Write three types of obstacles in chaining with examples. 

1 Answer

Answer :

1. Obstacle which can be chained across but cannot be ranged across. ,

Examples: Hill Intervening , rising ground.

2. Obstacle which can be ranged but cannot be chained across.,

Example: River, pond etc.

3. Obstacle which can be neither be ranged across not be chained across, Example: Building obstruction

Related questions

Description : Explain how will you overcome the obstacles over river during chaining operation.

Last Answer : A) river across the chain line. 1. Suppose AB is the chain line. Two points C & D are selected on this line on opposite banks of the river. 2. At C a perpendicular CE is erected and bisected at F. A perpendicular is ... ) X DF          CH=DF  = (CD/(CG-DF) )X DF        HG=CG-CH

Description : Describe in brief obstacles in chaining.

Last Answer : There are 3 types of obstacles 1. Obstacle to ranging 2. Obstacle to chaining 3. Obstacle to both ranging & chaining. 1) Obstacle to Ranging: The type of obstacle in which the ... type of obstacle the problem lies in prolonging the line beyond the obstacle & determining the distance across it.

Description : A 20m chain was found to be 6cm too long after chaining a distance of 1059m. It was found to be 9cm too short after chaining at the end 1985m. If the chain was correct before commencement of work find the true distance.

Last Answer : Given : Line ABC, AB=1059m, AC=1985m  L= 20m, No error at start, 0.06m too long at B,  0.09m too short  Find : True distance of AC = ? Solution : For part AB L = Length of chain= 20 m e = Average ... Total true distance of AC = True distance of (AB + BC)  = 1060.59 m + 922.52 m  = 1983.11 m

Description : Describe stepping method of chaining on sloping ground.

Last Answer : 1. If A and B are the two points on sloping ground, for which horizontal distance is to be measured. 2. Unfold the chain. By touching handle to station A, stretch it up to maximum possible ... 6. Thus total horizontal distance on sloping ground is calculated as d(AB) = L1+L2+L3 in meters.

Description : Explain Direct method of chaining on sloping ground with neat skeetch. 

Last Answer : While chaining on sloping ground, the horizontal distances can be computed by direct method i.e. By stepping. By stepping: It consist in measuring the distance in small horizontal lengths (e.g.L1). Let ... is continued in the correct line with point B. Then length of line AB=L1 +L2 +L3+L4

Description : Explain with neat sketch method of stepping of chaining on sloping ground.

Last Answer : Procedure : To measure the horizontal distance between points A & B on sloping ground following steps should be followed ( Refer above figure.) 1. Starting from point A, the chain is unfolded and ... . Finally calculate total chained distance as d(AB) = d(AP1) + d(P2P3) + d(P4P5)

Description : A 20 m chain was found to be 10 cm too short after chaining 1000 m It was found to be 20 cm too short after chaining 1800 m. If the chain was correct before commencement of the work find the true distance.  

Last Answer : Average error in chain for 1000 m length = (0 + 10) / 2 = 5 cm = 0.05 m too short True length up to 1000 m = (20 - 0.05) x 1000 / 20 = 997.5 m. Average error in chain from 1000 m to 1800 m length = (10 ... 1800 m length = (20 - 0.15) x 800 / 20 = 794.0 m. True distance = 997.5 + 794 = 1791.5 m.

Description : Explain the process of chaining on sloping ground by stepping method with neat sketch.

Last Answer : The procedure to measure horizontal distance between the points A and B on sloping ground is as follows. 1. Two persons-leader and follower are required for chaining. 2. The follower holds the end of chain at A. The leader goes ... between A and b L = AM, + MN' + NO' + OP' + PQ' + QB'

Description : Explain in brief linear measurements using: {i) Chaining (ii) Digital Tape

Last Answer : i. Chaining:  a. Linear measurement with chain carried out by two chainmen-Leader and follower.  b. The follower keeps the chain handle at starting station point, holds firmly it and directs the ... is at right spot, press the button and tape measures, calculates and displays distance on screen.

Description : Enlist the sources of error in chaining and state the precautions to be taken against error.

Last Answer : In general, the distance measurement obtained in the field will be in error. Errors in the distance measurement can arise from a number of sources: 1. Instrument errors: A chain may be faulty due to a defect ... confuse 10 m tag with 20 m tag. It should be avoided by noticing the 15 m tag.

Description : Describe in brief process of chaining on sloping ground.

Last Answer : In direct method which is also known as stepping method horizontal distance is directly measured as shown in fig. Horizontal distance between A and B is required to be measured. Procedure: i) A ... iii) The next step start from the C and the method is continued till point B reached. 

Description : Define 1)Ranging 2)Chaining

Last Answer : 1) Ranging The method of establishing intermediate points on a straight line between the two fixed points is known as ranging. 2)Chaining The method of measuring the distance with the chain or tape is called as Chaining.

Description : What is bench mark? State the types of bench mark and explain any one type.

Last Answer : Bench Mark- It is fixed reference point of known or assumed elevation. Types of bench mark1. Great trignometrical survey bench mark 2. Permanent bench mark 3. Arbitrary bench mark 4. Temporary bench ... Karachi are given in catalogue formed by department. They are also known as G.T.S. Bench mark

Description : State and describe the types of offsets. 

Last Answer : 1. Perpendicular offset- When the offset is taken at 900 to the survey line, then it is known as perpendicular offset. 2. Oblique offset- When the offset is taken at an angle other than 900 ( ... when offset is set by swinging chain or tape to survey line, such formed offset is called Swing offset.

Description : Explain types of bench marks.

Last Answer : Types of bench mark 1.Great trignometrical survey bench marka. These are the bench marks established with very high precision at regular intervals by survey of India Dept. all over the country . Their ... point. Such point should be on a permanent object so that next day it is easily identified.

Description : State different types of leveling. Explain any one in brief.

Last Answer : Types of Levelling  1. Simple Levelling.  2. Differential Levelling.  3. Fly Levelling.  4. Longitudinal or profile leveling.  5. Cross-Section Levelling.  6. Check Levelling.  1. ... B are taken. The difference of these readings gives the difference of level between A and B. 

Description : Explain four types of meridians. 

Last Answer : 1. True meridian: -The line which is passing through geographical north or south pole and given point on the surface of earth is called as true meridian. 2. Magnetic meridian:-The direction indicated ... particular zone. These lines are termed as grid lines and the centre line as the grid meridian.

Description : Explain ‘Declination of Magnetic needle’ and types of declination. 

Last Answer : Ans: The magnetic meridian at a place does not coincide with the true meridian at that place. The horizontal angle made by the magnetic meridian with the true meridian is called magnetic declination'. ... in others it points to the west of the true meridian called as West declination'

Description : State any four types of offsets and define them. 

Last Answer : i) Long offset: If length of offset more than 15 m. ii) Short offset: If length of offset less than 15 m. iii) Perpendicular offset: Offset taken perpendicular to chain line. iv) Oblique offset: Offset not taken perpendicular to chain line.

Description : Explain importance of Bench mark in leveling and state the types of Bench mark. 

Last Answer : Bench marks are fixed points or marks of known RL determined with reference to the datum line. These are very important points which serve as reference points for finding RLs of new points or for conducting ... 2. Permanent bench mark. 3. Arbitrary bench mark. 4. Temporary bench mark.

Description : Define Ranging. State types of ranging.

Last Answer : Ranging: It is process of locating points on ground along straight line. Types of ranging: 1. Direct ranging. 2. Indirect ranging

Description : Define bench mark and enlist the types of bench mark.

Last Answer : It is fixed reference point of known or assumed elevation. It is used either as a starting point for levelling or as a check while closing. There are four kinds of bench marks. i. Great ... ) bench mark. ii. Permanent bench mark. iii. Arbitrary bench mark. iv. Temporary bench mark.

Description : Write errors in leveling and corresponding precaution

Last Answer : i) Instrument error with respect to bubble tube, leveling staff. 1.If bubble tube is sluggish it may apparently be in the center though the bubble line is not horizontal. Precaution - ... reading. Precaution- Leveling should be properly done by bringing the bubble of bubble tube at Centre.

Description : Write any four advantages of intersection method of plane tabling over radiation method of plane tabling.

Last Answer : Advantages of intersection method: 1. Interection method requires less ground distance measurement than radiation method. 2. By this method we can locate inaccessible points which cannot be ... to radiation method, intersection method eliminates undulation error, bisection error and plotting errors.

Description : Write the functions of the following components of prismatic compass i) Prism, ii) Lifting pin, iii) Prism cap, iv) Agate cap

Last Answer : i) Prism: Reading printed on horizontal face of compass ring can be read from vertical position  ii) Lifting pin: When the instrument not in use the sight vane passes against the lifting pin which lift ... piece of hard glass provided on top of pivoted point, to reduce wear and tear of the point

Description : Draw sketch and write the procedure for setting offset to the left or right side of suvey line with open cross-staff.

Last Answer : Procedure for setting offset with open cross staff : 1. Keep the ranging rods at point P(fixed on survey line) and at point A1 approximately. 2. The cross staff with stadia rod is fixed ... can be fixed and perpendicular offset AB is said to be set to given survey line PQ in left side.

Description : Write the code of signals used in ranging with respect to : i) Correct position ii) Fix the ranging rod iii) Vertical position of ranging rod iv) Move slowly to left of observer 

Last Answer : i) Correct position : Both hands above Head and then Brought Down ii) Fix the ranging rod : Both Arms extended forward horizontally and the hands depressed briskly iii) Vertical position of ranging rod : 1 ... and moved to the Left iv) Move slowly to left of observer : Slow sweeps with Left Hand

Description : Write the uses of following survey instruments i) Ranging Rod ii) Pegs iii) Cross-staff iv) Plumb bob

Last Answer : i) Ranging Rod : Ranging rod are used for ranging. ii) Pegs : Pegs are used for marking the positions of stations or terminals points of survey lines. iii) Cross-staff : It is used ... It is also used for accurate centering of the surveying instruments like theodolite, compass, plane table etc. 

Description : With neat sketch, write the procedure of measurement of fore bearing with compass.

Last Answer : For measuring fore bearing of line AB, i) Place the compass over station A, center and level it.  ii) Looking through eye slit towards object vane, bisect the ranging rod at station ... which coincides with horse hair at observer end. The observed reading is the fore bearing of line AB

Description : Write-four uses of surveying.

Last Answer : Uses of surveying are: 1) Surveying is useful to plot ground details in various maps like topographic and cadastral maps. 2) It is useful in navigational movement planning through military survey. ... beneficial in collecting details of water bodies on earth like lake, pond, river, sea etc.

Description : The process of surveying is therefore in three stages namely:

Last Answer : (i) Taking a general view This part of the definition is important as it indicates the need to obtain an overall picture of what is required before any type of survey work is undertaken. In ... of quantities, datasheets, drawings and in land surveying maps and plan showing the features on the land.

Description : As used in survey

Last Answer : It's the operation of changing the face of telescope from left to right and vice versa.

Description : Tacheometric Surveying

Last Answer : Tacheometric is a branch of surveying in which horizontal and vertical distances are determined by taking angular observation with an instrument known as a tachometer. Tacheometric surveying is adopted in rough ... be prepared for investigation works within a short time on the basis of such survey.

Description : Explain the temporary adjustments of prismatic compass.

Last Answer : Temporary Adjustments of Prismatic Compass 1. Fixing the compass to the tripod The compass is fixed on a tripod by rotating screw head of tripod stand. 2. Centering the compass The prismatic compass ... prism is moved using focusing stud so that readings on graduated ring will be seen clearly. 

Description : State the fundamental axes and mention their relationship for a dumpy level.

Last Answer : Fundamental axis of dumpy level are as follows; i) The vertical axis ii) The axis of bubble tube iii) The line of collimation iv) The axis of the telescope Relationship between ... iii) Axis of telescope and line of collimation should coincide when dumpy level is correctly leveled.

Description : Describe with neat sketch, the optical square and explain its principle.

Last Answer : Principal of optical square :- the angle between the first incident ray and the last reflected ray is twice the angle between the two mirrors OR If there are two plane mirrors whose reflecting surfaces ... is 450 while that between the first incident ray and last reflected ray is 900 .  

Description : What consideration would you have while selecting survey stations and survey lines in a chain survey?

Last Answer : Following points to be considered while selecting survey stations and survey lines 1) Main survey station should be mutually visible. 2) All triangles should be well conditioned. 3) The survey line should lie ... of the area so as to form the frame work of triangles on it to cover maximum area. 

Description : What are offsets? How are they taken and recorded? Explain with sketch.

Last Answer : Offsets are lateral measurement to the base line. They are Located by judgment if short And by instruments (optical square or cross staff) if long and measured by metallic tape and shown with their chainages on base line

Description : Define fly leveling and profile leveling

Last Answer : Fly Leveling adopted to transfer bench marks from one place to other .In this leveling only FS & BS are taken.  Profile leveling:- The operation in which the object is to determine the ... known distanced apart along a given line to obtained the accurate outline of the surface of the ground 

Description : Define : 1) Bench mark 2) Datum surface 3) Line of collimation 4) Change Point 

Last Answer : 1) Bench mark: - It is a fixed reference point of known elevation.. 2)Datum surface :-It is any arbitrarily assumed level surface from which vertical distance are measured 3) Line of collimation:- ... which the fore and back sights are taken.  It is the point denoting the shifting of the level.

Description : State the situation where plane table is suitable. 

Last Answer : 1) It is most suitable for preparing small scale maps 2) It is suitable in magnetic are where compass survey is not reliable 3) It is most suitable for filling in details between stations fixed by triangulation 4) It is suitable where accuracy is not required.

Description : How would you detect presence of local attraction at a place ?

Last Answer : The presence of local attraction may be detected by finding difference of FB & BB of the line. If the fore bearing and back bearing difference is 1800 then there is no local attraction at both ... difference is not equal to 1800 then there is local attraction at both or any one station. 

Description : Define: WCB and Quadrantal Bearing system

Last Answer : Ans.: 1)WCB:-In this system the bearing of a line is always measured clockwise for the north point of the reference meridian towards the line round the circle the angle thus measured is called ... the bearing of a line is measured clockwise from the north point or south point whichever is nearest .

Description : State the two uses of survey based on geodetic surveying

Last Answer : Two uses of survey based on geodetic surveying:- i) To determine the precise position s on the surface of the earth. ii) Preparation of maps of large area like map of a country, state ... ) Establishment of GTS bench Marks across the country. iv) Preparation of military maps for defense purposes.

Description : State the important points kept in mind while recording the staff readings in level pages with respect first reading, intermediate reading, last reading, change point, carry forward from one page to next page-Remark

Last Answer : 1) First reading is on bench mark point and should be noted in back sight(BS) column 2) Intermediate reading (IS) should be taken on the points between first and last station. 3) Last reading ... column of next page 6) Remark column should have denote First and Last RL along with change points.

Description : State the purposes of following methods of leveling. i)Profile leveling, ii)Fly leveling, iii)Check leveling iv)Reciprocal leveling

Last Answer : 1. Profile leveling- To determine the undulation of ground surface along given line for alignment of road, canal or pipe, railway line 2. Fly leveling-It is used to for connecting B.M. to ... is used to find the difference in leveling between two points two point obstructed due to river or pond.

Description : Draw a sketch and explain how to find height of chajja or slab using dumpy level.

Last Answer : Explanation : 1. First the back sight reading is taken on floor level whose RL is known to us; from which RL of instrument axis can be find out by adding RL of BM and BS reading. 2. Now ... staff reading. 4. Finally height of chajja is calculated as RL of slab bottom -  RL of floor top.

Description : Explain temporary adjustment.

Last Answer : 1) Place the telescope parallel to foot screw (fig. a) 2) Bring the bubble at Centre by moving foot screw inward or outward simultaneously. 3) Then turn the telescope through 900 so that it ... 6) Once both positions give centered bubble, leveling of instrument is said to be completed.

Description : State fundamental lines and their relationships with each other of dumpy level.

Last Answer : Fundamental axes of dumpy level : i) The vertical axis ii) The axis of bubble tube iii) The line of collimation iv) The axis of the telescope Relations of Fundamental axes : i) The ... to the axis of the bubble tube. iii) Axis of telescope and line of collimation should coincide.

Description : State advantages of plane table survey one each with respect to booking and suitability

Last Answer : Booking of observations: i) Field work and plotting work done simultaneously ii) ) Notes of measurement are seldom required and possibility of mistakes in booking is eliminated. Suitability of PT ... and work where great accuracy is not required. ii) Mostly suitable for survey in plain terrain