Dred3ing Through Wells
Dred3ing Through Wells. A Timber Crib Is Frequently Sunk By Excavating The Material Through Compartments Left For That Purpose, Thus Undermining The Crib And Causing It To Sink. Holbw Iron Cylinders Or Wells Of Masonry With A Strong Curb, Or Ring, Of Timber Or Iron Beneath Them Are Sunk In ...
Economic Design Of Beams
Economic Design Of Beams. The Most Economic Propor Tion Of Steel Depends Upon (1) The Relative Cost Of A Cubic Unit Of The Steel And The Concrete, (2) The Ratio Of The Coefficients Of Elasticity Of The Two Materials, And (3) The Unit Working Stress For Each Ma Terial. The ...
Elmpleb Of Masonry Or
Elmpleb Of Masonry Or Plain-conozetz Pizza. ...
Empirical Formulas For The
Empirical Formulas For The Proportions Of Arcm. Numerous Formulas Derived From Existing Structures Have Been Proposed For Use In Designing Voussoir Arches. Such Formula3 Are Useful As Guides In Assuming Proportions To Be Tested By Theory, And Also As Indicating What Actual Practice Is And Thus Affording Data By Which ...
Empirical Rules For Thickness
Empirical Rules For Thickness Of Retaining Walls. Below Are Three Well-known Empirical Rules For The Thickness Of Masonry Retaining Walls Which Are Also Applicable To Walls Of Plain Concrete. Notice That The First Gives The Lightest Wall And The Last The Heaviest. Equation 13, Page 468, Is Three Or More. ...
Examples
Examples Or Plain Concrete Aron Culverts. Penn Sylvania Lines. Fig. 171 Shows The Cross Section Of A 3- By 3-ft. Plain Concrete Arch Culvert Built By T H E Pennsylvania Lines On A Coal Branch In Southern Indiana.* The Section Is Lighter Than Is Commonly Built By Railroads (for Example, ...
Examples Op Reinforced 0on0rete Arch
Examples Op Reinforced-0on0rete Arch 017lverts. 0. M. & St. P. Ry. Fig. 177 And 178, Page 600, Show The Cross Sections Of Two 8-foot Reinforced-concrete Semicircular Arch Culverts As Built By The Chicago, Milwaukee And St. Paul Railway, And Fig. 179 Shows The Cross Section Of A Three-centered Arch Culvert ...
Examples Of
Examples Of Bsin Foroed-concrete Bet•ining Walls. 0. B. Di Q. Standard. Fig. 121, Page 531, Shows The Typical Cross-section Of The Retaining Wall Employed By The Chicago, Bur Lington And Quincy Railway In Track Elevation In Chicago.* The Portion Above The Angle In The Back Is The Same For All ...
Examples Of Plain Concrete
Examples Of Plain Concrete Arches. We Will Close The Consideration Of Plain Concrete Arches By Giving A Few Details Of Some Of The Larger Arches That Have Been Built. Main Ribs Consists Of Two Three-hinged Steel Trusses 23 Ft. Apart. The Arch Will Be Concreted In Transverse Sections (˘ 1343). ...
Examples Of Plain Conorete Retaining
Examples Of Plain-conorete Retaining Walls. 119 Shows The Forms Used In Constructing The Wall.f The Wall Was Designed For An 8-foot Surcharge. The Concrete Was Laid In Three Courses, As Shown By The Dotted Line In Fig. 119. The Lower Course Was Laid Without Joints, The Second Course Had Tongue ...
Examples Of Reinforced Concrete
Examples Of Reinforced Concrete Arches. The Con Sideration Of Reinforced Concrete Arches Will Be Closed By Giving Some Details Of A Few Structures. It Is Hardly Possible To Make A Tabular Exhibit Cf Any Value Show Ing The Dimensions Of Reinforced Concrete Arches As Was Done For Voussoir And Plain ...
Examples Or
Examples Or Vovssoxa Arches. A Few Illustrations Of Actual Arches Will Be Given To Show Some Of The Details Of Construction Of Arches And Of Centers. Space Will Not Permit A Full Presentation Of All Important Details, But A Few Examples Will Be Given To Illustrate The General Principles Discussed ...
Exmpie Of Reinforced Conoexte
Ex&mpi.e Of Reinforced Conoexte Ping. Illinois Cen Tral Railroad. Fig. 148 Shows One Of The Reinforced Concrete Channel Piers Of The Illinois Central Railway's Double-track Bridge Across The Tennessee River, At Gilbertsville, Ky.t The Reinforcement Throughout Consists Of 3-inch Square Cor Rugated Bars (b, Fig. 28, Page 236). In The ...
Expansion And Contraction
Expansion And Contraction. The Coefficient Of Expansion Of Steel And Concrete Are So Nearly Equal That There Is No Likelihood Of Any Serious Stresses Being Developed By Differences Of Expansion And Contraction Of The Steel And The Concrete. The Coefficient Of Expansion For Steel Is 0.000,006,5 Per 1° F., And ...
Fiinctions Of A Bridge
Fiinctions Of A Bridge Pier. A Bridge Pier Has Two Functions: (1) It Must Support The Bridge, And (2) It Must Permit Water To Pass With The Least Possible Disturbance To That Water. The First Concerns The Stability Of The Pier, Which Depends Upon Its Vertical Cross Section; And The ...
Filling The Air Ohamber
Filling The Air-ohamber. When The Caisson Has Reached The Required Depth, The Bottom Is Leveled Off—by Blasting, If Neces Sary,—and The Working Chamber And Shafts Are Filled With Concrete. Sometimes Only Enough Concrete Is Placed In The Bottom To Seal The Chamber Water-tight, And The Remaining Space Is Filled With ...
Finish Of The Surface
Finish Of The Surface Of Concrete. The Character Of The Surface Is An Important Factor In The Appearance Of A Concrete Struc Ture. It Is Not Wise To Neglect Entirely The Looks Of Any Concrete Work; And In Some Structures The Appearance Is The Most Important Part Of Its Design ...
Finishing The Foundation
Finishing The Foundation. There Are Two Cases: (1) When The Heads Of The Piles Are Not Under Water; And (2) When They Are Under Water. 1. When The Piles Are Not Under Water There Are Again Two Cases: (a) When A Timber Grillage Is Used; And (b) When Concrete Alone ...
Form Of Block
Form Of Block. Concrete Blocks May Be Classified As Solid And Hollow. The First Con Crete Blocks Were Solid, But That Form Is Not Now Much Used, Since The Hollow Blocks Are Cheaper And Give Better Insulation Against Moisture And Heat Or Cold. The Hollow Space Usually Runs Vertically From ...
Form Or Cross Section
Form Or Cross Section. The Dimensions On The Top Will Depend Somewhat Upon The Form Of The Cross Section Of The Pier, And Also Upon The Style And Span Of The Bridge. The Examples Pre Sented Later Give Representative Dimensions. Theoretically The Dimensions At The Bottom Are Determined By The ...
Forms For Concrete
Forms For Concrete. }reshly Mixed Concrete Is Plastic Until The Process Of Setting Begins, And Hence Must Be Confined Within The Limits Set For The Finished Structure Until The Mass Hardens. This Is Usually Accom Plished By The Use Of Wooden Moulds Or Forms Which Are Built So That Their ...
Formulas For Bending Of
Formulas For Bending Of Reinforoed Oonoriste Beams. Reasons For Differences. Numerous Formulas Have Been Proposed For The Strength Of Reinforced Concrete Beams; But They May Be Grouped Into Two Classes, Viz.: (1) Emperical Formulas, Those That Express The Results Of Experiments; And (2) Rational Formulas, Those That Are Based Upon ...
Foundations
Foundations The Term Foundation Is Frequently Used Indifferently For Either The Lower Courses Of A Structure Of Masonry Or The Artificial Arrangement, Whatever Its Character, On Which These Courses Rest. For Greater Clearness, The Term Foundation Will Here Be Restricted To The Artificial Arrangement, Whether Timber Or Masonry, Which Supports ...
Foundations Under Water
Foundations Under Water The Class Of Foundations To Be Discussed In This Chapter Could Appropriately Be Called Foundations For Bridge Piers And Abut Ments, Since These Are The Principal Ones That Are Laid Under Water. The Principles To Be Considered Apply To Foundations In Water-bearing Soils. In This Class Of ...
Freezing Process
Freezing Process. The Presence Of Water Has Always Been The Great Obstacle In Foundation Work And In Shaft Sinking, And It Is Only Comparatively Recently That Any One Thought Of Transforming The Liquid Soil Into A Solid Wall Of Ice About The Space To Be Excavated. The Method Of Doing ...
General Form
General. Form Of Culvert. Splay Of Wings. There Are Three Common Ways Of Disposing The Wing Walls At The End Of The Arch Culvert, Which Are The Same As Discussed In Art. 2, Pipe Cul Verts—see * 1126-29. Face Masonry This Would Not Be Very Objectionable; But With Con Crete ...
Gimbal Design Of Culverts
Gimbal Design Of Culverts. Any Culvert Consists Of Two Distinct Parts, The Trunk And The Head-walls Or Wings At The Ends Of The Trunk; And Consequently The Design Of Any Culvert Consists Of (1) The Arrangement Of The Head-walls Or Wings So As To Protect The Embankment And Facilitate The ...
Guiding Thz
Guiding Thz °liabon. Formerly It Was The Custom To Control The Descent Of The Caisson By Suspension Screws Connected With A Framework Resting Upon Piles Or Pontoons. In A Strong Current Or In Deep Water, It May Necessary To Support The Caisson Partially In Order To Govern Its Descent; But ...
Hollow Spandrels
Hollow Spandrels. Since The Roadway Must Not Deviate Greatly From A Horizontal Line, A Considerable Quantity Of Material Is Required Above The Backing To Bring The Roadway Level. Ordinarily This Space Is Filled With Earth, Gravel, Broken Stone, Cinders, Etc. Sometimes, To Save Filling And Also To Lighten The Load ...
Hydraulic Cement
Hydraulic Cement The Most Important Cements Are The Prod Ucts Of The Calcination Of An Argillaceous Limestone, I.e., Are A Com Bination Of Lime, Silica, And Alumina (see § 102). Such Cements May Be Divided, According To The Method Of Manufacture, Into Three Classes, Viz.: Portland Cement, Natural Cement, And ...
Hypotheses For The Crown
Hypotheses For The Crown Thrust. From 3f 1195 It Is Clear That The Position Of The Line Of Resistance Can Not Be Known Until The Amount, The Direction, And The Point Of Application Of The Crown Thrust Are Known. Each Value For The Intensity Of The Thrust At The Crown ...
Improved Construction
Improved Construction. The Cost Of Labor And Material Required For Forms Is An Important Part Of The Cost Of Any Concrete Work, And Particularly Of Thin Walls Or Parts Of Buildings; And Con Sequently There Have Been Many Attempts To Reduce The Cost Of Forms. However, None Of The Improvements ...
Improving The Bearing Power
Improving The Bearing Power Of The Boil. When The Soil Directly Under A Proposed Structure Is Incapable, In Its Normal State, Of Sustaining The Load That Will Be Brought Upon It, The Bearing Power May Be Increased (1). By Increasing The Depth Of The Founda Tion, (2) By Draining The ...
In Wet Ground
In Wet Ground. The Difficulty In Soils Of This Class Is In Disposing Of The Water, Or In Preventing The Semi-liquid Soil From Running Into The Excavation. The Difficulties Are Similar To Those Met With In Constructing Foundations Under Water—see Chapter Xvi. Three General Methods Of Laying A Foundation In ...
Independent Piers
Independent Piers. The Art Of Constructing Foundations On A Compressible Soil Was Brought To A High Degree Of Development By The Architects Of Chicago Between 1870 And 1890, When The Principal Buildings Were Founded Upon A Bed Of Soft Clay. The Special Feature Of The Practice In That City Is ...
Laws Of Proportions Of
Laws Of Proportions Of Concrete. The Proper Proportioning Of The Ingredients Of A Concrete Is An Important Matter. The Ideal Proportion Would Be That Which Secures The Least Cost, The Greatest Strength, And The Maximum Density. The Cost Varies Chiefly With The Proportion Of Cement Used; And For The Same ...
Laying Concrete In Freezing
Laying Concrete In Freezing Weather. The Effect Of Cold Is To Retard The Setting Of Cement; And If A Mass Of Concrete Is Repeatedly Frozen And Thawed Before It Has Dried Out Or Has Set Hard Enough To Resist The Expansive Action Of The Frost, The Bond Between The Cement ...
Laying Th Brick
Laying Th! Brick. Since Most Bricks Have A Great Avidity For Water, It Is Best To Dampen Them Before Laying. If The Mortar Is Stiff And The Bricks Are Dry, The Latter Absorb The Water So Rapidly That The Mortar Does Not Set Properly, And Will Crumble In The Fingers ...
Limiting Pressure
Limiting Pressure. In Determining The Stability Against Crushing, It Is Not Wise To Compute The Factor Of Safety, Since The Computed Value Of The Factor Will Depend Upon The Value Assumed As The Crushing Strength Of The Masonry; And Therefore It Is Better To State The Maximum Pressure And Limit ...
Machine
Machine Toots. In All Large Stone-yards Machines Are Used To Prepare The Stone. There Is Great Variety In Their Form; But Since The Surface Never Takes Its Name From The Tool Which Forms It, It Will Be Neither Necessary Nor Profitable To Attempt A Description Of Individual Machines. They Include ...
Making And Placing Concrete
Making And Placing Concrete. There Is Considerable Diversity Of Opinion Among Engineers As To The Amount Of Water To Be Used In Making Concrete; But In Recent Years There Has Been A Decided Tendency Toward The Use Of More Water Than Formerly. Until Recently One Extreme Advocated The Use Of ...
Masonry Dams
Masonry Dams Dams Are Employed To Hold Back Water For Municipal Supply, For Power, And For Irrigation; And Are Made Of Earth, Wood, Steel, Loose Rock, Or Masonry. Only Masonry Dams Will Be Considered Here; And The Discussion Will Be Limited To Questions That Relate To The Stability Of The ...
Measurement Or Masonry
Measurement Or Masonry. The Method Of Determining The Quantity Of Masonry In A Structure Is Frequently Governed By Trade Rules Or Local Custom, And These Vary Greatly With Locality. Masons Have Voluminous And Arbitrary Rules For The Measurement Of Masonry; For Example, The Masons And Stone-cutters Of Boston At One ...
Measurzment Of
Measurzment Of The Method Of Deter Mining The Quantity Of Brick Masonry Is Governed By Voluminous Trade Rules Or By Local Customs, Which Are Even More Arbitrary Than Those For Stone Masonry (§ 585, Which See). The Quantity Is Sometimes Computed In Perches, But There Is No Uniformity Of Understanding ...
Method Of Placing Back Filling
Method Of Placing Back-filling. The Manner Of Depositing The Back-filling Has A Very Important Effect Upon The Stability Of A Retaining Wall, But Usually Receives Little Or No Con Sideration. If The Back-filling Is Dumped So As To Slide Or Flow Toward The Wall, The Pressure Against The Wall Is ...
Methods O Testing Diinability
Methods O! Testing Diinability. It Has Long Been Recog Nized That There Are Two Ways In Which A Judgment Can Be Formed Of The Durability Of A Building Stone, And These May Be Distinguished As Natural And Artificial. Each Element Acts By Itself, While In The Structure The Stone Is ...
Methods Of Determining Waterway
Methods Of Determining Waterway. There Are Two Methods Of Determining The Area Of The Waterway Required: (1) By The Use Of An Empirical Formula, And (2) By Direct Observation. The First Method Is The Only One That Can Be Employed In A New Country Or Where There Are No Other ...
Methods Of Preserving
Methods Of Preserving. Vitruvius, The Roman Architect, Two Thousand Years Ago Recommended That Stone Should Be Quarried In Summer When Driest, And That It Should Be Seasoned By Being Allowed To Lie Two Years Before Being Used, So As To Allow The Quarry Sap To Evaporate. It Is A Notable ...
Methods Of Waterproofing Concrete
Methods Of Waterproofing Concrete. In Recent Years A Great Deal Of Attention Has Been Given To Methods Of Rendering Con Crete Waterproof, But There Is No Uniformity As To The Best Practice. The Various Methods Employed May Be Divided Into Four Classes As Follows: (1) Grading The Aggregate And Proportioning ...
Mixing Concrete
Mixing Concrete. The Value Of The Concrete Depends Greatly Upon The Thoroughness Of The Mixing. Every Grain Of Sand And Every Fragment Of Aggregate Should Have Cement Adhering To Every Point Of Its Surface. Thorough Mixing Not Only Causes The Cement To Adhere To All The Surfaces, But Forces It ...
Mixing The Mortar
Mixing The Mortar. After The Lime Is Slaked, The Sand Is Spread Evenly Over The Paste, And The Ingredients Are Mixed With A Shovel Or Hoe, A Little Water Being Added Occasionally If The Mortar Is Too Stiff. The Mixing Should Be Thorough, I.e., Should Be Continued Until The Mortar ...
Multiplied By
Multiplied By Its Horizontal Distance From D. These Conditions Give Two Equa Tions Which Contain Two Unknown Quantities—the Thrust And The Distance Its Point Of Application Is Above C. After Solving These Equations, The Line Of Resistance Can Be Drawn By Any Of The Methods Already Explained. "if This New ...
Oaxiier
Oaxiier. Strictly, The Center Should Be Constructed With A Camber Just Equal To The Amount It Will Yield When Loaded With The Arch; But, Since The Load Is Indeterminate, It Is Impossible To Compute Accurately What This Will Be. Of Course, The Camber De Pends Upon The Unit Strain In ...
Objection To Reinforced Concrete
Objection To Reinforced Concrete. The Most Serious Ob Jection To The Use Of Reinforced Concrete Relates To Its Permanency. Concrete Is Weak In Tension, And Consequently When Reinforced Concrete Is Subjected To Any Considerable Tension, The Concrete Is Likely To Crack, And May Permit The Entrance Of Water Or Acid ...
Oenteb Of Pbessiibe And
Oenteb Of Pbessiibe And Center Of Base. In Construct Ing A Foundation The Object Is Not So Much To Secure An Absolutely Unyielding Base As To Secure One That Will Settle As Little As Possible, And Uniformly. All Soils Will Yield Somewhat Under The Pressure Of Any Building, And Even ...
Ola88iiwwation Of Limn And
Ola88iiwwation Of Limn And Oenient. Considered As Ma Terials For Use In The Builders' Art, The Products Of Calcination Of Limestone Are Classified As Common Lime, Hydraulic Lime, And Hydraulic Cement. If The Limestone Is Nearly Pure Carbonate Of Lime, The Prod Uct Is Common Lime, Which Will Slake Upon ...
Oompressive Stbfnoth Of Stone
Oompressive Stbfnoth Of Stone Concrete. The Results Of Experiments To Determine The Crushing Strength Vary Materially With The Form Of The Test Specimen And Also With The Condition Of The Pressed Surface. Usually The Test Specimen Is A Cube, But Occasion Ally Prisms Much Taller Than Broad Have Been Used. ...
Oost Of Mortar
Oost Of Mortar. Knowing The Price Of The Materials, It Is Very Easy, By The Use Of Table 22, Page 120, To Compute The Cost Of The Ingredients Required For A Cubic Yard Of Mortar. The Expense For Labor Is Quite Variable, Depending Upon The Distance The Materials Must Be ...