FLD-WORK-2

ELEMENTARY SURVEYING FIELD MANUAL FIELD WORK NO.2 TAPING ON LEVEL AND ON UNEVEN GROUND COURSE AND SECTION: CE120-0F / B2 SUBMITTED BY: NAME: SIBUG, MARY QUEENIE M. GROUP NO. 01

STUDENT NO.: 2013104313

CHIEF OF PARTY: LAMADRID, SAIMON Z.

DATE OF FIELDWORK: 10/08/2015 DATE OF SUBMISSION: 10/16/2015

SUBMITTED TO:

PROFESSOR: ENGR. IRA BALMORIS

GRADE

Table of Contents

I. II. III. IV. V. VI. VII. VIII. IX.

INTRODUCTION OBJECTIVES AND INSTRUMENTS PROCEDURES AND COMPUTATION QUESTIONS AND PROBLEMS PRELIMINARY DATA SHEET FINAL DATA SHEET RESEARCH AND DISCUSSIONS CONCLUSION FIELD WORK PEER ASSESSMENT

I.

INTRODUCTION In surveying, that under most circumstances, all distance are presumed to be horizontal distances. This dictates that every field measurements taken be either measured horizontally, or if not, reduced to a horizontal distance mathematically. Distance between points can be also determined using geometric or trigonometric computations working with related distance and angle measurements. In this field work, Surveyors use meter tape to measure a specific distance. Pacing is only used when the surveyors forgot a measuring instrument, taping has more precision than pacing. Taping is the linear measurement of the horizontal distance between two points using a surveyor’s tape. Observation of horizontal distances by taping consists of applying the known length of a graduated tape directly to line a number of times. In many instances, it is easiest to simply measure the horizontal distance by keeping both ends of the chain (steel tape) at the same elevation. This is not difficult if there is not over long distance or so of elevation change between points. Taping requires a minimum of two people. Using range poles, the line to be measured should be marked at both ends (in a vertical position), and at intermediate points where necessary, to ensure the unobstructed sight lines. The forward tapeperson is lined in by the rear tapeperson. Directions are given by vocal and signals. If the ground is not level, one or both surveyors must use a plumb bob. Normally, the only occasion when both surveyors have to use plumb bobs is when the ground rises or obstacles exist between two surveyors. If the ground is not level, one or both surveyors must use a plumb bob. Normally, the only occasion when both surveyors have to use plumb bobs is when the ground rises or obstacles exist between two surveyors.

II.

OBJECTIVES AND INSTRUMENTS 1. To develop the skills of taping the distance on a level ground where the tape is fully supported by the ground. 2. To acquire the skills of taping the distance on an uneven ground where the tape is only supported at the ends. INSTRUMENTS USED: 2 RANGE POLES CHALK 2 PLUMB BOBS 50 METER TAPE 1 Range Poles

2 Chalk/s

3 Plumb Bob

4 50 Meter Tape

INSTRUMENT DESCRIPTIONS: RANGE POLESSurveying instrument consisting of a straight rod painted in bands of alternate red and white each one foot wide; used for sightings by surveyors CHALK- Used to mark each distances measured by an instrument. PLUMB BOB- A cone-shaped metal weight, hung from a string, used to establish a vertical line or as a sighting reference to a surveyor's transit. 50 METER TAPE- Is an instrument used for measuring the ground or specific area not exceeding 50 meters. III.

PROCEDURES AND COMPUTATION

1. The professor assigns the accessible and unobstructed course to be measured by the student on a level ground by about 300-400paces. 2. The Chief of Party marks the end points by a chalk if it is on a pavement or by a 3’’ common wire nail (c.w nail) if it is on soft ground and designates it as end points A and B. 3. A range pole man holds the pole vertically and steadily during the entire taping procedure at B to keep the complete taping process aligned and straightened. 4. A 10-meter tape is stretched out on the ground on the straight path along A to B where the 0-end is held ahead. (Note: 0-end is nearer B than A). The rear tape man is responsible for giving the signal to the front tape man if his path is straight while the front tapeman is responsible to pull the tape taut once the tape is aligned already. 5. The front tapeman gets a pin and sticks it vertically in the ground exactly opposite the 0-meter mark of tape. 6. Rear tapeman holds 1 pin and the rest of the pins (10 pins) are held by front tapeman. 7. Both the front and the rear tapeman lift simultaneously the tape and move forward along the line AB to measure the next tape length. By now the rear tape man holds 1 marking pin which signifies one tape length. 8. The procedure 4-6 is repeated to complete the next tape length measurement. Make sure that the rear tapeman pulls the pin before lifting the tape to move on the next tape length. The rear tapeman holds 2 marking pins to connote 2 tape lengths have been measured. 9. Repeat the same process until all the pins being held by the front tapeman have been used up which signifies one tally (1 tally=10 tape

lengths). After a tally has been accomplished, the rear tapeman returns all the 10 pins to the front tapeman to proceed in measuring the length of the course. (it is suggested that the rear tapeman or the recorder tallies in the field computation sheet provided the number of one complete round) Note: One round is when all the ten pins are now being held by the rear tapeman). 10. Repeat the same procedure if more than one tally is needed. 11. Upon reaching point B the partial length must be measured accurately up to centimeters by the rear tapeman while the front tapeman is holding the 0-mark at B and both of them are holding the tape taut. 12. The number of small pebbles in the rear tapeman’s pocket now indicates the number of tallies made and the number of pins in his possession indicates the number of additional tapelenghts. This is recorded in the field computation sheet provided. 13. The course is measure back and forth to the complete the number of trials required by the professor.

COMPUTATIONS A.) Computation of an unknown distance. The number of tallies equivalent to the number of chalk marks being held by the rear tape-an, and the number of chalk marks is the number of tape lengths. Multiply the number of tallies by ten (10) and add it to the number of pins. The sum is then multiplied by the length of one tape length and then added to the last partial tape length to get the length of course AB.

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IV.

QUESTIONS AND PROBLEMS

1.) What are the different sources of taping errors? 

Personal Errors.



Temperature



Tension

2.) Discuss the different ways to lessen them or fully eliminate taping errors. 

The Surveyors must mark the ground correctly to guide them and to form a straight and consistent measuring.



The weather has a great effect on this field work, be sure to choose an average temperature.



Ask someone to guide you when measuring a distance so that, it will lessen taping errors.

3.) What is the total length of the course XY if the rear tape-man holds exactly holds 9 pebbles and 3 pins after measuring the course XY? Assume that one tape length is equivalent to 30m? 9 pebbles = 9 tallies 1 tally = 10 Total number of Tapelengths = 9(10)+3 = 93 Length of course = 93(30) = 2,790 m

V.

PRELIMINARY DATA SHEET

VI.

FINAL DATA SHEET

FIELD WORK 2

TAPING ON LEVEL AND ON UNEVEN GROUND DATE: OCT 8, 2015 GROUP NO: 1 TIME: 7:30am– 12:00nn LOCATION: th MIT West Bldg. 5 Floor WEATHER: CLOUDY PROFESSOR: Engr. Ira Balmoris 1. TAPING ON LEVEL GROUND

2. COMPUTATIONS Trial 1: 10(3) + 2(3) + 1.31 = 37.31

Mean=

37.31+37.2+37.325 3

=

37.318 Trial 2: 10(3) + 2(3) + 1.32 = 37.32 Trial 3: 10(3) + 2(3) + 1.325 = 37.325 . 3. TAPING ON AN IRREGULAR GROUND

4. COMPUTATIONS T. #1: 10(3) + 2(3) + 1.13 = 37.13 # 2: 10(3) + 2(3) + 1.22 = 37.22 # 3: 10(3) + 2(3) + 1.19 = 37.19

M . D=

37.13+37.22+37.19 =37.18 3

5. SKETCH

Photo no. 1 All members are trying to maintain a straight horizontal line.

Photo no. 2 Members are measuring a specified distance in the field work manual.

Photo no. 3 Members are doing the other part of their field work.

VII.

RESEARCH AND DISCUSSIONS THE PRINCIPLE: The precision obtained depends upon the degree of refinement with which the measurements are taken. Ordinarily, taping over flat, smooth ground with a steel tape or chain, divided in hundredths of a foot, provides a precision of one in three thousand to one in five thousand.

The precision taking a measurement of a distance by tape is better than taking a measurement using pacing, taping has lesser errors than pacing. In taping uneven or sloping ground, it is standard practice to hold the tape

horizontally and use a plumb-bob at one or perhaps both ends. On steeper slopes, where a full length of tape cannot be held horizontally without plumbing from above shoulder level, shorter distances are measured and accumulated to total a full tape length. This procedure is called as breaking tape. Taping downhill is preferable to measuring uphill for two reasons. First; in taping downhill, the rear point is held steady on fixed object while the other end is plumbed. In taping uphill, the forward point must be set while the other end is wavering somewhat. Second, if breaking tape necessary, the head tapeperson can more conveniently use the hand level to proceed downhill a distance, which renders the tape horizontal when held comfortably at chest height. In some cases, it becomes impractical to break chain. When the slope becomes so steep that frequent chaining (tape) points are required, a vertical surface must be measured across, or intermediate chaining (tape) points are not readily accessible, it may be more desirable to determine the horizontal distance indirectly. The most frequently used method is "slope chaining (tape)", where the distance along the slope is measured, the slope rate is determined, and the horizontal distance calculated.

VIII.

CONCLUSION This field work is all about taping a desirable distance, this will only be effective and efficient if the surveyors know the location. Location meaning, the weather is good and not crowded because taping a specific distance in a huge area is pretty serious. Errors may also appear in this field work not only

in pacing, finding the desirable distance with the use of taping needs an instruments and right procedures. I learned that taping in a location with leveled and unleveled ground may get its distance using the skills of the surveyors and with the use of the tech-equipment. Doing this field work, you may require more than 2 surveyors to guide and help you leveling and maintaining a horizontal line measuring the distance, you can assign people as the recorder, tapeman, and the chainman. We notice some errors in this field work it’s the tension, personal errors and sagged. Tension, while a certain amount of tension is desirable to help offset the sag effect, it will also stretch the tape. Steel will still stretch to some degree if tension is applied. Personal errors are from incorrect of setting pins, holding and reading the equipment. Lastly the sag, when a tape is suspended from each end and not supported along its length, the weight of the chain causes it to sag and pull the two ends toward each other. I would recommend that when the tape is checked against a known distance; the applied tension should be controlled, personal errors are common but be sure to check the sets of the equipment before recording or setting the pins, lastly sagging, It is impossible to exert enough outward force to fully overcome the sag. For all measurements, adequate tension should be applied to minimize the effective shortening of the tape.