Practical part -1- Distance measurement By Tape and pacing CONTENTS 10/16/2017

Transcription

1 Practical part -1- Distance measurement By Tape and pacing CONTENTS 1. How to make a surveying report? 2. Ranging 3. Ranging Rods and Offset Rods a. Direct ranging b. Indirect ranging 3. Distance measurement 1. Pacing 2. Taping 4. Instruments used in pacing 2 1

2 Practical part 1. How to make a Surveying Report? CONTENTS OF A REPORT 1. Introduction 2. Objective 3. Equipment and Procedure 4. Results and Calculations 5. Discussion 6. Conclusion 4 2

3 Title Page Civil Engineering Dep. Prepared By; 2 nd Stage / G 1 Report No. / 1 G 1 members / 1.Osman 2. Ali 3. Khdr 4. Hamadamin Date of Submission / Mark / Objective Apparatus Introduction 3

4 Sketching Procedure Results and Calculations 4

5 Discussion Data Sheet 5

6 Practical part Ranging When a survey line is longer than a chain length, it is necessary to align intermediate points on chain line so that the measurements are along the line. The process of locating intermediate points on survey line is known as ranging. There are two methods of ranging viz., direct ranging and reciprocal ranging. 12 6

7 3. Ranging Rods and Offset Rods Ranging rods are used for ranging some intermediate points on the survey line. Ranging rods are generally 2 to 3 m in length and are painted with alternate bands of black or white or red and white color with length of each equalizing 20 cm. The location of any survey station can be known from long distances only by means of ranging rods. If the distance is too long, a rod of length 4.0 to 6.0 m is used and is called ranging pole. The offset rod is similar to ranging rod with the exception that instead of the flag, a hook is provided at the top for pushing and pulling the chain or the tape. It is also used for measuring small offsets 13 Ranging Rods 14 7

8 A. Direct Ranging 15 Direct Ranging 16 8

9 Direct Ranging 17 Direct Ranging 18 9

10 Direct Ranging 19 Direct Ranging 20 10

11 Direct Ranging 21 Direct Ranging 22 11

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13 25 B. Indirect or Reciprocal Ranging Due to intervening ground, if the ranging rod at B is not visible from station A, reciprocal ranging may be resorted. Figure shows this scheme of ranging. It needs two assistants one at point M and another at point N, where from those points both station A and station B are visible. It needs one surveyor at A and another at B. To start with M and N are approximately selected, say M1 and N1. Then surveyor near end A ranges person near M to position M2 such that AM2N1 are in a line. Then surveyor at B directs person at N, to move to N2 such that BN2M2 are in a line. The process is repeated till AMNB are in a line

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15 Indirect or Reciprocal Ranging 29 Indirect or Reciprocal Ranging 30 15

16 Indirect or Reciprocal Ranging 31 Indirect or Reciprocal Ranging 32 16

17 Indirect or Reciprocal Ranging 33 Indirect or Reciprocal Ranging 34 17

18 Practical part : 1 st report Distance measurement by 1.Pacing 2.Taping 35 1.Pacing Pacing A distance between two points can be approximately be determined by counting the number of paces and multiplying it with average length of the pace

19 37 4. Instruments Used in Pacing The following instruments are used while pacing ; 1. Ranging rods and offset rods 2. Pegs or Pins 3. Plumb bob Plumb bob Pegs Ranging rods 38 19

20 Pacing 39 Pacing A 30 m B B 30 m A 40 20

21 2. Taping 41 Taping 42 21

22 Taping 43 Taping A 30 m B A 30 m B 44 22