Evaluation of the Janbu Modulus Number in clayey soils with using shear wave velocity (Case study: Tabriz City)

For assessing the consolidation settlement, it is mainly used by Terzaghi and Janbu theories. Main of this study is evaluation of the Janbu settlement modulus in clayey soils based on shear wave velocity with using down hole test. In continue, results with using artificial neural network analyses and statistical methods verified. The study area is The city of Tabriz is located in the northwestern part of Iran and has a variety of clayey soils, silty and marl types (yellow, green and gray) with different consolidation potential. In this research, by drilling three machine boreholes at depths up to 8 meters, complete physical, plasticity and consolidation experiments were carried out on 20 undisturbed samples. The in-field Downhole test was also used to determine the shear wave velocity in the boreholes. Moreover, shear wave velocity was evaluated in study area with using down hole test and based on effective vertical stress on study depths normalized. Results showed that the Janbu settlement modulus and normalized shear wave velocity in study area respectively are between 14.38 to 41.39 and 234 to 694 m/s. With considering that results of existing practical relationships for determining the Janbu settlement modulus were not appropriate in study area. In order to improve the practical relationships between the Janbu settlement modulus and normalized shear wave velocity artificial neural network and statistical methods with applying linear, logarithmic and exponential functions was performed. Results showed that exponential function for determining the Janbu settlement modulus in study area is favorable.