Loksewa aayog question on Surveying for civil and building architect

Principle of surveying is to work whole to part.  The curvature curvature of earth’s earth’s surface surface is taken into account only if the extent extent of survey survey is more than 260 sq. km Geodetic survey is dierent from plane surveying !ecause of the consideration of curvature of earth. "ydrographic survey deal with the mapping of a large water !odies#### canal system????? $ scale representing either three units or only one unit and the fractions upto scale######## second place of decimal point is diagonal scale######## if the smallest division of a vernier is longer than the smallest division of its primary vernier. scale% the verneir is k#a retrograde vernier.  The scale used used to measure measure and to set out the angles is scale of chords. LC = s/n where s/n where s& value of one smallest division on main scale% v & value of one smallest division on the vernier and n & num!er of divisions on the vernier A discrepancy is discrepancy is the dierence !etween two measured value and actual value. The designation of scale recommended by I! "#$" % "$&$ is A to ' '( & p ) v or v ) p Compensating Compensating errors in chaining or other survey are proportional p roportional to square root of the length of line.  The errors errors (hich are not possible to correct is compensating error. )egative errors are caused in chain* (hen its length is more than the standard length. Theory of probability is applied to accidential errors.  The most pro!a!le pro!a!le value of of an o!served o!served quantity availa!le from from a given set of o!servation is the one for which the sum of the square of errors is a minimum. This statement is called as the principle of least s+uare. The di,erence bet(een the most probable value of a +uantity and its observed value is residual error-also chec conditional error true error safe error0  The types of error which are are of cumulative cumulative nature and and can !e corrected corrected is k#a systematic error. error.

accidential errors! s+. root of n (here n = observations Cadastral map is a map having large scale An o,set scale-smallest measurement from chain line0  always has the *ero mark at its either middle or at the end. hort o,sets are measured (ith an ordinary chain. 1utt rods are used for measuring oset distance $ +0 m chain was found to !e 20 cm too long after chaining ,-00m. The correct length of the total distance chained will !e ,-0-m /f a chain is found too short on testing% it can !e adusted !y i. ii. iii.

straightening the links inserting additional circular rings 1attening the circular rings

no. of links in a +0m metric chain is ,-0  The distance !etween two neigh!ouring !rass rings are ,m. osets in chain survey is metallic tape $ chain ++’ long and consisting of ,6 links each 2 ,#,6 feet long is 2evenue chain-&mm dia chain0 2anging is the process of maing intermediate points in st. line 3oining t(o ends points in the 4eld.-so accurate changing isnot possible (ithout ranging0 min. direct ranging=5///min. indirect rangin=# imp. points selected at the ends of the chain lines to command the !oundaries of the curvey are k#a main stations check out tie# su!sidiary stations3 'ongest chain line passing through the centre of the area is base line- also chec chec line/tieline=to tae o,sets for detailed surveying0 "!6&7=permissible limit of error in chaining measurement of rough or hilly ground 8uring chaining along a st. line* the leader of the survey party has three arroe(s and (hile the follo(er has 4ve arro(s. the distance of the follo(er from the starting point (ill be & chains Invar tapes=nicel 9 steels//////metallic tapes=cloth 9 (ires

Chain survey=small areas in open ground 'or accurate (or* in comparison to chain* the steel band is used because it is practically ine:tensible ;ngineer