INVESTIGATION OF SPT VALUES BY SPATIAL ANALYSIS METHOD OYMAAĞAÇ (KAYSERİ) EXAMPLE


Acar M. C.

INTERNATIONAL BLACK SEA COASTLINE COUNTRIES SYMPOSIUM-3, Zonguldak, Türkiye, 18 - 20 Temmuz 2019, ss.304-313

  • Basıldığı Şehir: Zonguldak
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.304-313

Özet

Standard Penetration Test is a field test which is widely used in geotechnical investigations in our country as in many countries of the world. This test is one of the main parts of almost every soil inspection program. SPT-N value is used to estimate the density of sand and sandy silts, internal friction angle, unit volume weight. The SPT test, on the other hand, is also an undrained cut test. Therefore, empirical correlations can be given between SPT-N value and consistency limit and undrained cohesion of clays. For spatial analysis, the Inverse Distance Weighted Interpolation method was used from ArcMAP (V: 10.4.1) software which is Geographic Information System (GIS) software. Geographical Information System is needed to collect all kinds of data in computer environment by associating them with each other and their geographical locations and visualizing these data. In addition, uncovering the change of soil properties of fondation in soil surveys provides significant gains in terms of making fast, economical, reliable and feasible decisions for land use in the area in question. Advances in Geographic Information System technology saves time and effort, but minimizes error rates by evaluating geographical data in digital environment. For the GIS analysis, 60 drilling points with a total depth of 1071 m between 15 m and 24.5 m were discussed. The corrected SPT values (N60) taken at every 1.5 m intervals starting from 3 m depth from the drilling points were recorded as a database with the help of ArcMap program. In this analysis carried out within the boundaries of Kayseri Oymaağaç Neighborhood, point source data were converted to raster data, and the depth and spatial classification of the soil was determined as tightness, slackness and consistency. Also at these points (3 m, 4.5 m, 6 m, 7.5 m and 9 m), classification was made according to the Unified Soil Classification System. In this classification, the area layer was created around the point by using Thiesen Polygon Method. Thus, soil classes are modeled superficially with this layer. As a result of spatial analysis, thematic maps based on SPT values were examined and it was concluded that high plasticity clay (CH) or low plasticity clay (CL) layers were present in most of the land. In addition, these soils were found to have a ‘solid‘ and ‘middle solid’ consistency.