chain surveying report

7/25/2019 Chain Surveying Report

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CHAIN SURVEYING

SUMMARY & ABSTRACT:

Chain (Tape) surveying is the simplest form of detail surveying. In this method the

lengths of lines marked on the field are measured, while the details are measured by

offsets and ties from these lines. This field work was done for 3 field hours (i.e. in 1.

hours, in two meetings). !a"h group was e#pe"ted to submit a detailed report besides

the final plan of the area surveyed.

OBJECTIVES:

This field work aimed to train the student on the following pro"ess$

1. %ele"tion of a &en"h 'ark ("hain or base lines) and "ontrol points.. ire"t method of linear measurements (hori*ontal distan"e measurement).

3. %etting out right angles (offsets).

+. etermining the dire"tion of any line in the field with respe"t to magneti"

north bearing.

. etermining the topographi" survey details, and representing them in standard

or "onve"tional signs.

-. &ooking 'ethod.

. /lotting 'ethod.

APPARATUS & INSTRUMENT

1. Tapes (0metres fiber tape measure and .metres steel tape)

. 1 anging ods

3. &ooking &ook (note book)

PROCEDURE:

1. 2e started with a re"onnaissan"e of the area and sele"ted a suitable &en"h

'ark () and stations based on the "riterion given in 4ote 1.

. 2e measured all the "hain lines on"e in ea"h dire"tion using the dire"t

measurement method. %ee 4ote .

3. 2e then measured the offsets5or ties from every ne"essary point on the detailto the "orresponding base line6 using the pro"edure e#plained in 4ote 3.

+. 2e also measured on the details (on soft details, i.e. trees).

. &esides that, we then re"orded all the information and measurements properly

in the booking papers as e#plained in 4ote +.

-. dditionally we made the ne"essary "al"ulations and "orre"tions.

. 7inally, we drew all the details in a suitable s"ale to produ"e a detailed map of

the area. %ee 4ote .

CHAINAGE FIELD REPORT

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Note 1: CHAIN LINES & STATIONS SELECTIONS

To lo"ate a suitable stations and "hain lines, a re"onnaissan"e of the area was

undertaken by walking around the area re8uired to be surveyed. ny obsta"les

noti"ed were noted as "hallenges. The sele"ted stations were su"h that they produ"ewell formed linked triangles or bra"ed 8uadrilaterals.

The prin"iples we "onsidered were as follows$

1. 7ew long lines were used.

. 9bsta"les to ranging or "haining were taken "are off.

3. 2e made "he"k lines where possible to dete"t errors when plotting.

+. The lines we used were "lose to the details (to avoid long offsets (:13m) and

ties.

fter sele"tion of the Bench M!"# $A% B% C&Dwe drew the sket"h of the area and

marked the stations by wooden pegs, and gave a letter for ea"h station.

NOTE ': DIRECT DISTANCE MEASUREMENT

7or measuring any distan"e between and &, espe"ially when it is longer than the

tape length, the following ranging is needed$ ranging by eye.

1. The ranging rode should be pla"ed at the beginning point and the end point

&. The first man should pla"e the tape *ero point at .

. The se"ond man holding the third raging rod and the tape should move to the

dire"tion of & to a point of the end of the tape length. Then he should hold the

ranging rod verti"ally.

3. The first man at point lines up the ranging rod with that on point &. by

sighting as low as possible.

+. Then, the se"ond man should straighten the tape and mark this point.

. &oth men move ahead repeat the whole steps beginning from the first mark.

-. s measurements pro"esses, the se"ond man should re"ord the length.

Note (: SETTING THE OFFSET

!a"h point on our detail was related to the "hain line by offset or ties. This was

a""omplished by measuring all ;


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To set out offsets, a prism s8uare "an be used. To lo"ate the point at whi"h a 1 from

any point on the feature would meet the "hain line (say &) you "an follow the

following steps$

1. 9ne man should hold the ranging pole at the given point, while the other pole

is pla"ed at any point on the "hain line &.

. The observer holds the instrument and walk along the line & until he seeboth poles "oin"ide in ea"h other. Then the distan"e to this point along the

"hain line "an be measured beside the length of the perpendi"ular.

nother method "an be used by holding the *ero point of the tape at the given point

and swinging tape over the "hain line and mark the point on the "hain line at

minimum reading.

NOTE ): MEASURING THE BEARING OF A LINE

To measure the angle that any line makes with the magneti" dire"tion, you "an use a

prismati" "ompass. The pro"edure is as follow$1. /la"e the ranging pole verti"ally at point &.

. /la"e the prismati" "ompass over its tripod at point and level it using the

bubble and s"rews.

3. otate the "ompass until it is dire"ted to the pole and read the angle.

+. epeat the whole pro"edure for point &.

NOTE *: BOO+ING

The field book should be neat and "onsistent$

1. !a"h "hain line is represented by double line drawn through the "orner of the

page.

. !ntries start at the bottom of the page.

3. etail that is on the right?hand side of the line is booked on the right?hand side

of the page and voi"e versa.

+. The lengths from the beginning of the line are written inside the double lines

while the offset lengths outside.

NOTE ,: PLOTTING

. /lot the framework of "hain lines by$

1. raw the longest line a""ording to its bearing.. &uild up the other "hain lines by using beam "ompasses.

3. raw the "he"k lines, and if there are any errors, "he"k the drawn lines in the

in"orre"t triangles. (=ou may need to measure them in the field).

&. raw the detail for ea"h "hain line based on offsets and ties information. Then

"onne"t these points to get the details.

CHAINAGE FIELD REPORT

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chain surveying report

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