US2128657A - Dam - Google Patents

Description

Aug. 30, 1938. J nMApARAs 2,128,657

DAM v Original Filed April 10, 1933 I 5 Sheets-Sheet 1 fizz enter alias .01 /*Za James 4mm MM Mam. ##QMW WWW Aug. 30, 1938. J MADARAS 2,128,657

' v DAM Original Filed April 10, 1933 3 Sheets-Sheet 5 .flzvezrtar' v.

7/212 z'zas J/Za Jar'as 1 WW/Wh/WM Patented Aug. 30, 1938 UNITED STATES DAM Julius D. Madaras, Detroit, Mich.

Application April 10, 1933; Serial No.- 665,450 RenewedDecemb'er 28, 1936 12 Claims. (01. 61-33) Thisinvention relates to dam constructions and has as one of its objects to materially reduce the cost of installation ofdams as well as to improve the constructionthereof.

6:: The cost of dams constructed in accordance with conventional practice is approximately proportional to the square of the height of the dam, and inasmuch as the latter dimension is usually calculated from the bed rock to the water level, the cost of installation may be expressed mathematically as approximately proportional to K(hi+h2) +a where K is: aconstant, hi is the distance from the river bottom to bed rock ha is the effective height or, in other words, the distance fromthe river bottom to the water level, and.al. is a factor dependinglupon conditions existing-at the site=ofinstallation.v 1

The present invention contemplates materially reducing the costzof installation of dams by providing a construction composed of considerably less material 1 than. damsof the general character set forth inthe previous paragraph. and posbeyond the river bottom to bed rock so that the actual height ofthe dammay be calculated fromthe-river bottom instead of bed rockor, in other words, is the same as the effective-height referred to above in discussing conventional types of dams. As a consequence, the cost of a" dam constructed in accordance with the foregoing may be ex pressed mathematically as proportional to Khz+a+b where b isva factor peculiar to the cable structure of this invention instead vof the eXpresison K(h1+hz) +a employed in calculating costs of the present constructions of dams. The

saving in material and consequent saving in the cost .of installation effected bylthe invention will be apparent upon comparing the two aforesaidmathematical expressions.- j I p The foregoing aswell asnumerous other structuralfeatures will be ma'de moreapparent as this descriptionproceeds, especially when-considered in'connection with the accompanying drawings, wherein:

Figure -1- is a sectional view through an installation of a dam constructed in accordance with this invention;

Figure 2 is an enlarged fragmentary perspective viewfeaturing one type of cable connection;

Figure 3 is an enlarged sectional view through the upright wall of a'dam featuring the reinforcing means for the concrete and the-manner in which the c'able brackets are secured in place;

Figure 4 is a side elevation of the upstream face ofthe dam;

Figure 5 is a view similar to Figure 1 showing a modified form of construction;

Figure 6 is an enlarged sectional View through a portion of the upright wall of the construction shown in Figure 5 illustrating the adjustable cable connection with said wall;

Figure 7 is a detail sectional view showing the manner in which the cables are anchored in the foundation rock;

Figure 8 is a horizontal sectional view through another modified form of 'the invention;

- Figure 9 is a similar view illustrating still an other modification of the invention.

Referring now to the several specific embodiments of the invention featured herein and with special reference to the installation shown in Figure 1, it will be noted that the latter comprises a dam 15 formed principally from concrete and steel beams. The-dam l5'is provided with an upright wall section NS for obstructing the stream and is formed at the lower end thereof with a horizontally disposed apron I! extending laterally from the upstream side of the wall I6. The apron ll has a width substantially equal to the length of the wall I6 of the dam, and while the length of the apron may vary in dependence upon the installation, nevertheless, it is preferably about twice aslong as the height of the wall Hi.

In the embodiment of the invention shown in Figure 1, the apron I1 is seated upon the river bottom designated in the above figure by the reference character I8 and is anchored in the foundation rock below the river-bottom by suitable piling designated by the'reference character l9. In the present instance, the piling I9 is located directly below the upright wall It of the dam andat the upstream end of the apron ll. Under ordinary condtions, the above piling should be sufficient to prevent'skidding of the dam, but in the event it is desired to more effectively anchor the. dam,.the action of the piling may be supanchoring these ribs to bed rock through the medium of suitable cables 2|. By reason of the above construction, it is not essential to extend the upright wall 16 of the dam into bed rock as is the usual practice, and, as a consequence, a saving in material is not only realized, but a saving in labor is also effected. In other words, the actual height of the wall it of the dam shown in Figure l is equal to the distance from the river bottom to the water level as distinguished from the conventional dam construction wherein the actual height of the wall is represented by the distance from the foundation rock to the water level.

In accordance with this invention, the force of the water upon the upstream side of the wall i6 is resolved into different components, and this is accomplished herein by bracing the wall Hi from the apron H through the medium of a plurality of cables 22 varying in number in dependence upon the length and depth of the wall 56 exposed to the water pressure. In general, the upper ends of the cables 22 are anchored in the concrete wall l8 at spaced intervals, and the lower ends of the cables are suitably anchored in the apron H. In detail, the concrete wall I6 is reinforced by steel beams 23 embedded in the wall and suitable anchors 2 5 are welded or otherwise suitably secured to the upstream sides of the beams 23 as shown particularly in Figure 2 of the drawings. As will also be apparent from the above figure, the anchors 24 project through the upstream side of the wall it and terminate in suitable eyes 25 to which the upper ends of the cables are rigidly secured. In order toprovide for anchoring the lower ends of the'cables in the apron H, I provide additional anchors 26 secured within the concrete apron ill and terminating at the upper ends thereof in suitable eyes 2? to which the lower ends of the cables are suitably secured. The anchors 26 as well as the anchors 2 5 are inclined in directions coincident to the angle of inclination of the cables connected thereto so that the bending stresses on the anchors will be reduced to the minimum.

With the above construction, it will be apparent that the water pressure on the dam is equalized by the horizontal component of the force applied to the cables, and the upright wall [6 of the dam carries only the vertical component of the resultant force on the cables plus the weight of the dam. In other words, the overturning moment exerted on the wall l6 by the water pressure is resisted by the cables ZZinstead of by the weight of the wall itself as is the conventional practice. Moreover, with the above type of dam construction, the weight of the water supported by the apron serves to balance the upward force components on the cables or, in other words, the weight of the Water exerting the overturning force against the wall I6 of the dam is utilized for resisting this force by counteracting any tendency for the apron to move upwardly under the action of the same. It necessarily follows, therefore, that the material contained in the upright wall It of the dam need not be proportional to the square of the height of the wall as is the case in conventional installations, but may be considerably less since the wall is not depended upon to withstand the overturning moment. Perhaps the outstanding fundamental difference between the present dam construction and conventional practice may be more readily understood upon comparing the mathematical expressions governing the construction of the walls of both types of dams. The material necessary and the cost of installation of dams constructed in accordance with conventional practice is approximately proportional to K(h1|h2) +a where K represents a constant, hi is the distance from the river bottom to bed rock, ha is the effective height or in other words the distance from the river bottom to the water level, and a represents a factor determined in accordance with the conditions at the point of installation. n the'other hand, the material as well as the cost of installing the wall I6 is substantially equal to Khz-l-a-l-b wherein K represents the constant, a and 12 represent factors depending upon conditions existing at the side of installation, and where 11, represents both the effective and actual height of the dam since the latter dimensions are the same in the installation shown in Figure 1. By comparing the two aforesaid mathematical expressions, it will be apparent that the thickness of the wall in the present instance is considerably less than the corresponding dimension of the wall in conventional installations, and, as a consequence, considerably less material is required in forming the same. While the saving in building costs effected by materially reducing the amount of material to be handled is somewhat offset by the cost of the cable equipment necessary in the formation of the dam shown in Figure 1, nevertheless, when everything is considered, the total cost of building the dam featured in this figure would be considerably less than a dam of equivalent strength constructed in accordance with the usual practice.

When installing a dam constructed in accordance with Figure 1 wherein cables are employed to brace the upright wall I6, it is desirable to make some allowance'for the expansion of the cables due to stretching or temperature variations. In the present instance, expansion of the cables is compensated for by inclining the entire Wall I6 from the vertical toward the upstream side of the dam a distance predetermined in dependence upon the normal stretch or expansion of the particular cables employed. With this construction,.the wall will give more readily under the action of the water to take up any slack in the cables without fracture.

In order to prevent any possibility of the water on the high pressure side of the wall to escape through a crack or other aperture in the wall to the low pressure side thereof, the upstream side of the wall may be covered with sheet metal designated generally herein by the reference character 3D. The latter may be fabricated in the manner shown in Figure 4 and is secured to the wall I6 by welding the sheets to the portions of the anchors 24 extending therethrough as shown particularly in Figure 2.

As is usually the case, the dam I5 is provided with a number of spillways in. the form of open ings 3| through the upper regions of the wall I6 so as to provide for the escape of water from the high pressure side of the dam to the low pressure side thereof. In the present instance, the water escaping through the openings 3| is collected by suitable conduits 32 fixedly secured to the front side of the dam and communicating at the lower ends with suitable power means (not shown here- In construction of the type shown in Figure 1 wherein the apron ll of the dam is seated upon the subsoil or river bed above the foundation rock, it is highly desirable to prevent the water from buildingup a pressure against the-underside of the apron since such a conditi'on would reduce the effect of the water-abovethe apron'to anchor the dam. In the-present instance, the piling I9 at bothends of the dam is'in the form of a wall anchored in the bed rock "so as to minimize the escape of water into the space between thebed rock and apron I1. I-Ioweven'in order'to insure maintaining the aforesaid space relatively free from water under pressure, I provide'a drain 33 establishing communication between the said space and low pressure 'sideof the wall 15. If desired, a suitable pressure relief valve 34 may be fixed within the frontend of the drain so as to prevent any tendency for the water on the low pressure side of the dam to flow through the drain into the space between the-bed rock, and apron.

In certain types of installations, it is frequently desirable to provide relief gates in the lower regions of the wall l6 of the dam, and this may be accomplished herein by extending a conduit 35 through the lower portion ofthe wall l5 having the rear end welded to the sheet metal facing and having a manually controlled valve 36 positioned for convenient manipulation at the front side of the wall I6 to control the flow of water through the conduit. The conduit 35, as well as all of the other metallic parts of the dam which are exposed to the water, is preferably galvanized or formed of stainless steel so as not to corrode and become ineffective for accomplishing their respective functions. I

Referring now tothe modification of the invention shown inFigure 5, it willbe notedthat the same differs essentially from .the construction shown in Figure 1 in that theapron l l is omitted and the wall 46* is anchored in the rock foundaheight of the wall is calculated from the bed rock.

The wall I6 is also supported by a plurality of cables 22 differing from the construction shown in Figure l in-that thelower ends of the cables are embedded directly in the bed rock as at 3! and the upper ends of the;cables are adjustably secured to the wall l6 in the manner shown in Figure 6. In detail, a plurality of 'sleeves 38 are extended through the concrete wall l6 at an angle coincident to the angle of inclination of the associated cables, and the end of the sleeve at .the upstream side of the wall is preferably welded to the sheet metal facing 3!) on the wall I6 The facing 30 may be identical to the facing shown in Figure 1 with the exception'that it is preferably-secured to the concrete by suitable bolts 39 in the manner clearly shown in Figure 6. In the present construction, the rear face of the wall [6a is covered with sheet metal as indicated by the reference character 40, and the rear ends of the sleeves are welded in suitable openings formed in the facing 40. Slidably mounted within each of the sleeves 38 is a bolt Al having the rear end projecting beyond the upstream side of the wall [6 and terminating in an eye for attachment to the cables 22*. The forward ends of the bolts 4|, on the other hand, project beyond the facing 45 a sufiicient distance to receive suitable washers 42 and are threaded as at 43 at the 55 and opposite walls of the recesses.

construction, it is not necessary to adjustably extremities thereof to receive clamping nuts 44.

The clamping nuts engage the front ends of the washers 42, while 'therear ends of the latter are provided with hearing plates 45 fixed to the facing through themedium of bolts embedded in the concrete. While the eye-bolts snugly engage the sleeves 38, nevertheless, there is a possibility of the water escaping through the sleeves to the low pressure side of the'wall Ili and in order to prevent such a condition,'the ends of the washers engaging the bearing plates 45 are recessed as at 41 for receiving suitable packing glands 48. With the above construction, it will be apparent that expansion and contraction in the cables due to stress and temperature changes may be com- I permitting the major section of the wall l6 to 2 5 move in accordance with changes in cable length.

In the specific embodiment of the invention shown in Figure '8, the wall Ni is divided into three sections comprising a central section and end sections 5|. The central section 50 ex- 5} tends for the major length of the Wall [6 and has the low pressure side thereof rabbeted at opposite ends as shown by the reference character 52 for receiving the adjacent ends of the end sections 5|. The extreme ends of the sec- 35 tion 50 have-secured thereto suitable plates 53 extending rearwardly into suitable recesses 54 formed in the adjacent ends of the end sections 5|. The plates 53 extend for the full height of the central section 50 and slidably engage corresponding plates 55 fixed to the end sections 5| in the recesses 54 thereof.

Inasmuch as the recesses 5 in the end sections are open at the high pressure side of the wall IE it will be apparent that the water pressure acting upon the plate 53 will tend to maintain the same in tight frictional engagement with the cooperating plate 55so as to'prevent escape of the water between the plates. In order to insure maintaining a sufficiently tight joint between the plates to prevent escape of the water therebetween, I pro- "vide springs 56 suitably anchored within the recesses 54 in theend sections between the plates With this secure the upper ends of the cables to the wall I5 since a substantial part thereof is permitted to float in effect and thereby take up any variations in cable lengths.

The construction shown in Figure 9 is similar to the construction shown in Figure 8 in so far U as forming the walls 16 in sections is concerned,

. butdifiers therefrom in that the opposite ends of the central section are adjustably connected to the end sections through the medium of corrugated sheets 60. The corrugated sheets 60 also extend for substantially the full height of the wall 3 and are flexible so as to permit the desired movement of the central section in order to compensate for variations in cable length. It will also be observed from Figure 9 that the sheets 60 positively prevent escape of the water from the high pressure side of the dam to the low pressure side thereof.

What I claim as my invention is:

1. In a dam installation, an upright wall forming an obstruction for a stream and having a slab extending from the upstream side thereof at the lower end of the same whereby the weight of the water on the slab resists the overturning force exerted on the wall by the water, and means for resolving the overturning moment into different force components including cables having the upper ends anchored to the wall and having the lower ends anchored at longitudinally spaced points in said slab.

2. In a dam installation, an upright wall forming an obstruction for a stream and being insuflicient in itself to withstand the overturning moment exerted thereon by the water, a slab formed integral with the lower end of the wall and extending from the upstream side of the wall whereby the weight of the water on the slab serves to assist the wall in resisting the overturning force, and means for resolving the latter force into different components including cables having the opposite ends respectively anchored to the wall and slab.

3. A dam comprising a, concrete upright wall of relatively thin cross section insufficient to withstand the overturning moment exerted thereon by the water, a lateral concrete apron extending upstream from said upright wall and a series of cables between vertically spaced portions of said upright wall and horizontally spaced portions of said lateral apron.

4. A dam comprising a concrete upright wall of relatively thin'cross section insufficient to itself withstand the overturning moment exerted thereon by the water, a lateral concrete slab resting on the river bed and extending upstream from said wall for a distance greater than the height of said wall and a series of cables anchored to said wall at spaced points over the entire area thereof, the cables anchored to the lower portions of said wall being anchored in said slab, the cables anchored at higher points in said wall being also anchored in said slab at greater distance from said wall, projections extending downwardly from said slab to resist horizontal movement and means for anchoring said projections to bed rock.

5. A dam comprising a concrete upright wall and an integral concrete slab resting on the river bed, said slab being extended upstream for a greater distance than the height of said wall and a series of cables extending between said wall and said slab, said cables being anchored to said wall and said slab at a series of points spaced substantially uniformly over the entire surface of said wall and of said slab.

6. A dam comprising a concrete upright wall of relatively thin cross section. insufiicient to itself withstand the overturning moment exerted thereon by the water, a lateral concrete slab resting on the river bed and extending upstream from said wall, and a series of cables anchored to said wall at spaced points over the entire area thereof, the cables anchored to the lower portions of said wall being anchored in said slab and the cables anchored at higher points in said wall being also anchored in said slab at a greater distance from said wall.

'7. A dam comprising a concrete upright wall of relatively thin cross section insufficient to itself withstand the overturning moment exerted thereon by the water, a lateral concrete slab rest-.

ing on the river bed and extending upstream from said wall, a series of cables anchored in said wall and said slab respectively, and projections extending downwardly from said slab to resist horizontal movement.

8. A dam comprising a concrete upright wall of relatively thin cross section insufiicient to itself withstand the overturning moment exerted thereon by the water,v a lateral concrete slab resting on the river bed and extending upstream fromrsaid wall, a series of cables anchored in said wall and said slab respectively, projections extending downwardly from said slab to resist horizontal movement, and means for anchoring said projections to bed rock.

9. A dam comprising a concrete upright wall of relatively thin cross section insuflicient to withstand the overturning moment exerted thereon by the water, a lateral concrete slab extending upstream from said wall, a series of cables extending in. a vertical plane between. said wall and said slab, and a beam structure in said wall in the vertical plane of said cables to hold the vertical force component of tension in said cables in the same plane and the weight of wall and structure on it, and also hold the horizontal pressure of water in the section.

10. A dam comprising a concrete upright wall of relatively thin cross section insufficient to withstand the overturning moment exerted thereon by the water, a lateral concrete slab extending upstream from said wall, a series of cables anchored respectively to said wall and said slab, and means on the downstream side of said upright wall to control the tension in each cable.

11. A dam comprising a concrete upright wall of relatively thin cross section insuflicient to withstand the overturning moment exerted thereon by the Water, a lateral concrete slab extending upstream from said wall, a series of cables anchored respectively to said wall and said slab, and means to provide a differential static pressure between the upper and lower sides of said slab.

12. A dam comprising a concrete upright wall of relatively thin cross section insufficient to withstand the overturning moment exerted thereon by the water, a lateral concrete slab extending upstream from said wall, a series. of cables anchored respectively to said wall and said slab, a drain establishing communication between the underside .of said slab and the downstream side of said upright wall, and a pressure relief valve for preventing flow from the downstream side of said wall to the underside of said slab.

JULIUS D. MADARAS.

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