US1988613A - Manufacture of roads, yards, aerodromes, and the like surfaces - Google Patents

Description

Jan. 22, 1935 J. c. TELFoRD E1- AL 1,988,613

MANUFACTURE OF ROADS, YARDS, AERODROMES, lAND THE LIKE SURFCES Jan. 22, 1935. 1 C. TELFQRD ET AL 1,988,613

MANUFACTURE OF ROADS, YARDS, AERODROMES, AND THE LIKE SURFACES Filed March 25. 1932 4 Sheets-Sheet 2 Jan. 22, 1935. .1. c. TELFORD ET AL MANUFACTURE oF ROADS, YARDS, AERoDRoMEs, AND THE LIKE sURFAcEs l Filed March 25, 1932 4 Sheets-Sheet 3 u JaH/v fl/fwfo' M7/lfm Jan.v22, 1935. y J, Q TELFQRD Er AL 1,988,613l

MANUFACTURE 0F ROADS, YARDS, AERODROMES, AND THE LIKE SURFACES Patented Jan. 22, 1935 i;

.PATE

. cited, London,Y England inppli'cateitiwarch l25, 19.32,2 serial No. 601,142.'

`InGrreat Britain November 30, 1931 9 claims.

The present;inventiomhas for its objectthe provision of a strong f ,oundation for road o r the like surface suited to modern trame conditions which can be rapidly produced by comparatively unskilledlabour and with little or no interrupftionbythevveathe'r.lxV f v Thefoundation in accordancerrwith the invention comprises twofspaced layers offmetal plating havingv concrete or likecenentitious material sandwiched between themand is primarily characterized by. `the'` use' Lof; shearY vmembers between the metallic layers, I .The lshear members areV rigidly attached to the platingV ofboth layers and prevent such relative lateral movement between the layers asis the normal resultof the bending or exingofthefGWO layer metallic sandwich ioundation under load.` The'shear Vmerribers may `loe-madesloping lS0 ,as to, resist theshearg forces in a Similar manner@ Athe diagonal web members of a lattice girder; also they maybe arranged to lbe inclined in `varying directions sc as to be eiectivein resistingthe forces: in these di-v rections. vFor instance `in-jits simplest .formi a shear member'comprisesa strap withend flanges secured'tovthe layersfof plating andyset at such an angletothe y.Irlainpari, of thestrap that the'. latter is properly inclined. l Oppositelyvinclined' straps maybe used in pairs so-thatvthe .stresses from opposite directions-parer resisted by each'pair;y In a convenientmethod of construction .the in-g clined straps' of each Vpairfmay be combined to' form a distance ,piecebf box-like', or.frame-like form which` may be producedfrom metalstrip bentto trapezoidal shape, and disposedsc that, the

1 layers of lplating maybe secured -respect-ivelytov opposite parallel sides.l When the ldistance pieces maintain the spacingof the. layers at a. predetermined distance, so that whilst thefconcreteis hardening, materialsmaybe .stored on the top layer.

pairs of sloping shear memberspare employed each in the form ofja strap bent'once galong its length to form a stirrup or arch: the feet of,-

which are rigidly attached, for instance, by weld-V ing; to the bottom layer .of platinggmThe top layer of plating is `formed with slots 'through which the upwardly directed angles of theistir-` rupsproject. yA wedgeis then'inserted between.` the top plating andthe projecting archof each- Stirrup so that 'the ends of theslotare forcedi. venience in illustration. In an `alternative method oi construction the downwardly on to thev sloping legs of the stirrup and may be rigidlysecured thereto by welding. This method has the'advantage that novworkf manship Whateveris required on thebottom plat--` ing and from al constructional pointfof view there is the additional advantage that each leg ofthe stirrup shearmemberis indirecttension bel tween two welds. It will Ibe seen thatthis alter` native construction with stirrupishear members does not involve the use'of -bolts to which the average road making laboureris not accustomed.

In thevconstruction of a foundation in accord.- ance with the invention it ispreferable toarrange for the parts to be assembledrat the siteand ac-` cordingly the'metallic layers should'bebuilt` up from individual plates' of a size `convenient-for*l transport and manipulation and designedgto'be interconnected along their edges in situ tozormA substantiallycontinuous courses'that are capable` of retaining the filling'materal between them.y 2

The flat plates for usegin -the presentv methodl need Vhave no projections or attachments'before. reachingthe site and vaccordingly occupy the amount .of` space during. transport.

They arefpreferablymready formed however, withj any neces'saryholes for :use both with -thezat tachments between the'layers and iny theinethod-v of anchorage with the subsoil described morepar'` ticularly` below. Y L

i Thesite wherel it proposed to lay the roadI or like'foundationi'is, if necessary, preparedbyA the surface material being'iirst levelled and the subsoil consolidated. by rolling. 'I'he 'consolidated subsoil may then be covered withA a layer of sandy?? groundclinkerf'or other`suitablefmaterial to forrn'- a bed for the lowerlayer of plating.

f The invention wi1l"now-'beparticularlyade'i: scribed with -referenceto :the accompanying drawingswherein: e u ,i j

Figure V1A is a. plan view' o-filaV number of assembled plates connected by one formi of shear1 distance piece, three lplatesbeingfshown' in the' upper layer andi-six in'tl'ie lower layer'forvconI Figure 2 is a section on an enlargedscale along the yline y2'2 of` Figure 1. f

Figure `3 is anisometric'view- 'in part brokeny away vof an` assembly vof platesv witlicurb or but-1 tress plates along one edge-thereof.'

fFigure 4 is a sectionthroughfan' edgepartof the foundation `showing the connection AV of the upper and lower plates'with a curb plate;

Figures 5 and': are section `and plan view respectively 'ofrithe kind of fsheari'distance piece employed in the arrangementillustrated in IEig-` ures 1 to 3 shown on a larger scale in position between the layers of plating and in association with a securing bolt.

Figure 7 is a section of a similar distance piece secured to the plating by welding. A

Figure 8 is afplan- View 0f a number of assembled plates connected by stirrup shear members, two plates being shown in the upper layer and four in the lower layer. l

Figures 9 and 10v are respectively an end elevation and a side elevation` ofra"stirrup "shear member in position betweenthe4v layers of plating, and, .@,i' Y 9 Figure 1l is a diagrammatic fviewfof'the simplest form of shear member.

The simple distance piece or shear member illustrated more or less diagrammatically in'Figure 11 comprises a strap a with end'flanges b and c secured to the upper and lower layers of plating respectively. The flanges are set at such an angle to the main part' of the strap lthat theV latter is most efliciently inclined lfor taking up shear stresses. Another identical strap d shown in chain dotted lines may 'be oppositely inclined to resist stresses inthe other'direction. One preferred method -of building up a foundation in accordance with the invention is illustrated in Figuresl to 'l to which the following description relateszf VIt is desirable -to lay the -plates forming the bottom` layer in the following manner; Referring to Figure 3'the edgeof the road is-rst defined by vertical plates 1 `constitutirlg a curb or but-- tresspreventing the spread of the bedunderload or the washing away of the-subsoil by water which wouldk result the destruction of vthe foundation. Adjacent curbiplates 1 may be interconnected by butt. straps r2 and thetops of the plates may be inwardly turnedsubstantially at right angles to form a' flanger 3 for purposes of interconnectionl with the Atopl: layer` of splates. After the curb plates are inpositionthe laying of the bottom platesl adjacent to the curb Vis Yproceeded with. `The plates 4 of the-first row-are preferably flanged v'as Ashown i* by the c reference' numeral 5 to facilitate*theirfattachment' with the curb. `This attachmentfnot only servesftc tie inthe curb,; but :alsovaccurately locates ther rst row of plates. The plates 6.,subsequently laid down are progressivelylocated fromthe rst row by means of spikes 7 (seeespe'cially Figure 2)` driven through registeringholes 8 near the edges of adjacent plates and into thesubs'oil.v ,The holes in each `plate which" areprovided. forY thisr purpose vare preferably '1-symm'etrically arranged.A They are conveniently four :in number andare disposed at, a distanceoff one quarter fthe; length of the plate measured from theA -ends along Yboth longitudinal edges. In this wayiaadjacent rows ofA plates can readilyberelativelypositioned with the plates of one lrow .staggered with respect to those in ,the next.,;adjoining row. Also owing to.. the symmetrypof thearrangement Yof the holes, it is immaterial which side of a platel lisy uppermost or in which direction it is turned.j

` As already mentionedthe plates are delivered to the site without vvanyattachment, and the distance pieces aresecuredtheretobefore the plates are carried to theactual road *bedr These distance pieces are4 preferably Vdeliveredas complete units. In a convenient form of construction i1- lustrated in Figures 5, G .andf'lthey are 'produced by welding together the free ends oftwoangle members of strip metal,',one aqshort length 9 with outwardly :directed angegends l0 Vandthe other a longer piece 1l with inwardly directed Vflanged ends 12 adapted to meet the flanges of the first member and to be secured thereto by welding. In this manner a trapezoidal boxlike frame structure is obtained with opposite parallel sides, one longer than the other, for rigid attachment to the top and bottom plates respectively. If desired each distance piece may be made from a single strip bent to shape with its used and their disposition being the same in either case.

Where bolts are used throughout, the plates must be provided with bolt holes. In a plate measuring approximately 6 feet by 4 feet it is desirable for sixteensuch holes to be ar-l ranged symmetrically in four rows as shown best in Figures l and 3. Thesymmetry of the arrangement Vis optional but is designed to ensure complete reversibility of the plates and consequent simplicity in assembly. It is preferable to adopt the arrangement illustrated wherein the corner distance pieces 13 are diagonally arranged and associated with bolts so that the plates of the top layer may be located as subsequently described. The remaining distance pieces are secured by welding only, some 14 being arranged longitudinally of the plates and others 15 transversely to take up the stresses in these directions.v

The distance pieces 13 shown in Figures 5 and 6 for bolting to the plates yare/provided with bolt holes 16 and 17 opposite one anotherin 'the parallel sides or seatings 9v and ll respectively. The bolts `18 employed are inserted from vthe underside of the bottom plate through holes 19V and are suiflciently long to project through the distance piece and above the top'plate when the projections 2O act ultimately asa bond or key for the top dressing or surfacingpreventing creep. After the insertion ofthe bolt through the bottom plate the bottomfseating of thedistance piece is threaded thereon and a nut 21 screwed onto the bolt. The nut is tightened against Ythe bottom seating whilst the .free end ofthe bolt isy yfor the top plates by means of the projecting bolts 20. In those places where 'welding only is relied on, it is of course not necessary to provide bolt holes. e

After the'bottom layer of plates is completely laid it is, in the case of a road, finished 01T on the opposite edge with a second curb of the kind already described, and the edges of all the plates are then preferably secured by welding at intervals. The concrete 23 is then filled in to the depth of the distance pieces and the addition' of the top layer of plating is put in'hand. The individual plates 22 of the top layer and those of the bottom layer are staggered in every possible-sense so that the junctions between the plates in one layer are nowhere opposite the junctionsv inV `the other, thus adding materially to the,

strength of the assembled-structure. The 'dge plates.24"oftlrehupper layerar'e secured toffthe top flanges of the curb plates .referred topreviously..` The holes 25j provided .in the. top plates are designed to lie opposite the distancepieces. They are preferably-made considerablylarger thanthe securing bolts`18 and: may .be with advantageas much asofthree times-greater diameter, so as to allow. for any'. inequalities which mayv occur in the laying out iofthe top plates.. VThis hole is designed to bezcoveredby awashen-plate 26;.around'the bolt 18 and resting on the top plate 22,;v lto whichi its. edges. .can Ybe welded in. .situ -as shown in Figure, 5. Asecond securing nut 27 is thentightened onto the projecting -bolt shank and bears on top. of' the washer 26. `By this varrangement the top plate can be-readily. removed without damage, the sandwiched concrete out away vandthe lower plates taken up in case it is necessary to gain accesstoidrains, cables and the like under the foundation. In cases where the top plate is welded to the distance piece, the relatively large hole 25 already mentioned, permits of the welding of the top plate from above, directly on to the top seating of the distance piece part ofv which is uncovered by the hole as shown in Figure 7. As in the case of the bottom layer of plates, those of the top layer are designed to overlap one another slightly and may be interconnected along the edges by welding at intervals. f

The alternative method of construction illustrated in Figures 8 to 10 involves the use of shear members in the form of stirrups or arches 28 each formed from a length of metal strip bent conveniently to a right angle at the middle ofits ylength so as to form two sloping legs 29. The

platesV 30 of the bottom layer are delivered to the site unworked and the feet 31 of the stirrups are then secured thereto by welding with the angles 32 upwardly projecting. A regular diagonal disposition of the stirrups is shown in Figure 8 and is found in practice to be a desirable arrangement. The lower layer of plating is then laid and the concrete is lled in around the stirrups. The plates 33 of the top layer are formed with short slots 34 through eachof which the angular summit of one of the stirrups projects, the ends 35 of the slot resting respectively on the sloping legs 29 of the stirrup. Between the angular arch 32 of the stirrup and the plate 33 a wedge 36 is driven transversely of the slot thus holding the top plate in position and exerting tension on the legs of the stirrup. Whilst the parts are still in tension the ends 35 of the slot are'welded to the sloping legs 29.

The completed foundation is designed to be used for supporting a top layer of any suitable road surfacing material such as a bituminous macadam, stone sets, rubber or the like.

It is to be appreciated thatA any exing of the structure under load while in actual use, would lead to a slip or relative horizontal sliding movement between the plating and filler and such movement will quickly lead to a breakdown of the foundation if not prevented. By the construction described, certain of the devices between the platings and embedded in the filler are so formed andconstructed as to' absorb this relative horizontal and shearing movement and prevent such as objectionable movement. As such relative horizontal and shearing movement is thus absorbed in the structure itself, it is apparent that said structurev cannot sag or ex il. A road or llike foundation:embodyingftherevspaced-"lmetallic"platingsi devices for holding "said'platingsrin` spacedlfrelation;certain of said devices-. :comprisingfii inverted substantially V- shapedfstirrupsg'eachhaving feet welded to the bottom Aplating'an'dl'having its bend. or crotch upwardly directed to extend through an opening ihthe'- tgprplatin/gfff: l 2. A' road Vori.likelfoundation"embodying therein spaced metallic platings, devices for holding said` platings inG spacedrelatinp certain of said devices f comprising"1"` invertedl substantially `V- shaped members'each' having feet welded to thev bottom: platingwandhaving its bend or crotch upwardl'y directed toV extend .through associated openings iin the top-plating :and wedges engaged withsaidfbend or crotch of said members'above said topk plating and whichwedges force the top plate downwardly to bring portions of said'openings into engagement with the legs of said invertedpV-shaped members.

3. A road or like foundation embodying therein spaced top and bottom metallic platings, there being openings in the top plating, and inverted V-shaped members for holding said platings in spaced relation, certain of said portions of said top plating defining said openings being welded to parts of the legs of said inverted V-shaped members.l

4. A road or like foundation embodying therein, spaced separate top and bottom thin metallic iiexible platings, a iiller of rigid cementitious may terial therebetween, and devices, certain ones of which are operatively connected at their top end to one of said platings and othero-nes of which devices are operatively connected at their bottom end to the other of said platings, said devices being embedded in said ller and so formed and so arranged in saidller as to absorb horizontal stresses in any lateral direction as induced by the tendencyv of relative slipping movement between said platings and'ller.

5. A road or like foundation embodying therein, spacedtop and bottom platings, a filler of rigid cementitious material therebetween, devices operatively connected at their top and bottom portions to said platings and embedded in said ller, said devices being so formed and so arranged as to absorb horizontal stresses in any lateral direction as induced by the tendency of relative slipping movement between said platings and filler, and vertical curb plates closing the structure at each side thereof and formed to projectdownward into the subsoil upon which the structure is laid.

6. A road or like foundation embodying therein, spaced top and bottom platings, a filler of rigid cementitious material therebetween, de-

vices operatively connected at their top and bottom portions to said platings and embedded in said iiller, said-devices being so formed and so 7. A road or like foundation embodying therein, spaced top and bottom platings, a filler of rigid cementitious material therebetween, devices operatively connectedat their top and' bottom portions to said platings and embedded in said ller, said devices being, so formed and so .arranged'as to absorb horizontal stresses; in any lateral direction as induced-.bye the tendency j of relative vslipping movement between said platings and filler, vertical curb plates closing the'structure at each sidethereof and formed to project downward for'engagement in vthesubsoil upon which the structure is laid, said platings and curb plates having associated flanges operatively connected together. y I f Y i.

8. A road foundation comprising spaced separate top and bottom thinmetallic exibleV platings, a cementitious filler, between said platings, and shearing stress absorbing devices embedded in said iiller,V certain ,of said devices being en gaged with the top plating and ,extending toward the bottom plating and other of-said devices being engaged withl the-bottom plating and' extendingtoward the top casingand means for se` curing said platings `and said devices together in loperative relation.

\ 9.1A road or like foundation embodying therein spaced'apart top and' ybottom flexible metallic i platings, a filler of rigid cementitious material therebetween, devices connecting said platings together in .operative relation and being anchored lx1 the cementitious material, said devices y JOHN CHARLES TELFORD.

JOHNHINES. Y

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