Highway Alignment

8/10/2019 Highway Alignment

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Short: -t is desirable to have a short alignment between two

terminal stations. A Straight alignment would be shortest

though there may be several practical considerations which

would cause deviation from the shortest path.

(asy: - The alignment should be such that its is easy to construct

and maintain the roads with minimum problems. Also the

alignment should be easy for operation of vehicles with easy

gradients and curves.

Safe: - The alignment should be safe enough for construction and

maintenance from the view point of stability of natural hill

slopes, emban)ment and cut slopes and foundation of

emban)ments also it should be safe for the tra*c operation with

geometric features.

(conomical:- The road alignment could be considered economicalonly if the total cost including initial cos+, maintenance cost andvehicle operation cost is lowest. All these factors should

be given due consideration before wor)ing out theeconomics of each alignment.

The alignment should be such that it would oer maimumutility by serving maimum population and products.

Factors controlling alignment

or alignment to be shortest, it should be straight between the' terminal stations. This is not always possible due to variouspractical di*culties such as intermediate obstructions andtopography. A shortest route may have very steep gradients andhence not easy for vehicle operation. Similarly, there may beconstruction and maintenance problems along a route, which mayotherwise be short and easy. %oads are often deviated from theshortest route in order to cater for intermediate places ofimportance or obligatory points.

A road which is economical in the initial construction cost,

need not necessarily be the most economical in maintenance or invehicle operation cost. t may also happen that the shortest and

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easiest route for vehicle operation may wor) out to be the costliestof the dierent alternatives from construction viewpoint. Thus itmay be seen that an alignment can seldom ful$l all re&uirementssimultaneously/ hence a #udicial choice is made considering allfactors.

The various factors that control the highway alignment ingeneral may be listed as:

a! "bligatory points.b! Tra*cc! 0eometric designd! (conomicse! "ther considerations.

n hill roads additional care has to be given for/a! Stabilityb! 1rainagec! 0eometric standards of hill roads andd! %esisting length

a) Obligatory Points: There are control points governing thealignment of the highways. These control points may be dividedbroadly into ' categories.

2! 3oints through which the alignment is to pass

'! 3oints through which the alignment should notpass.

2! "bligatory points through which the road alignment hasto pass may cause the alignment to often deviate fromthe shortest or easiest path.

'! "bligatory points through which road should not passalso may ma)e it necessary to deviate from theproposed shortest alignment. The obligatory pointsshortest alignment. The obligatory points which should

be avoided while aligning a road include religiousplaces, very costly structures, unsuitable land etc.,

b) Trafc: The alignment should suit tra*c re&uirements. "riginand destination study should be carried out in the area and thedesire lines be drawn showing the trend of tra*c 4ow. The newroad to be aligned should )eep in view the desired lines, tra*c4ow patterns and future trends.

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c) Geometric design: 0eometric design factors such as gradient,radius of curve and sight distance also would govern the $nalalignment of highway

Engineering surveys or highway locations.

5efore a highway alignment is $nalised in highways pro#ect, theengineering surveys are to be carried out. The surveys may becompleted in 6 stages.

The stages of the engineering surveys are:

2. 7ap study.'. %econnaissance.

8. 3reliminary surveys6. inal location and detailed surveys.

. !a" study:

f the topography map of the area is available, it is possible tosuggest the li)ely routes to the road. n ndia, topographic mapsare available from the 9Survey of ndia with 2+ or 8;mcountdown intervals. The main features li)e rivers, hill, valleys,etc., are also so shown on these maps. 5y careful study of maps,it is possible to have an idea of several possible alternate routes

so that further details of these may be studied later at the site.

'. #econnaissance: The second stage of surveys for highwaylocation is the reconnaissance to eamine the general characterof the area for deciding the most general character of the areafor deciding the most feasible routes for detailed studies.

A $eld survey party may inspect a fairly road stretch ofland along the proposed alternative routes of map in the $eld."nly very simple instrument li)e abney level, tangent clinometer,barometer etc., All relevant details not available in the maps arecollected and noted down.


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The main ob#ectives of the preliminary survey are.

2. To survey the various alternate alignments proposed afterthe reconnaissance and to collect all the necessary

physical information and details of topography, drainageand soil.

'. To compare the dierent proposals in view of re&uirementsof a good alignments.

8. To estimate &uantity of earthwor) materials and otherconstruction aspects and to wor)out the cost of alternateproposals.

6. To $nalise the best alignment from all considerations.

Final location and detailed survey:

The alignment $nalised at the design o*ce after the preliminarysurvey is to be $rst located on the $eld by establishing the centreline. =et detailed survey should be carried out for collecting theinformation necessary for the preparation of plans and constructionsdetails for the highway pro#ect.

$ocation:

The centre line of the road $nalised in the drawings is to betranslated on the ground during the location survey. This is done

using a transit theodolite and by sta)ing of the centre line. Thelocation of the centre line should follow, as closely as practicable,the alignment is $nalised after the preliminary surveys.

%etailed surveys:

Temporary benchmar)s are $ed t interval of about '+; metresand at ll drainage and under pass structures. >evels along the $nalcentre line should be ta)en at all sta)ed points. >evelling wor) is ofgreat importance as the vertical alignment, earth wor) calculationsand drainage details are to be wor)ed out from the level notes. All

river crossing, valley etc., should be surveyed in details uptoconsiderable distances on either side. ?5% values of soils along thealignments may be determined for designing the pavement.

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%rawing &nd #e"ort

%rawings:

2. @ey plan showing the road between ma)lidurga railwaystations and hadonahally, via temple.

'. ?ontour plan of the given real stretch of length 2.; )m andgiven width, showing all details of the road and other features3lane table and direct conforming!.

8. >ongitudinal section showing all details including the centreline of eisting road and realigned road after redesign.

'cale:2cmB';m 3>A=! 2B';;; horizontal, 2B';; vertical.

6. Total 2; typical cCs are ta)en at straight and curved sectionsof the road showing eisting cross section detailsncludingshoulder and side drains and proposed sections afterrealignment, scale and of the proposed sections afterrealignment!'cale:2B2;;


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ighway Pro(ect:

*ew ighway Pro(ect:The new highway pro#ect wor) may be divided into the following

stages/

2. %oute selection.'. ?ollection of materials.8. ?onstruction stages including &uality control

'te"s in new "ro(ect wor+:

2. 7ap study : ith help of available topographicmaps of the area.

2 '. %econnaissance Survey: A general idea of a topography andother features, soil

identi$cation.

8. 3reliminary survey : Topographic details and soilsurvey

along alternate alignments,consideration of geometric design

andother re&uirements of alignments.

6. >ocation of $nal : Transfer of the alignment from thealignments drawings to the ground bydriving pegs

along the centre line of $nallychosen alignment.

+. 1etailed survey : Survey of the highway constructionwor) for preparation of longitudinal

andcross-sections, computations of earth

wor), &uantities and otherconstruction

materials and details of geometricdesign.

D. 7aterials survey : Survey of construction materials,their

collection and testing.

E. 1esign : 1esign details of emban)ment and

cut

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slopes, foundation ofemban)ments

and bridges, pavement layers.

F. (arth or) : (cavations for highway cutting and

drainage system, construction ofemban)ments.

G.3avement ?onstructions : 3reparation of sub-gradeconstruction

of sub-base and surface courses.

2;. ?onstruction ?ontrols : Iuality control tests during dierentstages of constructions and to chec)

the road.

#e,alignment "ro(ect

*ecessity o re,alignment:

2. mprovements of horizontal alignment design elements, such asradius, super elevation, transition curves, clearance on the innerside of the curve of shifting the curve to provide ade&uate sightdistance elimination of reverse curves and undesirable zig-zag

etc.,

'. mprovements of vertical alignments li)e steep gradients,changes in summit curves to increase sight distance. ?orrectionof undesirable undulations li)e humps and dip etc.,

8. %aising the level of a portion of a road which is sub#ected to4ooding, submergence or water logging during monsoons.

6. %e-construction of wea) and narrow bridges, and culverts andchanges in water-way at locations slightly away from the

eisting site.

+. ?onstruction of over bridges or under bridges

D. ?onstruction of a bypass.

E. 1efence re&uirements.

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ighway Geometric %esign

-m"ortance o geometric design:

The geometric design of a highway deals with the dimensionsand layout of visible features of the highway such as alignment,

sight distances and intersections.

The geometrics of highway should be designed to provideoptimum e*ciency in tra*c operations with maimum safety atreasonable cost. The designer may be eposed to either planning ofnew highway new wor) or improvement of eisting highways tomeet the re&uirement of the eisting and anticipated tra*c.

t is possible to design and construct the pavement of the roadin stages/ but it is very epensive and rather di*cult to improve thegeometric elements of a road in stages at a later date.

Geometric design o highway deals with ollowing elements:

2. ?ross section elements'. Sight distance considerations8. Horizontal alignment details6.


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counteracts the centrifugal force and thus governs the sageoperating speed. S)id occurs when slide without revolving or whenthe wheels partially revolve. hen the path travelled along the roadsurface is more than the circumferential movements of wheels dueto their rotation.

Slip occurs when a wheel revolves more than the correspondinglongitudinal movement along the roads.

>ongitudinal friction coe*cient values of ;.8+ to ;.6; have beenrecommended by %? depending on speed.

or horizontal curve design, %? has recommended the lateralcoe*cient of friction of ;.2+.

Pavement uneveness:

3avement uneveness measured using 3ro$lograph, 3ro$lometeror %oughometer. An e&uipment capable of integrating theuneveness of pavement surface to a cumulative scale and that givesthe uneveness inde of the surface in cmC)m length of road.

The J.S. 5ureau of public roads %oughometer is one such devicewhich could be towed by an automobile.

/neveness -nde0

m1+m#iding 2uality

n old pavementsn 5elow G+ (cellent G+ to 22G 0ood 2'; to 266 air 26+ to '6; 3oor 3ossible resur$ng! Above '6;


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'. Semi-barrier type )erb is provided on the periphery ofroadway where the pedestrian tra*c is high. @erb is 2+cmabove pavement.

8. 5arrier type )erb is provided in built up areas ad#acent to

foot paths with considerable pedestrians tra*c. Height of)erbs is above ';cm from pavement.

n rural roads submerged )erbs are sometimes provided atpavement edge between edge and shoulders.

#oad margins:The various elements included in road margins are shoulder,

par)ing lane, frontage roads, driveway, cycle trac), footpath, guardrail and emban)ment slope.

Shoulders are provided along the road edge to serve as anemergency lane for the vehicle compelled to be ta)en out ofpavement or raodway.

The minimum shoulder width recommended by %? is '.+m

ootpaths or side wal)s are provided in urban areas when thevehicular as well as pedestrian tra*c are heavy.

(mban)ment slopes should be as 4at as possible for the purposeof safe tra*c movement and also aesthetic reasons.

3idth o #oadway or ormation:

idth of %oadway is the sum of widths of pavements orcarriageway. ncluding separators if any/ and the shoulders.

The width of %oadway as per %?

'l*o

#oad lassi4cation#oadway width5 m

Plain #ollingterrain

!ountains andstee" terrain

2. =ational and State Highwaya! Single laneb! Two lane

2'.;2'.;

D.'+F.F;

'. 7a#or district roadsa! Single laneb! Two lane

G.;G.;

6.E+-----

8. "ther district roads

a! Singleb! Two lanes

E.+G.;

6.E+-----

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The sight distance available on a highway at any spot should beof su*cient length to stop a vehicle travelling at design speed.

%esign5

s"eed5 +m"h

'; '+ 8; 6; +; D; D+ F; 2;;

''% in m '; '+ 8; 6+ D; F; G; 2'; 2F;

SS1 for given D+ )mphBG8m. Hence designedSS1 is as per %?.

"ver ta)ing sight 1istance"S1!

f all vehicles travel on a road at the design speed, then theoreticallythere should be no need for any over ta)ing. n fact vehicles do notmove at the designed speed and particularly under mied tra*c

conditions.

The minimum distance open to vision of the driver of a vehicleintending to overta)e slow vehicle ahead with safety against thetra*c of opposite direction is )nown as the minimum overta)ingsight distances"S1!.

-# recommended O'% values:

'"eed+m"h

Time com"onent5 seconds'ae overta+ing

sight distance6metres)

For overta+ingmanocurve

Foro""osingvehicle

Total

6; G.; D.; 2+ D++; 2;.; E.; 2E '8+D; 2;.F E.' 2F 8;;D+ 22.+ E.+ 2G 86;F; 2'.+ F.+ '2 6E;

2;; 26.; G.; '8 D6;

As per %? recommendation and designed data results are same.

"S1 for '-way tra*c is assumed to be B 86;m

Overta+ing 7ones:

t is desirable to construct highways in such a way that thelength of road visible ahead at every point is su*cient for safeoverta)ing. "verta)ing opportunity for vehicles moving at designspeed should be given at fre&uent intervals. These zones which aremeant for overta)ing are called overta)ing zones.

%esign o hori8ontal alignment:

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%esign s"eed:

The design speed in the main factor on which geometricsdesign elements depend. The sight distances, radius of horizontalcurve, super elevation, etra widening of pavement length of

summit and valley curves are all dependent on design speed.

ori8ontal urves:

A horizontal highway curve is a curve is a plan to providechange in direction to the central line of a road. hen a vehicletraverses a horizontal curve, the centrifugal force acts horizontallyoutwards through the centre of gravity of the vehicle.

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Assume total reaction time 9t may be ta)en as '.+ seconds anddesign co-e*cient of friction as

fB ;.8+


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"S1 B 882.6Em

AS per %? D+)mph "S1 is 86;m

2. (T S(OSS

'. ?"=SST(=?O >7TS

8. ?A73A?T"= T(ST

6. ?A>"%=A 5(A%=0 %AT"= T(ST+. (>1 1(=STO 5O SA= %(3>A?(7(=T 7(TH"1

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0rain size analysis

Aim: -To determine the soil distribution is by sieving

Apparatus: - Set of standard sieves of dierent sieve sizes,balance, rubber covered pestle and mortar, oven riPe, sievesha)er.3rocedure:-

2! et sieving may be adopted in the case of clayey orcohesion soil or when the soil is not grained.

'! The soil $ner than 'mm size is oven dried at 2;+oto 22;ocand re&uired &uantity ta)en by riPing is weighed. Thissample is spread in a tray or buc)et and covered withwater.

8! n case of soils having fractions that are li)ely to 4occulatea dispersing agent li)e sodium heametaphosphate '.;g!

of sodium hydroide 2.;! and sodium carbonate per liter ofwater may be added to the water. The mi is stirred andleft for soa)ing.

6! The soa)ed soil specimen is placed over set of sieves ofsizes with the $nest sieve and pan at the bottom andwashed thoroughly.

+! ashing is continued till the water passing each sieve issubstantially clean. The fraction emptied carefully driedand weighed separately.

Tabular ?olumn :-

Sl=o

Sieve"penin

g3articlesizem

m!

7assof soilretaine

d

KretianedB mass of

soilmass of

soil

?ummalative K

retained

K$ner

2 6.E+ +.' 2.;6 2.;6 GF.GD' '.8D G.F 2.GD 8.; GE.;;8 2.2F 2G.E 8.G6 D.G6 G8.;D

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6 D;; 'G.E +.G6 2'.FF FE.2'+ 8;; F'.E 2D.+6 'G.FF E;.+FD 2+; 22'.' ''.66 +2.FD 6F.26E E+ D6.G 2'.GF D6.F6 8+.2DF pan 2E+.F 8+.2D 2;; ;

Result:- The given soil contains

1) Gavel !1.04"

2) #$%&!61.84"

3) #ilt an' cla( ! 35.16"

onsistenc( li*its 'ete*ination

using

casagrande type mechanical li&uid limit apparatus.

7aterials and e&uipments:-

2! li&uid limit apparatus consisting of a brass cup and rubber.'! 0rooving tools with 2cm gauge handle.8! AST7 and casagrande 5S! type.6! 0lass plate about 6;cm s&uare+! 6'+ micron sieve

D! electronic weighing machineE! moisture containersF! oven of oven 2;+o- 22;ocG! stop watch

3rocedure :

2! 5y means of the grooving tool gauge and ad#ustment plate,ad#ust cup of the li&uid limit apparatus to fall eactly 2cm onthe point of contact on the base.

'! Ta)e about 2+;gm of an air dried soil samples passing6'+micron. Sieve and mi thoroughly with distilled water togive a sti and uniform pasteC leave the soil for a suitablematuring time which may etend upto '6 hrs for heavy clays.

8! 3lace a portion of the paste in the cup, level o with a spatulathe top surface symmetrically to give a maimum depth of 2cm cut a uniform, straight groove by drawing $rmly agrooving tool through the soil paste along the diameter

through the centre of the hinge.

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6! Turn the handle at a rate of ' revolutions per second andcount number of blows until the ' pars of soil come in contactat the bottom of the groove along a distance of about 28-mm.The groove should be closed by a 4ow of the soil and not byslippage.

+! %ecord the number of blows at which the groove closes.%emove about 2+g of soil forming the edges of the groovethat 4owed together and determine the water content byoven-drying.

D! Transfer the remaining soil in the cup to the main soil sampleon the glass plate and mi thoroughly after adding a smallamount of water, clean the cup and grooving tool.

E! The test should always proceed from the drier to the wettercondition of the soil. >east of 6 tests readings were givenranging from 2+ to 6; blows for each addition of water soil ismied for at least + minutes.

"bservation:

Test =o 2 ' 8

=o. of 4ows

2; '2 '8

?ontainer

=o ;+ ;E 27ass conL wetsoulgm!

2D.6 2'.D 2+.'

7ass of cont L drysoilgm!

26.G 22.G 26.6

7ass of emptycontainer

G.2 F.D 2;.2

moisturecontentK!

'+.FD '2.'2 2F.D

>i&uidlimitgraph!

2E.+K

%esult:- The given soil has li&uid limit B 2E.+K

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3lastic limit test

"b#ect:- To determine the plastic limit of a soil and also tocalculate the plasticity inde.

Apparatus:-3orcelain dish, about 2'-cm in diameter spatula, about

'-cm wide ground Nglass plate about ';cm by 2+cm, oven, rod,6'+micron sieve electronic weighing machine.

3rocedure:2! 7i thoroughly about 8;g of soil passing a 6'+ micron sieve

with distilled water in the evaporating dish or on the glassplate until it is plastic enough to be shaped into a small ball.

'! Ta)e about 2;gm of the plastic soil mass. orm a ball of it andthem roll into a thread with the $ngers on the ground N glassplate. hen a diameter of 8-mm is reached, remoulded thesoil again into a ball.

8! %epeat this rolling and remoulding process until the threadstarts #ust crumbling at a diameter of 8mm. @eep thecrumbled threads for moisture content determination.

6! %epeat the test twice more with fresh samples and calculatethe plastic limit pas the average of three moisture contents.

+lasticit( ,n'e:-eo

$/te 'ete*ining the liui' li*it lan' lastic li*it p lasticit( in'e is

calculate' as ,p! l- p

Result:- The soil is silt an' non-lastic soil as lastic li*it is eo.

R lassi/ication:-$-4

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o*action Test

ect:- To 'ete*ine the oti*u* *oistue content an' *ai*u* '( 'ensit(.

$aatus:- (lin'ical *oul' a**e *oul' accessoies ,# sieves.

3rocedure:-

2! Ta)e a representive sample weighing approimately ';)g ofthoroughly mied dried material passing 6.E+mm s sieve.

'! ?lean the mould and $ it to the base ta)e the empty weightof the mould . the inside of mould is greased.

8! At least attach the collar to the inside of the mould is greased.

6! 7i the soil thoroughly ta)e about '.+)g of soil and compactit, in the mould in 8 layers and each layer he being compactedby '+ blows.

+! %emove the collar and cut the ecess soil with the help ofstraight edge clean the mould from outside and weigh it tonearest gram.

D! %epeat step 6 and + for about + or D time using a fresh part of

soil specimen and after adding a higher water content thanthe proceeding specimen.

"bservation

1iameter of mould B 2;cm B dHeight of mould B 2'.Dcm B h


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Tabular column

1etermination on 2 ' 8 6 +

7ass mouldL comp soilgm!

DD22 DE;G DF8+ DG;GDD6E

7ass compsoil gm!

2G8D '886 '2D; ''86 2GE'

(mptymould

'8FD '8FD '8FD '8FD 'F8D

5ul) densitygCcc

2.G+ '.;+ '.2F '.'+ 2..GG

?ontainer=o

28 2+ 6FD ;6 ';F

(mptyweight ofcontainergm!

G F 2' F.FF.;

?ontainerL wet soilgm!

2D.'' 2D 2G '6.6 26

?ontainerL dry soilgm!

2E.GF 26.D 2F.8 ''.D 28.2

K watercontent

6.'+ E.66 22..2 28.2 2+.6'

= bd2Lw)nCm8

2.FE 2.G 2.GD 2.GG 2.E8

%esult:- 2! 7aimum dry density of soil B '.;' )nCm8

'! "7? B 22.FK

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1etermination of ?alifornia bearing ratio

Aim :- To determine ?alifornia bearing ratio of sub-grade soil.

Apparatus :- 7ould, steel cutting collar, spacer disc, surchargeweights, dial ganges, s sieve of 6.E+mm and ';mm s sieve,miscellaneous scales, soa)ing tan), drying oven, $lter paper, dishesand calibrating measuring #ar.

3rocedure:-

1ynamically compacted specimen

2! Sieve the material through ';mm s sieve

'! Ta)e about +)g of representative sample for $ne grained soils

and about +)g for granular soils in miing pan.8! Add the water content e&ual to optimal moisture content.

6! 7i together the soil and water uniformly

+! ?lamp the mould along with etension collar to base plate

D! 3lace the coarse $lter paper on the top of the spacer disc.

E! 3our soil-water mi in the mould in such a &uantity that after

compaction about 2C8rd of the mould is $lled.

F! 0ive +D blows with rammer weighing '.D)g falling through82;mm evenly spread on the surface.

G! Scratch the top layer of compacted surface Add more soil and

compact in similar fashion $ll the mould completely in +

layers

2;! %emove the etension collar and trim o the ecess soil

by a straight edge.

22! %emove the base plate, spacer disc and the $lter paper

and not down the weight of mould and compacted specimen.

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2'! 3lace a coarse $lter paper on the perforated base plate.

28! nvert the mould containing compacted soil and clamp it

to the base plate.

Soa)ing of specimen

2. 3ut a $lter paper on the top of the soil and place the

ad#ustable stem and perforated plate on the top of the $lter

paper.

'. 3ut annular weights to produce a surcharge e&ual to theweight of the base material and pavement epected in actual

construction. (ach '.+)g weight is e&uivalent to Ecm of

construction. A minimum ' weight should be put.

8. mmerse the mould assembly and weights etc., in a tan) of

water allowing free access of water to the top and bottom of

specimen.

6. 7ount tripod of the specimen measuring device on the edgeof the mould and not down the initial reading of dial gauge.

+. @eep the let-up undisturbed for GD hours maintain constant

water level.

D. Ta)e the $nal reading at the end of period remove the tripod

and ta)e out mould allow to drain.

E. %emove the weights, perforated plate and top $lter paper and

weigh.

3enetration test.

2! 3lace the surcharge weights bac) on the top of the soa)ed soil

specimen, place the assembly on the penetration test

machine.

'! Seat the penetration piston at the centre of the specimen with

the smallest possible load the full contact is establishedbetween the surface of the specimen and the piston.

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8! Set the dial gauge and proving ring readings zero . apply load

on penetration piston at 2.'+mmCmin. noted down the load at

designated penetration.

6! At end detachet it form the penetration test.

%ry density by sand re"lacement method.

Aim : - To determine the density of the given soil by sandreplacement method.

Apparatus:- Sand pouring cylinder, trowel or bent spoon cylindricalcalibrating container, metal tray balance crucibles, oven, tongs,glass plate measuring #ar.

3rocedure:-

2! 7easure the internal volume of the caliberating containerfrom the volume of water re&uired to $ll the container.

'! ill the pouring cylinder with sand with in about 2 cm of the

top and weigh it

8! 3lace the pouring cylinder connected on the top ofcaliberating container.

6! "pen the shutter to allow the sand to run out and $ll thecaliberating cylinder.

+! hen there is no further movement of sand in the pouringcylinder, close the shutter.

D! %emove the pouring cylinder on a plane surface such asglass plate.

E! 3lace the pouring cylinder on a plane surface such as glassplate.

F! "pen the pouring cylinder on a plane surface such as glassplate. here there is no movement of sand in the cylinderclose the shutter.

G! eigh the pouring cylinder with remaining sand.

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7easurement of soil density

2! clean and level the ground where the li&uid $eld density is

re&uired.'! ill the pouring cylinder with dry sand with in about 2 cm of

the top and weigh it.

8! 3lace the metal tray with the central hole over the portion of

soil to be tested.

6! (cavate the soil approimately 2;cm dia and 2+ cm deep

with bent spoon. The hole in the tray will guide the dia of the

hole to be made in the soil.

+! ?ollect the ecavated soil in the metal tray weigh into the

nearest gram.

D! 1etermine moisture content of ecavated soil

E! 3lace the pouring cylinder covers the hole

F! "pen the shutter and allow the sand to run out into the hole

when there is no movement of sand the shutter is closed.

G! %emove the cylinder and weigh it.

sevations:-

1) #ie o/ ouing c(lin'e : 380** ht 115 ** 'ia.

2) #an' : assing 1.0** etaine' on 0.6** sieve.

"bservation and Tabular column:

?aliberation :-

2 nitial mass of cylinder L sand 72! gm E;'+' 7ass of pouring cylinderL sand before

pouring in calibrating cylinder! 7'!gm+2+;

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D 5ul) density of sand

=b 72

8! gCcm8!

2+E+B 2.8+gCcm8

22D'.8F

1ensity of soil in place

1 7ass tray L ecavated soil gm! 88GE2 7ass tray empty gm! 2E8F3 7ass ecavated soil 7! 2! N '! gm! 2DGD gms4 7ass cylinder L sand after pouring

sand in hole 76! gmE;'+

5 7ass of sand in hole L cone B 72N 76gm!

2E6G

6 7ass of sand in hole 7QB 72N 76 - 7' 28'87 sand28'8 BGF;2.8+

8 5ul) density of soil = M < gCcm8!

2DGD B 2.EGF;

Result:- 1) ,nsitu 'ensit( o/ soil ! 1.7 gCcm8

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Design of flexible pavement.

+ave*entis 'e/ine' as elativel( stale cust constucte' ove the natual soil /o theuose o/ suoting an' 'istuing the heel loa's an' ovi'ing an a'euate

eaing su/ace.

&een'ing on the *o'e o/ suoting an' 'istiuting loa's ave*ents ae classi/ie'

as /leile igi' an' se*i /leile.

The /leile ave*ents consists o/ a elativel( tin eaing su/ace uilt ove a ase

couse an' su-ase couse an' the( est on co*acte' su ga'e . The /leileave*ents ae ale to esist onl( ve( s*all tensile stesses.

Rigi' ave*entsae *a'e u o/ +otlan' ce*ent concete an' *a( o *a( not havease couse eteen the ave*ent an' the su-ga'e. $ igi' ave*ent can ta;e

aeciale tensile stesses an' is caale o/ i'ging s*all ea;ness an' 'eession

in the su-ga'e.

#e*i /leile ave*ent. ,s *a'e o/ '( clean concete o soil ce*ent an' ossessualities o/ inte*e'iate eteen /leile an' igi' ave*ents. $ se*i-/leile

ave*ent ossess aeciale /leual stength ut its *o'ulus o/ elasticit( is

consi'eal( loe than that o/ concete.

&esign o/ ave*ent thic;ness ( R *etho' as e ,R eco**en'ations

1) Given &ata:-

%u*e o/ esent co**ecial vehicles


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$'ot : -

$'ot cuve > in the gah. $s its vehicle 'ensit( anges /o* 450-1500

vehicles?,@>& ,TA?,%A# $R+>T

GR$&> 1

GR$&> 2

GR$%AB$R #A $#>

20??

100??

75??

aet

?

G#

75??


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Documents

Highway Alignment