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This menu describes natural factors that influence soils and other factors that may have an effect on seismic resistance of buildings.

1. Engineering-Geological map: Overall information regarding engineering-geological maps is arranged in the following types of files:
· Digital contours of soil types
· Description and other characteristics of soils in attributive tables
· Signs comprised of different colours and symbols.
The last file is the legend of the map and is used for building the geological column of the well. Seismic categories of soils have been corrected according to CNRA-94 requirements.
Compared to the paper map, the digital one is modified, as it is designed to work with larger construction map. E.g. soils different with coarse waste materials are combined under one sign or description.
View screenshot.

2. Hydrogeological Map: The map describes areas where depth of water occurrence lies at 0-2m, 2-5m, 5-10m and 10-20m. Areas which are less examined, the intervals have been set at 0-10m and 10-20m. Data in Hydrogeological map has been compiled in the files of digital code contours of the areas. The areas are represented as graphical objects characterized by the following attributes: depth of water occurrence and the code of sign, which corresponds to the depth of occurrence. Also a legend file is developed, which shows the depth occurrence of underground waters. View screenshot.

3. Seismic Microzoning Map: Seismic microzoning is designed for estimating the seismic influence on buildings and installations. Here it is necessary to estimate the factor of soil properties of buildings' and installations' basements for forecasting the outcomes of scenario earthquakes. The seismic database was developed based on 1:10000 scale map of S. Pirusyan and S. Simonyan. The map shows the areas that have 8, 9 and 10 magnitude seismic resistance and areas not suitable for construction. The 8 magnitude areas are basalts, monolith tuffs with 6-8m+ thickness and sandy loams with less than 2-5m thickness. 9 magnitude areas are gypsiferous colored clay and hrazdan soils, soils that include sandy loams, sands, loams, loose tuffs and coarse waste soils with 2-5m thickness. 10 magnitude areas are subsidence soils, sandy loams, volcanic sands with 6-10 thickness, water-saturated loams and dusty sands. Sandy loam areas having thickness of more than 8m and areas where hazardous processes (taluses, landslides, failures, etc.) occur are considered as not suitable for construction. Areas of dumps, quarries, wastes, natural steep slopes with angle of more than 15. View screenshot.

4. Relief Map: Digital relief map of Yerevan is based on topographic paper map, scale 1:10000 and consists of digital contour lines. Each contour line is presented by array of dots. Each dot is described by two coordinates and its height.
Yerevan's relief is described by contours after each 2 meters. In the southern part of the city relief are gentle and the contours are shown after each 1meter. On the contrary, contours of steep slopes and river canyons are shown after each 5 or 10 meters. Digital maps are developed for those areas from paper maps, scale 1:2000 and allow calculating morphometric slope angles, slope expositions and relief hill-shades. These parameters would allow highlighting areas that have great angle of relief slope, which are dangerous during strong earthquakes. The areas where relief's slope angle is greater than 15 degrees are highlighted on the map of seismic microzoning. Digital relief map can also be used for assessing damages from other natural hazards, such as landslides, taluses, mudflows and simulating scenarios for emergency situations.
View screenshot.

5. Wells: Wellog databases are needed for assessing the seismic resistance of the soils for evaluating the potential losses from strong earthquakes. The information of wells is arranged in the form of relative databases. First database has a structure of e-tables and includes the following properties of wells: its number, map coordinates, depth, ground water level and highest level of the junction. Each record in the database is a description of one well.
Before entering the data in the well database, 12 thousand well documentations have been analyzed for evaluating the reliability of its geological description and complying it with engineering-geological and hydrogeological maps. Out of those wells, 5000 bore-holes have been selected and entered into the database. For creating the legend and excluding the bad-quality wells, we have used 1:10000 scale engineering-geological map, and cross-sections to this map (authors G. Sahakyan et. al.). The description of each well corresponds to the soil on the map. Only those wells have been selected which have full compliance with geological column of the map and its cross-section. A link has been established between each soil interval and stratigraphic cross-section of Yerevan, which is presented in the file of geological legend. View screenshot.

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