Horizontal and Vertical Geotechnical Variations of Soils According to USCS Classification for the City of An-Najaf, Iraq Using GIS

The unified soil classification system (USCS) first proposed by Casagrande and subsequently developed by the Army Corps of Engineers. It widely used in many building codes and books. An-Najaf city is the most important city in Iraq due to its religious and spiritual value in the Muslim world, so it is fast expanding and continuous developing city in Iraq. The data from 464 boreholes in the study area for depths of 0–26 m have been used. 13 Soil samples were collected from each borehole with 13 depths level (0–26) m with 2 m intervals. The USCS was applied to the soil samples from 13 depth levels borehole. This research aims to create a geodatabase for soil properties for An-Najaf. The ArcGIS 10.5 software was used to interpolate the spatial data to produce 33 geotechnical maps for fine soil, coarse soil and USCS for 13 depth levels. For numerical soil data, Ordinary Kriging has been used for interpolation mapping of Fine and Coarse percentage data for each depth. For non-numerical (nominal) soil data (USCS class), the Indicator Kriging method is used. The results show that the coarse soil occupied 85–95% for depth 0–16 m and consist of (SP, SP-SM, SM) while fine soil occupied 5–15% consisting of (OL, CH, ML) subsequently, this soil when compacted has a permeability of pervious to semi impervious, good shearing strength, low to very low compressibility and acceptable workability as a construction material. The results also show that after 16 m depths until 26 m, the fine soil percentage increased to 40% with a coarse soil percentage of 60%, indicating changes in soil characteristics as the permeability became semi-pervious to impervious, fair shearing strength, medium compressibility and fair workability as a construction material. The study results will provide help and saving time, efforts and money in preliminary engineering designs.Validerad;2020;Nivå 2;2020-03-13 (johcin)</p

Bearing Capacity Map for An-Najaf and Kufa Cities Using GIS

An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the National Centre for Construction Laboratories &amp; Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.Validerad;2018;Nivå 1;2018-05-22 (andbra)</p

Chloride, Calcium Carbonate and Total Soluble Salts Contents Distribution for An-Najaf and Al-Kufa Cities’ Soil by Using GIS

The main objective of the paper is to create geotechnical maps for three soil chemical properties in An-Najaf and Kufa cities’ soil by utilizing of GIS tools. This properties are the chloride concentration, calcium carbonate (CaCO 3) and total soluble salts where they affect the durability of reinforced structural elements. This paper provides an easy accurate way to represent soil properties levels for different depths of soil and create reliable database that will help engineers and decision makers. The data included in this paper were collected for (464) boreholes with depths up to 35 m distributed on residential areas in all of An-Najaf and Kufa cities. Arc-Map of GIS 10.2.1 was used to produce the maps. It has been concluded that chloride content in the soil of the study area range from - 0.01 to 0.99% and with an average of 0.5. The maximum value found in at depth 4–6 m while the minimum value found in location at depth 4–6, 8–10 and 14–16 m. The chloride content in most of An-Najaf province has exceeded the permissible limit and for all, this required taking percussions to protect foundations. While calcium carbonate content in the soil of the study area range from 53 to 0.18 and with an average of 26.6. The maximum and the minimum values found at depth 4–6 m. Calcium carbonate content is within the permissible limits in most locations except in some locations.Validerad;2019;Nivå 2;2019-06-10 (oliekm)</p