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  3. How can we get angle value. Can u explain it deeply please?
  4. helpful and learn from it.
  5. The direction will be exactly towards west. Hence, no reduced bearing in this case.
  6. reduced bearing N90W or S90W
  7. if whole circle bearing of line 270°, then reduced bearing of the line is?
  8. I'll toss out a question... Long story short, I need a way to accurately measure position (& relative position in space) of multiple factors over a range of meter/yards with resolution of millimeters/100th of inch or better. This system monitors position of wheel/vehicle in contrast to a variable road surface. I can measure the wheel/vehicle via dual continuous 9 axis monitoring in real time but I also need a way to precisely measure the distance from a known height of sensor to the variable road surface to determine how the vehicle's suspension system should behave. Any ideas?
  9. didn't quiet get that angle value in first table
  10. Definition of BIM: Building information modelling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition. BIM benefits: Faster drafting without loss of cost and quality High level of customization and flexibility Optimization of schedule and cost Seamless coordination and collaboration Conflict detection and risk mitigation Easy maintenance of building life cycle Here is the nice info-graphic which compares BIM based process to the 2D drawings based process: Learn more about BIM solutions for structural engineers
  11. It is already described under the heading of Traverse including figures.
  12. what is open traverse and closed traverse?
  13. Traversing It is the method of establishing horizontal controls. Traverse Traverse is a series of connected lines forming or not forming a loop. In the first case it is called closed traverse (when the loop is formed) and in the second case it called open traverse (when loop is not formed). Vertical Control That is the reference point in vertical plane, it includes series of bench marks and points of known elevations. Horizontal Control It is the series of points in the horizontal plane of known co-ordinates. Types of Traversing Traversing can be further divided into two categories depending upon the type of instrument used, Compass Traversing Theodolite Traversing 1) Compass Traversing When prismatic compass is used for determining the direction of line, the method is called compass compass Traversing. 2) Theodolite Traversing When theodolite is used for measurement of angles or directions, the method is called theodolite traversing. By direction of line we mean the bearing of that line.
  14. Meridian Meridian is a reference direction with respect to which the direction of lines are mentioned. There are three types of meridian - True Meridian, Magnetic Meridian & Arbitrary Meridian 1 - True Meridian It is the reference direction of north pole of earth from a given station point. It is also called geographic meridian. 2 - Magnetic Meridian It is the direction of north pole indicated by magnetic needle. 3 - Arbitrary Meridian This is any assume direction to a well defined object. It may be useful for small areas. e.g A mosque is taken as reference and location of road will be mentioned with respect to this mosque. Direction of magnetic north with respect to true north is called magnetic direction. Bearings Bearing is the angle which a certain line make with a certain a certain meridian. Bearing with respect to true meridian is called true bearings while magnetic bearing is the angle which a line makes with respect to magnetic meridian. There are two ways to represent the bearings, Whole circle bearing (W.C.B) Reduced Bearing (R.B) 1) Whole Circle Bearing (W.C.B) It can be taken 0° to 360°. Quadrants are taken clock-wisely and angles are also determined in clockwise direction. 2) Reduced Bearing Reduced bearing or Quadrantal bearing is the angle which a line makes from North or South Pole whichever may be near. It is value is from 0° to 90°. Using the above figures you can easily convert the Whole Circle Bearing into Reduced Bearing. Some Examples are given are below. Whole Circle Bearing (W.C.B) Reduced Bearing (R.B) 135° S45E 37° N37E 65° N65E 125° S55E 215° S35W 300° N60W
  15. History of Electronic Distance Measurement In surveying distance measurements were always a challenge for surveyors specially when long distances were to be measured with high accuracy. In 1950 scientist tried to calculate the distance by using light beam to travel over unknown distance with measured time. Ordinary lights travels at a velocity of 186,000 miles per second, therefore the time taken will be very small to cover a short distance . This idea was soon dropped but the scientists succeeded in finding a low velocity light beam in form of Infra Red Rays generated by solid state Gallium Arsenide Diode (GAD). This was put into laboratory experimentation in 1960 and finally instrument called Electronic Distance Measurement came into existence. Initially the instruments were very expensive but as the demand increased the price was within the reach of most professionals. Revolution in Surveying due to EDM Modern EDM equipment contains hard-wired algorithms for reducing the slope distance to its horizontal and vertical equivalent. For most engineering surveys, Total stations combined with electronic data loggers are now virtually standard equipment on site. Basic theodolites can be transformed into total stations by add-on, top-mounted EDM modules. The development of EDM has produced fundamental changes in surveying procedures e.g Traversing on a grandiose scale, with much greater control of swing errors, is now a standard procedure. The inclusion of many more measured distances into triangulation, rendering classical triangulation obsolete. This results in much greater control of scale error. Setting-out and photogrammetric control, over large areas, by polar coordinates from a single base line. Offshore position fixing by such techniques as the . Deformation monitoring to sub-millimeter accuracies using high-precision EDM The latest developments in EDM equipment provide plug-in recording modules, capable of recording many thousand blocks of data for direct transfer to the computer. There is practically no surveying operation which does not utilize the speed, economy, accuracy and reliability of modern EDM equipment. For example the EDM instrument Model # LEICA RM100 BUILDER POWER have the following particulars, Absolute circle reading Laser plummet Endless drives 30x magnification Dual-Axis compensation High resolution LCD display Electronic laser distance measurement Graphic sketches EDM measurement with red laser on target Upload and transfer data Data editing and exchange Connectivity to 3rd party devices Hence, the advent of EDM equipment has completely revolutionized all surveying procedures, resulting in a change of emphasis and techniques. Taping distance, with all its associated problems, has been rendered obsolete for all base-line measurement. Distance can now be measured easily, quickly and with great accuracy, regardless of terrain conditions.
  16. Angle measurement For angle measurement with theodolite vertical hair is used. Basically there are two methods horizontal angle measurement, Repetition method (For single angle) Reiteration method (For more than one angle) 1 - By Repetition method Let suppose it is desire to measure the angle A from the following figure. We will use repetition method for this purpose. Procedure Setup the theodolite at station A. Bisect the point B with vertical hair of theodolite and move telescope in clockwise and direction to bisect at point C. Note this circle reading in the book and fix this circle reading, then again bisect the point B by keeping the circle reading fixed. Now, release the circle reading and rotate the telescope again in clockwise direction till it bisect again point C. Similarly get 3rd and 4th repetition and note the circle reading after 4th repetition in the book. Change the face of telescope and repeat the above steps, an example and method of booking observations have given below, Inst. Station Angle Face Repetition Circle Reading (° ′ ″) Angle value(° ′ ″) Mean of faces (° ′ ″) A BAC L 1 25 20 00 25 20 10 25 20 9.5 4 101 20 40 R 1 25 20 03 25 20 09 4 101 20 36 2 - By Reiteration method This method is used if there are more than one angles to be measure from a certain station point. Consider the following fiqure, we will measure angles AOB and BOC using this method. Procedure Setup the theodolite at station O, bisect the point A with a certain circle reading with face left. Rotate the instrument in clockwise direction and bisect B, note the circle reading. Then rotate and the telescope till it bisect the point C, note this circle reading also. All these reading will book into face left position. Transit the telescope and rotate the instrument through 180°, this time bisect the point C firstly and then rotate telescope in anti clockwise direction towards B and then ultimately towards A. Put these readings in face right position. You can do more than one sets of measurements for the accurate results, i have done one set and booking method is as follows, Inst. Station Stn. Sighted Face Circle reading(° ′ ″) Mean of faces(′ ″) Angle value(° ′ ″) O A L 10 20 05 20 06 AOB 37 10 05 R 190 20 07 B L 47 30 10 30 11 R 227 30 12 BOC 41 10 14 C L 88 40 20 40 25 R 268 40 30 One should start observation with some initial circle reading say 25°, if we start our observation with zero circle reading our calculations for computing mean will be little bit difficult.
  17. Types of Sewers 1. Sanitary Sewer It carries sanitary sewage i.e, wastewater from municipality including domestic and industrial wastewater. 2. Storm Sewer It carries storm sewage including surface runoff and street wash. 3. Combined Sewer It carries domestic, industrial and storm sewage. 4. House Sewer It is the sewer conveying sewage from plumbing system of a building to common/municipal sewer. 5. Lateral Sewer This sewer carries discharge from house sewers. 6. Submain Sewer This sewer receives discharge from two or more laterals. 7. Main/Trunk Sewer It receives discharge from two or more submains. 8. Outfall Sewer It receives discharge from all collecting system and conveys it to point of final disposal. Types of Sewer Systems 1. Separate System If stormwater is carried separately from domestic and industrial wastewater, the system is called separate system. Separate systems are favored when: There is an immediate need for collection of sanitary sewage but not for stormwater. When sanitary sewage needs treatment but the stormwater does not. 2. Combined System It is the system in which the sewer carry both sanitary and stormwater. Combined system is favored when: Combined sewage can be disposed off without treatment. Both sanitary and stormwater need treatment. Streets are narrow and two separate sewers cannot be laid. 3. Partially Combined System If some portion of storm or surface runoff is allowed to be carried along with sanitary sewage, the system is known as partially combined system. In urban areas of developing countries, mostly partially combined system is employed.
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