104 VICTORIAN INSTITUTE OF ENGINEERS.

104 VICTORIAN INSTITUTE OF ENGINEERS.

PAPER

"INDUSTRIAL BUILDING CONSTRUCTION: ECONOMY, STABILITY AND STANDARDISATION."

By R. F. Kneale.

Introduction.

This paper does not involve investigation into theories or proofs, but is an introduction to something practical as afford-ing an incentive to further reasonable application of the first essentials of construction and their relationship to Economy, Stability and Standardisation.

(The writer introduced this paper by a series of projected pictures depicting ancient structures and their diversity of types ; included were some modern comparisons.)

Structures of ages long past were built of stone without the aid of a cementing medium, or else were of rammed earth or bricks that were sun-dried. Mass was an element of design with characteristic style that ensured stability. To-day this end is assured by strict adherence to the fundamentals of stress and strain.

Architecture is the art of building and is coeval with the earliest dawn of civilisation. It presents to a large extent the history of the human family written in stone, brick and other durable material. Architecture is one of the great arts and has been influenced by religion, tribal life, organised society, the need of public buildings and the development of domestic life. Much recent interest in this art is due to investigations in Mexico, Peru and other countries, which reveal the works of nations long since dead.

Modern structures, because of the involved conditions and demand for economy with speed of construction and other factors, call for the ability of the engineer in the matters of design and execution. Engineering enters particularly into industrial projects and general developments. Modern civilisa-tion demands the engineer more each year.

This is an age conspicuous for the use of steel, the produc-tion of which creates one of the great basic industries that influences so many branches of active life. The extent of involvement with the many phases of modern civilisation is

105 INDUSTRIAL BUILDING CONSTRUCTION

revealed when one realises that the production of one ton of steel produced requires 3i tons of coal and the transport of about 7 tons of raw materials. Equipment used in the operation of securing and treating of materials, creates an immense scope for a number of industries.

Steel construction is indispensable, for it will permit of the widest spans, heaviest loading and most expeditious erection. Steel sections are shaped to economical profiles, the material being homogeneous and having carrying capacities which are computed with accuracy. The sections are rolled in the great mills and subsequently fabricated in the workshop as complete units, or for field assembly.

New methods and materials as applied to construction have affected the characteristics of the modern building fabric, either from a structural or from the aesthetic standpoint. Those of the older school often hesitate regarding newer applications.

Brick and stone, often referred to as "masonry," being of historical standing, are of proven stability and remain as ever materials of basic importance. In the modern framed struc-tures, which are designed so that loads are carried by the steel or reinforced concrete framing ; the walls may be made thinner and of lighter construction generally.

Provision is made in a modern building for various com-forts such as mechanical heating and reconditioning, also sewer-age, electrical, water and other essential general services ; structural features are developed accordingly.

Skeleton construction is where external and internal loads and stresses are transmitted per the medium of a framework of steel or reinforced concrete, from the top to the bottom of the building.

Fire-resisting construction calls for protection of the steel framing by a covering of slow heat-conducting material; this may be ensured with reinforced concrete, brick, terra cotta, tiles or burnt clay. Windows must be metal-framed, glazed with wirecast glass and all openings provided with steel shutters. The walls are generally composed of any of the following or allied materials: brick, concrete, stone, expanded metal and plaster. asbestos cement sheets, etc. For other than fire- resisting, such materials as glass, corrugated sheet iron, etc.,

may be used.


KEY SHEET TO PLATES. Plate 1.—Standardised 50'0" Span Steel Truss and Canti-

lever Frame : Showing various possible applications and miscellaneous details.

Plate 1A.—Roof Truss, 30'0" span, and miscellaneous de-tails Timber construction. Note the strengthening side pieces in conjunction with tie beam, knee bracing and princess bolt at either end ; permitting of lighter tie beam, yet forming a rigid stable connection and brace to column Standard connections and general details for use throughout the building are illus-trated. End framing can be designed in keeping with the truss, but assembled to columns so that the face of rafter members will be in the same alignment as face of end girts.

Plate 2.—Large Storage Building, showing application of 50'0" trusses and cantilever frames; also brick curtain wall with composite steel, concrete, brick piers, etc., in lieu of orthodox heavy wall. Typical industrial buildings, figs. 1 and 2: Shelter, simple form; column ends fixed for direction, the equivalent strut length being L-over-2, permitting of lighter material ; warren frame member eliminating columns under central truss.

Plate 3.—Miscellaneous : Foundation under brick wall, showing stress condition in concrete, necessitating bars at top and bottom. Structural steel stand for tanks, cumulative unit type, permitting of progressive increases ; each additional tank being accommodated by the addition of one set of frame units. Figs. 1, 2, 3 and 7 depict various types of trusses, viz.: The Pratt and Howe trusses, which, while suitable for steel, are used extensively for timber construction; the choice being according to loading characteristics and economy, with due consideration being given to size and lengths of strut members. The Fink truss is a usual type for steel construction. The saw-tooth is either for wood or steel and can be made a good standardised unit for assembly in buildings as depicted on Plate 2, Figs. I and 2. Fig. 4, Column Footing, as described in the general text. Fig. 5, Drop Panel, for economy in floor slab design. Fig. 6, Concrete Tee, for economy in design if beams supporting slab floors; refer to general text.

Plate 4. Typical Retaining Wall of reinforced concrete, permitting of multiple basement floors. Figs. 1 to 6 are typical simple illustrations of welded joints.

Plate 5.—Fig. 1 : Arch of receding steps as constructed by the ancient Mayas and other early inhabitants of America. Fig. 2, simple design of orthodox arch. Fig. 3, Tabernacle Building. Salt Lake City, Utah, U.S.A., under construction. (Built by the early pioneers of the West, between the years 1865 and 1867. Unique among structures.)

SU/TF]BLE CLEATS FOE. PL NS

71J ,F7gFrE,P MEMBE 773 BE

S77.7NOF7A?0/ZEO.

GOLUMN FOOTINGS.

® FOR /0"x41"R. S. J.

®FOR 8"X6" R.SJ.

® FOR 8" X 4" R. S J.

® FOR 7"x 3=" R. S. J.

® 8r ® ARE SUGGESTED FOR

END FRAME COLUMNS. BOL 770

BOL TEO

R. S. J COL.

3'.x 3"+%4 L

50'-0" CENTERS

7w 3i.i • /5 ~ ,* ~. /25J. T/E

=1=11 41=1==

qRY/G'.4riVY O~ TV A'OVL CHqii7 Gr.iSSETJ n9YSC LCrrEWO Q'r KEY AL A7/Y

./ I I~

Ix 8 S✓ COL

LONGITUDINAL BRACING KNEE ~

à x-x

ti

NoaQ,,,,,,,,, ,,,,,n.,,,-- ,,,,.,,,,..,,,,..,,,, , NOR Q

,, SINGLE BAY BUILDING- TRUSS TYPE

NoaQ

DOUBLE BAY BUILDING TRUSS TYPE x-x

S1E cotUM/vj'

0 \/\ /I\ ~ ~~ 0 ~~ 0

ORE, ]ER PP LESS 7.6,7es, ,OS A?EgU/~PE~

~ kEY A3' A7N OF 17 TvP/C.vL J'TEEL ST~p(/CTU.PE. •

FJLTEQ/l4A77✓E ME77-/00 Q~ BA?AC//YG

~ ~ \

--NoRQ _ . NoRQ , aV,,vi,naV„/NSW,

MULTIPLE BAY BUILDING WITH CANTILEVER FRAME TRUSS TYPE

STANDARDIZED 50'-0" SPAN TRUSS & CANTILEVER FRAME.

SHOWING VARIOUS POSSIBLE APPLICATIONS & MISCELLANEOUS DETAILS. NoaQ NoaQ

• . _Ÿ-_ ....

SINGLE BAY BUILDING WITH CANTILEVER FRAME EACH SIDE TRUSS TYPE PLATE I R. KNEAL E

li; B" cooeS. Bolt 41.3" G i.t

§'e 6-Cal d Coach Bakt

CONCRETE FLOOR 6 UNDER NG Jb 3 r- - GIRT PwctrNO COLUMN - AT EDGE -

5.cy1;g60 4'6 .3d ql.5ea...;rt,

ca.t gloss, eerlseas at Reo{. (Sae Spec) .

.....1 fo be locatee. ro o..a a..a of W

COrr. Sk.ed. Orator r SOU.

ce..t:oG3a Cahf:y.

of

tò .«: Ve«1:14.t.:.q R.eqwt .

! 20‘r Tac... coc.lee Sta - type

l.o-. Ve.rtilat:.q 2•egc (8:.ep.o.t.)

Piste

ba. .2aAIiy Ioce 1

4"• lï Cerbel Piiçe

oled for 21.tary ga«gerai

4•.r 3• CorbeL Piece.

O f tU bolt.:.q te. post

Skew ...;1 Toe ng:e:ty

S. Correct. al.Or...wt

\~•~@J~~,.~.1.1 Yh ~/: ~~~ ~IIJ(c ~~~~

No 6lo B e.C. abric o.

. I~... M.5.gods o) B'• cis , boH..wOys

b 1GOJU fro«. bolt

3`.3" Fros.. e .

,o Terra coana.

Sterat /~Iryk1

•4"M.. cheer. Plot 8". Ii tiltu s:ae

cef b..r 4'.4' is r,bar ego e rely sKew roilri, e. bolted

Ib R:40.6

- JUNCT.o1V Oar GtaTS nT CoWMry - (~ DETAIL SHOWING METHOD OF FIXING GIRT TO COLUMN -

Ilt".II"M.íFl.t K.elal.d.

f.., le'

^ f /sl;e;«g oleo,.

er I a.rjeelnemw two'

U ~

1.!!:)T l' Eeae

- SECTIOrJ"YY '=

g'M.S . .C.I. Be.e.lea wach.,- DETAIL DOOR G WD[ - y i

Soo. G.sid. (see 00.11

Co..T..c.bo act : Laosrat acc«rotey pottúra. (o, éllq: ee O

— De.T.4IL. DOOR GUIDE II, THRESHOLD -(co.+cacn FLOOR.) -

fi'. 2"

Stoop.. P rl:..

I<ow Tore coarse, ak.eel.

6n6"T:..bcr

6.11 M... arole...

S..Nee..t tf6alpa:ee of c....N al, 2}"x 2"e ö- L wa>he. r r M.s wa.k..e. M.5.Na>her.

b-. 1!6vr 6d

8'. It'k.ry:t.d:...l T.c LSt.,.t s..r.ee.. 1

Lep wee-, ter

e.mrl

v

DIMI jÿ 4.0. Koko . Nk

Drìll s c i«K o f K.

f.31' c a'K Ma_óolh

c rc. Teme emten

Iron. Sheet.y

4•e Iß . 6' I.e. Cn.14

pece. ra.l.n r Cob.

LGe retool)

aalt I2"la..y

Sat .:.. o..c+ale 2'Iefc

I i ., req. o Foot. .t be .. Mort

c t d cc«rottly poe:o«c. I

I I

\

~S7~SSL'~

~~ II!yia

61o«Q. I

a

~'

y,/osl.crs beat./ or pla'n• s regr..~.ca. o be ~

2 O« •_ _.a «ae. k.eam s« f ... an ca«..

P ;„ . - 1 M1,e ease .f Fr.«ees. bolts a.pac;al 2? i 2•, s r fi Íe...a i. i4"COaeh golfs

2 Le .•9(R wssh~tu to bN used. ...Oro, will ;rcl..dcihe O plotè ~ s;ee -Ce..n~...:,I<

1.,11 wreak y Tie Hr aplas 2I6'eI' tb;cK tl9wq~,ar.rgpsea. Ne.d ta yi.t.

30- 0'

h. - :

F11 1461Dr~il ~.k.a Melos \ÿ~ i.. T

t MF rl

1)-

e0

4"r 11" Coact. Bolt s wo.her

c t e Ocoee .nte q..t.

4 ere ar ~ plzje.3ft (

ba.e)ynF.e>

b . ' Hobs I.e

6'_ q•eVea•. I...gB.oe.eefe 6". 3".

~ll ÿa.aMawle. â B.o.

bre: (I.ae b.achds t, be ../c1aa1M1

4...wee I-. w cweset pe s.t•è..e fee rtepectJe d.wwaye.

'ANGLE RUNNER

ât CONNECTION

TO COL'

—DETAIL OF COLUMN

ANS ~. • BRACKET-

MA AI

i~Geo..t«q a«du . t...a - _ ?

r...e.e.

NOON." 6 rah Sat

DLTAIL or L CONNECT ore - 'ray SSTo GOL .STRUT

33"i 2i". 4Tt„a.

_ —

were/AN/me . _ ' Fit A.aa.B.ow.,cB..s

j ~ jt•iW.a...l'al+i. _ . 4

DETAIL OF PULLEY-c.1.-?,qr 2í:2.4L x 61.r.

s•, a• gorier.. Te. •

4" Perl.r., S..pport_

.w.d Board

–=TAIL Of HANGER BRACKETS - Z or,

a" ~na.Fl.t 4$•I.,q e..aeKr r..P, /6..bec .aeexues~aLro.xacar..at

- SecTIoN Z .Z. II

– FRONT CEVATIOH — - DETAIL OF PULLEY PIN -

– 2 era..- M. - DETAIL OF COL. FOOTINGS -

4".I*~"T.reorere K'I.«g. 51ce.w «o:l.. te 8wrer s G;rt

Terre coals. Ce..Sl.ed. . .n I -•1 E/t.~ee.ak Bdf, e..a. b 1~-

~~te

—

r

]

- O[ia.b OF 000A ew.oe

Note

A". lïco...b I:eaSf h .

All Corbel pieces for Grits ose le.lt.ólly clot 6 ladle& as sta..Aar& ebac. articles . It 1s I:'.tteeaace. *hat dti 1s Shoot.. ana to a

stae.ear. 6 as far as possible. oeaa4 of mill of wcrkel.op :w bOInk.O for yeraral Constructow

at Sir r .

1rO..od.a.+[ Mo..4.:..O4rNq..:rea. (se, zo.dF:cara...)

~M1'.3-G'rl (~')

– DOOR GUIDE

4•. r B.a.w~

a 4mr g..:ae s bogie. te L

b.neKrt bo r...... of ere

Ha. Bolk t.,ce«. Ib.; ass.

22`.2.4% 4". Brae leer l se.~ L)

6 — 2

• $L3 DING DOORS_

TRUSS 30' Orr SPAN &. - MISCELLANEOUS BUILDING DE.TAILS -

TIMBER CONSTRUCTION PLATE 1A R. KN6ALE

INDUSTRIAL BUILDING CONSTRUCTION


Economy. High land values, taxation and general economic factors

demand methods of construction and design with a view to conservation of space and area relative to location, also earliest revenue-earning possibilities.

'l'o-day time governs a building project, and we plan the erection period in terms of months, weeks and hours, instead of years, as did the people of ancient times, who had great armies of slaves to accomplish the task of raising stone on stone and transporting supplies; based on the great manpower available.

In the consideration of economy, speed of construction is essential and should include. such matters as site preparation, workshop fabrication and field assembly. It is important to note that where unit or partial fabrication can be executed independently the site may be prepared simultaneously. These factors applied in a practical manner and well organised will have an important bearing in the building finance scheme.

Standardisation, later referred to, plays an important part in the carrying out of speedy and efficient construction. Materials most suitable for this purpose are steel and concrete ; while for the less durable structures and in cases of war necessity wood is used. Steel construction ensures economy in the most general way and of all materials has the highest load-carrying capacity; such structures may be designed to a great degree of accuracy with a minimum of material, being readily adaptable to standardisation, with corresponding unit fabrica-tion. Steel in buildings conserves space and permits of maxi-mum floor area and facilities for any subsequent additions or modifications.

For industrial buildings the steel frame construction is most adaptable where arrangements have to be made for the accommodation of industrial plant; this form of structure also permits of any later additions or alterations as might be required from time to time.

Mild steel can be accepted with confidence, for it is the product of specialised scientific research.

Concrete, Reinforced.—This form of construction is not entirely new. The principles relative to the application of re-inforcement were understood by the ancient Romans, who em-ployed it somewhat generally in characteristic manner. The reinforcing bars were of bronze and the concrete was made of lime mixed with volcanic scoria and aggregate of rather large fragments of broken stone. Sometimes iron bars were used; there are instances where these have been found to be in good condition after having been embedded for approximately 2000 years. There are also instances where timber has been used for

INDUSTRIAL BUILDING CONSTRUCTION 109

reinforcement. Modern research has evolved a cement true to definite specification. It is due to the known values of cement and steel and relative ratios that units can be computed, con-structed and erected in accordance with standards laid down by various codes.

Steel reinforcement embedded in concrete is effectively protected against corrosion; it is important that rods be free of mill scale and extraneous coatings , except rust, which actually effects a chemical combination with the cement, producing a lasting cohesive bond and protective insulation.

Reinforced concrete is a subject of far-reaching possibilities and beyond the scope of this paper. The most involved method of dealing with design does not always yield the surest result; as one writer says: "There is always a danger of being lulled into a false sense of security by abstruse mathematics — there is no magic charm in complicated and intricate computations; there is indeed some danger, and the safest guide in most matters is to cling fast to common sense."

The author proceeded to outline the theory of design of reinforced concrete.

Flat slabs may be economically designed by the introduction of the drop panel, as shown on Plate 3, Fig. 5. The column footing indicated on Plate 3, Fig. 4, shows a portion in broken line which actually for economy could be dispensed with, if design was properly investigated and form work duly considered. The compression in the concrete may be assumed to be spread over a width equal to b -{- 2T and reinforcing bars calculated accordingly.

Electrically welded, steel wire mesh, is an ideal reinforcement for concrete slabs and surfacing. work. This fabric is a wire mesh comprising a series of parallel longitudinal and transverse wires, each with a welded junction at point of con-tact. The material is cold drawn steel wire with a permissible working stress of up to 25,000 lbs. per square inch, often designated by various Codes or in By-laws as 20,000 lbs. per square inch.

Expanded metal of diamond-shaped meshes cut and expanded from medium steel can be used with advantage. The cold working process in manufacture draws the diamonds in a similar manner to the drawing of steel wire and has a harden-ing effect on the fabric; the elastic limit is therefore raised to a point almost equal to that of high carbon steel, while yet retaining high ductility and uniformity of quality.

Electric welding has revolutionised the methods of fabrication and general execution of steelwork construction ; it is rather of recent development, but has attained a place of 'great

1 3

9

7

~


industrial importance. In order to accept such a comparatively new method for fabrication of structures it is important at the present stage of evolution to give full consideration to the ability and experience of the welder. Savings up to about 30% are possible by means of welded design.

It is generally noticeable that when a new process or fabric is introduced in any constructional project there is a tendency to apply methods similar to those adopted during past eras. Design technique must necessarily be investigated and adjust-ments made to fit in with the usually applied orthodox methods. Efficiently carried out, great economy in material and labour is effected by the welding process through good design and plan-ning; it is essential that the following be kept in mind : maxi-mum unit construction in the shop with a view to field bolt assembly at site of the respective units; transport and handling size, including manipulation during erection. Walls and Framed Structures.

The evolution of steel and concrete framed structures has introduced revolutionary changes in wall construction, necessi-tating complete revision and the application of new design. The walls are treated as substantial curtains or screens between the vertical and horizontal framing members, etc. A number of suitable facings are available for incorporation in various com-binations to produce architectural expression ;; panel walls of this type may be constructed of various materials, including brick and concrete or terra cotta, with appropriate finish. These walls are not required to carry structural loads and should depend entirely upon the framework for support.

It will be advantageous at this juncture to call attention to the types of walls, in order that one may bear in mind the specific function of each. (a) "Bearing Wall."—A wall supporting the whole or part

of the interior load of a building. These walls may be built in piers, which shall be deemed as forming the ver-tical framework of the building; the portions of the walls between the piers to be regarded as curtain walls.

(b) "Curtain Wall."---A wall built between the vertical or the vertical and horizontal framework of a building, and which does not carry any load other than its own dead weight.

(c) "Parapet Wall."—A wall built above the line of the roof, irrespective of such roof being either sloping or flat.

(d) "Division Wall. "—A wall other than an external wall, and which extends the full height of a building ; it may or may not pass through the roof. A division wall may be a bearing wall.

111 INDUSTRIAL BUILDING CONSTRUCTION

3 Fr c.

,e.

WE'Eg AN-47-E"

\/1 TYPICAL WELDED COMBINATIONS OF STANDARD SECTIONS GIVING ECONOMIC VALUES 4.e. —

Loss WEIGHT, GREATER SECTION MODULI AND RADII OF GYRATION VALUES ETC.

Re-PEN TO ANY STRUCTURAL HANDBOOK ON WELDED STEELWORK

RECOGNIZED STANDARDS ARE ESSENTIAL.

P7. 6

kg'VE-E" .../0//VT-5. R.KivsiE. PLATE 4.


(e) "Partition Wall" or "Partition."—A wall subdividing any floor, and which does not carry any load other than its own dead weight.

(f) "Party Wall. "—A wall used or built to be used in com-mon by two or more buildings.

(g) "Retaining Wall."—A wall constructed for the purpose of holding back or retaining earth or other material. These walls must be designed to adequately resist the stresses to which they may be subjected.

In the matter of steel or reinforced concrete frames accom-modating curtain walls, the panels, when of brick or similar material, are to be anchored to the columns at least every 3 feet in height with suitable steel flats secured to the columns and projecting several feet into the wall.

Curtain walls can often be adopted in building design and prove a most economical application. Minimum thickness external walls can be specified providing they are constructed as panels between substantial framing supports by way of columns or piers.

It is suggested in regard to the design of walls that appro-priate recognised building regulations or codes be investigated. With regards to fire-resisting and non-fire-resisting bearing walls, etc., of _ reinforced concrete, the S.A.A. Code for " Con-crete in Building," which is recognised as the Australian authority, should be referred to.

Before leaving the subject of walls, a word should be said concerning "cavity walls." These prevent the penetration of dampness from the exterior to interior of a building because of the air space. The provision of a cavity is especially recom-mended if the face of the wall is exposed to heavy rain. It is usual to build a 41-inch external wall or skin, and a 4i-inch or 9-inch internal wall, suitable bonding . being built in between the inner and outer wall. Ventilation of the cavity is essential and may be obtained by the provision of air bricks, built in the upper and lower parts. Cavity walls are considered to have a substantial factor of safety for resisting weather, and in exposed positions are preferable to solid walls.

An appropriate reference relative to long-range economy, to be provided for during the initial stages and at the time of construction, is in regard to "dampness." The prevention of damp penetration is very important and has an effect on the life and usefulness of a structure ; it is essential to provide necessary damp courses for walls, and counter-measures against penetration when floors are below the outside ground level.

4


Basement and multiple basement floors call for particular con-sideration ; increased percolating pressure is at times manifest, due to deep excavation and resultant head of water. Concrete is enhanced in water-resisting qualities by the addition of one of the waterproofing preparations during mixing; extra mass, richer mix, or incorporation of mastic asphalt membranes in suitable positions, being all counter-measures.

A greater variety of building essentials are of recent years available, due to increased development of the basic materials. Glass is beginning to have an influence in design. As a material of construction it may not lend itself architecturally, but in building can be most useful, e.g., for lighting to the exclusion of timber, or metal window frames; insulating qualities; decora-tive possibilities ; and, structurally, in the form of bricks, tiles, etc.

Brick Veneer.—This form of construction has satisfac-torily been adopted for many new buildings, showing a saving in cost of about 10 per cent. when compared with other typical brick construction. It is most essential that properly seasoned timber framing be used, and any defects after thorough examina-tion rectified ; selection of timber is very important. Where permissible by municipal Building By-laws, this method of construction enhances the chances of rebuilding and recon-ditioning old houses.

There is low cost in asbestos cement sheeting for walls, with such advantages as ease of construction, fire-proofing and elimination of painting. Fibrous plaster and gypsum products generally are forms of prepared materials suitable for economical applications.

Methods have been evolved for moulding entire walls flat, involving a minimum of forming, and then subsequently raising them; provision having been made for general assembly and final finishing. Because of low cost and expeditious assembly this system may prove an economic method for future development.

Let us refer to Plate 2, "Large Storage Building."—This building comprising in width two 50'0" roof trusses and two 10'6" wing lean-to spans, i.e., 121' total width by a length as required in multiples of 12'0" bays; and has open sides with one permanent end of concrete; brick and steel composite construction ; the other end being steel framing.

To construct the permanent end of brick in the ordinary.

way in accordance with municipal regulations would require a wall of substantial thickness with heavy piers ; the total weight


would greatly increase and the foundations would have to be made larger. Wind pressure would become an important con-sideration, requiring special design providing the necessary resisting moment ; this moment would have to allow for the possibility of no assistance from the steel framing whilst under construction. If the brickwork is dependent on the steel fram-ing of the building, the procedure of construction could not be simultaneous with that of the steel ; if independent, the brick wall would need to be self-contained for stability, requiring very heavy construction. Considering the time factor, also labour and material, with a view to economy; the project has been designed on the basis of a screen or curtain wall, with the steel columns encased in a concrete core as depicted on Plate 2. The writer is able to say that the proposition as here shown is one that has materialised, having received the sanction of one of our leading Commonwealth capital city building authorities.

The saving in brickwork was over 45 per cent., with a corresponding foundation reduction. The additional necessary steel to be included was small in proportion to the saving; therefore, from the economical aspect, the composite wall was justified.

On Plate 2 is also shown a simple form of shelter where the column ends as designed are fixed for direction, the equiva-

L lent strut length thus becoming —, permitting of lighter material. 2

Roof Trusses.—These vary in design and type, according to the nature of the building, its location, loading, etc. Refer-ence to Plates 1 and lA will illustrate various applications. The trusses depicted are orthodox in design, but with adaptable features; these are still economical for general application. Welding has brought about new design and types which are becoming adaptable. Single continuous members, either of uni-form or variable section, are being incorporated in units, con-sisting of lengths of suitable sections of steel joist welded to-gether to form continuously the columns and rafters of single span buildings. This method of rigid frame construction has its difficulties in design.

Various spring bow-type ,trusses have been advocated by different manufacturers.

With industrial buildings, the writer considers it hard to improve upon the ordinary orthodox trusses for the purpose of standardisation, adaptability and utility. The saw-tooth type of roof is extensively used. In designing Pratt or Howe


trusses, as shown on Plate 3, Figs. 2 and 3, it is a point of economy to consider any possible loading which may be applied to the truss inside the building, e.g., runway joists, etc., and to investigate as to the most suitable type, taking into account the compression and tension members.

Regarding the fixing of girts, whether steel or wood, the writer considers it much better to affix them to the outside of the columns per cleat; this means simplified cutting of girts and gives the most unobstructed positioning and fixing of general building bracing.

It is important to note that a "War Emergency Revision" of the British Standard Specification for "The Use of Struc- tural Steel in Building" permits of increased stresses in steel construction where a high standard of workmanship and super-vision is maintained, but in no case without the prior knowl-edge and consent of the owner of the building ; this has also been considered by the S.A.A. Code. It is pointed out that this phase of economy is only to be taken advantage of in neces-sary cases, with a full realisation that such relaxations may be modified or withdrawn if experience or altered circumstances warrant such action. The measure is only temporary (refer to latest British and S.A.A. Standards).

Design for long and efficient service must be considered when planning a structure. A knowledge of design and pro-perties of materials is of paramount importance in any project where construction is contemplated. An accurate estimate of loading and possible deterioration, in conjunction with stresses, should be investigated. Consideration must be given to available finance, labour, kind of material, source of supply, economical types, possible shop fabrication of units, and transport facilities, etc.

It may sometimes prove advantageous, in conjunction with the points mentioned, to use fewer and larger members; and thus obtain better economy than with a greater number of lighter or compounded members, requiring more labour. This aspect is limited to a line of demarcation, which, if exceeded, would excessively add to the total weight and make handling, shop fabrication, and field assembly more difficult

Stability.

The strength, rigidity and necessary flexibility of a struc-ture are matters of design, and concern the relative values and the reciprocal functioning of the respective components. It is assumed at this stage that the complete structure has been de-


signed to withstand all loads intended to be applied by man's agency, and also that the elements of wind, rain and snow, etc., have been considered in both the sense of dead and live loads.

The matter of stability, as discussed in this paper, is mainly relative to foundations and any other precautions taken to ensure a rigid and permanent structure.

The overturning moment caused by wind or other auxiliary, or deliberately applied forces, must be calculated from first principles. The resisting moment, with ample safety factor ranging in the ratio of from 2 to 4, must in like manner be deduced. The bulk (mass) and spread of the foundation are calculated accordingly, the latter according to the permissible bearing value of the ground and the former for weight accord-ing to the spread of the latter. It is important that the engineer considers a system of balance when proportioning a foundation, as this neglect can lead to a degree of instability.

Close investigation of the natural state of the ground where constructional work is to - be carried out is of uttermost importance.

Data pertaining to the bearing capacity of soils must be available or ascertained relative to respective sites. Some soils have compressible characteristics which call for more than bearing capacity, and must include the probable settlements under definite loads applied over considerable periods of time

Sizes of foundations are fixed to compensate for lack of soil stability and bearing resistance by spreading the load of the superimposed structure over a greater area, thus reducing the pressure per square foot to within a safe margin.

Testing Soil for Foundation.

Temperature, frost and moisture can change the usual characteristics of exposed soil, and for this reason tests of open ground should be protected against such influences for the period of the test. If exposed soil has any tendency to materially and progressively change, it should be left open for a period of time to permit of observation regarding general inherent tendencies, otherwise hasty tests may prove misleading.

Relative to foundations or bases for buildings or struc-tures, the essential excavations are mostly through surface stratum which can be tested for bearing by direct loading of a slab or base of reasonable predetermined area ; this should be at least 1 square feet; the standard unit for computation being 1 square foot. Larger areas are preferable for bearing and compression tests. Any trial pit should be at least 2 feet larger

- -

- _ _

- .

1 ;

°ht

q

.fl.

rK_(

ÍI

)

~ .

:S/K

L

II .

V e -

. .

_ _

_ u

,

t~

~,

C - ~_~

~~

~ / ~~

~ ~

L LT

AT

IW

AT

RI

All

ÿ

~:~~~

~

z %

.-

_.—

, 7,

. _

.

ÇZ

\ —

j ~

%

.

•~

/

~~

~, ~

• ~Yry

~%

VYj

\ ~

~\

~II~~ /•\ . / \ ~

// .~

~

\ ~

~

~~-

~~

~

I

F3

••3h

<4R

-

~_

~

III

~

: ~-~

-~' - -

~ ~

- ~

-'-

„~

Í

Í ~

/

/ ~

~

. \ /

? ~

-

~

F/G

. 2 /-IeF

T r T

15

y

I

/

~~

41

11

\ d/,

ry ~ \~

/ \~/ \~/ \j/

n

~ C

I

•

yy.

~+ !I~

i

/'\

`~/

~

11

h

•'`/\\

ry

m/~

\'/ \\ // \\

'//

'\

-

•~

~

1=

~

G.9

HO

WE

1iP

V51

C

I I

i

•

_ =

/II~

~~

~

~

\~

'

~

q-o

. ~

9-

O

I~~

_ Ì

_ ~

~~

-_J

' ~

I~

~'

1

1 g. O

- :-

1

9-n' i

I y.

O..

' ~

9-0

" i

; i

~

L

J

L

_ _ _-

1 ~

L

I I I

114

'_O-

~ L

-~-

~-

EY

VO

cL

EVF

TiO

/V

-_

1_ 1

~ -- -=

L-

---~

-- -

- -

- -

I ~!

~ 1

____J

l

_J

___~_-

S/OE E EVCiT/ON

~ •

~

~ 1

~ 1

ST

QU

CTU

.P.~

STE

EL STl

7N0

fae

T

F7/YK

S Í /

• . \

~ ~

\

~ /

\

~ I

~ ~

~~~

®~

ÌG ; i

~ cuM

U p

Ti✓E

u /r

71./P

C

_~

_ ,

k.~

L~

~

i,~ ~

'~c ~

\ . _

. j~\

- /

~ -‘

I I

I I

I L 1

_I

1 1

_I

I I

I I

I i

1 1

1 y~

, r ~

/

Í ~

IE

~

1'

i l- ~

I1

11

11

11

11

111

~

I111

1111

1~1

1I11

1 'H- \ V/

\ \ /

~ ~~

'- r

i

x

!I

~_

~

, l

1 1

~ ~

~

_~

~

~

1

1

J 1 _

I/ r 1

1

1 1 1

r 1 l

1 : ,

.~

• I/

ì'ìi

~

11

II

1

1 _

.

.

,__-~~ ,

~i/ ~~ p,1/ 'f~

fJr

~

~

%%

P

L N

O

li

Ì ..

•

'~.ÌÀ

`::•:

.~~

• :~,%

,r;.

•I'~

'•••.

~_ ~~.':

. :.

:.-.

.'•.'.':

'r

----L

-

: ~

8:.:

:,::.~

,:..•

; . . d

A.

~

%

: I,.

_ _

_•~~

.-----

~~~~

~~

. ,

~trrr

~~

~~

w~

6,.~

„E

•

9O

K S

E .ei

~•G

uoL

VE

~

J

10

iL A

lEF

,a:n

G

_ _

_

_ - -

~F

X~~

K

s

Y.O

L B

EF

/N

G

O~E

Fic

/Cn

_ "

- -

~T

mw

m. v

lE. +'

+':u

c/

VE

P1

Fi.e

1r

~m

' ill.

II.

~

.riE

ivr

• _

a✓rvu

~

~~~

rrov

.i w

vuvor+

riav o

eoc.rco

F

/G 4 CO

LUM

N fb

OT

/ NG

,~p„:.0

0r».•

ro

co

o

r -

B~~d

vI

N G ro

~w

6

FT

i

m- wii:G

iW

~

Ala

rm, ~

~

r

...

•. `

» ~

~~

R~~

~r

WF

7LL

FO

UN

OF

7T/

o N SN

OW

ING

ST

,FE

SS

CY7N

LYT

/CW

Ov

~~

_

. . .

. ,

'.' l i

t I' '.

,.r.

. e~~

•+.mr.. .n.. -

o

I

gl i

1i ~

'~~~

~.el

n..

~~

cNr

fON

C. F

i TC

ME

fEJS

~rF7

Tin G

BA

RS

FT

MP

A C

~T

TOM

. ~F

S. s

. o,e

oc A

.oiv

EL

. ~

_-

_ _

_- LS~

I

f .

F, L

I 'I

'

~

dM.

o. c

OOE

~

/G.R

cON

OE

~E'rE

T ee M

1

1..

I

~~

ENr

•cav

c~rr

ciN

WCa"s

..

çR°n

~

M

ISC

ELL

AN

EO

US

APPL

/CA

TI O

NS

ew

e G

O.C

or°

p`=""

R K

NO

ICE

P

LAT

E 3.

Ì. I 1

j!

_:

_. _. _

__ _

; f

~ INDUSTRIAL BUILDING CONSTRUCTION 117


all round than the bearing slab. The dimensions of a slab for a test will actually depend upon the bearing capacity of the soil; the area included should enable a load of about twice the assumed safe bearing value being placed uniformly and sym-metrically upon it. Such convenient material for loading as bricks, bags of sand, suitable stones, pig iron, steel billets, etc., could be utilised. An equivalent load to give the safe pressure per square foot which the soil is intended to carry is first applied to the slab, being packed on steadily. After allowing a period of two to three days' rest, further increments are pro-gressively added until twice the initial loading has accumu-lated; these increments should have a period of two to three days between applications. The greater settlements generally occur during rest, time being necessary for the soil readjust-ment under load. The final loading should be left undisturbed for five to ten days, or longer if any doubt should be manifest as to the earth having ceased to settle with the necessary recovery to stable equilibrium. If at the end of the rest periods between applications of partial loading, settlement is still discern-ible, no further loading should take place until it has ceased, as it may indicate that the earth is approaching the yield point. The method of test outlined can be compared with the require-ments of the S.A.A. Code, No. CA.1 — 1939 - Appendix F. "Foundations," clauses 8, 9 and 10. Arrangements should be made prior to loading the testing base piece for measurements of settlements to be taken at intervals of about 6 or 12 hours, particularly after completing each progressive stage of loading.

A datum peg, or bench mark, should be fixed conveniently near, and a dumpy level set up equidistant from the datum mark and the test load. A vertical graduated rod should be fixed in the centre of the loaded slab (or platform), from which readings should be taken. Other methods can be devised for registering readings of settlement.

The minimum depth permissible for a foundation to be carried can be deduced from Rankine 's theory of earth pres-sure, but is not usually applied in ordinary work except when soft clay forms the subsoil. A depth decided upon to counteract the effects of frost, drought or water generally includes, with reserve, any calculated depth, based on the theory evolved by Rankine.

Making choice of the most economical footing or base ,for a particular job involves consideration of mass concrete or a minimum bulk of concrete shaped for maximum value and reinforced. The necessary excavation can often be a factor in making the choice as affecting the total cost.


When designing a reinforced concrete footing, for reason-able minimum bulk, the bars should be uniformly spaced in two rectangular directions. (Refer Plate 3, Fig. 4.) Design should be computed on the basis of moments and bearing area, with investigation of tension, compression, shear, bond and punching shear.

At times it is unavoidable that an exterior footing close to a building line, if placed symmetrically under its column, would project beyond the boundary. It is not good practice to locate the whole of the footing inside the line with the disadvan-tage of eccentrically loading it and causing uneven soil bearing.

pressures. The difficulty can be overcome by compounding the exterior with an appropriate adjacent interior footing; the mass and its area is so proportioned that the resultant pressure due to loading on both columns passes through the centre of gravity of the combination.

To support a line of columns adjacent to the building line a continuous footing in the form of an inverted tee beam is quite an economical method. It has the characteristics of a double cantilever anchored into the central web, transversely and to a lesser degree longitudinally reinforced.

Where soils will not bear heavy loads, various forms of foundations become necessary and are designed according to any of the following (a) Grillages are used where it is desirable to avoid great depth

of excavation ; thin substantial stratum may overlie others of a yielding nature and necessitate a shallow excavation with ample spread.

(b) Piles are used in some cases and are driven into the ground over the whole foundation area; the ends are finally made level and embedded in concrete.

(e) Caissons are used for heavy loads where the foundation must go down to bedrock.

(d) Cantilever constructions are used where it is inadvisable to undermine existing walls in adjoining property. Footings should be designed in accordance with the S.A.A.

Code for "Concrete in Buildings" as a basis. The foundation for a retaining wall must be below the

frost line, which can be as far as three feet under the surface in a temperate climate and deeper in a cold climate. The founda- h tion and wall must be well drained, otherwise increases stresses Gnd undue deterioration may set in. The difference in co-efficient of friction value between wet and dry clays is about


from 0.17 to 0.2, and therefore can mean a substantial loss of stability if water-logged conditions prevail. Accumulation of water behind a retaining wall in a cold climate may freeze and cause bulging, thus accelerating failure.

Earth Pressures.-Considering vertical surfaces according to Rankine 's formula.

1— sin $ P = wh for level ground surfaces.

1 + sin 9

For easy application the following derivations serve to give practical results :-

P — Intensity of pressure horizontally at any depth h. Weight of earth

per cub. ft. (v,)

Angle of repose of earth in degrees.

Pressure in lbs. per sq. ft. at. any depth (h) in feet.

100 30 33 h. 100 35 27 h. 110 ... 30 36 h. 120 30 40 h.

where a foundation is being formed, and can be rather specu-lative in the absence of experienced judgment. Without a definite test the following . (from the S.A.A. Code, No. CA.1 — 1939) can be taken as a fair approximation and general guide for foundations only.

Allowable Intensity of Bearing on Subsoils. Kind of Materials. Tons per sq. ft

Alluvial soil, made ground, very wet sand .. Soft clay or loam

Up to 1

Ordinary clay and dry sand mixed with clay „ 2 Dry sand and dry clay .. .. , 3 Hard clay and firm, coarse sand .. 4 Firm, coarse sand and gravel .. .. .. .. Shale rock .. .. 17

6 S

Soft sandstone . .. .. .. .. .. .. .. „ 12 Medium sandstone . „ 20 Hard sandstone (free of seams up to a depth

of 6 feet) .. .. .. .. .. .. .. .. „ 30 Igneous rock .. .. .. .. .. .. „ 40 Note.—Where the foundations are on ground liable to loss

of side support, the allowable intensities of bearing pressure shall be 33; % less than the above-mentioned values.

It is often difficult to decide on a bearing value for ground


General Foundation Work.—With a rock bottom it is quite good practice to cut the rock to form the required level bed and fill in any crevices or pockets with good cement concrete.

Sand is a good base or bed if confined and kept free from water scouring, from which action it requires absolute protection.

Gravel forms an excellent bed and has a very high com-pressive value. It must be protected also against undue scouring action.

Drainage.—Where a locality is low lying or soil charac-teristically damp because of some (sub strata) formation tending to accumulate seepage water, a building site within such area should be properly drained and provision made against future recurrence of the condition before any building constructional work is commenced.

Dampness in the soil has a detrimental effect upon health and causes serious defects in buildings generally ; certain materials of construction become impregnated with dampness, which is a perpetual menace. Various counteracting applica-tions are resorted to for cure and prevention. Dampness should always be investigated ; levels must be checked and means taken to rectify the cause. A good system under ordinary conditions consists of narrow, deep trenches in conjunction with agricul-tural drainpipes and broken stone, laid with proper falls.

If a site is unusually wet and draining off without infringe-ment of others' rights a problem, it will be necessary to make special and exhaustive investigation, as the resulting benefits will more than compensate the efforts expended.

Referring to Plate 3, "Wall foundations, showing stress condition in concrete, necessitating steel bars at top and bot-tom." — Superimposed concentrated loads; uneven bearing capacity of soils ; hidden but adjacent boulders, or patches of earth with very poor bearing capacity under wall foundation, etc., have convinced the writer of the advisability of reinforcing where doubt exists at the top as well as the bottom of a founda-tion. Plate 3 shows the double reinforcement, and also illus- trates failures where only a bottom system of bars exists. •

Regarding the stability of brickwork and masonry, it is to be noted that no tensile stress is permissible at any point in the surface of a joint; the limiting distance of the centre of pressure from the centre of area is:


For a Rectangular joint, Thickness of the joint 6

„ „ Solid circular joint, Diameter 8

„ „ Hollow circular joint of outside diameter D, D2 D12 and inside diameter D1, 8D

The above is a useful, simple, approximate method of com-putation for each section respectively. In as much as the foundation of any structure is a measure of its stable life, it is most important that this short treatise on the subject of stability and its important relation to economy be given careful consideration.

Standardisation. Industrial standardisation over the past 50 years has deter-

mined the status of nations in peace and war. The manufacture of armaments, for instance, is based fundamentally on stan-dardisation for mass production, interchangeability and economy of labour and material. Among ancient nations, stan-dardisation was manifest for the purpose of simplicity and convenience in the various building materials such as stone and brick, etc., and also the manufactures of utensils, pottery, etc.

The development of the machine in this age has made possible the application of standards to unlimited utilities of man, par-ticularly in view of the greater and increasing demands.

It is part of the purpose of this paper to review the advan-tages of a standardisation, and simplification of requirements and applications pertaining to industrial building construction.

Referring to activities of various established authorities.—The Standards Association of Australia, recognised and supported by the Commonwealth and State Governments, being free to act in closest touch with industrial requirements and modern technical knowledge, stands for the promotion of stan-dardisation and simplified practice. The following are some included: "Structural Steel in Building," "Concrete in Building" and "Welding," etc.

Outside of the S.A.A. publications is a "Handbook of Structural Timber Design" issued by the Council for Scientific and Industrial Research, Division of Forest Products. This book includes all •essential information on the use of Australian timbers for structural purposes, and gives complete tables, strength values and computations.

There is also a "Handbook for Welded Structural Steel-work" issued by the Institute of Welding, London. This book provides necessary technical data for general design of welded structures.


The various handbooks with properties, data and loading tables, etc., as applicable to structural steel and concrete, are available, and become valuable helps in design.

Building by-laws and regulations to a greater or lesser degree keep all building operations within their control.

A uniform code embracing practical- standards relating to construction, etc., is under consideration in Victoria and should be looked upon as a step in the right direction.

The Department of Scientific and Industrial Research, England, is. dealing with current building problems arising out of the present war . conditions. Guided by a committee of the Building Research Board, numerous structural innovations based on scientific applications have been introduced. The great.

demands on the steel industry have made the conservation of this material for the production of munitions of paramount importance. Engineers in conjunction with Government departments and research bodies are co-operating.

Standard designs, embracing economical features have been adopted and are included in recommendations with the object of saving weight of steel, etc., consistent with safety. Competent engineering knowledge is necessary in the carrying out of the various modifications to orthodox design. Maximum economy should be a determining factor in any system of standards applied when replacing factory buildings that have been de-stroyed, or for the establishment of additional ones as required by the national effort.

Structural steel, more than any other material, is well adaptable to construction of units in the workshop and for field assembly.

Refer to the "key sheet" for explanation of drawings and illustrations on Plates 1 to 5. The applications described are with a view to standardisation and economy.

Materials of construction are now so numerous that modern design may be varied without alteration to essential basic standards relating to the main structure.

Construction of houses suitably designed may be expedited by the introduction of standardised units and methods, wall sections and frames being fabricated separately with all necessary assembly provisions.

Such matters as light, ventilation, heating, etc., have an influence on the type of structure and should be considered with a view to future possible extensions. Equipment for these purposes has been standardised to a great extent, and is being further evolved for greater ease and speed of manufacture.


Metal-framed windows of various types have also been standardised and fitted into the scheme of industrial building construction.

Shuttering.—As a means of carrying out concrete construc-tion, this requires particular attention and can be adapted to systematic methods ; it must be substantial and capable of with-standing constructionàl loadings, owing to wet concrete and any resulting undue pressures in vertical sections of columns or walls, due to the hydrostatic head, depending on the rate of filling and prevailing temperature. This can cause bulging and collapse. It is essential to consider weights of slabs placed horizontally and any overturning moments.

For standardisation purposes steel shutters are appropriate and have an economical value over those of timber, as they can be used repeatedly. It is not usual to use wood shutters more than half a dozen times, as after this the cost of reconditioning would justify new sets; whereas steel shutters can be used for more than fifty operations.

Various materials giving smooth surfaces and being adap-table for straight or curved work have been introduced during recent years. These may be used a great number of times without being affected by moisture.

Sequel to Discussion In considering the projected pictures preceding the paper,

depicting ancient structures and their diversity of types; Mr. W. E. Pyke drew attention to the absence of the keystone in the structures of the ancient Americans, and requested a little more information regarding the method of construction adopted.

The following is submitted The Mayas never developed the arch as the Romans used it.

Though they built structures to a height of 200 feet — the equivalent of eighteen story modern buildings — they never employed the principle of the keystone. Instead they placed one stone before another to form a sloping interior that came within a stone-width of converging at the top ; a flat ceiling stone was then placed over this, the whole forming an arch of ' receding steps. (Refer Plate 5, Fig. 1.)

As a result, their , buildings in many cases had walls much thicker at the top than at the bottom, and except in cases where columns supported rafter arrangements, the interiors were small compared with the exteriors.

Standing silently against a tropical sky and rising from piles of broken stones with tangled tropical growth, the remains of these typical buildings stand sentinel-like in Yucatan, Hon-duras and Panama. They are quite ancient witnesses to the worth of the engineers of past ages who constructed them.

Ra

tio

of R

ise

to

Spa

n.


$., --+ a> a> • • i+ • cd a) cd ,., 5

-' C Il IO 4.> °óóA~ CO

I ~âb~ O .~~U

~~

e Wc.)m g ,d.D+O;

~~

~apv . 0.

i~ 6q cd m o ~' ~ -Q p . re ~ ~m Q

~~ O~~ w b 0 ~ o g

~~a,.~ ci ~ • c.) -0 ~ C F;4N n d~ ~~ ~o ~ O g b4

Q

. 4+PwO +, ÿ.i~ c óa)~ Ó w o ~ d s. rd ~

N El e ,+R~~. o d

dd~o5

b~w 3 ~'i~

Ci ~ÿR~ ce, ,14-) O

d ~, . a o ~

,e~zs,~v m : 44 ~i 6A~..t~

;O ~ 6 eC U ~ m

cdeb

N cd ~Nwÿ

ocd rn +,U

P.+>o~

~~ ' t p d

p~~â° Ob ~ O~ 0wW ~ d Ó ~ ~ ~ a Ay O bO O C +~

"->"c1-0.4-',-, rÿ+

co

o

m~

0

C

N w C aO.'

d 0 oO 4 +~ u O ~ aQ• y 0

Q3~

~m g C ~

4 4-1 bAEo~a +'-. ~ Q m ~~ww

'

0 4 ;:à. `~ O ú~~~

~v^ä

. As+0

'4 .0d~ ~ E OO H y +~ O i.?~QA+ z~Gu ~ +, a, ~~, W•.+ .-0 O ÿ A cd 0 uo Q~ C a) ~ .0 0 .= O O --' 4.1 ^O ~~ 'd'

cd C b;_ ••~ r a~ LO Il d ~ d: Q •a> O+' "

.

.

.

'~

~ ~

~~

~ • b a

d â op

4 m +' ,

a o

Np , d ~ ~, cd

ari .a ~ .un F. w . ~ C ~~ 0 D+ oÓ'e mH '~

Cd O

. d'

ma .+, ) +~

', +~

•~~

~

p~bp~ . d +, p ~~•.,

.0 O F, F cd O a) ri F, ~ ..z $.,,

.

~ Id: 4-1

w~ N Cp — ~ ~- .x +~ ÿ ~ ~q, H ~

w y

~~

,

~~

1:1)R#

O

~

A

~~m~ ~ ~ ~A ~ v H N~ ÿ

p „A ~P o ~ o~ v H a+' â P

ocnoo O ~r, u as~ ;,~

~~ ~ s .t

o N u m ~c ~

Uâ Um~~ cd ~° v ~ F .c ~z 1-4 ~w yPaObAa) 44- 4° O ^~~ A •N~~Ú

v •

cd o cC ~ö C bg*.~* ~ E g .5 a. ab y m o cd

H~ ó~~a ~ •~ ~.~ a A.â ~ó w 0 ó ~~+D m

F â 0 : ~ÿ~~ 2 O

0ca ~ -.w 0.)'H y • ~ ó

°~ +,

~ $ V2 o ho o~4~ H~.~.~ o~^ s +~ 0 n~',f~ FcA.•v-~.e.~ ¢,•, bo

a)ó

~ °ÿ ' 3•-, + ry Ca en

.p ..0 N ~ ~ y O..0'ó rn ~ w

~ O~ ~ q vwcd ~U y o ,g,..,

4 PZ +a

a, g y gNo o a, P•.,.-1.., .ti d-~

b 3 . . U

w1 ~ C ~ O

~ r-i IL:

~ OÿF,

~ ; ~ ~ +~ ~ -!1:2a)bp ~ cd s, •

~ ~ V-1 bA ~ ~ í: O'ÿ-p cd co

N ~ ~ C) ^C ,„

i. °

~ 0

..0 d ów F +

C ~ ÿ ~ .0, ~ ~~

~d^ ~ W -,"' Sa

C d Sa S•, .0 GL 0 •n ¢, GL cd cd Ik!a:• d@!I;!flllll


The arch proper, and as designed generally, is governed by the architectural features of the structure or permissible space ; thus the engineering consideration is often subjected to the aesthetic; economy therefore becomes secondary.

The semi-circular and segmental forms of arches are the simplest to construct and the most stable ; elliptical and three-centred arches have not the same strength, and when used should be given added strength and safety factors. The full strength of an arch is greatly dependent on careful construction and quality of materials ; all stone should be cut true to shape and accurately bedded, with joints thin and close, to give a minimum of stress and distortion when settling. It is important to note that when abutments are of ample size, the segmental arch is the strongest, but when of necessity the abutments are small the semi-circular or pointed arch should be used.

A true arch without spandrels has high, compressive and tensile stresses on investigation, but if the spandrel is reckoned as load-bearing, the stresses are reduced. Considered methods of construction call for well-built spandrels. This permits of In ore latitude in the design of the arch.

See Plate 5 re simple approximate method for design of an arch.

Reference in the discussion was made to the large taber-nacle building at Salt Lake City, Utah, U.S.A., as depicted under construction on Plate 5. This building is an immense auditorium, elliptic in shaper and can seat up to 8000 people ; it is 250 feet long by 150 feet wide and 80 feet in height, being unique in construction. The self-supporting roof rests upon pillars or buttresses of red sandstone, which are from ten to twelve feet apart in the entire circumference of the building. These buttresses support great wooden arches, which span 150 feet. The arches are of a lattice truss construction, and are held together with great wooden pegs and bindings of cowhide, there being no nails or iron of any kind used in the framework. The building was erected between the years 1865 and 1867. This was in the early pioneer days of the West, and accounted for the absence of nails and steel in the structure.

In the interior one is impressed with the great vaulted ceiling and acoustic characteristics.

The discussion on the paper finally concluded by referring to the evolution of the modern, building, with its lighter weight and economy of materials and space, particularly the type as now built for industrial purposes.

Library Digitised Collections

Author/s:

Kneale, R. F.

Title:

Industrial building construction: economy, stability and standardisation (Paper & Discussion)

Date:

1941

Persistent Link:

http://hdl.handle.net/11343/24859

File Description:

Industrial building construction: economy, stability and standardisation (Paper & Discussion)

104 VICTORIAN INSTITUTE OF ENGINEERS.

Documents

Transcript of 104 VICTORIAN INSTITUTE OF ENGINEERS.