US 2322855 A
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T." P. LENAHAN nA'rUs Fon RAIsI ,855 NG AND PERMANENT nucTunEs June 29, '1943. l
METHOD AND AFPA SUPPORTING HEAVY ST Filed Feb VINVENTQR THOMAS R LENA'HAN Patented June 29, 1943 Y METHOD AND APPARATUS FOR RAISING AND PERMANENTLY SUPPORTING HEAVY STRUCTURES Thomas P. Lenahan, Duncan, Okla., assignory to Halliburton Oil Well Cementing Company,
Application February 9, 194,2, Serial No. 430,096
2 Claims. (Cl. (i1-51) This invention relates to method and apparatus for raising and permanently supporting heavy structures such as dams, bridge piers, docks, foundations and the like, which have settled or shifted.
Load sustaining structures of the type mentioned are sometimes located in places where V:there is a layer of unstable earth, such as silt or sand, over the load bearing substratum or bed rock. As a result, the structure sometimes sinks below its intended level, either wholly or at one Vside orcorner.
In accordance with the present invention, it is proposedto raise and permanently support such structures by the employment of a hydraulic jack in which cement slurry is either used -as the actuating liquid or follows the actuating liquid, the jack being so constructed that when the structure israised the desired) amount, valves may be closed and the cement allowed to harden,
leaving the jack permanently in place, it then -becoming a reinforced concrete column. I
If the structure is relatively small, or if only one corner of it has sunk` into the earth, it may be vpossible to bring it back into the desired position by the use of only one jack. If a large structure-has to be raised, however,` any number yof vjacks may be employed and the arrangement `for supplying the cement` slurry thereto may be such that the jacks exert their lifting force either one after the other or simultaneously. I Accordingly, it is an object of the present invention to provide a novel system for raisinga heavy structure such as a pier and for permanently holding it in place.
It is another object of the present invention to devise novel methods of raising heavy structures and for holding them in place.
Other objects and advantages reside in certain novel features of the method and the arrangement of parts, as will be apparent from the iollowing description taken in connection with the accompanying drawing, in which:
Figure 1 is a diagram showing a planview of a pier with a system of jacks, valves, pumps, etc., for raising it in accordance with the present invention; and
Figure 2 is a partial cross-sectional view of a hydraulic jack constructed in accordance with the principles of the invention.
Referring to the drawing in detail, and first to the arrangement of Figure 1, it will be seen that a pier is there illustrated at II. In order to illustrate the invention, let it be assumed that the entire pier has sunk into the earth and that it; is desired to raise the same uniformly at all points.
In accordance with the present invention, suitable lifting members IZ are secured to the pier at spaced points. In the diagram ofV Figure 1, six such lifting members are illustrated. 'These may be sections of I-beams or other structural steel members and are secured to the pier in any suitable manner.
Beneath each of the lifting membersv I2, `hydraulic jacks I3 are mounted, the jackspreferably extending down to bed rock. The hydraulic jacks I3 are each supplied with individual supply conduits `I4. Each of these conduits is provided with a .Valve 'I5 and is connected to the supply conduits I6, to which liquid under pressure may be supplied from a pump I1.
` The pump I1 may supply Water or other liquid tothe conduits I6 to initially fill the jacks I3. At the desired time, the water maybe replaced `by cement slurry. InFigure 1, thecement mixer may `all be suppliedwith liquid simultaneously or successively. Likewise, any group of jacks may selectively be supplied with liquid. Thus, if -desired, the valves I5 at the rightof the figure may remain closed, while those at the left are opened and Yliquid suppliedto the left-hand jacks,` after which those valves may be closed and the ones on the right-hand side of the figure opened to raise the right-hand side, so that first one side of the pier 'and then the other is lifted, the pier thus being rocked back and forth as it is lifted.
An important feature of the invention resides in the construction and mounting of each ndividual hydraulic jack. To place the jack in position, a hole is first drilled along side the pier where it is desired to locate the jack, the hole going down to bed rock. The equipment for drilling this hole may be such as is commonly used in drilling oil wells.
Such a hole is illustrated at 2l in Figure 2. After the hole is completed, casing 22 is lowered therein and secured in place by placing cement 23 in the annular space between it and the wall of the hole 2|. The manner of carrying on this operation may be the same as that employed in cementing surface casing in oil wells.
The casing 22 may extend above the surface of the ground as illustrated, and is provided with a discharge conduit 24 equipped with a Valve 25.
Lowered into the .casing 22 is a jack pipe 26. Preferably this pipe should extend to the bottom or nearly to the bottom of the hole 2|. It is some longer than the casing 22 and extends up through structure providing a suitable stuing box, as illustrated at 2l. An ordinary Bradenhead such as is used in the oil elds may serve as the stuflng box.
The upper end of the jack pipe 26 is provided with a cap 28 positioned just beneath the lifting members I2 secured to the pier II. In the arrangement illustrated, the conduit I4 equipped with the valve I referred to above, is connected into the jack pipe 26.
It will be seen that with the structure illustrated, liquid may be supplied from the pump I'I to `the interior of the jack pipe 26, the liquid flowing in the direction of the arrows of Figure 2, assuming the valves I5 and 25 are open. If desired, the lower end of the jack pipe 26 may be provided with suitable discharge ports 29 to facilitate this circulation. (If desired, the circulation might be in the opposite direction, the pump II then being connected to pipe 24.)
As illustrated, if at any time the valve 25 is partially or wholly closed, pressure Will build up within the jack and cause the jack pipe 26 to exert a lifting force upon the member I2.
Where conditions are ideal, no liquid will be placed in thejack prior to the time that cement slurry is placed therein. In such a case, the valves I5 and 25 will both Vbe opened, slurry pumped into the yjack and circulated in the direction of the arrows, until a return is had through the conduit 24. The valve 25 will then be closed, and the supply of cement-slurry to the jack continued until the'member I2 has been raised the desired amount, at which time the pumping will be discontinued, the valve I5 closed and `the cement allowed to harden.
At other/times it may be necessary or desirable to use water or other liquid for 'exerting the necessary pressure to lift the structure,
n this liquid to be followed by cement slurry with the valves I5 and 25 carefully controlled, so that 'the desired position of the jack pipe 26 is maintained.
In any event, cement will ultimately be left not only in the jack pipe 26, but also in the annular space between it and the casing 22.
After the cement has hardened it, will be seen that a very rigid column is provided, consisting of the outer body of cement 23 interlocking the casing 22 with the earth, an intermediate body of cement between the casing 22 and the jack pipe 26 and an inner body of cement left within the jack -pipe 26.
Of course, after the cement has hardened, the valves I5 and 25 and the connecting pipes I4 and 24 may be removed from the column.
If the pier or other structure is raised by rocking motion, as mentioned above, the cement in one set of jacks may be allowed to harden before slurry is supplied to the other set, the apparatus being capable of use in several different ways.
Also, it is, of course, possible to force cement or other supporting material under the pier or other structure during or after the yapplication of the method and apparatus of this invention.
While only one embodiment of the invention has been shown and described herein, it is obvious that various changes may be made in the method of application or in the structure, without departing from the-spirit of the invention or the scope of the annexed claims.
1. The method of raising and permanently supporting a structure which consists in drilling a plurality of holes in the earth, placing a casing in each hole, cementing the casings in place, placing jack pipes in the casings through stufling boxes, lling the jack pipes and the casings with liquid, exerting hydraulic pressure on the liquid to raise the jack pipes replacing the liquid in the jack pipes and casing with cement slurry while maintaining the hydraulic pressure therein, and holding the pressure until the cement hardens, the hydraulic pressure being exerted on the liquid alternately, to rock tl'ie structure slightly in raising the same.
v 2. The method of raising and permanently supporting a structure which consists in drilling a hole in the earth, placing a casing therein, cementing the casing in place, placing a jack pipe in the casing through a stung box, filling the jack pipe and the casing with a liquid, exerting hydraulic pressure on the liquid to raise the jack pipe, replacing the liquid in the jack pipe and casing by cement slurry while maintaining the hydraulic pressure therein and while maintaining the jack pipe in its raised position and holding the pressure until the cement hardens. l
THOMAS P. LENAHAN.