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About Softwares used in the Project:

Following softwares were used:

1.  QGIS 2.0.1-Dufour

2.  Google Earth Pro 7

3.  Google Sketchup 20134.  MatLab 2009

QGIS:

QGIS (previously known as "Quantum GIS") is a cross-platform free and open source desktop geographic

information systems (GIS) application that provides data viewing, editing, and analysis capabilities. QGIS

allows to create maps with many layers using different map projections.  QGIS allows maps to be

composed of raster or Vector layers. 

Typical for this kind of software the vector data is stored as point, line, or polygon-feature. Different

kinds of raster images are supported and the software can perform georeferencing of images.

Use of QGIS in the project

QGIS`s Attribute Editing capabilities were extensively used for the project. Mathematical and

Boolean operations were performed on the dataset to calculate results. Geoprocessing tools were used

to display seismically vulnerable regions on the map.

Google Earth Pro

Google Earth is a virtual globe, map and a GIS program that offers users access to world-wide imagery,

and a large number of location-based layers. It is also a browser and authoring tool for geo-enabled web

content. It is also a very useful tool for visualizing data from GPS units. The Pro version of Google Earthadds the capability of downloading aerial photographs at much higher resolution than the free

consumer version of Google Earth. High-resolution aerial photography from Google Earth Pro may be

used to form a highly precise base layer for a GIS data set.

  Images may be imported and georeferenced by importing the image as an "image overlay

  Tabular data in text format may be exported and geocoded by address or latitude/longitude

using Google Earth Pro

  All images and tabular files can be converted into KML format using Google Earth Pro

Use of Google Earth in the Project:

Collection of geo referenced datasets in the seismic vulnerable region to get Co-ordinates &

Plan of all the buildings was done using google earth pro.

Google Sketchup 2013

Google SketchUp is 3-D modelling program, and also works with Google Earth products. It is available in

two versions - Google SketchUp (Free) and Google SketchUp Pro

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Google SketchUp : Google SketchUp has capabilities to build models of anything one can imagine -

furniture, buildings, cities. Google SketchUp Pro : It is 3D modeling software for professionals. 3D models can be created, either by

starting from scratch or by using existing data by importing drawings, CAD plans, photos, aerial imagery

and other information. The modeling tools in SketchUp Pro is used to develop ideas into 3D. It alsoincludes LayOut, which is the 2D companion to SketchUp Pro for creating deliverables like permit and

construction drawings, presentation documents and full-screen digital presentations. Use of Google Sketchup in the Project:

Using base layer of google earth image, volumetric shadow analysis was done to obtain height

of the buildings.

MatLab:

MATLAB (matrix laboratory) is a numerical computing environment and fourth-generation programminglanguage.  Developed by MathWorks,  MATLAB allows  matrix manipulations, plotting of functions and

data.

Use of MatLab in the project

MatLab `s calculation capabilities were extensively used for the project. Mathematical modeling

was used for the generation of response spectrum code from Bhuj Earthquake data.

Volumetric Shadow Analysis

Volumetric Shadow Analysis was used for generation of 3D building models from Google Earth database.

The method was used to extract building heightsand building footprints from a single image using

direction of sun and camera angle.

Steps Followed:

1.  From direction of light and camera, construct the shadow and the wireframe of the

building for an assumed building height in the 3D space

2.  Project the model back to image space.

3.  Reconstruct the shadow and the wireframe of the building by building height

4.  Increase/Decrease building height from initial value at regular interval.

5.  As the building height is changed, shadow is reconstructed by changed height and re-

projected onto the image.

6.  Until the shadow projected matches against actual shadow of the image building height

is changed.

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7.  When the shadow projected matches against the actual shadow, building height

becomes the actual building height and the boundary of the wireframe projected onto

the image becomes the boundary of the building footprint.

Estimation of Direction of Sun and Camera:

The direction of sun and camera was obtained from Google Earth Image.

From Paper “Generation of  3D building Models from commercial image database through

shadow analysis” 

T.Lee and T. Kim Inha university

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Model Specifications :

Madhapur area

Area - 3KM*3KM window around hi tech city theatre

Lat 17.441880N

Long 78.386979E

Date/Time Stamp: 2013-01-14T14:08:56Z

Selected Region:

Generation of Dataset :

Calculation of building heights Using Volumetric Shadow Analysis performed by using Google

Earth. Below is the brief procedure:

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  Using timestamp on image date (2013-01-14T14:08:56Z), time of image is found out and

Approximate angle of sun is calculated.

  Same is inserted in sketchup which in turn gives shadow of the buildings

  In sketchup, base layer of google earth image is placed.

  The rooftop of building is extruded in such a way that the shadows approximately match .Based

on the obtained heights of the building, the time periods and frequencies are calculated.

  Thus the georeferenced part of the Madhapur area is constructed.

Calculation for Most Vulnerable Time Period:

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From response spectrum analysis of Bhuj Earthquake, Following response spectrum is

constructed using MATLAB.

 

The Resonant frequency is 0.5924 Hz

Tabulated results are as follows,

Start Freq(Hz) End Freq(Hz) Type of Damage

0 0.061 No Damage

0.061 0.40894 Moderate Damage

0.40894 0.59204 Severe Damage

0.59204 1.59912 Minor Damage

1.59912 10 No Damage

From the response spectrum analysis, for bhuj earthquake all the buildings lying in the

frequency of 0.40894 to 0.59204 are vulnerable.

Calculation of the Time Periods:

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Time Period calculation for the building was done using IS1893 part 1 cl. 7.6 which states that:

The approximate fundamental natural period of vibration (T) in seconds, of a moment-resisting

frame building without brick infill panels may be estimated by the empirical expression:

  For RC frame building

Where,

h = Height of building, in m.

Inverse of time period gives the frequency in Hz.

Using a QGIS Attribute query, time periods and frequencies of all the buildings in the Madhapur

region were calculated.

Segregation of Building`s Damage Extent:

By using query builder of QGIS following query was executed to get the damage extent.

CASE

WHEN “Freq”>0 AND “Freq”<0.061 THEN “NO DAMAGE” 

WHEN “Freq”> 0.061 AND “Freq”< 0.40894 THEN “Moderate Damage” 

WHEN “Freq”> 0.40894 AND “Freq”< 0.59204 THEN “Severe Damage” 

WHEN “Freq”> 0.59204 AND “Freq”< 1.59912 THEN “Minor Damage” 

WHEN “Freq”> 1.59912 THEN “NO DAMAGE” 

END

Estimation of Affected People:

Since the selected area has clear demarcation of residential and commercial usage, following

assumptions were made to calculate approximate number of people present in the utility.

  Floor Height - 3m and 10 people per floor (Residential)

  Floor height -5m and 30 people per floor (Commercial)

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Following queries were executed for the residential and commercial buildings to get affected

population.

Residential Region Commercial Region

“population”=10*”ELEVATION”/3  “population”=30*”ELEVATION”/5 

Check for Pounding:

Pounding describes collision between adjacent buildings or different parts of the same building

during strong vibrations. It may cause either architectural or structural damage or both and

may lead to partial or complete collapse of the structure.

Pounding check is done for lateral storey drift of 4% of height of building.

Following query was executed to get maximum story drift.

“DRIFT”=0.04*”ELEVATION” 

Results:

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From the above calculations seismic vulnerability map and casualty prone areas are

demarcated.

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