Rock mass rating and Kinematic analysis for slope stability investigation of Utari dam, Lalitpur district, Uttar Pradesh
Rock mass characterization of Utari dam in Lalitpur district of Uttar Pradesh was done to identify different stability classes of rock mass. For better stability of Utari dam, foundation conditions were carefully studied by detailed field investigations of the site supplemented by laboratory tests. During feasibility and preliminary stages, rock mass characterization of slopes was conducted to identify the vulnerable zones of failure. Rock mass characterization was done by compilation of information obtained from intact rock as well as from rock mass to determine its grade and long term slope stability of the site. On the basis of Rock Mass Rating (RMR) and Geological Strength Index (GSI) slope stability is identified which lies under good quality rock mass. Kinematic analysis was conducted to find out the probability for different types of structurally controlled slope failure. Microscopic analyses were conducted to identify the degree of chemical alteration of feldspar. Clay formation by sericitization along joint planes is harmful for the stability of dam structure. Remedial measures must be taken to reduce the extent of chemical alteration. Granitoids at dam site forms a compact and stable foundation consisting of four sets of joints in which two sets were prominent which are dipping on the upstream side of the dam which reveals good condition on the dam site as leakage from reservoir will be minimum and least up thrust on the dam structure.
Journal of the Geological Society of India