds. additional sections are added at the top end as will be readily understood and the universal joints employed allow the workman operating the tool to be in a location to the side of the vertical axis of the hole bored. The hole is bored until a hard permanent bottom is reached at which time, the tool is removed and it will here be particularly noted that the joints provided in the tool allow of easy removal of the tool as the sections can be folded or turned as the tool is pulled out.

It will be readily apparent that the jointed tool used 'permits of the work being carried out in the cellar as no diiculty is experienced in the boring operation or in the removing of the tool as in the first part of the work, the sections are added as they are required and in the latter part, the sections can be turned or folded when the tool is being withdrawn, this being quite important where the head room space is probably eight or nine feet which is the usualheight of a cellar.

After the tool has been removed, a wooden or such like form indicated in dotted outline at 16 Figure 1 is introduced, this form having the upper edge thereof terminated in a location sufficiently clear of the adjacent inner lower corner of the footing to permit of concrete being poured to fill the pier hole A and that part of the excavation between the earth walls 7 and 8 and the earth wall 6 and the form 16.

Prior to pouring the concrete, reinforcing rods 17 are placed in the hole and spread in the manner best shown in Figures 3 and 4 in the moulding area directly underlying the footing and after sufficient concrete has been poured to fill the hole within a few feet of the upper end thereof, we insert centrally in the poured concrete, a reinforcing Vertical rail 18 which extends well up into the cavity underlying the footing. Subsequent to the spreading of the wires and the placing of the rail, the work of pouring the concrete is continued until the upper level of the concrete is spaced two or three inches from the under side of the footlng.

The concrete pier 19 with enlarged bearing head n 20 so formed is then allowed to set and after it has set suiiiciently, one puts concrete 21 into the open space appearing between the footing and the head of the pier, the concrete being firmly tamped "il" in by a tamping bar and Sledge or hammer. The tamping will be carried on from the side towards the interior of the building and the earth wall forms a backing against which to tamp. The

tamping bar will be wide so that the concrete can be tightly packed. The form 16 can be removed prior to tamping if desired. After the concrete which is tamped in has set, the work in so far asthe pier described is concerned is complete. Subsequently other piers will be moulded in position under the footing in like manner, the spacing of the piers and the number thereof being determined by the one in charge.

This method of underpinning the footing will insure of ample support for the wall provided of course that the piers are taken down to a hard permanent bottom and the building isnot too heavy and further all work can be readily carried out with a minimum amount of excavating, expense and time.

Where a wall forming part of a heavier structure is to be underpinned, such as a large house, apartment block and so forth, we may employ, instead of a single row of piers located centrally under the footing in the manner as just described, two rows of piers located underneath and to the sides of the centre of the footing, a number of the piers in the rows being connected together by a reinforced concrete head which carries the footlng.

In Figures 7 to 11, we have shown such an arrangement. The work of excavating and boring the holes for the piers is carried on from the interior of the cellar in the same manner as hereinbefore described and the piers are placed in groups of four, there being four spaced holes 22 bored, these leading down directly from the four corners of the excavation made underneath the footing 2. In vertical cross section, the excavation made under the footing is of the same general form as that before described but in this case, we desire that the earth end walls of the excavation converge upwardly as indicated at 23 and 24, the reason of which will be later explained.

To facilitate working of the tool in boring the pier holes, it may be necessary to angularly chip out angular notches 25 in the inner corner of the footing as this will allow the tool to more readily enter and be operated in those pier holes bored under the outer edge of the footing.

After the excavation under the footing has been properly shaped and the four pier holes bored, one will insert a form 26 and will then insert reinforcing wires or rods 27 in the pier holes and as the work of filling the holes with concrete progresses, vertical rails 28 will be inserted in the holes. When the pouring of the concrete has reached the level approximately at the top ends of the pier holes, we insert further reinforcing rails, there being a pair of horizontal lying rails 29 placed on the upper ends of the rails 27 and running longitudinally, in the same direction as the footing, a pair of rails 30 resting on the latter pair of rails and running transversely of the footing and a further pair of rails 31 lying on the rails 30 and running parallel with the rails 29.

After the rails have been putin place and suitably tied together and other wire reinforcements put in place, the pouring of the concrete continues up to within two or three inches of the under side of the footing, at which time, the concrete is left to set. We then have four reinforced concrete piers 32 capped by a reinforced concrete head 33, this head immediately underlying the footing. To complete the work, the space between the under side of the footing and the upper face of the head is lled in with concrete 34, this concrete being tamped into place in the same manner as that disclosed in the early part of the specification. When the concrete 34 has set, the footing is amply supported at that point by the head and four piers passing down to a hard permanent bottom.

Similar piers and heads can be placed under the footing in the same manner at desired intervals and if wished, the ground between the adjacent ends of successive pier heads can be excavated and the excavated area filled in with a moulded concrete block such as indicated by the reference numeral 35 Figure 11.

Where this is done, it is desirable to choose the length of the rails 30 so that they will project beyond the side faces of the pier heads and will become bonded in the concrete of the intervening blocks 35. We might also mention that these blocks 35 can be otherwise reinforced and particular attention is also drawn to the fact that the upwardly converging ends of the heads 33 form an annular bearing area for the intervening blocks.

If blocks be used between all the pier heads 33, the footing will be continuously supported.

In connection with the blocks, we might mention that 'concrete will be finally tamped in between the upper face of the block and the footing in the same manner as is done between the heads and the footing.

What We claim as our invention is:-

The method of preparing or underpinning the foundation wall of a building which consists in making a limited excavation at one side of the wall location and underneath the footing or site thereof and shaping the wall of the excavation underneath the footing to form a mould for a pier head, then utilizing a boring tool having a jointed handle to bore a hole from the bottom of the excavation downwardly to a firm foundation, the jointed tool being operated from ground level, then removing the tool and placing reinforcing members in the hole and the excavation underlying the footing or site thereof, then pouring concrete to provide a concrete pier in the hole and a moulded concrete pier head in the excavation underlying the footing and nally ramrning concrete between the pier head and the footing.

SAMUEL O. BRUNE. OSCAR PETERSON.

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