Spatial variation of permeability and consolidation behaviors of soil using ordinary kriging method

The present study is aimed at finding out spatial distribution of permeability characteristic of soil using ordinary kriging method at any location using the data from a few boreholes at NIT (National Institute of Technology) Patna Bihta campus. Kriging is also popularly known as BLUE (i. e. Best Linear Unbiased Estimator) which can be used to interpolate the data obtained from a few locations to get an estimate of any parameter at other locations throughout the study area. In the present work, soil samples collected from eight boreholes have been tested to obtain various geotechnical properties including liquid limit (LL), plastic limit (PL), plasticity index (IP), coefficient of volume compressibility (mv) etc. These values have been used as inputs in an Ordinary Kriging model to calculate coefficient of consolidation (Cv) and coefficient of permeability (k) throughout the NIT Patna, Bihta campus and build contour plots of (Cv) and (k) over the NIT Patna campus to show their spatial variation. The novelty of the current work lies in the first time proposed method for developing the spatial distribution of(Cv) and(k). Markov correlation matrix has been used to develop the correlation behavior of the parameters considering different values of correlation length. In the present study, it is found that the coefficient of consolidation Cv of soil ranges 10−8 (m2/sec). The Kriged values of k are in the range of 10−11 to 10−10 (m/s). Finally, semi-variogram have been shown to display the auto-correlation of the measured data points and cross-validation of data set which establish that the Kriged data are reasonably correlated. Also, various error estimators such as Mean Error, Root Mean Square Error, Average Standard Error, Root Mean Square Standard Error, Mean Standard Error have been calculated using the Kriged data points over the entire area and, it is found that the error level in the predicted Kriged data are reasonably small.