civilguruvu.com DESIGNATION OF MAGNETIC BEARING The magnetic bearings are designated in two systems, namely 1. Whole circle bearing (WCB) and 2. Quadrantal bearing (QB) 1. Whole Circle Bearing (WCB)Whole Circle Bearing (WCB) and Quadrantal Bearing (QB): The magnetic bearing of a line, with respect to the magnetic north measured in clockwise, established by the prismatic compass … Read more
FORE AND BACK BEARINGS In compass surveying, two bearings are observed for the each line, one from each end. Fore Bearing: The bearing of a line measured in the direction of the progress of survey is called Fore Bearing or Forward Bearing (FB) of a line AB Back Bearing: The bearing of a line measured … Read more
MAGNETIC DECLINATION OF COMPASS SURVEYING The horizontal angle between the magnetic meridian and true meridian is known as “Magnetic Declination”. (a) The north end of the magnetic needle is pointed towards the east side of the true meridian, the position is termed ‘Declination East . (b) The north end of the magnetic needle is pointed … Read more
TRAVERSING OF COMPASS SURVEYING The surveying which involves a series of connected lines is known as Traversing. The sides of traverse are known as Traverse legs’. In traversing, the lengths of the Traverse legs are measured by chain or tape. The directions of traverse legs are fixed by compass or Theodolite. If the traversing is … Read more
COMPASS SURVEYING — Purpose, Principles, Field Procedure, Errors And Precautions In chain surveying the area to be surveyed is divided into connected triangles and only linear measurements are taken The chain surveying is suitable when the area to be surveyed is small and fairly flat. However, when the area to be surveyed is large, then … Read more
CHAIN SURVEYING—PURPOSE AND PRINCIPLE OF CHAIN SURVEYING Chain surveying is one of the methods of land surveying. Chain surveying is the simplest and at the same time most accurate method of surveying, when the area of land to be surveyed is limited. In this type of surveying, only linear measurements are taken in the field, … Read more
EQUIPMENT USED FOR CHAIN SURVEYING The following equipments are used for chain surveying (a) Metric chain (20 or 30 m) (b) Arrows (c) Metallic tape (d) Ranging rods (e) Offset rod (f) Cross-staff or Optical square (g) Plumb-bob (h) Wooden pegs (i) Mallet (J) Field book (k) Pencils, Eraser, Knife etc., CHAIN Chains are prepared … Read more
RANGING AND CHAINING OF SURVEY LINES RANGING A SURVEY LINE Process of establishing intermediate points on a survey line, The process between two stations is known as ranging of survey lines or simply ranging. Ranging must be done before chaining a survey line, if the distance between two stations is more than the length of … Read more
FIELD WORK PROCEDURE Field work procedure in chain surveying shall be carried out as per the following steps. 1.first Reconnaissance: Earlier to the starting of survey work, the surveyor should walk around the whole area to be surveyed, and check the possibility of arrangement of frame work. During his investigation, he should also fixes … Read more
OBSTACLES IN CHAIN SURVEYING OBSTACLES IN CHAIN SURVEYING The objects, which create obstruction or difficulty in continuing the chaining of a survey line, are called obstacles. There are many obstacles which create obstruction to the chaining or ranging, they may be pond, Hill, river, valley, building etc. Various methods are adopted to overcome these … Read more