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Surveying-1

by Kiran ShindeKiran Shinde
Type: PracticalInstitute: Sivaji university Specialization: Civil EngineeringOffline Downloads: 10Views: 305Uploaded: 7 months ago

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Kiran Shinde
Kiran Shinde
AGTI, DACOE; Karad Surveying- I INDEX Pract. Brief Syllabus No. 1 A Revision of differential leveling (Collimation plane method) 1 B Leveling – (Rise and fall method ) 2 Use of Dumpy level, Tilting Level and Auto Level 3 Reciprocal leveling 4 Sensitivity of bubble tube 5 A Permanent Adjustments of dumpy level Two peg Method A and Method B 6 A Evolution of Constants of Planimeter 6 B Study and Use of digital Planimeter 7 A Method of Plane table Surveying (Radiation) 7 B Method of Plane table Surveying (Intersection) 7 C1 Two Point problem in Plane table Surveying 7 C2 Three Point problem in Plane table Surveying 8 A Study and use of theodolite, construction 8 B1 Measurement of Horizontal angle (Repetition method ) 8 B2 Measurement of Horizontal angle (Reiteration method ) 8 B3 Measurement of magnetic bearing of a line by theodolite 8 C Measurement of vertical angle, 9 Study and Use of Minor Instruments 10 Block contouring project 11 Theodolite Traverse Project Date Page no Sign This is to certify that _______________________________________________________ Roll No.________/Exam no. ________of SECOND Year class, division _______________has satisfactorily completed __________ experiments in Surveying -I during the year ___________ Exam No. : ___________________Date : ___________________ Subject In charge Head, Department of Civil Engg. Principal 1
AGTI, DACOE; Karad Surveying- I Experiment No- 1A LEVELLING - COLLIMATION PLANE METHOD TITLE : To calculate the reduced levels of points OBJECTIVES :  To study to use of dumpy level  To study the methods of calculating R.L. by collimation plane method. INSTRUMENTS:    Dumpy level Leveling staff Field note book THEORY : Dumpy level The dumpy levels originally designed by gravity constant of a telescope take firmly secure to the stage carried by the vertical spindle. The modem term of dumpy level has the telescope tube along with the bubble tube is attached to the top of the telescope. This term is called as solid dumpy level. The name dumpy originally from the fact that formerly this level was equipped with an inventing eye piece, hence was shorter than eye level of the same magnifying power however modern terms generally erecting eye piece so that inverting image the staff visible in the field of views. In dumpy level three clamp screws is provided to control the movement of spindle about the vertical axis for small or price movement slow motion screw is also provide. The leveling head generally consist of two parallel plates with either three foot screw or four foot screws. The upper plate is known as tri batch and the lower plate is known as trivet which can be screwed on to a tripod. Adjustment of dumpy level a) Temporary Adjustments a. Setting Up the level b. Leveling Up c. Elimination of Parallax i. Focusing the eye piece ii. Focusing the objective b) Permanent Adjustments: 1. The axis of bubble tube should be perpendicular to the vertical axis (Adjustment of level tube) 2
AGTI, DACOE; Karad Surveying- I 2. The horizontal cross hair should be in a plane perpendicular to the vertical axis (Adjustment of cross hair)) 3. The line of collimation of the telescope should be parallel to the axis of bubble tube. (Adjustment of line of sight) METHODS OF REDUCED LEVEL (RL) CALCULATION  Height of instrument method (Collimation Plane Method)  Rise and fall method COLLIMATION PLANE METHOD In this method the height of instrument (HI) is calculated for each setting of the instrument by adding back sight to the elevation of the BM. The elevation of reduced level of the turning point is then calculated b subtracting from HI. the fore sight. A) Line of collimation: It is the line joining the intersection of the cross hairs to the optical centre of the object glass and its continuation B) Axis of telescope: It is the line of joining the optical centre of the object glass to the centre of eyepiece C) Method of finding the R.L. by collimation plane method: It consist of finding the elevation of the collimation plane for every up of the instrument then obtaining the reduced levels or points with reference to the respective plane of collimation. For the first set up of the instrument is determined by adding the back sight to the reduced levels of the bench marks. The reduced level of the intermediate points and the first change poil11 are obtained by subtracting the staff reading taken on these points from the elevation of the plane of collimation when the instrument is shifted the second position a new plane of collimation is set up. The levels of the two planes of collimation are corrected by means of the BS and FS taken on the change points The elevation of these change points is obtained by a adding the BS take on the change point (CP) from the second position of the level to the reduced level of the first set up. The RL of the successive points and the second CP are found by subtracting their staff reading from the elevation at this plane of collimation. The process is repeated until all the RL are worked on completing the RL s the accuracy of the arithmetical work should be checked Relevance: 1. This process is useful to find RL of any point. 2. As direct method is used bench are accurate. 3. It is use to find level difference both two points for temporary work 3
AGTI, DACOE; Karad Surveying- I PRUCEDURE           Fix the instrument firmly on the ground. Temporary adjustment is done. Keep the staff at BM. Note the reading. Remove the staff and keep the points where the RL should be required to be found out. If all points are not visible the shift the instrument. Note last reading from first instrument station in FS column. Shift level and make temporary adjustments. Keep the staff at last point. Take the reading note in BS column. 10. Shift the staff keep it at required points. OBSERVATION TABLE: Sr. No. Station Back Readings Inter Fore Collimation Plane Reduced Levels Remarks Note: - The field observations are taken and entries of reading are made in field book. FORMULA USED: - Collimation plane method RL of collimation = RL of BM + B S reading RL of any point = RL of Collimation—(IS/FS) reading (for one place of level) ARITHMETICAL CHECK: -The difference between the sum of back sight and sum of fore sight should be equal to the difference between first and last RL i.e. ∑B.C. - ∑F. C. = Last RL - First RL 4

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