GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE: GUDLAVALLERU DEPARTMENT OF CIVIL ENGINEERING

Size: px

Start display at page:

Download "GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE: GUDLAVALLERU DEPARTMENT OF CIVIL ENGINEERING"

Hector Park
6 years ago
Views:

1 SURVEYING FIELD WORK II LABORATORY Name Regd. No : :. Year & Semester :.. Academic Year :. GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE: GUDLAVALLERU DEPARTMENT OF CIVIL ENGINEERING

2 GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE::GUDLAVALLERU DEPARTMENT OF CIVIL ENGINEERING Surveying Field Work II- Lab Manual

3 GUDLAVALLERU ENGINEERING COLLEGE SESHADRI RAO KNOWLEDGE VILLAGE:: GUDLAVALLERU DEPARTMENT OF CIVIL ENGINEERING S.n o INDEX Date Name of the Experiment Signature of the faculty

4 CURVE SETTING BY RANKINES METHOD AIM: To set the curve using deflection angles by Rankines method. Apparatus: Tape, Theodilite, Wooden pegs, arrows, ranging rods. Theory: In this method a tape is used for making linear measurements and a theodilite is used from making angular measurements. This method is also known as Rankines method, the tangential angle method (or) deflection angle method. The method gives accurate setting out and is generally used for railways and important highways. Procedure: 1. Set up the theodilite at the point of curvature T 1 and level it. 2. Set the verniner A at zero and clamp the upper plate. Loosen the lower plate and sight the intersection point V exactly using lower tangent screw. Now the line of sight is in the line of rear tangent T, V and vernier A reads zero. 3. Release the upper plate, and set the vernier A to the deflection angle 1. The line of sight is now directed along the chord T,A. Clamp upper plate. 4. Ask the assistants to a steel tape. One will hold the zero and of tape pinned at T 1. The other holding an arrow a mark equal to first chord length C 1 on the tape. One will swing the tape around T 1 till the arrow is bisected by the line of sight. Fix the first peg at A. 5. Unclamp the upper plate and set the vernier. A to be deflection angle 2. The line at sight is now directed along T,B. 6. With the zero end of the tape at A and arrow at a mark on the tape equal to second chord length C 2, ask the assistant to swing the tape around A until arrow is bisected with the line of sight. Fix the second peg at point B & arrow point.

5 It may be noted that deflection angles are measured from tangent point T 1 and chord lengths are measured from the preceding point. The chord length swings are indurdual, not commutative. 7. Repeat steps 5 and 6 till the last point is reached. The last point so located must coincide with tangent point T 2 already fixed from the point of intersection. If the discrepancy is large repeat the work of setting out. If the discrepancy is small, adjust the last few pegs. Result: Hence the required curve is obtained by Rankine s method.

6 DETERMINE OF AREA OF PLOT USING TOTAL STATION AIM: To determine the given plot s surface area. Apparatus: Total station and prism with other accessories. Theory: The computations of areas and volumes is often required in civil engineering practice. One of primary aims of land surveying is to determine the are of land under survey. Which is usually the property of an individual or institution. In plane surveying the team area refers to the orthogonal projection of ground on a horizontal plane, not actual the ground surface. (a) Make a quick eye ball plan view sketch of the map area in the field book. This will b e an important reference to which you will later append information such as the location of home stations, back sights etc. (b) Take a few minutes to walk around your map area figure out where the optional places for home stations, back sights and transverses are. (c) Select a suitable location and setup instrument and do all necessary station adjustments and job selection. (d) Allocate the [Area] soft key to [meas] mode screen. (e) Press [Area] to begin surface area calculation. (i) Sight the first point on the line enclosing the area and press [meas]. (ii) Press [OBs] to begin observation. The measured values are displayed. The [OBs] function requires each point to be observed individually before area calculation is performed. (iii) When [Read] is pressed registered co-ordinates can be recalled and used in subsequent measurement. (iv) Press [ok] to enter the values of point. (f) Repeat d until all the points have been measured. Points on the enclosed area are observed in a clock wise or counter clock wise direction. (g) After all the points necessary to calculate the surface area have observed press [calc] to display calculated area.

7 (h) Press (ok) to quit area calculation and return to [MEAS] mode. Result: The area of given points is m 2.

8 DISTANCE AND ELEVATION USING TACHOMETRIC PRINCIPLES AIM: To determine the distance and elevation of a given object using principles as Tacheometric principles. Apparatus: Tacheometry is a branch as surveying in which the distances and elevations are determined from instrument observations alone, with no chaining whats ever. The instrument observations with special tittings. A staff is held at the various positions of interest and readings are taken. From these the horizontal distance and vertical intercept are derived using optics and geometry. Procedure: a) Select a suitable instrument station A from where both object and Bench mark are visible. Set up Tacheometer over the station A and do all the necessary station adjustments and level it accurately with respect to altitude level. b) Direct the telescope towards the top of object bisect accurately and clamp both the plates. c) Read staff intercept and central stadia hair readings. d) Read both verniers C and D and determine the vertical angle QPQ. e) Determine again the angle QPQ with face sight. f) Find the mean value α of the angle QPQ. g) Set the vertical vernior the zero with the altitude bubble central, take a back sight on the staff held at B.M. Let S be staff reading. h) Determine the R.L of Q as under R.L of Q = R.L at B.M + V-r. D = Ks cas 2 α + C cas α V = (Ks Sin 2 α) + C sing α. 2 Result : a) The distance between the given object and instrument station is 25.6 mts b) The elevation of the object is mts.

9 DISTANCE AND GRADIENT BETWEEN IN ACCESSIBLE POINTS AIM : To determine the distance and gradient b/w two in accessible points using theodolite. Apparatus: Theodilite is quite likely the most versatile and intricate surveying instrument for measurement of horizontal and vertical angles. Theodilite enable the surveyor to measure angles. To an accuracy ranging from 1 to 0.1. The distance between any two points can be calculated in directly. With the help of observations of horizontal angle between them. From two supplementary stations separated by a known distance. By determining the elevation of the stations using principle trigonometric leveling one can determine the gradient between then. Procedure: a) Let P and Q be the two given in accessible points. b) Take two auxiliary stations A and B separated by distance d nearly parallel to the points P and Q. c) Set up the theodilite over A and do all the necessary adjustments. d) Initialize the horizontal circle to zero with telescope bisect point P. e) Clamping upper and lower screws top as point P is bisected by telescope Invertical plane and the vertical angle α is noted. f) Swing the telescope in the horizontal angle PAQ. Clamping upper and the lower screw top as points Q is bisected by rotating telescope screws top as points Q is bisected by rotating telescope is vertical and the vertical angle α is noted. g) Swing the telescope in the horizontal plane to measure horizontal angle PAB. h) Shift the instrument to station B and perform all necessary station adjustments. i) Measure vertical angle to P(P 1 ) and Q(P 2 ) and horizontal angles LQBP and LQBA.

10 Result : Distance between in accessible points (S 1 ) = M Gradient between two points AB is M

11 DISTANCE AND GRADIENT MEASUREMENT USING TACHEOMETER. AIM: To determine the distance and gradient of the any two in accessible points using principles of tacteometry. Apparatus: Tacheometer, leveling staff, tape. Theory: Tacheometery is a branch of surveying in which distances and elevations are determined from instrument observations above, with no chaining what so ever. The instrument used is the tacheometer with special fittings. A staff is held at the various positions of interest and readings are taken from these horizontal distance and vertical intercepts are derived using options and geometry. Procedure: 1. Let P&Q be two given in accessible points. 2. Take two auxiliary stations A and B separated by distance d nearly parallel to points A and B. 3. Set up the tachometry over A and B. Do all the necessary adjustments. 4. Initialize the horizontal circle to zero with telescope bisecting point P. 5. Clamping upper and lower screws then point P is bisected by rotating telescope invertical plane and vertical angle B, is noted. 6. Swing the telescope in horizontal plane to measure horizontal angle PAQ. Clamping upper and lower screws top at point Q is bisected by rotating telescope in vertical plane and vertical angle F 2 is noted. 7. Swing the telescope in horizontal plane to measure the horizontal angle PAB. 8. Slift the instrument the stations B and perform all necessary station adjustments. 9. Measure vertical angle to BB 1 and horizontal angle QBP and QBA. Horizontal distance (P) = Ks cas 2 θ + C.Caso Vertical distance (V) = Ks sin2 θ + C sin θ Q 2 Calculate3 distance between P and Q.

12 Gradient = Distance between P &Q Distance PQ Result: 1. The distance between PQ.? 2. The Gradient?

13 ELEVATION OF AN CIVIL BLOCK BASE ACCESSIBLE AIM: To determine the elevation of the civil block whose base is accessible. APPARATUS: Theodilite, staff and tape. Theory: Trigonometric leveling is an indirect method of leveling in which the relative elevations of various points are determined from the vertical angles measured with theodilite and the horizontal angles measured with tape. Procedure: (a) A station A is selected such that both the civil block and bench mark are visible. (b) Set up the theodilite over the station A level it accurately with respected to the altitude level. (c) Direct the telescope towards the top of object G Bisect Q accurately and clamp both the plates. Read both verniers C and D determine the vertical angle QP Q. (d) Determine again the angle QPQ with face right. (e) Find the mean value α 1 of the angle QPQ 1. (f) Set the vertical vernier to zero with the altitude bubble central. Take a back sight on the staff held at the B.M. (g) Determine the R.L of Q as below. h = D tan α. R.L = R.L at B.M + S 1 +h. RESULT: The elevation of the Civil block is? 1 in

14 ELEVATION OF OBJECT USING TOTAL STATION AIM: To determine elevation of object whose top is in accessible. Apparatus: Total station and prism with other accessories. Theory: A Rem measurement is a function used to measure the elevation of a point where a target cannot be directly installed power line, over had cables and bridges etc. Procedure: 1. Select a suitable location and set up instrument and do all necessary adjustment and job selection. 2. Allocate the Rem soft key to the Meas mode screen. 3. Select the target directly or directly over the object and measure target height with total station. 4. After inputting the height measured accurately sight the target. Press Dist in page of meas mode to carry out measurement. The measured distance data, vertical angle and horizontal angle displayed. Press stop to stop measurement. 5. Sight object and then press Rem. The REM measurement is started and height from the ground to object is displayed in Ht. 6. Press stop to terminate the measurement operation. 7. To Re observe the object, sight the target, then press OBS. 8. Press (ESC) to finish and return to the MEAS mode screen. Result: The elevation of given water tank = m = 21.49m.

15 g) Shift the instrument to the station B and set it so that the line of collimation is at the level of line of collimation at the station A in other words the staff reading on the B.M should be S. When the altitude bubble in central, sight the point Q and measure the vertical angle QRQ 1. Take the mean value of the verniers C and D. Change the face and take the average value α 2. h) Determine the R.L. of Q as under R.L of Q = H1 of instrument +H. dtan α 2 H =, h = D tan α, h = (D+d) tan α 2 tan α 1 Result : The elevation of civil block is = mt

16 GRADIENT BETWEEN IN ACCESSIBLE STATION USING AIM: Determine of gradient between in accessible stations using total station. Apparatus: Total station and prism with other accessories. Theory: Missing line measurement is used to measure the slope, distance, horizontal distance and horizontal angles to a tangent from the target which is the reference (start) without moving instrument. Procedure: (a) Select a suitable location and setup the instrument and do all necessary adjustment and job section. (b) Sight the target of the starting position and press [Dist] in the first page of [MEAS] made in begin measurement. (c) Sight second target press [MLK1] in the third page of [MEAS] to begin observations. The following values are displayed. (i) Slope distance as starting position and 2 nd target. (ii) Horizontal distance of starting position & 2 nd position. (iii) Height difference of starting position and 2 nd target. (d) Sight next target and press [MLM] to begin observation slope distance, horizontal distance and height difference between multiple points and the starting position can be measured in this way. (i) Press [OBS] to observe starting position. Sight the starting position and press [OBS]. (ii) When [MOVE] is pressed the last target measured becomes the new starting position to perform missing line measurement of next target. (e) Press [ESC] to end missing line measurement. Result: The slope between the two in accessible points is 1 in m.

17 MEASUREMENT OF HORIZONTAL ANGLE BY REITERATION AIM: To determine the horizontal angle by reiteration method. APPARATUS: Theodolite, ranging rods and other accessories. Theodolite is quite likely the most versatile and intricate surveying instrument for the measurement of horizontal and vertical angle. Theodolite enable the surveyor to measure angle to an accuracy ranging from 1 to 0.1. Theodolites enable the surveyor in laying off horizontal angles, determining difference in elevation, setting out curves, prolonging survey line etc., The method of reiteration method (or) method of series is suitable for the measurement of angle of a group having a common vertex point. Several angles are measured successively and finally the horizon is closed. PROCEDURE: 1. Fix the stations (P,Q,R,S, etc.,) between whom the angles should be measured by fixing ranging rods. 2. Set a station X from where all the stations between whom horizontal angle should be measured. Set up the instrument and do the necessary station adjustments. (Setting up, centering, leveling and elimination of parallax). 3. Release all clamps turn the upper and lower plates in opposite directions. Till the zero of the scale and vertical circle is to the left. Clamp both the plates together by upper clamp and lower clamp and bring two zeros by upper clamp coincidence by turning the upper tangent screw. Take both vernier readings. The reading on verniner B will be also 180 if there is no instrumental error. 4. Similarly, bisect successively Q,R,S etc., thus closing the circle. Read both the verniers at each bisection. Since the graduated circle remains in a fixed position throughout the entire process each included angle is obtained by taking the difference between two consecutive readings. 5. On final sight to Q, the reading of the vernier should be the same as the original setting. If not, note the reading and find the error due to slip etc.,

18 and if the error is small, distribute it equally to all angles. If large, repeat the procedure and take a fresh set of readings. 6. Repeat 3 to 5 with the other face. 7. The horizontal angles are then obtained with face left and face right. RESULT: The horizontal angles are?

19 MEASUREMENT OF HORIZONTAL ANGLE AIM: To determine horizontal angle by Reception method. APPARATUS: Theodilite, ranging rods, other accessories. THEORY: Theodilite is quite likely the most Surveying instrument for the measuring of horizontal and vertical angles. Theodilites enables the surveyor to measure angles to an accuracy ranging from 1 to 0.1. Reception method, an angle is measured two or more times by allaowing the vernier to remain clamped each time at the end of each measurement instead of setting it back at zero when sighting at the previous station, is used to estimate errors due to eccentricity of verniers and centres, in adivstments of line of collimation and tunnion axis, in accurate graduations and inaccurate bisection. PROCEDURE: a) Fix the stations (P and Q) between whom the angle should be measured by fixing ranging rods. b) Select a station X from where all the stations between which horizontal angles should be measured are clearly visible. Set up the instrument and do the necessary station adjustments (setting up and centering leveling and elimination of parallax). c) Release all clamps, turn the upper and lower plates in opposite directions till the zero of one of the verniner (A) is against the zero of the scale and the vertical scale is to the left. Clamp both the plates together by upper clamp and lower clamp and bring the two zeros into exact coincidence by turning the upper tangent screw. Take both verniner readings. The reading on verniner B will be if there is no instrumental error. d) Loose the lower clamp and direct the telescope towards the point P. Clamp the lower clamp and bisect point P accurately by lower tangent screw.

20 e) Un clamp the upper clamp and turn the instrument clockwise about the inner axis towards Q. Clamp the upper clamp and bisect Q accurately with the upper tangent screw. Note the reading of verniers A and B to get the approximate value of angle LPXQ. f) Unclamp the lower clamp and turn the telescope to sight P again. Bisect P accurately by using the lower tangent screw. It should be noted that the verniner reading will not be changed in this operation since the upper plate is clamped to the lower. g) Unclamp the upper clamp turn telescope clockwise and sight a bisect Q accurately by upper tangent screw. Measure angle LPXQ again. It will about nearly twice the previous value. h) Repeat the process until the required number of times (usually 3). The average angle with face left will be equal to final reading divided by 3. i) Change face and make three more repetitions as described above. Find the average angle with face right, by dividing the final reading by 3. j) The horizontal angle is obtained by taking the average of two angles obtained with face left and face right. Result: The horizontal angle between station is

21 SETTING OUT A SIMPLE CURVE BY MANUAL METHOD AIM: To set a simple curve by method of off sets from the chords produced. Apparatus: Chain, tape, Ranging rods, arrows, cross staff and lime powder. Theory: The design and construction of curves is an important aspect of route surveying of rods, railways canals etc. A curve is provided at the intersection of the straight lines to effect a gradual change in the direction. A horizontal curve is provided at the point where the two straight lines intersect in. The horizontal plane and vertical curve is provided where the two straight lines at different gradient intersect. Setting out interval along the curve. Calculation: a) Tangent length and length of curve are determined. b) Depending on the full chain stations, the length abnormal chord and first and last sub chords and first and last sub chords is determined. c) Offset length = (Chord length) 2 2 x Radins of curve Procedure: a) Locate the tangent points T 1 and T 2 and find out their changes. b) Determine the lengths of the first sub chord (C ), normal chords (c) and the last sub-chord (C ). So that the pegs are at full chain stations. c) Keep the zero mark of the chain (or) tape at T 1 and spread the chain (or tape) along the back tangent T 1 and measure a distance T 1 A 1 = C 1 = length of the first sub chord. d) With T 1 as the centre and T 1 A 1 as radius, swing the chain such that A 1 A = (C ) 2 /2R and fix the first peg at A. e) Now spread the chain along the chard T 1 A 1 and pull it straight in that direction to the point B 2 as radius, swing the chain to a point B such that B 2 B = C (C+C)/ 2R fix the second pet at B. f) Spread the chain along the chord AB to point C 2 and fix third peg at C such that C 2 C o 3 = C 2 /R as in step 5.

22 g) Continue the above process till the last bit one peg is fixed. h) Fix the lat peg by taking an off set to C (C+C ) from the prolongation of the proceeding chord. i) The last peg so fixed will coincide with the point of tangency T 2 already fixed in step 1. Result: The simple curve of Radius 150 m is set.

SREE VAHINI INSTITUTE OF SCIENCE AND TECHNOLOGY

SREE VAHINI INSTITUTE OF SCIENCE AND TECHNOLOGY EXPERIMENT NO: 1 DATE: STUDY OF THEODOLITE AIM To study about the Temporary and Permanent adjustments of a Theodolite ADJUSTMENTS OF THEODOLITE The Theodolite should be properly adjusted to obtain accurate