introduction to surveying under ece

B Y :

R A K E S H K U M A R V E R M A

A S S T . P R O F E S S O R C I V I L E N G G . P . I . E . T .

Elements of Civil Engineering

Amer Fort, Rajasthan Agra Fort

TajMahal

Civil Engineering

One of the oldest of the engineering professions

Includes the designing, planning, construction, and maintenance of the infrastructure

Works include roads, bridges, buildings, dams, canals, water supply

Concerned with determining the right design for these structures and looking after the construction process

Egyptian pyramids and Roman road systems are based on civil engineering principles

Design

Planning

Construct

Field Surveying Planning and Drawing

Estimation & Implementation Maintenance

Civil Engg. in Daily routine

Water Treatment Plant

All have been designed and constructed by civil engineers

Morning

Shower

Water Supply System

Network of Roads

Structural Bridges

Tall Buildings

Importance and Applications of Civil Engineering

building good quality transportation systems like highways, airports, rail lines, sea ports, etc

fire control systems and installing quick fire exit points in the buildings

minimizing the loss of life during fire accidents

purify the contaminated air, water and soil

Continue……..

Other principal works in which surveying is primarily utilised are

1. to fix the national and state boundaries;

2. to chart coastlines, navigable streams and lakes;

3. to establish control points;

4. to execute hydrographic and oceanographic charting and mapping; and

5. to prepare topographic map of land surface of the earth.

Diamond Crossing Indian Railway

Delhi

Palais Royale Mumbai

China’s Dawang Mountain Resort

ITC Maurya Hotel in New Delhi

Signature tower, Abu Dhabi

Survey

Opinion Survey

Surveying

American Congress on Surveying and Mapping (ACSM) defines as;

Surveying is the science and art of making all essential measurements to determine the relative position of points or physical and cultural details above, on, or beneath the surface of the Earth, and to depict them in a usable form, or to establish the position of points or details.

This is being carried out by finding the spatial location (relative / absolute) of points on or near the surface of the earth.

Land Surveying

The science of determining the relative positions of points on the Earth’s surface

Primary Division of Survey( based on accuracy)

Geodetic Surveys

Plane Surveys

Takes into account the true size, shape, and gravity fields of the Earth

The geoid is the equipotential surface of the Earth’s gravity field which best fits global mean sea level

Provides significant precision

Establishes highly accurate control networks

Geodetic Survey

Surveying aims

to measure the Horizontal Distance between points.

to measure the Vertical elevation between points.

to find out the Relative direction of lines by measuring horizontal angles with reference to any arbitrary direction and

to find out Absolute direction by measuring horizontal angles with reference to a fixed direction.

Plane Survey

Assumes the Earth’s surface to be a plane (flat)

More common than geodetic surveys

Precise enough for small-scale surveys in a limited area, such as a construction site

Used to determine legal boundaries, construction surveys, and small-area topographic or control surveys

Plane Surveying

When radius of curvature of the earth is not taken into account.

Small area and small distances are covered

Degree of accuracy is comparatively low.

American survey put 250 km2 for treating survey as Plane, but controlling factor should be degree of precision rather than extent of area.

Based upon Nature of field

Based upon Method Employed

Land Survey

Marine Survey

Astronomical Survey

Triangulation

Traversing

Types of Surveying

Based upon Object of Survey

Based upon Instrument Used

Geological Survey(Object is to survey different strata in the earth crust)

Mine Survey (Mineral wealth such as coal, gold)

Military Survey(Points of strategic importance)

Surveying by Total Station

Chain Survey

Theodolite Survey

Compass Survey

Plane Tabling

Photographic and Aerial Surveys

Types of Surveying

Topographical Survey Cadastral Survey

Determine natural features of a country such as hills, valleys, lakes woods etc. and also arterial features such as roads, buildings, canals, towns etc.

Details such boundaries of houses, town, fields and other properties pathways are determined.

1. City Survey

2. Engineering Survey

Land Survey

Engineering Survey

Engineering Survey can be further divided into:

Reconnaissance (To determine the feasibility and rough cost of the scheme)

Preliminary Survey (For collecting more precise data)

Location Survey(For setting out the work on the ground)

Geodetic or Trigonometrical Surveying

When the radius of curvature of earth is taken in to account.

Large area and large distances are covered.

Object of geodetic survey is to determine precise positions on the surface of earth.

Refined Instruments and Methods are used.

Conducted by Government agencies.

No. Plain Surveying Geodetic Surveying

1 The earth surface is considered as plain Surface.

The earth surface is considered as Curved Surface.

2. The Curvature of the earth is ignored

The curvature of earth is taken into account.

3 Line joining any two stations is considered to be straight

The line joining any two stations is considered as spherical.

4. The triangle formed by any three points is considered as plain

The Triangle formed by any three points is considered as spherical.

5. The angles of triangle are considered as plain angles.

The angles of the triangle are considered as spherical angles.

6. Carried out for a small area < 250 km2

Carried out for a small area > 250 km2

‘Earth’ As considered

spherical in shape

Plumb Line

Geoid, Actual surface of earth

Geodetic survey line, equal elevation from center of earth

Horizontal survey line, equal elevation Horizontal plane

Rod Rod

Geodetic vs. Plane Survey

Types of Surveys

Control Survey

Topographic Survey

Property Survey

Site Survey

Construction Survey

Control Survey

Establish precise horizontal and vertical positions of points that serve as a reference for other surveys

Topographic Survey

Gathers data on the location of natural and man-made features, contours, and ground elevation to create a topographic map

Property Survey (or Boundary Survey)

Establishes property lines for a lot

Used to create a plat

Site Survey (Plot Survey or Lot Survey)

Combination of a property survey and topographic survey

May be required to receive a construction permit

Construction Survey

Locates points and elevations that can be used to establish correct locations and elevations for engineering and architectural projects

National Spatial Reference System (NSRS)

Common set of reference points for all surveys

Horizontal Datum = Collection of points of known latitude and longitude

Vertical Datum = Collection of points of known elevation

Benchmark (BM) = Permanent mark that establishes a point of known elevation

Optical Equipment

A theodolite measures

vertical and horizontal

angles

A total station is an

electronic/optical

surveying instrument

Optical Equipment

Automatic (Auto) Level

Commonly used on building sites

Internal compensator can automatically level the instrument

Measures difference in elevation between the line of sight and a point

Auto Level

Bulls Eye

Level

Telescope

Leveling

Screws

Horizontal

Angle

Rotation Ring

Eyepiece Horizontal

Tangent

Knob

Sight

Diopter

Adjustment

Ring

Mirror

Kennedy

Professional Tape Measure

Field Book

Other Equipment

Tripod Leveling Rod

Reading the Rod Stadia hairs

Horizontal

crosshair

Vertical

crosshair

View through the telescope

Reading the Rod

Upper Stadia Reading = 5.30 m

Rod Reading = 5.25 m

Lower Stadia Reading = 5.20 m

Stadia Readings

• Estimate distance between rod and instrument

• Rod intercept is the difference between stadia readings

• Estimated distance

• Stadia multiplier typically = 100

– Indicated on inside of instrument case or in Instructional Manual

Example

Upper Stadia Reading = 5.30 ft

Lower Stadia Reading = 5.20 ft

Rod Intercept = 0.10 ft

Differential Leveling

The establishment of differences in elevation between two or more points with respect to a datum

Earth Surface

Datum line or plane BM

BS FS Staff

Staff

Instrument

Point of unknown elevation

GPS Technology

Global Positioning System

A global navigation satellite system

Developed by the U.S. Department of Defense

A constellation of satellites that broadcast radio signals

Receivers intercept several satellite signals in order to determine precise location

GPS