Effective Designs for Slopes in Road Construction

CHAPTER2 ADAM NUGENT

2.2 General TRAIN

2.3 Terrain Irregularties • By filling low spots or cuts 2types of side through are diagrams

2.3 cont • The road surface below and above for normal of ground the earth removed in marking • The dropped over th e overside proposed track line providesed all or material • B. In a through cut the outline road bed beneath the surface of the ground

IUn a filll the entire road lines above the normal surface of ground fillers are to avoid over routine low areas building sand • Slopes are inevietable wherever there are acts and fillls wherewver there are slopes you can expect to have eroision and stability

Designs • Cuts • Fills and slopes

When constructed does not come with scope others well inform slope supervisor designer can prevent the neccessity of major repair work and can minor repair that poor design creates design of slopes as used in cuts and fills depend upon knowledge

30,000 tons over a 2442 • Designs of slopes as used cuts and fills • Depends upon a knowing stability and route for waterer

Ordinary stability 1 ½ horizontal to vertical 1 / 2: 1 without danger of sliding rock may be soiled as of a ratio from 1/8 ½ to horizontal to vertical depandatory _+ • 18 inches 2:1 3:1 Compostio of the rock

2. Cuts are sometimes made through can be rock soil sift over bed E. ERoision sand traps and wash away Commerical rail lines rely to depend routes open for conviences Occurrences are washed must be avoid These ways preventing erosions with do to the under wood dikes picket fence

AND PLANT GROWTH RETAINING WITH 1. IntercINter carpting ditches and dikes where drasinage to detail 2. Planet nook soile together giving it addition stabilty For civilian railroad 3. Permitalbe slopes

2.4 BALLAST • Subgrqades prepeared dirt surface of the roadbed • Goood ballast material workable durable strong enough resist crushing angular in shape to resist uneven and to permeit drainage when compacted • Balllast supports the cross ties • Rest prepaved for roadbed

Good material should be workable durable sstrong enough to resist drainage capacicted resist unpacking angular shape reisist unpackig angular shape reist movement permit drainage • Ballast supports the crosstie resists upon it holding them firmly in place

Ballast to proper alinement and surface It reduces dust deters the growth of the vegation along the tracks Balllast materials then selection and ballast section

Ballast materials Type road bed as a out where satisfactory where drainage is to hard to get Thew material used for ballst depends upon there a ____And_____ Brief description of properties of the more occurrence ballast materials follow A. Broken or crushed stone from ¾ to 2 ½

Ballast materials • For this diffficlt to handle always expensive • Drainaqg excellent tends to hold the track firmly in place • Resist being crushed • Trap rock fine rock • Stone used for the ballast • Stone • B. gravel in adewuate wuantites is usually to most railroads • Gravle pits pit run un processe

Ballast comes form pit usually screened or screened washed before use • Good gravel only small dust over sand • Light cuvures branch lines • Process and yard tracks

wash or screeen the gravel • 2% percent dust • 40 % sand of weight • SLAG reduces ore

RailRoads run frequent circuit Iron other making metals are _____ Slag is abundant cheap and better ballast crushed stones CINDERS Ballast worth fine drainage Properties ease handling Under ballast is wuickly reduced to objectionable dust under traffic yards cinder easily obtainable economical Sand used for the ballast It has excellent DRAINAGE HOWEVER DOESN’T MAKE A GOOOD BALLAST BLOWN AWAY CREATES DRY AREA MAKES TRACK RESURFACING DIFFICULT SAND BE USED BALLAST ONLY WXPENSIST LIGHT TRAFFIC F. OTHER MATERIALS BALLASR INCLUDES SHALE SMALL ORES STONE CALLED CHAST IMPURE DULL COVER FLINT LIKE QUARTERS FOR CHAST SELDOM EXCELLS UNDER OR GRAVELING The selection such material s must be made on th e some basing as other or the order ballasr materials therefore must be able to withstand the movement of the wste with out being crushed

2.6 ballast section • Toi insure the balllast holds the track in place cross tie area submerged until top 2 inches adeuate drianage • Ballast must be deep enough to movement depths of 4inches under to bottom 8 to 10 inches are prefereable • Given ballast for miltary man laws and other less

Sometimes condsired difficult to handle is always expensive but it provides excellent drainage tends to hold the tracks firmly resist being crushed into dust easily cleaned • Desired ballast for trackage for heavy tonnage high speed services • Trap rock grravel

2.8 Summary roadbed provides means • For holding track a base surroundind lend to prevent water from standing on the track • Minor terrian irregularties on the right of the way are compensated for low spots through high spots • Slopes unprotection eroision ditch sikes • A material suched as crushed rock underslag gravel or sand id used as ballast to stablize the distribute the wght of the train rock bed in train drainage • Amt depth dispostion of ballast sub are govenered by the traffic and the terrain

‘section Drainage 2.9 • All major track damage is done by water

Roadbed • Seldom roadbed ideal draingage on either miltary or commericial lines • Impatence atteached to acheving good draignage if pointed ou tin large commerical lines • Cold is damaging only because freezes • First and formest drainage • Sides ditches and drains water pockets or correctes drains are constructed

2.10 • Needed drainage a pimping tie ballast pushed into the subsoil of the roadbed each trian posses lift ties up water creeps into to ballst starts hole unlevels instability

WATER POCKETS RESULT • CONT ADDING BALLLAST UNDER PUMPING TIES EVENTUALLY RESULTS • ACCUMALATON of porous c an be drained out water pocket forms • Obiviously a water pocket doesn’t offer the same resistance to train loads as soiled roadbed • Such a variable support results in uneven track are spongy roadbeds

Water pockets • Size sub sub soil tore up on ballast sectios • Cutting off any possible drain out a water pocket in fills under heavy trafic an d freezing waters and in freezing weather • 1. In deep cut water pockets adequate drainagwe extreme weather called • Wet cuts

water pockets • In a cut results in a reduced train speeds and extensive track maintence • Infills pockets can be infilled or eased drainage normally expected to prevent the pocket • In the fills or embankment water pockets are dangerous and are economical lialbities • on embankments water pockets may ease the fill to fall just train over the track • Here they could be caused y using a small ammt of pourous material In porportion to lg amt of permit soil • Under heavy traffic oper hvy loads trains loads trains over a line with poor ballast of ton results of phase much greater ealerier to prevent or eliminate

INTRODUCTION • 195 colonial express in Washington dc 1 Airborne

Effective Designs for Slopes in Road Construction

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