SlideShare uma empresa Scribd logo
1 de 21
Baixar para ler offline
30838893 chain-survey
Surveying
     Primary divisions of surveying:
             1. Plane Surveying
             2. Geodetic Surveying

Plane surveying does not take into account the curvature of
the earth’s surface, and the surface of the earth is treated as a
plane surface.

If the area to be surveyed is more than 1000 km2, the angles
measured on the surface of the earth can not be in a plane
surface, but are in a curved surface.
Therefore, Geodetic surveying (which consider curvature of
earth) is used for achieving high precision for large areas.
Classification of Surveying

 Classification of surveying broadly based on:

               1. The function of survey
               2. Instruments employed

Classification based on
                               Classification based on
function of survey:
                               Instruments Employed:
Land surveying
                               Chain survey
City surveys
                               Compass survey
Route surveys
                               Plane-table survey
Mine surveys
                               Levelling survey
Geological surveys
                               Photogrammetric survey
Military surveys etc.
                               EDM survey
Principles of surveying


1. Fixing a point in relation to points
   already fixed


3. Working from the whole to the part
Definitions of some basic terms

Level surface: is the equipotential surface of the earth’s gravity field.
- A body of still water provides the best example of a level surface.
Horizontal line: A line tangent to a level surface is a horizontal line.
Horizontal plane: is a plane which is tangential to a level surface at a
particular point.
Horizontal angle: An angle measured between two intersecting lines
in a horizontal plane.
Vertical Line: is a line perpendicular to the horizontal plane
Vertical Plane: A plane containing a vertical line
Vertical Angle: Angle between two intersecting lines in a vertical
plane
Elevation: The vertical distance of a point from an assumed datum or
mean sea level.
Difference between a PLAN and a MAP

The distinction between plan and map is arbitrary. It is difficult
to say exactly when a plan becomes map.


In general a PLAN is ORTHOGRAPHIC REPRESENTATION of
features on or near earth on a horizontal plane. The earth’s
curvature is not taken into account. Therefore preferable for
smaller areas to avoid distortions due to curvature of the earth.


A MAP is also a graphical representation of features but differs
from a PLAN when the scale is small and is constructed usinga
projection system other than ORTHOGRAPHIC. In general MAPS
will give some additional information such as about the
topography with the help of contours.
Land Surveying
Need:-
  To secure necessary data of a part of land for the purpose of
  demarcating its boundaries, determining its area, preparing its plan
  or map, execution of engineering project etc.
Collection of Data:-
Collection of data can be done by any one or combination of surveying
  methods.
Ex;- Chain surveying, compass surveying, theodolite surveying,
  remote sensing etc.
Factors controlling the type of surveying:-
7. Depending on accuracy required
8. Extent and type of the area to be surveyed
9. Time available for the survey work
10.Economic aspects
Execution of surveying

Surveyor has to choose the best approach so
that work can be completed
      within given time-frame
and
      available funds.
Measurement of Horizontal Distances

The commonly used techniques in the basic
engineering are:
  Pacing
  Measuring Wheel
  Taping and/or Chaining
  Electronic distance measuring devices
  Optical devices
Pacing
   A pace is defined as ONE STEP
   A stride is consider TWO steps
   The ability to pace distance is very useful
   A person can determine their pace by counting the number
    of paces necessary to walk a distance that has been
    previously measured.
Measuring Wheels
Tape and Chain
Electronic Distance Measurement (EDM) Systems



EDMs are very useful in measuring distances that
   are difficult to access or long distances
Chain Surveying
Chain surveying the simplest method of surveying in which only linear
measurements are made and no angular measurements are taken.


The area to be surveyed is divided into a number of triangles and the sides
of the triangles are directly measured in the field.


Since the triangle is a simple plane geometrical figure, it can be plotted
from the measured length of its sides alone.


In chain surveying, a NETWORK of TRIANGLES is preferred.
Preferably all the sides of a triangle should be nearly equal having each
angle nearly 60o to ensure minimum distortion due to errors in
measurement of sides and plotting.
Generally such an ideal condition is not practical always.
Usually attempt should be made to have WELL CONDITIONED TRIANGLES
in which no angle is smaller than 30 o and no angle is greater than 120o.
Chain Surveying

The arrangement of triangles to be adopted in the field depends
on the shape, topography and the natural or artificial
OBSTACLES met with.

Chain surveying is suitable for the following cases:
2. Ground fairly level and open with simple details
3. Large scale plans (1 cm = 10 m)
4. Extent of the area comparatively small


Chain surveying is unsuitable for the following cases:
7. Area crowded with many details
8. Wooded countries
9. Undulating areas
10. Extent of large area
Chain Surveying
Definitions:
Main survey stations
-Is a point where TWO SIDES OF A TRIANGLE MEET.
- THESE ARE THE POINTS AT THE BEGINNING AND AT THE END OF
THE CHAIN LINE.
Tie stations (or) subsidiary stations:
-These are the points selected on the main survey lines for running
auxiliary lines.
Main survey lines:
- These are chain lines joining the main survey stations
Tie or subsidiary lines
-The chain lines joining the tie stations or subsidiary stations are
called as tie or subsidiary lines.
-These lines help in locating the interior details which are far away
from the main survey lines.
Chain Surveying
Definitions:
Base Line
- the longest of the main survey line
- various survey stations are plotted w.r.t. this line.
Check Lines:
-Those lines which are run to check the accuracy of the field work are called
as check lines or proof lines.
-The length of the check line in the plan must agree with its measured length
in the field.
- each triangle must be provided with a check line.
Offsets:
- Offsets are lateral distances measured from survey lines
-Offsets are taken from survey lines to determine the locations of details.
-Perpendicular offsets are called as simply “OFFSETS”
-Oblique offsets are called as oblique offsets.
Chain Surveying



        Tape and Chain
Chain Surveying


Metric surveying chains:
Length of chain: 20 m or 30 m
Number of links per meter length : 5
Length of each link : 20 cm
Tallies are provided at every 5 m
Small brass rings are provided at every meter except where
tallies are provided.
Metallic tape:
Length of tape: 20 m or 30 m
The linen tape is reinforced with fine brass or copper wires
to prevent stretching or twisting of fibres and is then called
as a metallic tape.
Chain Surveying


Arrows:
These are also called as marking or chaining pins
10 arrows are provided along with each chain.
Used to mark end of the chain during the process of
chaining.


Cross Staff: - used to make perpendicular lines
Basic Trignometry


    C        a           A2 + B2 = C2
                 B

b            c         a+ b+ c = 180o
        A



            sin b = B / C
            cos b = A / C
            tan b = B / A

Mais conteúdo relacionado

Mais procurados

Levelling, terms related to levelling, methods of levelling
Levelling, terms related to levelling, methods of levellingLevelling, terms related to levelling, methods of levelling
Levelling, terms related to levelling, methods of levellingMir Zafarullah
 
Theodolite ppt in 7
Theodolite ppt in 7Theodolite ppt in 7
Theodolite ppt in 7Arun Kama
 
Chain surveying.1
Chain surveying.1Chain surveying.1
Chain surveying.1Decentumang
 
LEVELLING METHODS AND INSTRUMENTS IN SURVEYING
LEVELLING METHODS AND INSTRUMENTS IN SURVEYINGLEVELLING METHODS AND INSTRUMENTS IN SURVEYING
LEVELLING METHODS AND INSTRUMENTS IN SURVEYINGATHIRA B K
 
Levelling in Surveying
Levelling in SurveyingLevelling in Surveying
Levelling in SurveyingRAHUL SINHA
 
Compass Surveying.ppt
Compass Surveying.pptCompass Surveying.ppt
Compass Surveying.pptWaseemUllah71
 
Instruments used in surveying
Instruments used in surveyingInstruments used in surveying
Instruments used in surveyingMir Zafarullah
 
Theodolite surveying part1
Theodolite surveying part1Theodolite surveying part1
Theodolite surveying part1Naufil Sayyad
 
Surveying and levelling
Surveying and levellingSurveying and levelling
Surveying and levellingParimal Jha
 
surveying instruments
surveying instrumentssurveying instruments
surveying instrumentsSelf-employed
 
Chain surveying and offset
Chain surveying and offsetChain surveying and offset
Chain surveying and offsetMir Zafarullah
 
Surveying part 1 unit 1 and 2
Surveying part 1 unit 1 and 2Surveying part 1 unit 1 and 2
Surveying part 1 unit 1 and 2Warish Khan
 

Mais procurados (20)

Levelling, terms related to levelling, methods of levelling
Levelling, terms related to levelling, methods of levellingLevelling, terms related to levelling, methods of levelling
Levelling, terms related to levelling, methods of levelling
 
Theodolite ppt in 7
Theodolite ppt in 7Theodolite ppt in 7
Theodolite ppt in 7
 
Surveying and Leveling
Surveying and LevelingSurveying and Leveling
Surveying and Leveling
 
Chain surveying.1
Chain surveying.1Chain surveying.1
Chain surveying.1
 
Theodolite traversing
Theodolite traversingTheodolite traversing
Theodolite traversing
 
LEVELLING METHODS AND INSTRUMENTS IN SURVEYING
LEVELLING METHODS AND INSTRUMENTS IN SURVEYINGLEVELLING METHODS AND INSTRUMENTS IN SURVEYING
LEVELLING METHODS AND INSTRUMENTS IN SURVEYING
 
Levelling in Surveying
Levelling in SurveyingLevelling in Surveying
Levelling in Surveying
 
chain surveying
chain surveyingchain surveying
chain surveying
 
Theodolite survey
Theodolite surveyTheodolite survey
Theodolite survey
 
Tacheometry ppt
Tacheometry pptTacheometry ppt
Tacheometry ppt
 
Compass Surveying.ppt
Compass Surveying.pptCompass Surveying.ppt
Compass Surveying.ppt
 
Surveying
SurveyingSurveying
Surveying
 
Instruments used in surveying
Instruments used in surveyingInstruments used in surveying
Instruments used in surveying
 
Theodolite surveying part1
Theodolite surveying part1Theodolite surveying part1
Theodolite surveying part1
 
Surveying and levelling
Surveying and levellingSurveying and levelling
Surveying and levelling
 
surveying instruments
surveying instrumentssurveying instruments
surveying instruments
 
Theodolite survey
Theodolite surveyTheodolite survey
Theodolite survey
 
Chain surveying and offset
Chain surveying and offsetChain surveying and offset
Chain surveying and offset
 
Levelling
LevellingLevelling
Levelling
 
Surveying part 1 unit 1 and 2
Surveying part 1 unit 1 and 2Surveying part 1 unit 1 and 2
Surveying part 1 unit 1 and 2
 

Destaque

Destaque (9)

Plane table surveying
Plane table surveyingPlane table surveying
Plane table surveying
 
Surveying instruments
Surveying instrumentsSurveying instruments
Surveying instruments
 
Presentation of surveying
Presentation of surveyingPresentation of surveying
Presentation of surveying
 
Modern surveying instruments - Assignment
Modern surveying instruments - AssignmentModern surveying instruments - Assignment
Modern surveying instruments - Assignment
 
Plane table survey
Plane table surveyPlane table survey
Plane table survey
 
Plane Table Survey
Plane Table SurveyPlane Table Survey
Plane Table Survey
 
Compass Surveying
Compass Surveying Compass Surveying
Compass Surveying
 
Chain surveying
Chain surveyingChain surveying
Chain surveying
 
Surveying
Surveying Surveying
Surveying
 

Semelhante a 30838893 chain-survey

Semelhante a 30838893 chain-survey (20)

Surveying i
Surveying iSurveying i
Surveying i
 
Chapter 1
Chapter 1Chapter 1
Chapter 1
 
Chapter 1
Chapter 1Chapter 1
Chapter 1
 
1.5_Basic Engineering_Day 7.pptx
1.5_Basic Engineering_Day 7.pptx1.5_Basic Engineering_Day 7.pptx
1.5_Basic Engineering_Day 7.pptx
 
1.1 Linear measurement original: Chaining & Ranging
1.1 Linear measurement original: Chaining & Ranging1.1 Linear measurement original: Chaining & Ranging
1.1 Linear measurement original: Chaining & Ranging
 
INTRODUCTION TO SURVEYING
INTRODUCTION TO SURVEYINGINTRODUCTION TO SURVEYING
INTRODUCTION TO SURVEYING
 
Basics of surveying
Basics of surveyingBasics of surveying
Basics of surveying
 
Unit 1
Unit 1Unit 1
Unit 1
 
Surveying pdf
Surveying pdfSurveying pdf
Surveying pdf
 
handbook of civil engineering
handbook of civil engineeringhandbook of civil engineering
handbook of civil engineering
 
Distance Measurement & Chain Surveying
Distance Measurement & Chain SurveyingDistance Measurement & Chain Surveying
Distance Measurement & Chain Surveying
 
DEFINITIONS, PRINCIPLES AND CHAIN SURVEYING
DEFINITIONS, PRINCIPLES AND CHAIN SURVEYINGDEFINITIONS, PRINCIPLES AND CHAIN SURVEYING
DEFINITIONS, PRINCIPLES AND CHAIN SURVEYING
 
Surveying (introduction)
Surveying (introduction)Surveying (introduction)
Surveying (introduction)
 
Fundamentals of surveying
Fundamentals of surveyingFundamentals of surveying
Fundamentals of surveying
 
Basic civil
Basic civilBasic civil
Basic civil
 
Basic Civil and Mechanical Engineering
Basic Civil and Mechanical EngineeringBasic Civil and Mechanical Engineering
Basic Civil and Mechanical Engineering
 
Triangulation
Triangulation Triangulation
Triangulation
 
SURVEYING UNIT-1 31033
SURVEYING UNIT-1 31033SURVEYING UNIT-1 31033
SURVEYING UNIT-1 31033
 
overview and clasification of surveying ppt.pptx
overview and clasification of surveying ppt.pptxoverview and clasification of surveying ppt.pptx
overview and clasification of surveying ppt.pptx
 
Surveying
Surveying Surveying
Surveying
 

Último

Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024D Cloud Solutions
 
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdfJamie (Taka) Wang
 
9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding TeamAdam Moalla
 
Nanopower In Semiconductor Industry.pdf
Nanopower  In Semiconductor Industry.pdfNanopower  In Semiconductor Industry.pdf
Nanopower In Semiconductor Industry.pdfPedro Manuel
 
Crea il tuo assistente AI con lo Stregatto (open source python framework)
Crea il tuo assistente AI con lo Stregatto (open source python framework)Crea il tuo assistente AI con lo Stregatto (open source python framework)
Crea il tuo assistente AI con lo Stregatto (open source python framework)Commit University
 
Spring24-Release Overview - Wellingtion User Group-1.pdf
Spring24-Release Overview - Wellingtion User Group-1.pdfSpring24-Release Overview - Wellingtion User Group-1.pdf
Spring24-Release Overview - Wellingtion User Group-1.pdfAnna Loughnan Colquhoun
 
AI Fame Rush Review – Virtual Influencer Creation In Just Minutes
AI Fame Rush Review – Virtual Influencer Creation In Just MinutesAI Fame Rush Review – Virtual Influencer Creation In Just Minutes
AI Fame Rush Review – Virtual Influencer Creation In Just MinutesMd Hossain Ali
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintMahmoud Rabie
 
Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Adtran
 
Machine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfMachine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfAijun Zhang
 
PicPay - GenAI Finance Assistant - ChatGPT for Customer Service
PicPay - GenAI Finance Assistant - ChatGPT for Customer ServicePicPay - GenAI Finance Assistant - ChatGPT for Customer Service
PicPay - GenAI Finance Assistant - ChatGPT for Customer ServiceRenan Moreira de Oliveira
 
Cloud Revolution: Exploring the New Wave of Serverless Spatial Data
Cloud Revolution: Exploring the New Wave of Serverless Spatial DataCloud Revolution: Exploring the New Wave of Serverless Spatial Data
Cloud Revolution: Exploring the New Wave of Serverless Spatial DataSafe Software
 
UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8DianaGray10
 
Comparing Sidecar-less Service Mesh from Cilium and Istio
Comparing Sidecar-less Service Mesh from Cilium and IstioComparing Sidecar-less Service Mesh from Cilium and Istio
Comparing Sidecar-less Service Mesh from Cilium and IstioChristian Posta
 
Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1DianaGray10
 
NIST Cybersecurity Framework (CSF) 2.0 Workshop
NIST Cybersecurity Framework (CSF) 2.0 WorkshopNIST Cybersecurity Framework (CSF) 2.0 Workshop
NIST Cybersecurity Framework (CSF) 2.0 WorkshopBachir Benyammi
 
OpenShift Commons Paris - Choose Your Own Observability Adventure
OpenShift Commons Paris - Choose Your Own Observability AdventureOpenShift Commons Paris - Choose Your Own Observability Adventure
OpenShift Commons Paris - Choose Your Own Observability AdventureEric D. Schabell
 
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...Aggregage
 
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPA
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPAAnypoint Code Builder , Google Pub sub connector and MuleSoft RPA
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPAshyamraj55
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6DianaGray10
 

Último (20)

Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024
 
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf
20200723_insight_release_plan_v6.pdf20200723_insight_release_plan_v6.pdf
 
9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team
 
Nanopower In Semiconductor Industry.pdf
Nanopower  In Semiconductor Industry.pdfNanopower  In Semiconductor Industry.pdf
Nanopower In Semiconductor Industry.pdf
 
Crea il tuo assistente AI con lo Stregatto (open source python framework)
Crea il tuo assistente AI con lo Stregatto (open source python framework)Crea il tuo assistente AI con lo Stregatto (open source python framework)
Crea il tuo assistente AI con lo Stregatto (open source python framework)
 
Spring24-Release Overview - Wellingtion User Group-1.pdf
Spring24-Release Overview - Wellingtion User Group-1.pdfSpring24-Release Overview - Wellingtion User Group-1.pdf
Spring24-Release Overview - Wellingtion User Group-1.pdf
 
AI Fame Rush Review – Virtual Influencer Creation In Just Minutes
AI Fame Rush Review – Virtual Influencer Creation In Just MinutesAI Fame Rush Review – Virtual Influencer Creation In Just Minutes
AI Fame Rush Review – Virtual Influencer Creation In Just Minutes
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership Blueprint
 
Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™
 
Machine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdfMachine Learning Model Validation (Aijun Zhang 2024).pdf
Machine Learning Model Validation (Aijun Zhang 2024).pdf
 
PicPay - GenAI Finance Assistant - ChatGPT for Customer Service
PicPay - GenAI Finance Assistant - ChatGPT for Customer ServicePicPay - GenAI Finance Assistant - ChatGPT for Customer Service
PicPay - GenAI Finance Assistant - ChatGPT for Customer Service
 
Cloud Revolution: Exploring the New Wave of Serverless Spatial Data
Cloud Revolution: Exploring the New Wave of Serverless Spatial DataCloud Revolution: Exploring the New Wave of Serverless Spatial Data
Cloud Revolution: Exploring the New Wave of Serverless Spatial Data
 
UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8
 
Comparing Sidecar-less Service Mesh from Cilium and Istio
Comparing Sidecar-less Service Mesh from Cilium and IstioComparing Sidecar-less Service Mesh from Cilium and Istio
Comparing Sidecar-less Service Mesh from Cilium and Istio
 
Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1
 
NIST Cybersecurity Framework (CSF) 2.0 Workshop
NIST Cybersecurity Framework (CSF) 2.0 WorkshopNIST Cybersecurity Framework (CSF) 2.0 Workshop
NIST Cybersecurity Framework (CSF) 2.0 Workshop
 
OpenShift Commons Paris - Choose Your Own Observability Adventure
OpenShift Commons Paris - Choose Your Own Observability AdventureOpenShift Commons Paris - Choose Your Own Observability Adventure
OpenShift Commons Paris - Choose Your Own Observability Adventure
 
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
The Data Metaverse: Unpacking the Roles, Use Cases, and Tech Trends in Data a...
 
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPA
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPAAnypoint Code Builder , Google Pub sub connector and MuleSoft RPA
Anypoint Code Builder , Google Pub sub connector and MuleSoft RPA
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6
 

30838893 chain-survey

  • 2. Surveying Primary divisions of surveying: 1. Plane Surveying 2. Geodetic Surveying Plane surveying does not take into account the curvature of the earth’s surface, and the surface of the earth is treated as a plane surface. If the area to be surveyed is more than 1000 km2, the angles measured on the surface of the earth can not be in a plane surface, but are in a curved surface. Therefore, Geodetic surveying (which consider curvature of earth) is used for achieving high precision for large areas.
  • 3. Classification of Surveying Classification of surveying broadly based on: 1. The function of survey 2. Instruments employed Classification based on Classification based on function of survey: Instruments Employed: Land surveying Chain survey City surveys Compass survey Route surveys Plane-table survey Mine surveys Levelling survey Geological surveys Photogrammetric survey Military surveys etc. EDM survey
  • 4. Principles of surveying 1. Fixing a point in relation to points already fixed 3. Working from the whole to the part
  • 5. Definitions of some basic terms Level surface: is the equipotential surface of the earth’s gravity field. - A body of still water provides the best example of a level surface. Horizontal line: A line tangent to a level surface is a horizontal line. Horizontal plane: is a plane which is tangential to a level surface at a particular point. Horizontal angle: An angle measured between two intersecting lines in a horizontal plane. Vertical Line: is a line perpendicular to the horizontal plane Vertical Plane: A plane containing a vertical line Vertical Angle: Angle between two intersecting lines in a vertical plane Elevation: The vertical distance of a point from an assumed datum or mean sea level.
  • 6. Difference between a PLAN and a MAP The distinction between plan and map is arbitrary. It is difficult to say exactly when a plan becomes map. In general a PLAN is ORTHOGRAPHIC REPRESENTATION of features on or near earth on a horizontal plane. The earth’s curvature is not taken into account. Therefore preferable for smaller areas to avoid distortions due to curvature of the earth. A MAP is also a graphical representation of features but differs from a PLAN when the scale is small and is constructed usinga projection system other than ORTHOGRAPHIC. In general MAPS will give some additional information such as about the topography with the help of contours.
  • 7. Land Surveying Need:- To secure necessary data of a part of land for the purpose of demarcating its boundaries, determining its area, preparing its plan or map, execution of engineering project etc. Collection of Data:- Collection of data can be done by any one or combination of surveying methods. Ex;- Chain surveying, compass surveying, theodolite surveying, remote sensing etc. Factors controlling the type of surveying:- 7. Depending on accuracy required 8. Extent and type of the area to be surveyed 9. Time available for the survey work 10.Economic aspects
  • 8. Execution of surveying Surveyor has to choose the best approach so that work can be completed within given time-frame and available funds.
  • 9. Measurement of Horizontal Distances The commonly used techniques in the basic engineering are: Pacing Measuring Wheel Taping and/or Chaining Electronic distance measuring devices Optical devices
  • 10. Pacing  A pace is defined as ONE STEP  A stride is consider TWO steps  The ability to pace distance is very useful  A person can determine their pace by counting the number of paces necessary to walk a distance that has been previously measured.
  • 13. Electronic Distance Measurement (EDM) Systems EDMs are very useful in measuring distances that are difficult to access or long distances
  • 14. Chain Surveying Chain surveying the simplest method of surveying in which only linear measurements are made and no angular measurements are taken. The area to be surveyed is divided into a number of triangles and the sides of the triangles are directly measured in the field. Since the triangle is a simple plane geometrical figure, it can be plotted from the measured length of its sides alone. In chain surveying, a NETWORK of TRIANGLES is preferred. Preferably all the sides of a triangle should be nearly equal having each angle nearly 60o to ensure minimum distortion due to errors in measurement of sides and plotting. Generally such an ideal condition is not practical always. Usually attempt should be made to have WELL CONDITIONED TRIANGLES in which no angle is smaller than 30 o and no angle is greater than 120o.
  • 15. Chain Surveying The arrangement of triangles to be adopted in the field depends on the shape, topography and the natural or artificial OBSTACLES met with. Chain surveying is suitable for the following cases: 2. Ground fairly level and open with simple details 3. Large scale plans (1 cm = 10 m) 4. Extent of the area comparatively small Chain surveying is unsuitable for the following cases: 7. Area crowded with many details 8. Wooded countries 9. Undulating areas 10. Extent of large area
  • 16. Chain Surveying Definitions: Main survey stations -Is a point where TWO SIDES OF A TRIANGLE MEET. - THESE ARE THE POINTS AT THE BEGINNING AND AT THE END OF THE CHAIN LINE. Tie stations (or) subsidiary stations: -These are the points selected on the main survey lines for running auxiliary lines. Main survey lines: - These are chain lines joining the main survey stations Tie or subsidiary lines -The chain lines joining the tie stations or subsidiary stations are called as tie or subsidiary lines. -These lines help in locating the interior details which are far away from the main survey lines.
  • 17. Chain Surveying Definitions: Base Line - the longest of the main survey line - various survey stations are plotted w.r.t. this line. Check Lines: -Those lines which are run to check the accuracy of the field work are called as check lines or proof lines. -The length of the check line in the plan must agree with its measured length in the field. - each triangle must be provided with a check line. Offsets: - Offsets are lateral distances measured from survey lines -Offsets are taken from survey lines to determine the locations of details. -Perpendicular offsets are called as simply “OFFSETS” -Oblique offsets are called as oblique offsets.
  • 18. Chain Surveying Tape and Chain
  • 19. Chain Surveying Metric surveying chains: Length of chain: 20 m or 30 m Number of links per meter length : 5 Length of each link : 20 cm Tallies are provided at every 5 m Small brass rings are provided at every meter except where tallies are provided. Metallic tape: Length of tape: 20 m or 30 m The linen tape is reinforced with fine brass or copper wires to prevent stretching or twisting of fibres and is then called as a metallic tape.
  • 20. Chain Surveying Arrows: These are also called as marking or chaining pins 10 arrows are provided along with each chain. Used to mark end of the chain during the process of chaining. Cross Staff: - used to make perpendicular lines
  • 21. Basic Trignometry C a A2 + B2 = C2 B b c a+ b+ c = 180o A sin b = B / C cos b = A / C tan b = B / A