SURVEYING REVIEWER.pdf

SURVEYING REVIEWER FIELD WORK SAFETY RULES: 1. Traffic Safety: 2. Site Inspection: 3. Weather Considerations: 4. Safety Briefings: Instrument Safety: 1. Tripod Safety: 2. Leveling Instruments: 3. Total Station Safety: 4. Battery Safety: Data Collection and Recording: 1. Data Integrity:...

SURVEYING REVIEWER FIELD WORK SAFETY RULES: 1. Traffic Safety: 2. Site Inspection: 3. Weather Considerations: 4. Safety Briefings: Instrument Safety: 1. Tripod Safety: 2. Leveling Instruments: 3. Total Station Safety: 4. Battery Safety: Data Collection and Recording: 1. Data Integrity: Double-check all measurements and data entries to ensure accuracy before leaving the field or laboratory. 2. Record Keeping: Maintain detailed records of all field and laboratory activities, including observations, measurements, and instrument calibrations. ENVIRONMENTAL AND ETHICAL CONSIDERATIONS: 1. Environmental Impact: Minimize environmental impact by avoiding damage to vegetation, soil, and wildlife during fieldwork. 2. Respect Property Rights: Obtain necessary permissions to access private property and respect landowners' rights. A. SURVEY PARTY 1. CHIEF PARTY – The person who is responsible for the survey party's overall direction, supervision, and operational control. 2. ASSISTANT CHIEF PARTY – the person whose duty is to assist the chief party and takes over the survey party during the absence of the chief. 3. INSTRUMENT MAN- The person who is to set up, level and operate surveying instruments He/ She responsible for checking the instrument to make sure that the instrument to be used in the field work operation is working properly. 4. TECHNICIAN- the person who is responsible for use and operation of all electronic Instrument required in a field work operation. 5. RECORDER- the person whose duty is to keep a record of all sketches, drawings, measurements and observation taken or needed for a fieldwork operation. 6. HEAD TAPE MAN – the person who is responsible for the accuracy and speed of all linear measurements with tape. 7. REAR TAPE MAN – the person whose duty is to assist the head tape man during taping operations and in other related work. 8. FLAGMAN- the person whose duty is to hold the flagpole or range pole at selected points as directed by the instrument man. 9. RODMAN- The person whose duty is to hold the stadia rod or leveling rod when sights are to be taken on it. GENERAL SAFETY RULES: 1. Personal Protective Equipment (PPE):Always wear appropriate PPE, such as safety glasses, a hard hat, high- visibility clothing, gloves,and steel-toed boots when required. 2. Training:Ensure that all personnel are adequately trained 3. Emergency Procedures: Familiarize yourself with the location of emergency exits, first-aid kits, fire extinguishers, and eyewash stations. Know how to use them. 4. Hazard Communication: Be aware of chemical hazards in the laboratory. Label and store chemicals properly, andunderstand the safety data sheets (SDS) for each chemical. 5. Equipment Inspection:Regularly inspect and maintain surveying instruments and equipment. Report any damaged ormalfunctioning equipment to supervisors. 6. No Eating or Drinking:Do not consume food or beverages in the laboratory area to prevent contamination or accidental ingestion of hazardous materials. SURVEYING is the art and science of taking field measurements on or near the surface of the Earth. Survey field measurements include horizontal and slope distances, vertical distances, and horizontal and vertical angles TWO MAIN REASONS WHY WE PERFORM SURVEY: 1. To gather data which we can plot to scale in a plan or a map also called preliminary surveying. 2. To layout dimensions taken from the design plan or what we called field surveys. 2 TYPES OF SURVEY Control survey- establish reference points and reference lines for preliminary and construction surveys. Construction survey- provide the line and grade for highways, street, pipelines, bridges, Buildings and site grading. FUNDAMENTAL PRINCIPLES OF SURVEYING: C.1 LOCATION OF A POINT BY MEASUREMENT FROM TWO POINTS OF REFERENCE- the relative position of a point to be surveyed should be located by measurement from at least two control points of reference, the positions of which have already been fixed. techniques to obtain the relative position of a point. 1. Rectangular Tie Ins - (also known as the right angle offset tie) 2. Polar Tie-Ins - (also known as the angle distance technique) 3. Intersection Tie-Ins - this method is useful in specialized location survey 4 Positioning Tie-Ins - it locates Topographic feature by direct positioning techniques like ground scanning techniques, satellite positioning techniques and remote sensing techniques. C2. Working from whole to part- Working from a whole to part is done to ensure that the errors and mistakes of one portion does not affect I. Types of surveying A. Primary Division of Surveying Plane survey - ignores the curvature of the earth this is because in plane surveying it covers a small area, so any line joining two points are considered as straight line. is used in an area with less than 250 km^2 Geodetic Survey - considers the curvature of the earth, so any line joining two points are called curve line and the triangle formed by the any three points are what we called spherical triangle and the angle formed are spherical angle. Geodetic surveying is used in an area with greater than 250km^2. A. TYPES OF SURVEYING Cadastral survey - it is the type of surveying that measure the property boundaries guided with the Law of Land Ownership. Construction surveys - surveys that made while the construction is in progress to have control in elevation, horizontal position and dimension. It provides data that is necessary for cost estimation Hydrographic survey - deals with bodies of water. Mine survey - it includes both surface and underground surveys. Photogrammetric survey - it is mixed of science and technology Route survey - a collection of data that is necessary to determine the required alignment and grades In designing and constructing of railroads, highway, pipelines, and canals. Topographic survey - is a type of survey that gather data about the elevation of point of the land anD present them as a contour line. MEASUREMENT OF DISTANCES Measurement - is the process of determining the extent, size dimension of a particular quantity in comparison into a given standard. 1 Horizontal Distance- the distance between two points that laid on the ground of the earth 2 Slope Distance – it refers to the change in the elevation of the land over the horizontal. 3 Vertical Distance- is the distance between two vertical direction. Distance by Taping or Gunter’s Chain- Surveyors have measured distances with ropes, lines, or cords for many centuries. Equipment required for Taping Steel Tapes Fiber Glass Tapes Range Pole- used for sighting points, for making ground points and for lining tape men in order to keep them going in the right direction. Taping Pins- also known as Chaining pins used for marking the ends of tapes or intermediate point while taping.  Plumb bobs- is a pear shaped or globular weight which is suspended on a string or wire and used to established vertical line Woven tapes, typically 50 feet long, can be metallic or nonmetallic, with nonmetallic being made of strong synthetic yarns and water- repellent fabric containing brass or copper wires. Hand Level- used for taping and rough determination of elevation. it consists of a metal sighting tube on which mounted a bubble tube. Clamping Handles- Leather thong is usually placed through the loops provided at the ends of the tapes DISTANCE BY PACING Pacing – is done in the preliminary survey to make a rough estimate. Pace - the length of the step while walking. Pace Factor – is determined by dividing the known distance by the average number of paces required to transverse it. FORMULA AVE= SUM N Pace factor= (known measured distance) (average no.of paces) Pace distance = [ pace factor x Ave. number of paces] Distance by Tachymetry - The tachymetry or tachometry which means "swift measurement", is derived from the Greek words taklus, meaning "swift", and mertron, meaning "measurement”. A. STADIA METHOD- This method provides a rapid means if determining horizontal distances B. SUBTENSE BAR- For fast and accurate measurement of horizontal distances DISTANCE BY MECHANICAL DEVICES Odometer- the odometer is a simple device that can be attached to a wheel for purposes of roughly measuring surface Measuring Wheel- a measuring wheel is very similar to odometer except that this is more portable and self- contained measuring device Optical Ranger Finder-hand held or mounted on a small tripod, can be used to determine distances approximately simply by focusing. ERRORS IN MEASUREMENT Errors - is the difference between a measured value and the “true” value. A. Types of Error 1. SYSTEMATIC ERROR - The magnitude and the algebraic sign can be determined 2. Random Error- accidental error (no human can perform perfectly) Source of Errors: 1. Instrumental Error - due to imperfection or faulty adjustment of the instrument this error will arise, for example the measuring tape is too long or a leveling instrument is not properly adjusted. 2. Personal Error - these arise from limitations of the human senses of sight, touch and hearing. 2. Natural Error - these are caused due to variations in nature like variations in wind, temperature, humidity, refraction, gravity and magnetic field of the earth. Accuracy - indicates how close a given measurement to its true value. The greater the accuracy, the smaller the error. Precision - refers to the degree of refinement and consistency with which any physical measurement is made. Mistakes - are inaccuracy in measurement because of some aspect of surveying operation is performed by surveyor with carelessness, inattention poor judgement and improper execution. Distance Correction TYPES OF CORRECTION: Incorrect Tape Length Rules for Correction 1. (Tape too long,add) 2. (Tape too short,subtract) Example 1: 1. A distance is measured with 100-m steel tape and is found to be 865.24m. Later a tape is standardized and is found to have an actual length of 100.05m. What is the correct distance measured? Solution: Measured Value = 865.24m Total Correction= (+0.05) (865.24/100) = + 0.43 m Corrected Distance = 865.60 m Example 2: A distance is measured with a 50m steel tape and is found to be 2320.35m. Later the tape standardized and is found to have an actual length of 49.93m. What is the correct distance measured? Solution: Measured Value = 2320.35m Total Correction= (-0.07) (2320.35/50) = - 3.25 m Corrected Distance = 2317.10 m CORRECTION DUE TO SLOPE Example: 3 Slope Distance AB and BC measures 320.2 m and 650.72m, respectively the difference in elevation are 11.11m for A and B, and 9.05m for points B and C. Using the formula for gentleslopes, determine the horizontal Length line of ABC. Assume that the line AB has a rising slope and BC a falling slope. CORRECTION DUE TO TEMPERATURE The tape lengthens as the temperature rises and shortens as temperature falls. Any changes in length of a tape due to variations in temperature is critical when undertaking precise measurements. Tape used in surveying is standardized at a specific temperature. Ct =CL (T-Ts) Where: C= is the coefficient of linear expansion or the amount of change in length per unit length per degree change in temperature. L= length of the tape or length of the line measured. T= is the observed temperature of the tape at the time of measurement. Ts = temperature at which the tape was standardized. If tape was made of steel, C= 0.0000116 per degree Celsius. The resulting sign of Ct will be either (+) positive or (-) negative and is added algebraically to the length measured to obtained correct length. Example: 4 A steel tape with a coefficient of linear expansion of 0.0000116 /1°C is known to be 50m long at 20°C. The tape was used to measure a line which was found to be 532.28 meters long when the temperature was 25°C. Determine the.) Temperature correction per tape length, b.) Correction for the measured line, and c.) Correct length of the line. Solution: a.) correction per tape length due to temperature Ct =CL (T-Ts) = 0.0000116(50) (25°-20°) = +0.0029 (The positive sign indicate that the tape is too long) b.) Correction for the measured line Ct ‘=CL (T-Ts) = 0.0000116(532.28) (25°-20°) = 0.03087m c.) Correct length of measured line L’= L ± Ct ‘ 532.28m +0.03087m L’ = 532.310m (the correction is added since the tape is too long)