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Laying of a COMPUND CURVE USING TRANSIT AND TAPE

Table of contents

Introduction --------------------------------------------------------------2

Objectives and instruments ---------------------------------------------- 3

Procedure and Computation --------------------------------------------4

Preliminary data sheet ----------------------------------------------------5

Sample Computations -----------------------------------------------------6

Setch -------------------------------------------------------------------------!"inal data sheet -------------------------------------------------------------#

Pictures ----------------------------------------------------------------------$%

&esearch and discussions ------------------------------------------------$$

Conclusion -------------------------------------------------------------------$3

Intro!ction

$

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Laying of a COMPUND CURVE USING TRANSIT AND TAPE

' compound curve is consist o( t)o or more consecutive curves that aretan*ential+ In surveyin*, a compound curve is a t)o-arc simple curve havin*its centers on the same side o( the common tan*ent at the junction+ 'multicompound curve has three or more centers on the same side o( thecurve+ hou*h their radii are in the same direction, they are o( di.erent

values+

In this /eld )or, )e )ill lay out a compound curve usin* a theodolite andtape+ "rom the concepts and techni0ues )e have learned (rom the simplecurves, )e are *oin* to apply them in this /eld )or to lay out t)o simplecurves havin* di.erent radius and determine their common tan*ent+

Ob"ecti#es$

2

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Laying of a COMPUND CURVE USING TRANSIT AND TAPE

$+ o be able to lay a compound curve by incremental chords and

de1ection an*le method+2+ o master the sill in levelin*, orientin* and usin* the transit

e.ectively+3+ o )or cooperatively )ith ones *roup mates and eciently per(orm

the re0uired tas+

Instr!%ents$

Tape

sed to measure horiontal

distances as )ell as slopes+ suallyin 3%m, 5%m or $%%m in len*th+

' theodolite is a precisioninstrument used (or

measurin* an*les bothhoriontally and vertically+

heodolites can rotate alon*their horiontal ais as )ell

as their vertical ais+

Marking pins

3

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2 range poles

Strai*ht round stals, 3 to 4 cm thicand about 2 m lon*+ hey are madeo( )ood or metal+ hey are used tomar areas and to set out strai*ht lineson the /eld+ hey are also used to marpoints )hich must be seen (rom adistance, in )hich case a 1a* may be

attached to improve the visibility+

Proce!res$

$+ he pro(essor *ives the (ollo)in* data7

&$8 9999m &28 9999mI$8 9999 I28 9999

:ac)ard an*ent direction7 9999999 ;aimuth or bearin*$(ollo)in* the *iven direction o( the bac

tan*ent $and mar the location on the *round at a distance $(rom

PC+5+ Set the horiontal vernier to ero a*ain and start locatin* intermediate

points o( the /rst curve until you reach PCC usin* incremental chord

len*ths and their de1ection an*le (rom the bac)ard tan*ent+6+ pon reachin* PCC, trans(er the instrument at PCC+!+ '*ain level the instrument and )ith the telescope inverted position,

si*ht the >$+#+ '(ter locatin* >$, plun*e the

telescope into the normal position

and locate >2)hich is alon* the line

(rom >$to PCC, and at a computed

distance 2(rom PCC+?+ @rive a pin directly on >2+$%+ Once a*ain, set the horiontal vernier ' at ero readin* )hile

si*htin* the position o( >2+

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$$+ sin* the incremental chord len*ths and their de1ection an*les,

lay intermediate points o( the second curve on the *round until you

reach P+

Preli%inary Data S&eet$

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Sa%'le Co%'!tations$

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S(etc&$

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)inal Data S&eet

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)iel *or( + Laying of a Co%'o!n C!r#e Using Transitan Ta'e

@ate7 Oct 2!, 2%$5 Aroup Bo+7 4

ime7 $2pm-473%pm =ocation7 &ial Par

eather7 Sunny Pro(essor7 Dn*r+ Ira :almorisData S!''lie$

&$8 2%m &28 $5m

I$8 3%E I28 25E

:ac)ard an*ent @irection7 B$5ED ;aimuth or bearin*