7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 1/15

SPECIAL METHODS OFSPECIAL METHODS OF

LEVELINGLEVELINGMohd Efendi Daud (Dr. Sc)

B.Surv (UTM, Malaysia) Msc (UTM, Malaysia), Dr.Sc, (Nagoya Univ., Japan)

(Geomatic Division)

Faculty o Civil & Environmental Engineering!niversiti "un #ussein $nn Malaysia %' atu *ahat

 +ohor M,-,S/,.*hone 0 12'342445 1672%342'5 Fa8 0

12'342E9mail 0 efendi:uthm.edu.my 

;e<0 htt=0>>???.@ass.uthm.edu.my> 

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 2/15

/nverted Staf 

How to readinverted staff

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 3/15

BS IS FS HoC Reduce Level Remarks

0.770 56.325 55.555 TBM 1= 55.555m

1.632 54.693 road side

-2.417 58.742 under the bridge

-2.963 -3.167 56.529 59.492 under the bridge

-0.2487 59.016 under the bridge

-3.104 -2.901 56.326 59.430 under the bridge

1.218 55.108 road side

1.975 1.354 56.947 54.972 road side

1.387 55.560 TBM 1= 55.555m

94.4AA 94.4A2 33.333

94.4A2 33.3

0.005 0.005

 h = BS - FS (Normal case)  = BS - (-FS) - Inverted caseRL = BM +BS + FS

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 4/15

Beci=rocal -eveling

o B and ! distan"es rough#$ e%ua#so that instrumenta# and natura#

errors "an"e# out.o &n some situations' su"h as ri(er or

(a##e$ "rossing' it is not a#)a$s

*ossib#e to ba#an"e B and !distan"es.

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 5/15

+ro"edure,&nstrument at ,ead sta/ at ' distan"e to

&nstrument at B

ead sta/ at ' distan"e B to

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 6/15

h1 = X1 - Y1

h2 = X2 - Y2

 h = (  h1 h!)"! #$

 h = 1"! ((%1&'1) (%!&'!))

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 7/15

"rigonometric -eveling

on"e*t,

Based on so#ution o right triang#e

Ssin  or #tan 

e#e(4 = e#e(- 

H

SV

 AB

C

α

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 8/15

 A

B

no) e#e(ation o , )ant to :nd e#e(ationo B

,s <eore0 S sin

#ere hi ,D and r C

elev  elev, 1 hi 1 9 r

C

E

D

SV

α

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 9/15

G*S -eveling

o Modern ;+ *ro(ide 3< #o"ation

o ' ' and h e#i*soida# height>' or

o ?atitude' #ongitude' and h e#i*soida#height>

???

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 10/15

Geoid9Elli=soidBelationshi=

Mean Sea Level(Geoid)

lli!soid "errain

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 11/15

Converting #eights

o on(ersions bet)een e##i*soid heightsand e#e(ations

o @ = orthometri" height reer to ;eoid>

o h = e#i*soida# height reer to e#i*soid>

o <etermining geoid height A>

o #9h

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 12/15

Suggestions orBod ;or@ 

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 13/15

o  The rod shou#d be *ro*er#$ etended and"#am*ed.

o  TaCe "are to ensure that the bottom o the so#e*#ate does not be"ome en"rusted )ith mud' dirt'and so on' )hi"h "an resu#t in mistaCen readings.

o Dnsure that a## *oints used as turning *oints T+>are suitab#e.

o MaCe sure that the rod is he#d in *re"ise#$ thesame *osition or the B at it )as or the ! ora## T+.

o & rod is he#d tem*orari#$ near to' but not on' a

re%uired #o"ation' the a"e o the rod shou#d beturned a)a$ rom the instrument so that theo*erator "annot taCe a mistaCen reading.

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 14/15

Suggestions or/nstrument

;or@ 

7/23/2019 GEOMATIC - Leveling_Special Method

http://slidepdf.com/reader/full/geomatic-levelingspecial-method 15/15

o Ehen setting u* the instrument' gent#$ or"ethe #egs into the ground b$ a**#$ing )eight on

the tri*od shoe s*urs ---F to in"rease stabi#it$.o  The #o"ation o the #e(e# setu* shou#d be

"hosen so that $ou "an GseeH the maimumnumber o rod #o"ations' *arti"u#ar#$ B and! #o"ations.

o +rior to taCing rod reading' the "ross hairshou#d be o"used shar*#$. 

o ead the rod "onsistent#$' at either the to* orthe bottom o the "ross hair.

o Ae(er mo(e the #e(e# beore a ! is taCen.

o he"C the #e(e# bubb#e remains "entered