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INTRODUCTION
An art and science of determining the relative position of point on above or beneath the surface of the earth by means of angular and linear measurements is defined as Surveying. It is the most important subject matter before and during all engineering works like civil engineering works such as designing and construction of highways, water supply systems, irrigation projects, buildings etc. The main objectives of surveying courses allocated for civil engineering students is to promote them the basic knowledge of different surveying techniques relevant to civil engineering works in their professional practice. To begin any engineering work, the preliminary work done is the surveying, which provides a basic framework for the conception, design and execution of any engineering work. The information about these features are gathered by measuring the horizontal and vertical distances between the objects, by measuring the angle between the lines and by establishing points by predetermined angular and linear measurements. The actual measurements are accompanied by mathematical calculations for determining distances, angles, directions, locations, elevations, areas and volumes. The information thus collected is then portrayed graphically by the construction of maps, profiles, cross-sections and other diagrams.
The process of surveying consists of fieldwork of taking measurements and office work of continuing and drawing necessary to the purpose of the survey. The fieldwork is the vital part for any kind of survey. As a surveyor, he/she must have sound knowledge, instrument handling skills, personal traits of friendship, sociability by rational and logical, be able to lead and command etc.
This survey camp has been introduced as the partial fulfillment of the course. The main objectives of this camp held at Budhanilkantha School, Narayansthan, Kathmandu and Baluwa Khani, Kapan are aimed to provide opportunities to become familiar with and face actual field related problems to civil engineering Survey. The camp is designed to further
enhance the knowledge of different surveying works and to build confidence among the students, since only the critical concepts are not sufficient to tackle with actual field problems.
This is a detail report of the works, which were performed by group no. 8, having five members, during the camp period. It briefly explains the working procedures and technique used by this group during that camp period. In addition, it also contain observations, calculations, methods of adjustment of error, main problem faced during work and their solution, results of all calculations and their assessments with some comments is presented in a concise form. Each member has had equal contribution in performing the given tasks and preparing this detailed report.
Principle of Surveying The fundamental principles of plane surveying are:
Working from whole to part : It is very essential to establish first a system of control points with higher precision. Minor control points can then be established by less precise method and details can then be located using minor control points by running minor traverse. This principle is applied to prevent the accumulation of error and to control and localize minor error. Location of point by measurement from two points of reference : The relative position of points to be surveyed should be located by measurement from at least two (preferably three) points of reference, the position of which have already been fixed. Consistency of work : Keeping consistency in method, instrument, and observer etc. the survey work of desired level of accuracy could be performed. Independent check : Every measurement taken in the field must be checked by some independent field observation so that the mistake is not passed unnoticely. Accuracy required : Proper method and proper instrument should be used depending upon amount of accuracy required. Accuracy of angular and linear values should be compatible.
Description of works:
Traversing:
i) No. of Major Traverse stations: 19 ii) No. of Minor traverse stations: 13 iii)No. of minor loops: 2 iv) Length of perimeter of Major traverse: 1,260.840 m vi)Longest leg length of Major traverse: 95.473 m vii) Shortest leg length of Major Traverse: 49.664 m Details of the data taken are in the observation sheet. Scale: Topographic map: 1:
Major and minor traverse 1:
Contour interval = 1m Detailing: i) Area: The minor traverse area covers the Principle Office, Guards’ Block, Auditorium, Canteen, Science Block, Math Block, Music Block & a Football Ground.
Road Alignment:
i) Road Type: Village Road ii) Surface: Earthen iii) Length of the road: 444.154m iv)No. of intersection points: 9 v) Cross section: 10m left and 10 m right on both sides of the centerline. vi) Longitudinal section: in every 20m of the length Details of the data taken are in the observation sheet Scale: Topographic map: 1:
Longitudinal section: Horizontal=1:
Vertical= 1:
Cross sectioning: Horizontal= 1:
Vertical= 1:
Contour interval: 1 m
OBJECTIVE
Since the commencement of the civilization of men, surveying has been developing since then. The art of surveying and the preparation of maps have been practiced since the ancient times. In absence of the accurate maps, it is near impossible to lay out the alignment of roads, canals, bridges, tunnels, transmission power lines and waves relaying towers accurately. Surveying is the preliminary step for the execution of such projects. The main objective of the survey camp is to provide a basic knowledge of practical implementation of different surveying works. It helps to build up the self-confidence level by implementing different surveying works. Other objectives of survey camp can be further listed as follows:
To become familiar with the surveying problems that are arise during the field works. To became familiar with the parts of the instruments, their functions and handling the surveying instruments for its use in surveying. To become familiar with the spirit and importance of teamwork, as surveying is not a single person work. To complete the given project in scheduled time and thus knows the value of time. To collect required data in the field in systematic ways. To compute and manipulate the observed data in the required accuracy and present it in diagrammatic and tabular form in order to understand by other engineers and related personnel easily. To tackle the mistake and incomplete data from the field while in office work. To be acquainted with the complete method of report preparation.
INDEX AND LOCATION MAP
Index map of the Budhanikantha
Map of the Budhanilkantha School
06: 30 to 07: 00 : Breakfast. 07: 00 to 11: 30 : Survey work. 11: 30 to 12: 30 : Lunch (in rotation, without stopping work.) 12: 30 to 18: 30 : Survey work. 18: 30 to 19: 30 : Night class 19: 30 to 20: 30 : Dinner 20: 30 onwards : Calculations
1. PROJECT AREA
1.1 LOCATIONS AND ACCESSIBILITY
Budhanilkantha School is located about 6 km towards north of Kathmandu city. It took around an hourdrive to reach Budhanilkantha School from Kalimati, Kathmandu. The project site is situated in about 1400 m. above mean sea level. There are ample amount of local transportation facilities connecting this VDC with the main city which has enhanced it development. Well- pitched Road connects this VDC with the capital. Country: Nepal Region: Central Development Region District: Kathmandu Zone: Bagmati Location: Budhanilkantha VDC. Sites: Theodolite traversing and Tachometric detailing at Budhanilkantha School Road Alignment at Budhanilkantha School Bridge Site at Kapam VDC
1.2 TOPOGRAPHY AND GEOLOGY
Before starting our job, we should study about the existing position of the project area related to the natural grid line so that we can relate our result into the natural grid. The latitude and longitude of Budhanilkantha is as follows:
(The chart above is based on data from the Nepal Bureau of Standards & Meteorology) In Budhanilkantha School, there were various species of tall trees with moderate trunk. The vegetation consists of a variety of natural forest types, depending on altitude and aspects. Also various cultivated plants and trees can be found.
1.4 OTHERS
Budanilkantha is a village in Kathmandu District in the Bagmati Zone of central Nepal. At the time of the 2001 Nepal census it had a population of 133,244. The famous Budhanilkantha temple lies in the same VDC.The Budhanilkantha statue of the Hindu god is the largest and most beautiful stone carving in all of Nepal. It is also the most enigmatic carved from a single block of basal stone of unknown origin, the Budhanilkantha statue is 5 meters in length and it lies in a reclining position inside a recessed tank of water (representing the cosmic sea) that is 13 meters in length.
2. TOPOGRAPHICAL SURVEY
Topographical surveying is the process of determining the positions of natural and artificial features of the locality by means of conventional signs up on a topographical map. Topographic surveys are three-dimensional; they provide the techniques of plane surveying and other special techniques to establish both horizontal and vertical control. Hence the fieldwork in a topographical surveying consists of three parts. It establishes both horizontal and vertical control. It locates the contours. It also locates the details such as rivers, streams, lakes, roads, houses, and trees etc.
2.1 OBJECTIVES
The main Objective is to prepare the topographic map of the given area with horizontal control and vertical control with required accuracy. This also includes the calculation and diagrammatic Representation of the area with the help of coordinates in the paper with gridlines.
2.2 BRIEF DESCRIPTION OF THE AREA
The topographical survey was performed in the Budhanilkantha School. The major traverse runs through the school area, which covered the whole area of the school. The minor traverse was run within the major traverse through the plot of the given map, which covers several supporting buildings of the school. The main buildings are:
Principal Office Staff Quarters Canteen Auditorium Science Block, Maths Block, Music Block
2.4 EQUIPMENT & ACCESSORIES
The equipment used during the preparation of topographic map are as follow:
Theodolite Total station Leveling Staffs Ranging Rods Measuring Tapes 30m & 50m Leveling Instruments Plumb Bob Nails, Pegs Compass Marker Pen Umbrella Hammer
2.5APPLICATION OF ELECTRONICS SURVEY TECHNOLOGY
TOTAL STATION
A total station is an optical instrument used a lot in modern surveying and archaeology and, in a minor way, as well as by police, crime scene investigators, private accident reconstructionists and insurance companies to take measurements of scenes. It is a combination of an electronic theodolite (transit), an electronic distance meter (EDM) and software running on an external computer known as a data collector With a total station one may determine angles and distances from the instrument to points to be surveyed. With the aid of trigonometry and triangulation, the angles and distances may be used to calculate the coordinates of actual positions (X, Y, and Z or northing, easting and elevation) of surveyed points, or the position of the instrument from known points, in absolute terms. 16 | Page Group-
Some total stations also have a GPS interface which combines these two technologies to make use of the advantages of both (GPS - line of sight not required between measured points; Traditional Total Station - high precision measurement especially in the vertical axis compared with GPS) and reduce the consequences of each technology's disadvantages (GPS - poor accuracy in the vertical axis and lower accuracy without long occupation periods; Total Station - requires line of sight observations and must be set up over a known point or within line of sight of 2 or more known points). Most modern total station instruments measure angles by means of electro-optical scanning of extremely precise digital bar-codes etched on rotating glass cylinders or discs within the instrument. The best quality total stations are capable of measuring angles down to 0.5 arc- second. Inexpensive "construction grade" total stations can generally measure angles to 5 or 10 arc-seconds. Measurement of distance is accomplished with a modulated microwave or infrared carrier signal, generated by a small solid-state emitter within the instrument's optical path, and bounced off of the object to be measured. The modulation pattern in the returning signal is read and interpreted by the onboard computer in the total station. The distance is determined by emitting and receiving multiple frequencies, and determining the integer number of wavelengths to the target for each frequency. Most total stations use a purpose- built glass Porro prism as the reflector for the EDM signal, and can measure distances out to a few kilometers, but some instruments are "reflectorless" , and can measure distances to any object that is reasonably light in color, out to a few hundred meters. The typical Total Station EDM can measure distances accurate to about 3 millimeters or 1/100th of a foot. Some modern total stations are 'robotic' allowing the operator to control the instrument from a distance via remote control. This eliminates the need for an assistant staff member to hold the reflector prism over the point to be measured. The operator holds the reflector him/herself and controls the total station instrument from the observed point.
The traverse line of sight should not be near the ground level to avoid the refraction Thinking the above given points into consideration, the traverse stations were fixed. Then two way taping was done for each traverse leg. Thus, permanent fixing of the control points completes recci.
TRAVERSING Traversing is a type of surveying connecting number of survey lines forming the framework. It is also a method of control surveying. The survey consists of the measurement of Angles between successive lines or bearings of each line. The length of each line. The directions and the lengths of the survey lines are measured with the help of an angle-measuring instrument such as theodolite and a tape. If the co-ordinates of the first station and the bearing of the first line are known, the co-ordinates of all successive points can be computed as follows:
XB = XA + L CosӨ YB = YA + L SinӨ Where, L=Length of traverse leg Ө=Bearing of AB There are two types of traverse. They are as follows:
I. Closed traverse If the figure formed by the lines closes at a station i.e. if they form a polygon or it starts and finishes at the points of known co- ordinates then the traverse is called closed traverse.
II. Open traverse If a traverse starts and finishes at points other than the starting point or point of known co-ordinates, then the traverse is called open traverse. The traversing performed in Budhanilkantha School is closed traverse. While forming the major traverse which ran out covering internal periphery of Budhanilkantha School compound, we were given with the length and bearing of one line i.e. line joining CP1-CP2. By the reconnaissance we established 19 major stations which formed one closed loop and minor stations(13) which formed 2 minor loops with major traverse legs.
III. Link Traverse: A link traverse is the type of traverse where an open traverse is linked at its ends to an existing traverse to form a closed traverse. The closing line may be defined by coordinates at the end points, which have been determined by previous survey. The difficulty is, where there is linear disclosure, it is not known whether the error is in the new survey or the previous survey.
