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Publication numberUS2957341 A
Publication typeGrant
Publication dateOct 25, 1960
Filing dateJan 16, 1956
Priority dateJan 16, 1956
Publication numberUS 2957341 A, US 2957341A, US-A-2957341, US2957341 A, US2957341A
InventorsAuguste Menard Louis Francois
Original AssigneeAuguste Menard Louis Francois
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Soil testing apparatus
US 2957341 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Oct. 25, 1960y L.. F. A. MENARD 2,957,341

son. TESTING APPARATUS Filed Jan. 16. 1956 :lil

'SOIL TESTING APPARATUS Louis Franois Auguste Menard, v612 W. Church St., Champaign, lll.

Filed-Lian. 116, 1956, Ser. No. 559,296

1 Claim. (Cl. 73-84) This invention relates to a newl soil testing apparatus. A large portion of the difficulties encountered in foundation work is due to the nature of the soil. Researches carried out during recent decades have permitted a better understanding of the foundation problems and it was considered as good practice to require the measure of compressibility and strength of the soil at practically every site which was considered for a structure of any importance. Engineers began to bore holes in order to obtain soil samples with elaborate sampling devices. The samples were forwarded to soil mechanics laboratories to be analyzed. The results were often very poor and the method was expensive and time wasting.

I have developed a new means to measure the compressibility and the strength of the soil directly in the ground.

The advantages of my apparatus are that it yields immediate and inexpensive leld results of the main soil characteristics required to compute a foundation and to control the compaction of earth dams. The results are reliable for any soil.

My equipment is very light and can be used very easily in remote and deep sites. The equipment is lowered in a bore hole at the desired depth. It is designed to apply a uniform and gradually increasing pressure on the well of the bore hole and to measure the correlative increase in diameter of the bore hole. With my apparatus, at any pressure and at any depth, the lower the compressibility of the soil the larger the increase in diameter. Furthermore, the apparatus measures the limit pressure, which is the maximum pressure that the soil can sustain without bursting.

It is among the objects of my invention to plot the curves of the increase in diameter of the hole in relation to the pressure in the cell. The mechanical properties of the soil are computed through a physical and mechanical interpretation of these plots.

Referring to the drawings, Fig. l is a sectional diagrammatic view of my soil testing apparatus; and Fig. 2 is an enlarged longitudinal sectional view showing the cell when expanded.

The pressure on the soil is applied by means of cylindrical inilatable elastic and distortable cell structures, which, referring to the drawing, I have denoted therein by reference numerals 1, 2, and 3. EaEch cell structure consists of rigid tubular cores 15, 16 and 17 and of expansible tubular hermetic elements 9, and 11, sleeved over the core and tightly fixed at its extremities 4, 5, 6 and 7 on rings.

Each cell structure is thus in the shape of a cylindrical toroid, the outer wall only of which is deformable while the other walls are rigid. The three cells 1, Z and 3 are furthermore rigidly clamped to each other by means of a number of tie bolts while maintaining the independence of each cell.

At the upper end of the upper cell and lower extremity of the lower cell, special protection collar 8 made of stii leather and xed on rings, is required for restricting end expansion and bursting of the expansible elements 10 and 11. It is required that the elastic membranes 9, 10 and 11 be thin enough to contact the entire surface of the bore hole, even under a very low inside pressure.

The details of the longitudinal half section cell structure are shown in enlarged Fig. 2. One end of the cell arrangement is omitted as both ends of the device are the same.

The detailed view in Fig. 2 shows in dotted lines the conditions of the cell when expanded. The initial outer deformable wall 10 of the cell structure has been displaced to 10'; the end protection 8 has been displaced to 8 and prevents the deformable membrane from expanding upward. between the ring 4-and the wall of the bore hole.

An equal pressure is applied in each of the three cell structures. As some secondary effects take place at the upper and lower boundaries of the stressed portions of the hole, the increase in diameter of the hole is not equal in the central cell structure and in the upper and lower cells.

Diagrams of the displacement of the soil at selected depths may be plotted as a function of the pressure inside the cell and of the speed of the time required for the build-up of the pressure. The physical and mechanical characteristics of the soil can then be deduced from these diagrams and mechanical equations, their interpretation being based upon the fact that, upon inilating the cell structures, isostatic surfaces of revolution are generated in the soil coaxially with the said cells.

When studying the phenomenon from a theoretical point of view, the above interpretation and equations are more mathematically accurate when the isostatic surfaces approximate most closely to cylinders.

In order to take this fact into account, the increase of diameter of the hole, is only measured at the level of central cell 1.

-In order to measure the increase in diameter of the hole, the central cell structure is filled up with an incompressible iluid such as oil, water or alcohol. As the length of the cell structure cannot change, there is a direct correlation between the increase in diameter of the hole and the increase in volume of the cell.

Incompressible fluid under pressure may be applied from the ground surface for expanding the central cell lthrough a pump 14 and conduit means 12 connected to the core of the cell and communicating with the interior of the expansible element. The calibrated reservoir 18 connected with the pump is used to measure the quantity of fluid introduced under pressure.

As the lluid should be incompressible and no air bubbles should remain in the cell, a return conduit means 19 with a valve 20 is connected with the cell and used to evacuate the air completely.

A pressure gage 13 connected to the return conduit means 19 is used when the valve 20 is closed in order to measure the pressure applied in the cell.

Fluid under pressure may be applied from the ground surface for expanding the upper and lower cell through a pump 14 and conduit means `12 connected to the cores of the cells 2 and 3. A pressure gage connected to a return conduit means 19" is used to measure the pressure applied in the upper and lower cell.

The test is carried out as follows: the cell structures are lowered in a bore hole at the desired depth; an incompressible fluid is applied under pressure in the central cell through pump 14. As the pump is connected to a calibrated reservoir, the volume of the fluid in the corresponding cell is always known. Simultaneously, iluid is applied under pressure in the upper and lower cell through pump 14 in such a way that the pressure read on the pressure gage 13' be always equal to the pressure 3 readon the pressure'gage 13. The volume injected through the pump 14 is plotted against pressure read on the pressure gage 13 or 13.

From the foregoing, it is believed thatAthe apparatus for practicing my invention will be readily comprehended by persons skilled in the art. `It is to be clearly understood, however, Athat various changes in the apparatus herewith shown and described as outlined above, may be resorted to without departing from the spirit of the invention, as defined by the appended claim.

Having thus described my invention, I claim:

Apparatus for measuring compressibility and bearing capacity of soil comprising a cell structure to be lowered into a test bore hole, said cell structure being a multiple cell arrangement having a main cell and 'outer cells whereby the outer cells restrict endwisev expansion of the main cell when pressure is applied, each said cell structure comprising a rigid tubular core, an expansible tubular hermetic element sleeved over said core, conduit means connected to the core and communicating with the interior of said expansible element, whereby fluid under pressure may be applied from the ground surface for expanding said element, means for measuring the quantity of fluid introduced into said expansible element, and pressure gages communicating with said conduit means for measuring the pressure applied thereto.

References Cited in the le of this patent UNITED STATES PATENTS 2,284,707 Wilson June 2, 1942 2,314,5'40 Huntington Mar. 23, 1943 2,564,198 Elkins Aug. 14, 1951 FOREIGN PATENTS 668,561 Germany July 28, 1928 501,186 Italy Nov. 23, 1954

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2284707 *Jan 18, 1940Jun 2, 1942Wilson Francis JApparatus for measuring soil or hydrostatic pressures
US2314540 *Dec 30, 1941Mar 23, 1943Phillips Petroleum CoApparatus for measuring volume of bottom hole portion of well bores
US2564198 *Jan 15, 1945Aug 14, 1951Stanolind Oil & Gas CoWell testing apparatus
DE668561C *Dec 6, 1938August Wolfsholz Dr IngVerfahren zur Bestimmung der Tragfaehigkeit von Bodenschichten in beliebigen Tiefen
IT501186B * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3175392 *Oct 16, 1961Mar 30, 1965Charles Mikolyczyk EdwardSoil testing apparatus
US3216200 *Jul 15, 1960Nov 9, 1965Fenix Gilbert JUnderground pressure vessel construction method
US3234788 *Dec 17, 1962Feb 15, 1966Antoine-Auguste Talobre JosephCylindrical jack for drill holes and combination thereof with a recording device
US3364737 *Apr 19, 1965Jan 23, 1968Electricite De FranceInstrument for testing the mechanical behaviour of materials at various depths in a borehole
US3442122 *Dec 5, 1966May 6, 1969Thorley AlanTesting probe for soils
US3442123 *May 1, 1967May 6, 1969Thorley AlanTesting probe for soils
US3633408 *Sep 10, 1970Jan 11, 1972Us Air ForcePressurized omnidirectional stress transducers gage system
US3772911 *May 20, 1971Nov 20, 1973Denisov VGround strain gauge
US3858441 *Jul 12, 1973Jan 7, 1975Comeau Henri JulesSoil testing apparatus
US3956926 *Oct 29, 1974May 18, 1976Phillips Oliver VStress measuring apparatus
US4075884 *Feb 14, 1977Feb 28, 1978Terra Tek, Inc.Fracture specimen loading machine
US4149409 *Nov 14, 1977Apr 17, 1979Shosei SerataBorehole stress property measuring system
US4461171 *Jan 13, 1983Jul 24, 1984Wisconsin Alumni Research FoundationMethod and apparatus for determining the in situ deformability of rock masses
US4539851 *May 21, 1984Sep 10, 1985Iowa State University Research Foundation, Inc.Soil and rock shear tester
US4543820 *May 17, 1984Oct 1, 1985Iowa State University Research Foundation, Inc.Tapered blade in situ soil testing device
US4598591 *May 16, 1984Jul 8, 1986Intra-CoforApparatus for determining the variations in volume of an expandable deformable cell embedded in soil and subjected to internal pressure gradients
US4662213 *Feb 3, 1986May 5, 1987Iowa State University Research Foundation, Inc.Back pressured pneumatic pressure cell
US5050690 *Apr 18, 1990Sep 24, 1991Union Oil Company Of CaliforniaIn-situ stress measurement method and device
US5099696 *Dec 26, 1989Mar 31, 1992Takechi Engineering Co., Ltd.Methods of determining capability and quality of foundation piles and of designing foundation piles, apparatus for measuring ground characteristics, method of making hole for foundation pile such as cast-in-situ pile and apparatus therefor
US5105881 *Feb 6, 1991Apr 21, 1992Agm, Inc.Formation squeeze monitor apparatus
US5576494 *May 26, 1995Nov 19, 1996Osterberg; Jorj O.Method and apparatus for subterranean load-cell testing
US5900545 *Oct 28, 1997May 4, 1999Carnegie Institution Of WashingtonAt depths in subterranean rock formations in the earth
US7380462 *Mar 13, 2006Jun 3, 2008G-Tech. Co., Ltd.Apparatus and method for measuring supporting force of large diameter ferroconcrete piles
US8739633Dec 24, 2010Jun 3, 2014Japan Agency For Marine-Earth Science And TechnologyUnderwater work device and underwater strain gauge device
EP0490420A2 *Nov 27, 1991Jun 17, 1992Services Petroliers SchlumbergerDownhole penetrometer
EP2009184A2 *Jun 12, 2008Dec 31, 2008Porr Technobau und Umwelt AGMethod for calculating the radial enlargement and/or concentration of hydraulically binding material of DSV bodies
WO1997015804A1 *Oct 21, 1996May 1, 1997Carnegie Inst Of WashingtonStrain monitoring system
WO2011078362A1 *Dec 24, 2010Jun 30, 2011Japan Agency For Marine-Earth Science And TechnologyUnderwater work device and underwater strain gauge device
Classifications
U.S. Classification73/84, 73/149, 73/784
International ClassificationE21B49/00, E02D1/00, E02D1/02
Cooperative ClassificationE21B49/006, E02D1/022
European ClassificationE21B49/00M, E02D1/02B