US1619651A

US1619651A - Earth anchor for structural towers

Info

Publication number: US1619651A
Application number: US755655A
Authority: US
Inventors: Edward E Buechele; Sidney A Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 1924-12-13
Filing date: 1924-12-13
Publication date: 1927-03-01
Anticipated expiration: 1944-03-01

Description

E. E. BUECHELE ET AL EARTH ANCHOR FOR STRUCTURAL TOWERS v March l, 1927. l 1,619,651

Filed Dec. 13. *1924 2 sheets-sheet 1 1,619,651 March 1, 1927. E ET BUECHELE ET AL v EARTH ANCHOR FOR STRUCTURAL TOWERS Filed Dec. l5. 1924 2 Sheets-Sheet 2 Patented Mar. 1, 1927.

UNITED STATES nPAfriia'r OFFICE.

EDWARD E. BUECHELE, 0F WEST' vrEW,` AND SIDNEY A. ivrARfiiIN, 0F BRADEORDWOODS, PENNSYLVANIA.

EARTH ANCHOR FOR STRUCTURAL TOWERS;

Applicationkled December 13, 1924. Serial No. 755,655.

The present invention relates to structural towers of the type used in supporting high tension transmission lines, telegraph or telef phone lines, radio antennae, and for similar purposes, and more particularly to an earth anchor for such` towers.

It has heretofore been proposed to support each leg of a tower by means of a stu formed of an angle connected at its lower end to a grillage formed of angles and imbedded in the earth at a considerable dis-` tance `below the ground level, the legs of the tower being connected to the upper ends of the stubs either slightly below or slightly above the ground level and the stubs being reinforced intermediate theirV ends to take care of lateral and bending strains.

This method of anchoring tower's'is objectionable because of the great amount of excavation work required for setting the grillages so far beneath the ground level. Another objection is that with the increase in the size and weight of towers the stubs are subjected to such great bending strains that they are liablev to fail in spite of being rein forced to take care of such strains.

By the present invention we provide an anchor construction in which the weight of the tower is? supported by a base or grillage imbedded only a short dista-nce below the ground level. A stub extends vdownwardly from each grillage in a relatively small hole which may be provided by drilling. Each stub has anchor means attached to its lower end and the hole islled with crushed stone or rubble to a considerable height above such anchor means andthe remainder of the hole filled with earth and rammed. Each stub extends a slight distance above its grillage and has a leg of the tower attached to its upper end. Any upward pull on the stubs, due, for instance, to' wind pressure on the tower tending to overturn the saine, causes the anchormeans at the lower ends of the stubs to exert an upward thrust on the crushed rockI or rubble in the holes above the anchor means.` This crushed rock or rubble presses laterally on the'earth walls of the holes and is thereby effective' to 'prevent any upward movement-of the stubs. Of course,

the packed earth filling` the holes above theV rock or rubble also assists in resisting the upward pull on the stubs:- Thus'it will be grillages forI protecting the soil beneath them from frost and to a certain extent from rain water or water resulting from .melting snow or ice.

The invention is illustrated in the Vaccompanying drawings, wherein:

Figure l is a diagrammatic side elevation of atower having` earth anchors embodying our invention;

Y Figure 2 is a'.hori.zontal section along the lilies Il-e-II of Figs'. 3 and 4;

Figure 3' is a side elevation, partly in`sec.

tion, of the anchor shown in Figure 2;

s1. i y j l* igure fl is a view similar to Figure 3 but `taken at right angles thereto;

Figure 5 is a section through the two.

vertical angle bars of which the stub: is comprised I F igureG is a section on the line VI-Vl of Figure 3, showingthe lower endy portiony of the stub on a larger scale;

Figure 7 is a detail view oii- .a larger scale of the lower end portion of the stub;

Fig. 8' is a horizontal section along' the lines VIH-VIH of Figs. 9 and l0, showing a modiiied'form of anchor.

Figures 9 and l() are views of such modified fornisimilar to Figures 3 and 4L;

Figure ll is a section through the verticalI l angle' bar which forms the body of the stub of this modified form of anchor;

Figure l2 is a section on the line. Xl'L-XII of Figure 9 showing the lower end portion of the stub on a. largerscale; A

Figure 13 is a detail side view of thc lower end portion of the stub on a larger scale, andv y v Figure-14; is ay diagrammatic sideelevation of av towerprovided with earth anchors of thev form Vshown-'in Figures S to 1'3 inclusive.

In Figure 1 we have illustrated diagraminatically a structural tower A having legs 2 and diagonals 3. The legs of the tower are connected to earth anchors B which, in accordance with our present invention, will preferably be constructed as hereinafter specifically described. j

iIn the form of the invention ilhistrated in Figures 2 to 7, inclusive, each earth anchor comprises a laterally extending base or grillage A adapted to be imbedded a relatively slight distance below the ground line Gr--Gr and a stub 5 extendingr downwardly from the center of the grillage in a relativelysmall and deep hole 6 which may be provided by drilling.

The grillage may be formed of a plurality of spaced parallel `beams 7 tied together at their ends by angle bars 8. Supported byV the beams and extending transversely and centrally thereof are two spaced parallel channel beams 9; Y

The stub 5 comprises two angle bars 10 arranged with their j angles facing away from each other, as shown more particularly in Figure 5. These bars extend between the channel beams 9 and are secured to said channel beams by connecting angles 11 adapted to be riveted or bolted to the legs of the angle barsV and to the webs of the channel beams. A leg 2 of the tower is adapted to be secured to the, upper end of the stub in any appropriate manner, as by having one `of the angle bars-10 extend a slight distance above the adjacent channel beam and riveting the lower end of the leg to such projecting end.

At its lower end the stub has anchor means attached thereto. This anchor means may be of any appropriate construction to provide laterally projecting shoulders for engagement with the crushed rock or rubble 12 which is placed in the hole 6 above the anchor means. As illustrated, however, the anchor means comprises angles 13 which are secured to the legs of the angle bars`10. Reinforcing angles 14 are placed against the legs of the angles 13 and rivets 15 are passed through these reinforcing angles, the legs of the angles 13 and the legs of the angle bars 10, thus securing the parts rigidly together'. The angles 13 have horizontal flanges 16 at their upper ends which provide the laterally projecting shoulders referred to.

In order to protect the soil upon which the grillage rests from the action of frost and water, we provide a protecting cover therefor. This cover comprises plates 17 attached at their inner side edges to andV supported by angles 18 secured to the webs of the channel beams 9. The plates 17 are supported at their outer side edges andV end "edges upon a rectangular frame comprising four channel beams 19 connected at the` 10, thus completing the cover. The channelV beams9 are connected at their outer ends with angles 211 secured to the channel beams 19 of the frame.

The rectangular frame formed by the channel beams 19 and the

cover plates

17, 21 and 23 inclose a chamber 25 on the earth bottom of which the grillage rests. ln order u for the frost to ai'ect the ground iiiimedi ately below the beams 7 `it would liaveto penetrate to a distance d below the channel `beams 19 eeual tc the horizontal distance s between the beams` and the channel beams 19. lt will thus be seen that by making the distance great enough the protecting cover` will avoid any likelihood of the ground .be-4 i neath tliebeanis 7 from being affected by frost. lt will also be apparent that this protecting cover `provides. a substantial Water-shed for protecting Nthe ground beneath the beams from rain Water or water resulting from melting sncw or ice.

lll)

In setting the anchor in the ground, the

ground will first be excavated to provide a rectangular cavity to place the grillage lat the desired distance below the ground line G-G. The hole G will next be formed to the desired depth. The `stub will then be placed in the hole and the latter filled to the desired height with the crushed rocla:` j

oi rubble 12. After the rock or rubble is rammed the remainder of theV hole is filled Y with dirt which is compacted in the` hole. The grillage will V,then be placed 4in the cavity and connected to the upper end `of the stub. The grillage may be wholly or partlyassembled at the place of erection asinay be found to be most desirable. After `the anchors for a tower have been thusI set in ci the tower coiii nected thereto, the cavities above the gril-` the ground and the legs lages and their protecting Vcovers will be.

filled in te the ground line GHG. Y

The modified forni of i anchor shown in Figures 8 lto 13, inclusive, is designed for lighter tower constructions, such as shown in lFigure 14, and does not differ essentially from that already described. The stub B comprises a single angle bar 26 the legs of cured to the ends ofthe angles 27Y and eX- tend at right angles thereto.

The grillage of this modified construction .comprises I-beams 29 and channel beams` 30.

The protecting cover for the grillage comprises a rectangular frame composed of channel beams 3l and cover

plates

32 and 33 connected to the channel beams 30 and 3l in appropriate manner.

Vhen a structural tower is to be provided with earth anchors in accordance with our invention7 the grillages will be designed to sustain the load due to the weight of the tower and the stubs will be designed to withstand the tension stresses to which they will be subjected due to upward pull on the stubs caused by forces tending to overturn the tower. The grillages which are embodied in the surface soil which is generally not as compact as the deeper soil, have a considerably greater khorizontal area than the anchor means and serve to take the load on the legs and relieve the stubs of downward thrust or bending strains. Since the hole in which the grillage is buried is shallow, it may be easily made much Wider than the deep hole in which the stub and anchor means is buried. Of course the forces tending to overturn the tower will be resisted to some extent by the weight of the grillages and their protecting covers. Any upward pull on the stubs will be resisted mainly by the crushed rock or rubble in the holes above the anchor means at the lower endsof the stubs. The upward thrust on this crushed rock or rubble filling will cause the pieces of rock or rubble to be thrust laterally into the earth walls of the holes. The holes must therefore be deep enough so that this lateral thrust of the crushed rock will not cause the earth walls of the holes to give way.

While we have shown and described certain preferred embodiments of our invention, it will be understood that the invention is not limited to the details of construction shown and described but that it may be otherwise embodied within the scope of the appended claims.

We claim:

1. A structural tower having a plurality of spaced legs and earth anchors secured thereto. each anchor comprising a stub eX- tending downwardly in a hole provided therefor and adapted to withstand the tension stresses to which it may be subjected due to the upward pull on the stub caused by forces tending to overturn the tower, said stub having anchor means at its lower end adapted to cooperate with filling material placed above said anchor means to transmit forces due to such upward pull to the surrounding earth and thereby prevent upward movement of the stub, and a laterally extending base at the upper end of the stub for sustaining the portion of the weight of the tower distributed to the leg and adapted to be secured in place after the anchor means is buried.

2. A structural tower having a plurality of spaced legs and earth anchors secured thereto, each anchor comprising` a stub eX- tending downwardly in a hole provided therefor' and adapted to withstand the tension stresses to which it may be subjected due to the upward pull on the stub caused by forces tending to overturn the tower, said stub having anchor means at its lower end adapted to cooperate with filling material placed above said anchor means to trans* mit forces due to such upward pull to the surrounding earth and thereby prevent upward movement of the stub, and a laterally extending base at the upper end of the stub for sustaining' the portion of the weight of the tower distributed to the leg and adapted to be secured in place after the anchor means is buried, said base having a considerably greater horizontal area than the anchor means.

3. A structural tower having a plurality of spaced legs and earth anchors secured thereto, each anchor comprising a laterally extending base adapted to sustain the portion of the weight of the tower distributed to the leg, and a stub extending downwardly from said base and adapted to withstand the tension stresses to which it may be subjected due to upward pull on the stub caused by forces tending to overturn the tower, said stub having anchoring means at its lower end adapted to cooperate with filling material placed above said anchor means to transmit forces due to such upward pull to the surrounding earth and thereby prevent upward movement of the stub.

4. A structural tower having a plurality of spaced legs and earth anchors secured' thereto, each anchor comprising av laterally extending base adapted to sustain the portion of the weight of the tower distributed to the leg, a stub extending downwardly from said base and adapted to withstand the tension stresses to which it may be subjected due to upward pull on the stub caused by the forces tending to overturn the` tower, said stub having anchoring means at its lower end adapted to cooperate with filling material placed above said anchor means to transmit forces due to such upward pull to the surrounding earth and thereby prevent upward movement of the stub, and a protecting cover for said base forming a frost insulating chamber on the bottom of which said base rests.

In testimony whereof we have hereunto set our hands.

lEDWARD E. BUECHELE.

SIDNEY A. MARTIN.

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