Flashcards
Surveying Lec
Flashcards do conjunto (63)
- 1has traditionally been defined as the science, art, and technology of determining the relative positions of points above, on, or beneath the Earth’s surface, or of establishing such points.Surveying
- 2Its earliest applications were in measuring and marking boundaries of property ownership.Surveying
- 3Throughout the years, its importance has steadily increased with the growing demand for a variety of maps and other spatially related types of information and the expanding need for establishing accurate line and grade to guide construction operations.Surveying
- 4The oldest historical records in existence today that bear directly on the subject of surveying state that this science began in Egypt.Egyptians
- 5recorded that Sesostris (King of Egypt) divided the land of Egypt into plots for the purpose of taxation.Herodotus
- 6Early surveyors were calledrope stretchers
- 7developed the science of geometry.Greek thinkers
- 8applied science to surveying in 120B.C.Heron
- 9He authored ________ which related the methods of surveying a field, drawing a plan, and making related calculations. It also described one of the first pieces of surveying equipment recorded, ______.The Dioptra, the diopter
- 10Significant development in the art of surveying came from the practical-minded Romans.Romans
- 11Ingenious instruments were developed and used. Among these were the ___________groma (used for sighting),
the labella (an A-frame with a plumb bob for
leveling), and the chorobates (horizontal
straightedge for leveling). - 12The art of surveying advanced more rapidly. The need for maps and location of national boundaries caused England and France to make extensive surveys requiring accurate triangulation; thus geodetic surveying began.18th and 19th Century
- 13is the simplest type of surveying in which the area to be surveyed is divided into a number of triangles. The length of the sides are measured and the interior details are recorded. The whole area is then plotted in a suitable scale to produce a map.Chain Surveying
- 14is a type of surveying in which the plot of the land to be surveyed is enclosed by a series of straight lines making angles with one another. The length of the lines and the angles are measured and plotted with all interior details on a drawing sheet to a suitable scale to produce a map.Traverse Surveying
- 15is a graphical method of surveying in which the field works and the plotting are done simultaneously. It is particularly adopted in small mapping.Plane Table Surveying
- 16is a type of surveying in which the relative elevations of different points on the surface of the Earth are determined.Ordinary Leveling
- 17Plane surveying can be divided into the following:1. Chain Surveying
2. Traverse Surveying
3. Plane Table Surveying
4. Ordinary Leveling - 18utilizes a network of well-defined triangles on the plot of land to be surveyed. One of the lines is considered as the baseline and all other lines and angles are then measured accordingly.Triangulation
- 19used in leveling across streams, gullies, and other obstructions to eliminate instrumental errors. The level readings are taken from two setups at two different points. The difference in levels between the two sites with obstructions is determined through this survey.Reciprocal Leveling
- 20method where a telescoping sight instrument is used to measure distances. This method incorporates a theodolite controlled by an operator and a level staff held by another surveyor at a distance. Both vertical and horizontal distances are computed through stadia readings.Tacheometry or Stadia Surveying
- 21a method in which the meridian, azimuth, latitude, longitude, etc. of the plot to be surveyed is determined with the help of celestial bodies.Astronomical Surveying
- 22a method where the maps are prepared from photographs taken from suitable camera stations. The output is a map, a drawing or a 3D model of some real- world scene or object.Photographic Surveying
- 23Geodetic surveying can be divided into the following:• 1. Triangulation
• 2. Reciprocal Leveling
• 3. Tacheometry or Stadia Leveling
• 4. Astronomical Surveying
• 5. Photographic Surveying - 24made for the purpose of locating structures and providing required elevation points during their construction.Construction Surveys
- 25pertains to mapping of shorelines and the bottom of bodies of water.Hydrographic Surveys
- 26are made to obtain the relative positions and elevations of underground shafts, geological formations, and so on.Mine Surveys
- 27utilizing data obtained by camera or other sensors carried in airplanes or satellites.Photogrammetric Surveys
- 28are reference surveys used to establish a network of horizontal and vertical monuments that serve as a reference framework for other survey projects.Control Surveys
- 29laid out to get linear measurements. These are graduated in feet or meters together with decimal parts of these units.Steel tape
- 30used as guides or markers when sighting points, and for lining up tapemen in order to keep them going along the correct direction.Range poles
- 31used for marking the ends of tapes or intermediate points during taping. These are sometimes referred to as taping arrows.Chaining pins
- 32used in taping to project a point on the tape down to the ground, or to project a point on the ground up to the tape.Plumb bob
- 33used in surveying to establish point son the ground. They are driven into the ground and are used in staking out a building.Wooden hubs/pegs
- 34used at the end of a tape for reading the pull applied to the tape during measurement. These are used only in precise taping work.Spring scale
- 35SURVEYING INSTRUMENTS • For taping:• Steel tape
• Range poles
• Plumb bob
• Chaining pins
• Wooden hubs/pegs
• Spring scale - 36consist of a telescope which fixes the direction of the line of sight and which can be rotated through 360 degrees in the horizontal. The instrument is simple in construction and has fewer parts to become worn or displaced.Dumpy level
- 37has a telescope tube supported by two y-shaped uprights fixed to a horizontal bar. By releasing the two clamping collars which fit across the tops of the Y’s, the telescope can be lifted clear of the Y-supports. This is not commonly used since other levels are better constructed for leveling work.Wye level
- 38has a self-leveling feature. As soon as the bull’s eye bubble is centered, the line of sight is automatically leveled and kept leveled when a compensator takes over. These are especially useful under conditions of unstable ground and wind, and where speed in leveling work is an important consideration.Automatic level
- 39consists of a tube through which the observer sights. On top of the tube is a small bubble reflecting through a prism so it appears to move vertically as seen by the observer sighting through the tube at a level rod. It is used where extreme accuracy is unnecessary and in taping to determine if the tape is held horizontally.Hand level
- 40designed for measuring horizontal and vertical angles. Transit is the one of the most versatile mechanical equipment but also the most complicated. Most have been supplanted by the total stations.Engineer’s Transit
- 41a precision surveying instrument for measuring angles. The telescope is short, inverting, internal-focusing and equipped with a glass reticle. A modern theodolite is compact, simple in design, and light in weight, yet rugged enough to withstand severe usage.Theodolite
- 42used in conjunction with an instrument such as a transit or level to determine distances or differences in elevation. It can be read by the surveyor while sighting through the telescope and noting the apparent intersection of the cross-hairs of the rod.Level rod
- 43SURVEYING INSTRUMENTS For leveling:• Dumpy level
• Wye level
• Automatic level
• Hand level
• Engineer’s transit
• Theodolite
• Total station
• Level rod - 44regarded as the most fundamental of all surveying observations.Distance measurement
- 45Distances are not necessarily linear, especially if they occur in the spherical earth.Distance measurement
- 46For relatively small distances, we can consider straight line as one existing in the Euclidean (geometric) space.Distance measurement
- 47is a practical measure of distance.Pacing
- 48• consists of counting the number of steps, or paces, in a required distance. • No equipment is needed. • offers relatively low accuracy.Pacing
- 49• Length of a step in walking • May be measured from heel to heel or toe to toePace
- 50the ratio of the measured distance to the number of paces made by a individual to cover the measured distance. 𝑃𝐹 = 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒/ 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑐𝑒𝑠Pace Factor
- 51converts the number of revolutions of a wheel of known circumference to a distance.odometer
- 52is operated by looking through the lens, adjusting the focus until a distant object viewed is focused, whereupon the distance to that object is obtained.optical rangefinder
- 53Sometimes called Tachymetry which means swift measurements.TACHEOMETRY (STADIA)
- 54This is a surveying method used to quickly determine the horizontal distance to, and elevation of, a point.TACHEOMETRY (STADIA)
- 55obtained by sighting through a telescope with two or more horizontal cross wires at a known spacing.Stadia observations
- 56was introduced in 1771 by James Watt. 12Stadia
- 57This indirect distance measuring procedure involves using a theodolite to read the horizontal angle subtended by two targets precisely spaced at a fixed distance.SUBTENSE BARS
- 58The length between the two targets is commonly 2 meters. • By using trigonometry, the following formula can be derived: 𝐻𝐷 = 1/ tan (𝜃/2)SUBTENSE BARS
- 59a method of measurement utilizing a steel tape or synthetic tape. • It is fairly quick, easy and cheap, and hence is the most common form of distance measurement.Taping or chaining
- 60• Taping accessories:1. Range poles
2. Chaining pins
3. Plumb bobs - 61On steeper slopes where the length of the tape cannot be held horizontally, shorter distances are measured and accumulated to total of a full tape length. This procedure is known asBreaking Tape
- 62Once appropriate errors are determined, the corrected distance for a measured line can be determined by substituting into the following equation. The application of this equation will always be correct, provided the correct algebraic sign is used for each correction. • 𝐶𝐿 = 𝑀𝐿 + σ 𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛𝑠TAPE CORRECTIONS
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- Descrição
- FlashCards sobre Surveying Lec, criado por Cassy Rivera em 19-01-2025.
- Criado por
- Cassy Rivera · jan 2025
- Atualizado
- 19 jan 2025
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