Elementary Surveying (Lecture) PDF

ELEMENTARY SURVEYING (LECTURE) SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leve...

ELEMENTARY SURVEYING (LECTURE) SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Definition of Terms Bench mark (BM) - a fixed point of reference whose elevation is either known or assumed. Backsight (BS) - a reading taken on a rod held on a point of known or assumed elevation. Foresight (FS) - a reading taken on a rod held on a point whose elevation is to be determined Backsight distance – measured from the center of the instrument to the rod on which u backsight is taken. Foresight distance – the horizontal distance from the center of the instrument to the rod on which a foresight is taken. Turning point (TP) - an intervening point between two bench marks upon which point foresight and backsight rod readings are taken to enable a leveling operation to continue from a new instrument position. Rod Reading Leveling Instrument Parts of Automatic Level SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Differential Leveling What is Differential Leveling: Differential leveling is a technique used to determine differences in elevation between points that are remote from each other. Differential leveling requires the use of a surveyor's level together with graduated measuring rods. An elevation is a vertical distance above or below a referenced datum. In surveying, the referenced datum is typically the MSL (Mean Sea Level). HI = ELEV1 + BS ELEV2 = HI – FS Arithmetic Checking: Elev BM2 = Elev BM1 + ΣBS - ΣFS Differential Leveling HI = Elev BMA + BS Elev TP1 = HI – FS Problem 1: Differential Leveling Complete the differential level notes shown below and perform the customary arithmetic check. Level notes from BM1 to BM4 STA BS HI FS ELEV BM1 1.256 127.133 m TP1 1.116 1.886 TP2 1.228 1.527 BM2 1.189 2.246 BM3 1.070 2.017 TP3 1.831 2.656 BM4 2.765 Problem 1: Differential Leveling Complete the differential level notes shown below and perform the customary arithmetic check. Level notes from BM1 to BM4 STA BS HI FS ELEV BM1 1.256 128.389 127.133 m TP1 1.116 127.619 1.886 126.503 TP2 1.228 127.320 1.527 126.092 BM2 1.189 126.263 2.246 125.074 BM3 1.070 125.316 2.017 124.246 TP3 1.831 124.491 2.656 122.660 BM4 2.765 121.726 Sum of BS= Sum of FS= 7.69 13.097 SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Profile Leveling What is Profile Leveling: Profile leveling is the process of leveling along a fixed line to determine the elevations of the ground surface along the line (also known as longitudinal sectioning). It is a method of surveying that has been carried out along the central line of a track of land on which a linear engineering work is to be constructed. HI = ELEV1 + BS ELEV2 = HI – (FS or IFS) Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 125.50 m 0 + 00 3.0 Problem 2. Complete the following set + 10 2.3 of profile level notes and show the TP1 3.13 0.64 customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 =126.45 125.50 m 0 + 00 3.0 Problem 2. Complete the following set + 10 2.3 of profile level notes and show the TP1 3.13 0.64 customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 126.45 125.50 m 0 + 00 3.0 =123.45m Problem 2. Complete the following set + 10 2.3 of profile level notes and show the TP1 3.13 0.64 customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 126.45 125.50 m 0 + 00 3.0 123.45m Problem 2. Complete the following set + 10 2.3 =124.15m of profile level notes and show the TP1 3.13 0.64 customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 126.45 125.50 m 0 + 00 3.0 123.45m Problem 2. Complete the following set + 10 2.3 124.15m of profile level notes and show the TP1 3.13 0.64 =125.81m customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 126.45 125.50 m 0 + 00 3.0 123.45m Problem 2. Complete the following set + 10 2.3 124.15m of profile level notes and show the TP1 3.13 =128.94 0.64 125.81m customary arithmetic check. 0 + 22 2.7 + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 Problem 2: Profile Leveling STA BS HI FS IFS ELEV BMa 0.95 126.45 125.50 m 0 + 00 3.0 123.45m Problem 2. Complete the following set + 10 2.3 124.15m of profile level notes and show the TP1 3.13 128.94 0.64 125.81m customary arithmetic check. 0 + 22 2.7 =126.24m + 30.5 2.8 + 34.2 3.1 + 39.3 0.5 + 42.5 0.8 TP2 2.16 1.28 + 45 0.9 + 48.6 1.2 + 50 1.7 + 53.7 2.8 TP3 0.82 2.37 TP4 1.35 3.5 + 75 3.0 BMb 1.99 SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Double Rodded Leveling What is Double Rodded Leveling: Double rodded leveling is a surveying technique used to determine the difference in elevation between two points. This method involves the use of two leveling rods, one at each point, and a level instrument. The rods are positioned at a fixed distance apart and are read simultaneously through the level instrument. SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Reciprocal Leveling What is Reciprocal Leveling: Reciprocal leveling is a surveying technique in which readings are taken from both directions between two points in order to reduce errors. SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Stadia Method / Leveling Inclined Stadia Sights: In actual field practice, most stadia measurements are inclined because of varying topography but the interval is still read on a vertically held rod. ID = Kscos ∝ + C HD = Ks cos 2 ∝ + C cos ∝ VD = Ks cos ∝ sin ∝+ Csin ∝ DE = HI + VD – RR Problem 3: Stadia Leveling The following data were obtained by stadia measurement: vertical angle = +18o23’ and observed stadia intercept = 2.2 m. The stadia interval factor of the instrument used is 95.5 and C = 0.30 m. If the height of the instrument is 1.62 m and the rod reading is taken at 1.95 m, determine the following: a. Horizontal stadia distance from the instrument setup at A to the rod held at point B. b. vertical stadia distance from the center of the instrument to the point on the rod bisected by the horizontal cross hair. c. Inclined distance from the instrument center to the point on the rod bisected by the horizontal cross hair. d. Difference in elevation between the point over which the instrument is setup and the point on which the rod was held. SURVEYING METHODS – VERTICAL DISTANCES - Direct Leveling Methods Differential Leveling Profile Leveling Double Rodded Leveling Reciprocal Leveling Stadia Leveling / Method - Indirect Leveling Methods Trigonometric Leveling Trigonometric Leveling Trigonometric Leveling: Trigonometric leveling is a surveying technique used to determine the height difference between two points by measuring the angle of elevation or depression between them. This method involves the use of a theodolite or total station, which is an instrument used to measure angles in the horizontal and vertical planes. Problem 4: Trigonometric Leveling A theodolite is set up at a benchmark whose elevation is 237.5 ft. A level rod is put at point B. A rod reading of 3.88ft is taken at a zenith angle of 73 degrees 27 minutes and an inclined distance of 568.73 ft. If the height of instrument is 4.5 ft, find the elevation (ft) of point B. Questions and clarifications?