Stability of Lateritic Soil Cutting of Maharashtra Subjected to Rainfall Infiltration

The Konkan region of India consists of laterite soil and has a number of laterite soil cuttings through which the Konkan railway passes. Each monsoon, slope failures in several laterite soil cuttings occur, resulting in loss of life, economy, and properties. This study investigates the stability of lateritic cutting at MIDC-Zarap in Ratnagiri district, Maharashtra, subjected to rainfall infiltration using the Mohr-Coulomb saturated/unsaturated constitutive model in GeoStudio 2D software. The concept of unsaturated soil mechanics is used in the analysis, wherein the matric suction plays a vital role. The soil is collected from the cutting in Ratnagiri district of Maharashtra for the basic soil classification tests. The input parameters for the soil water characteristics curve are obtained from the grain size distribution data. The shear strength parameters are estimated by back analysis of the old cutting geometry that failed due to rainfall. The analysis is then performed for a new cutting geometry under the effect of rainfall infiltration. The parametric study is conducted for the new geometry for varying the rainfall intensity and duration. Results show that for the given soil parameters, the cutting with the new geometry is stable under heavy to exceptionally heavy rainfall.