Issue 53

A. Namdar, Frattura ed Integrità Strutturale, 53 (2020) 285-294; DOI: 10.3221/IGF-ESIS.23.22 292 mineralogy, the morphology and the moisture content are changed with soil mixture and result in developing a new safe bearing capacity. For the design of the mixed soil, the attention to the soil mineralogy supports the geotechnical engineering design. Analyzing the soil mechanical properties influence on the safe bearing capacity of the soil guides the geotechnical engineer to use proper soil which impacts on mineralogy and morphology of the mixed soil for achieving the best safe bearing capacity. For example, selecting the suitable percentage of a soil may increase soil strength because of the soil mineralogy or morphology. On the other hand, a combination of soil mineralogy and morphology controls moisture content of the soil. However, adjusting the moisture content of the mixed soil governs the strength of the soil. The results of this study reveal the importance of mineralogy science for civil engineering. It is an indirect relationship between mechanical properties of the mixed soil and the load transfer from the structure to the subsoil. Considering the effect of optimum moisture content (%), density (kN/m 3 ), angle of friction (deg) and cohesive of soil (kN/m 2 ) on the safe bearing capacity of the soil separately could not provide a suitable prediction, while combining the effect of all mechanical properties on predicting safe bearing capacity provides suitable results in safe bearing capacity prediction. It has been reported in [24] that the mechanical properties of the soil foundation significantly control the lateral and vertical displacements of the subsoil and the failure pattern of the subsoil. In this study, an experimental report was used for the prediction and the probability analysis of the soil safe bearing capacity using advance SC techniques. There are several excellent research works available in the literature which apply different methods of statistical analysis, for example many research works can be referred to investigation on materials damage assessment [25-28], fatigue strength [29-31], crack analysis [32-33], strain analysis [34-35], and nonlinear displacement mechanism [24]. The application of statistical analysis on these researches enrich literature for industrial and educational sections. C ONCLUSION n most of the mixed soil used in a construction site, the safe bearing capacity behaves differently and results in various structures stability. The mineralogy and the morphology of mixed soil are considered in the safe bearing capacity of soil through the application of the arti fi cial neural network (ANN) for the prediction of soil foundation behavior considering mechanical properties of the mixed soil. This feasible technique supports the application of soil mixture in geotechnical engineering design. The following goal has been reached in the present study.  The internal angle of friction of soil has more influence on the safe bearing capacity prediction.  Increasing density, cohesive and internal angle of friction of mixed soil results in increasing safe bearing capacity of the soil foundation, while increasing moisture has a negative influence on the safe bearing capacity of the soil. However, the combination of soil mineralogy and morphology controls moisture content of the soil and adjusting the moisture content of the mixed soil governs the strength of the soil mixture. Increasing optimum moisture content of the soil causes the reduction of density, cohesive and internal angle of friction of mixed soil, resulting in a reduction of soil safe bearing capacity.  Most of the safe bearing capacity occurs below 1000 (kN/m 2 ). It is important for achieving high bearing capacity with proper interaction of mechanical properties of the mixed soil.  For prediction of the safe bearing capacity, the R 2 and RMSE for all mechanical properties effects on safe bearing capacity are 0.98 and 0.02, these values can provide a suitable accuracy for prediction safe bearing capacity of the mixed soil. The higher inaccuracy is obtained when only the influence of the cohesive of the mixed soil is considered in prediction of the safe bearing capacity. It can be concluded that the mechanical properties interaction increases the safe bearing capacity. The method presented in the present work can be a guideline to apply soil mixed design in geotechnical engineering to improve the subsoil quality.  Plasticity is the main factor involved in the soil safe bearing capacity [1], it has not been evaluated in the present work and it could be a future research work. In the study of the plasticity, the level of moisture content and the mineralogy are two variables that could be analyzed using a suitable statistical technique to find their relationship with soil foundation safe bearing capacity. R EFERENCES [1] Namdar, A. and Pelko, M. K. (2009). Bearing capacity of mixed soil model, Fract. Struct. Int., 3 (7), pp. 73-79. DOI: 10.3221/IGF-ESIS.07.06. I