Патент USA US2277286код для вставки
March 24, 1942. P. BECHTNER 2,277,286 METHOD AND MEANS FOR IMPEDING THE S'EPAGE OR FLOW OF WATER Filed Nov‘. §, 19156 (M , . .hi.§ MJIJ..I M ' INVENTOR ’ IDAUL BECHTNER BYg . . ATTORNEYS Patented Mar. 24, 1942 ‘ 2,277,286 , UNITED STATES [PATENT OFFICE ' 2,271,286 METHOD MEANS FOR IIVIPEDING THE SEEPAGE OR FLOW OF WATER iPaul-Bechtner, Chicago, Ill.', assignor to Ameri can Colloid 00., Chicago, 111., a corporation of South Dakota Application November 5, 1936, Serial No. 109,245 ’ 13 Claims. (Cl. 61--30) I have discovered that water seepage may be This invention relates to improved methods prevented and that structures of various types and means for impeding the flow of water and may be safeguarded against-leakage by blocking for reinforcing structures to prevent the seep the path of. ?ow of .the water with bentonitic or age of watervtherethrough. The seepage and ?ow of water through earthworks, dams, ma 5 highly colloidal clay which possesses the‘ ca sonry constructions, water barriers and the like " causes untold economical loss, much of which can be prevented by the. invention-herein de . scribed. Seepage through water barriers, such as dams, 10 co?erdams, and water-retaining walls may bev caused by any} of several conditions. The bed pacity to swell and gelatinize upon ‘contact with water. The type of clay best suited for the pres ent' purposes is the true bentonite obtained in regions of Wyoming and South Dakota, although other highly colloidal, or bentonitic clays which possess the property of swelling and gelatinizing in water to a substantial degree are also use-M ful. The degree of their e?ectlVeness depends upon the closeness with which this swelling propplaced on porous bodies of materials such as sand _ 15. erty corresponds to that of true bentonite. True bentonite is a material consisting prin or gravel. Barriers formed of concrete or of rock may not be impervious to flow. The cir cumstances may require that‘ the barrier be ' cipally of the mineral “Montmorillonite” and oc any of the usual materials are likely to crack curring naturally in combination with about 25 or develop minute openings which allow seep to 45% water. For commercial use this mate age, or they may be formed of aggregate, sheet, planks or the like, which are inherently sus 20 rial isgdug, dried to contain about 9% moisture, and then granulated or powdered. Some physi- ' ceptible to leakage through scams or crevices in cal characteristics which distinguish bentonite the structure. from other clays are its permeable texture and In the sealing of mines against the ?ow of its extremely small grain size. From 65 to 70% underground water‘ it is common practice to provide a wall of concrete across the mine shaft, 25 of the grains of a Wyoming bentonite are finer than .2 micron; over 85% are ?ner than 2 mi yet such an expedient often fails to accomplish crons. ~These grains or particles, when wetted, its purpose because of theleakage allowed by adsorb ?lms of water that are thicker than the shrinkage of the setting concrete away from the, films which form on other clay-like materials, walls against which it is cast. Such leakage, once started, sometimes results in destruction of the 30 and after 'the bentonite has been wetted the wall and complete release of the backed-up water. " water cannot be expelled, even at high pressures. The strong adsorptive power of commercial ben- Similar problems are encountered in efforts tonite, which will adsorb almost ?ve times its to exclude water from core trenches, excavations weight of water, is therefore partially attributa and "foundation walls of buildings and to con?ne water to prescribed ditches or channels, In fact, 35 ble to the preponderance of extremely small grains or particles, providing tremendous sur these are but a few of the many circumstances ‘face area for the exertion, of adsorptive powers, ‘ under which it is highly desirable yet di?icult effectively to prevent the ?ow or seepage of wa ter. \ I ' and the ?lm retaining capacity of these parti cles. ‘ \An object of ‘my invention is to Provide im- , w proved methods and means for inhibiting the‘ seepage of water through pervious structures and for safeguarding against seepage or ?ow through structures that are normally impervious but ,ca 45 pable of developing leaks. - - Commercial bentonite swells, when contacted with water, as much as 10 to 20 times its dry volume. One factor which causes this swelling is the separation of the small particles by the water ?lms adsorbed thereon. Another is the distinctive nature of the particles themselves, which are composed of minute plate-like struc— tures that possess the peculiar property of al lowing water molecules to penetrate their crys ‘ water seepage or ?ow. tal lattice. The crystal structure itself is thus Another object of my invention is to provide ,- such methods and means which are-permanent 50 expanded. A third factor is the mutual repul sion of the particles, due to like negative po ' ly effective regardless of shrinkage, cracks, or Another object is to provide improved barriers which are constructed better to insure against shocks ‘and distortions caused by subsidence, _ earth movements and the like. Another'object is to provide special methods and means by which it is possible to correct ex isting conditions of seepage or flow without re ' quiring freedom from contact with ‘the water. Stillcfurther objects and advantages of the invention will be apparent from the following description. larity. ' , 3 ‘ In its swollen condition bentonite ‘has several advantageous properties; it will carry materials 55‘ in suspension; it exerts a cohesive effect; when left quiescent it forms a permanent gel the vis cosity of which increases upon aging. An im ‘portant aspect of the swelling of bentonite which I have discovered is that it will swellv only to the 60 extent necessary to ?ll available space, without 2 2,277,286 exerting substantial pressure when con?ned against further swelling. Another important quality is that repeated drying and contraction of swollen bentonite in no way impairs its ca pacity to swell again upon renewed contact with water. These properties make it an ideal ma the ditch through pervious earth adjacent there to. Fig. 9 is a cross section of a structural unit of bentonitic clay, constituting a special feature of the invention. Fig. 10 shows another embodiment of a struc- . terial for incorporation in a dry or slightly moist tural unit. state into dams and other water barriers, at In Figures 1 to 4, inclusive, I illustrate im points where leakage possibilities occur, so that proved dam constructions utilizing the principles in case cracks or other leakage develop the 10 of my invention. Within the dam structure at bentonite will come into contact with the leak points likely to be affected by seepage, cracks or ing water and swell to stop the leak but will the like, I provide inserts of bentonite so that not create‘ pressure which might cause further water seeping through the structure will contact breaks. the bentonite. I have discovered that a blanket or wall of For example, in the construction of Figure 1, bentonite which possesses the capacity to swell the dam I0 faces against abutment walls I2 and upon contact with water will permanently resist I3, and at the meeting surfaces of these mem seepage or ?ow of water therethrough. When bers wells l4 and I5, extending for the height the bentonite is contacted with water it swells of the dam into the concrete or other material to ?ll available voids or spaces. Thereafter it is 20 of which the dam is formed, are provided. The impervious, and it remains impervious to water wells are filled with a dry bentonitic clay hav as long as water is present. If water is not con-' ing the capacity to swell and gelatinize upon tinuously present the bentonite may contract contact with water. Figure 2 may be considered as it dries, but its resistance to seepage is im as a section taken vertically along the axis of mediately restored upon renewed contact with 25 the dam and through the well IS. The abutment , water. ‘ I have found also that bentonite confined with in masonry structures or the like, when wet, ‘ I3 is illustrated as comprising a concrete portion positioned on rock at I8. Well I5 extends, for the height of the dam, across the joint I 6 between the main wall I 0 and the abutment, and it is does not exert swelling pressures su?icient to harm the structures in any way, yet it forms an 30 filled with bentonite as indicated at ll. impervious seal with the con?ning surfaces. Figure 3 represents an arch-like dam having a Furthermore, the bentonite, either in dry or wet central wall 20, wings 2| and 22,. and, at the swollen condition, may be subjected to shocks, joints between the wall 20 and the wings, wells earth movements or subsidence without destroy which con?ne masses 23 and 24 of bentonitic ing its sealing power. The swelling capacity of 35 clay. In Figure 4, a dam 25 positioned on bed the material is completely exhausted only when rock 26 is provided with an insert of bentonitic it is suspended freely in many times its volume clay at 21, bridging the seam between the dam of water. Accordingly, by utilizing a blanket or and the rock. . vwall of bentonite to block the ?ow or seepage Dams constructed with inserts of bentonite at of water I am able to effect permanent imped-_ 40 points susceptible to leakage are surprisingly re ence of such ?ow or seepage under many diffi sistant to the passage of water. The shrinkage cult conditions. Appropriate combinations pf of setting concrete, earth movements, contrac bentonite and strength giving structure produce tion and expansion due to changing tempera barriers that are resistant to water under great tures, etc., are likely to result in water per pressure. 45 meable seams and crevices. The presence of a Several preferred modes of practicing my in mass of bentonite at such points, however, pro vention are illustrated diagrammatically in the vides permanent protection against seepage. drawing, wherein When the confined bentonite is contacted with Fig. 1 is a diagrammatical plan view of an water which has traversed the structure to the embodiment of‘ my invention in which inserts of 50 location of the bentonite it immediately adsorbs. bentonite are employed to reinforce a dam water, swells enormously, and forms a gelatinous against water seepage. . mass which itself is impervious to water and pro Fig. 2 is a diagrammatical vertical section vides an impervious seal with the con?ning walls through a portion of a dam at a joint between of the structure. the main wall of the dam and the-abutment. 55 Although the insert 21 of bentonite in Figure 4 Fig. 3 shows an application of my invention is illustrated as surrounded by dam structure similar to Fig. 1 in which the bentonite is placed and bedrock, other arrangements may be fol in wells adjacent the connection of the main lowed without sacri?cing results. Substantial portion of a dam with the wings thereof. ly dry bentonite is notable for its extreme density Fig. 4 represents a vertical cross section of 60 and compressive strength when packed into a another type of dam construction,.in which a compact mass. Wherever the bentonite is sub blanket of bentonite is interposed between the ject to flowing water currents which would car bedrock and the bottom of the dam. ry away the gels as they formed this erosion Fig. 5 illustrates the application of the inven may be prevented bymaintaining a layer of sand tion to the closing of a mine or conduit against 65 or other erosion resistant material between the the ?ow of water therethrough. bentonite and the ?owing water. The bentonite Fig. 6 illustrates the use of a blanket of ben then forms a tight-?lter-cake on the surface of tonite to protect the foundation wall of a build the sand. '1 ing against water seepage. Figure 5 is a diagrammatical showing of a con Fig. '7 is a partial view, in vertical section, of 70 struction which is effective to block the flow of a floor provided with an underlying layer of water through mines, or water conduits in gen bentonite. eral. A pair of spaced forms or bulkheads 32 Fig. 8 represents, in cross section, a trench or and 34 extends across a mine shaft 30, and a ditch bordered by a blanket of bentonite in such mass of bentonite or similar colloidal clay is manner as to prevent the seepage of water from 75 located ‘at 35 between these forms. The forms 3 2,277,286 may be of wood, masonry or any other suitable material. 'The bentonite may be in ?nely digided that remains impervious as long as ‘water is pres ent and is not destroyed by subsidence, earth form, or in the form of blocks or bricks, or it ‘may be combined with other material, for ex ample, sand or gravel. In the use of this embodiment of the inven movements or the like. » . The drawing and the foregoing description re lating thereto are illustrative of only a few of the many improved constructions resulting from tion distinct, advantages are obtained as com the use of the invention and of only a few modes pared with concrete walls and other types of barriers heretofore employed for the same pur of applying the same. To the skilled engineer it will be obvious that the invention may be poses. The leakage permitted by the shrinkage 10 utilized in many di?erent ?elds and in many of concrete walls away from the walls of a mine different ways.‘ ' - - While‘ strong gels‘ and high resistance to water penetration are obtained by the use of pure, or conduit \during the setting of the concrete is completely avoided. Whenever the form 32 al lows backed-up water at 38 to contact the ben tonite at 36, the bentonite ?rst contacted ad‘ bentonite or pure bentonitic clay, I have discov- , ered also that the resistance of the mass to high water pressures may be increased by employing . sorbs water, swells and forms a gel which is , permanently resistant to seepage. The same ef feet is produced whether the water contacts the ‘ bentonite along, the walls of the mine or conduit . or remote from the walls. 20 A characteristic feature of this and the other embodiments of the invention is that the swelling/ of only a‘ small portion of the mass of bentonite, ' the portion ?rst contacted with water, is usually effective to block seepage through'to other‘ por mixtures of bentonite or bentonitic clay and other granularv materials, for example, sand. For example, when a mixture of equal parts of ben tonite and beach sand is poured into a T-shaped section of 3 inch pipe to a height of 20 inches in the longer arm of the T and lightly tamped therein, the mass is not moved by continuing water pressures of 1000 lb. per square inch, and the water penetrates the mass a‘ distance of only tions of the mass. Thus these other portionsu'e about 5 inches. tain their full capacity to absorb and swell. and ’ W _ > An important advantage of the invention re block further ?ow or seepage in the event that sults from the variety of methods which may be_ the ?rst gel formation should be disturbed. employed to form the seepage-resistant mass of Another important advantage .is that the ex" 30 bentonite. In one embodiment ordinary com pense and care incident to the. provision of bar mercial powdered or granulated bentonite may be riers such as concrete walls are avoided. The used. Even when loosely put in place as by pour forms 32 and 34 need not be impervious to water; ing, such ?nely-divided material provides a per- » it is su?icient that they give strength to the bar manent barrier against seepage, since vthe swelling rier and that form 34 include no openings permit- " ' power of dry bentonite is so great that voids in ' ting escape of the bentonite therethrough. The ' the mass are blocked upon contact with water. blanket or wall‘ 35 of bentonite is formed with-7 The physical strength of such a mass may be out difficulty, and it is effective as soon as formed, increased by tamping or packing the bentonite in in contrast to concrete which requires consider place. . ' able time to set. In addition, the bentonite may 40 Under somé circumstances of use it is imprac ‘be removed easily; whereas the destruction of a tical to provide temporary or permanent support barrier composed of masonry is a difficult task. ing means for the bentonite before forming the My invention is also applicable to impede the ' mass; 1. e., the bentonite must be placed ?rst. seepage of water through foundation walls and For example, in sealing a wall against leakage I ?oors of buildings, as illustrated in Figures 6 45 from the outside earth the most practicable pro and 7. Between the foundation wall 40 of a ‘' cedure may be to form the mass of bentonite building (Fig. 6) and the adjacent soil 42, a adjacent the wall and then ?ll in the earth. Ac-v blanket‘of bentonite is interposed as indicated‘ cording to another embodiment of my invention at 44. As in the other embodiments described this may be accomplished by incorporating the H above, the bentonite swells when contacted with 5 bentonite with from one to one and a half times water and forms an impervious barrier which as much water to form a stiff putty-like mass prevents the water from seeping to and through which is su?iciently cohesive to adhere to rough I or around the wall 40. An arrangement such as or smooth surfaces. In this form it will continue that shown in Fig. 7 is particularly suitable for to adhere as long as it is moist; yet it retains the ground ?oors of buildings placed in low, damp about 70 to 80% of its potential absorbent and ground. A blanket 41 of bentonite is placed on swelling property, to ‘be exerted when water is the base 46 for. the ?oor, and the ?oor 48, which brought into contact. , . ‘ may be of concrete or any other suitable‘mate Still other embodiments of the invention pos rial, is applied over the bentonite. sessspecial advantages for use under certain Figure 8 illustrates a mode of applying the 60. conditions. The stiff putty-like bentonite pre invention to the prevention of seepage from a pared, as above described is improved for use ditch or the like formed in pervious soil. In the construction of the ditch a blanket 52 of bentonite ' ,where water‘ is present by fashioning ‘it roughly into bricks or blocks each having a quantity of dry ?nely-divided bentonite in its interior. Sim ilar results may be obtained, as illustrated in is placed adjacent the wall of, the earth 50, and this blanket 52 is covered by“ erosion resistant material as indicated at 54, forming the bottom of the ditch. A preferred type of covering mate rial for this and similar embodiments of the in vention includes a layer of ?ne sand next to the blanket of bentonite and a layer of gravel or the like adjacent the sand. The blanket of bentonite effectively prevents the seepage of the water at 56 from the ditch through the underlying soil. - Figure 9, by forminga bricklike body ‘Ill of hen tonite which has been moistened only sufficiently to produce slight coherence and then contacting the outsides of thesbody with water, as by dipping or spraying. The water does not,- penetrate far into the body but causes the bentonite at the surfaces thereof to swell and form a cohesive sheath or enclosure as indicated at _'|2, which As the bentonite is contacted woth water it swells strengthens the unit so that it can be handled to form an impervious gelatinous barrier, one 75 and placed in position. Another suitable pro 4 2,277,286 cedure (see Figure 10) is to use a fabric enclosure, of such seepage or ?ow and ?lling into and con~ for example, a paper cartridge as indicated at 80, ?ning within said space a mass of substantially ?lled with dry bentonite 82. Still another, which is useful under circumstances prohibiting the dry, ?nely-divided swellable bentonite mixed construction of a solid blanket of bentonite, as in the prevention of seepage through water covered porous rock or gravel structures, is to force a ’ with sand, said mass being of su?icient thickness and bentonite concentration to form across said path, upon contact by the water, a water-imper vious barrier of swollen bentonite adjacent its heavy pumpable suspension of bentonite into the face merging into substantially unswollen ben structure and thus build up a blanket of bentonite in the path of seepage. The' invention is not ‘limited to the speci?c tonite ‘within the mass. _ 8. A water barrier comprising rigid supporting illustrative uses and methods of use described water seepage or ?ow and a compact mass of structures having space therein in the path of hereinabove, although these possess their own ?nely-divided swellable bentonite con?ned across individual advantages. When dry or swellable said path in said space, said mass being of su?i bentonite is applied to expansion joints, shrink 15 cient thickness and bentonite concentration to age joints, or adjacent corners where cracks are swell at its face and form across said path, when likely to develop in concrete dams, or when used contacted by water, a water-impervious barrier of swollen bentonite merging into substantially unswollen bentonite‘. 9. The method of blocking the flow of water this is within the scope of my invention, and inas 20 in any water barrier where, upon coming in con tact with water, it will swell and stop the leakage, under pressure through a determinate path much as I have discovered that bentonite can be which comprises restraining the water from a used in this manner without developing appreci part of said path, forming across said path at able pressures on swelling, innumerable further said part a compact mass including substantially uses for bentonite in sealing water barriers, based on the principles I have disclosed, will occur to 25 dry swellable bentonite of sumcient thickness and bentonite concentration to swell adjacent the those skilled in this art. I claim: ' \ water face and form across said path a water-M impervious barrier of swollen bentonite merging l. A dam comprising a masonry wall positioned on a supporting bed and abutting against end into substantially unswollen bentonite, providing abutments, said masonry having a compartment 30 supporting structure of su?icient strength to hold said mass in place against the water pressure and therein at a point susceptible to leakage, and a con?ning said mass by said structure, and ?nally compact mass of swellable bentonite con?ned admitting the water into contact with said mass. within said compartment. 10. A water barrier for preventing seepage or 2. A dam comprising a masonry wall positioned on a supporting bed and abutting against end 85 ?ow from a body of water through a determinate V path comprising rigid supporting structure hav abutments, a compartment extending along the joint between said wall and an abutment, and a ing space therein across the water path and a compact mass of swellable bentonite ?lling said compact mixture of ?nely-divided swellable ben tonite and granular material con?ned across said 3. A water dam comprising a concrete dam (0 path in said space, said mixture being of suffi cient thicknessand bentonite concentration to structure having pockets of swellable bentonite swell at its face and form across said path, where therein. contacted by water, a water impervious barrier 4. A self-sustaining structural unit for the for? of swollen bentonite marging into a reserve mass mation of barriers impervious to water compris ing ?nely divided, slightly moist swellable ben 45 of substantially unswollen bentonite. 11. The method of preventing ?ow or seepage tonitic clay in the interior thereof and wet ben of water through rigid structures susceptible to tonitic clay constituting a cohesive enclosure compartment. therefor. water penetration which comprises placing and supporting adjacent a side of such structure and 5. The method of making structures resistant to seepage or ?ow of water therethrough which 60 across the path of water penetration a compact blanket including ?nely-divided, swellable ben comprises positioning a mass including swellable tonite and of sut?cient thickness and bentonite bentonite across the path of such seepage or ?ow concentration to swell at its face upon contact and con?ning said mass between spaced rigid by the water and form across said path a water supporting structures, said mass being of suffi cient thickness and bentonite concentration to 55 impervious barrier of swollen bentonite merging into swellable bentonite, and providing means swell and form adjacent the water face, when adjacent the face of said blanket for holding the contacted by the water, a supported, water-im same in place. pervious barrier of swollen gelatinous bentonite 12. A bulkhead or the like for preventing water merging into swellable bentonite. , 6. The method of preventing ?ow or seepage 60 ?ow through a determinate path ‘comprising sub stantially rigid structures spaced apart and ex from bodies of water which comprises forming tending across the water path, said structures and supporting and con?ning across the water being susceptible to water penetration, and a path a compact blanket of ?nely-divided, sub compact mass of ?nely-divided bentonite, con stantially dry swellable bentonite-of su?icient thickness and bentonite concentration to swell 65 ?ned within the space between said structures. 13. A bulk head or the like for preventing adjacent its face upon contact by the water and water flow through a determinate path compris form across said path a water-impervious barrier ‘ of swollen bentonite merging into a reserve mass ing substantially rigid structures spaced apart and extending across the water path, said struc of substantially unswollen bentonite. 7. The method of making structures such as 70 tures being susceptible to water penetration, and a water-impervious mixture of ?nely-divided ' dams, bulkheads, masonry walls and like water barriers impervious to seepage or flow there bentonite and sand con?ned within the space through from bodies of water, which comprises between said structures. providing space in the structure across the path PAUL BECH‘I'NER.