Studies to Determine In-Situ Strength Parameters of Stone Masonry of Massanjore Dam, Jharkhand

In India most of the dams have become aged. Due to ageing, various distresses have been observed in these dams which has raised apprehensions about structural safety of these dams. For assessing structural safety of the dam’s in-situ material properties are required as input parameters. This paper is based on such a study to determine in-situ strength parameters of stone masonry of Massanjore Dam, Jharkhand. Field studies by flat jack tests were carried out by CWPRS, Pune to compute in-situ stresses, static modulus of deformation and Poisson’s ratio. Evaluated compressive strength of masonry for applied pressure was compared with design strength. The evaluated modulus of deformation, Poisson’s ratio and compressive strength are used for carrying out stability analysis of dam. Six flat jack tests (5-horizontal and 1-vertical) each were conducted on downstream (D/S) face as well as on upstream face (U/S) in random rubble stone masonry. Average Em values by flat jack test for random rubble stone masonry was 12.95 and 15.90 GPa for downstream and upstream faces, respectively. Average Poisson’s ratio values by flat jack test for random rubble masonry was 0.215. The range of evaluated compressive strength of masonry for applied pressure was ranging from 50.09 to 92.28 kg/cm2.