{"references": ["1.\tGrappo Sembenelli. P., ASCE and G. Sembenelli (1999), Deep Jet -Grouted cut- OFFs in riverine Alluvia for Eratan Coffer dams, Jour of Geotechnical and Geoenvironmental Engineering , Vol. 125, No. 2, PP 142-153. 2.\tGui. M.W., M.ASCE, k. Soga, M.D. Bolton and J.P. Hamelin (2002), Instrumented Borehole drilling for Subsurface investigation. Jour. Geotechnical and Geoenvironmental Engineering Vol. 128, No. A, PP 283 \u2013291. 3.\tMillind V.Khire, Craig H, Benson and Peter J. Bosscher (1997). Water Balance Modeling of earthen Final covers, Journal of Geotechnical and Geoenvironmental Engineering, Vol 123, No. 8, PP 744-754. 4.\tMohammed Aslam. M.A. and A. Balasubramanian (2002). Delineation of Palaeochannels using remote sensing and Geophysical DATA around Talakad in Cauvery river basin, India. Jour of Geophysics, Vol. XXIII No.2, pp 43-50. 5.\tMoses Edwin J., Suresh Francis, Manivel. M and Balasubramanian. A. (1994) Drainage Basin Characteristics of Ayyar basin, Tamil Nadu using IRS 1A LISS II data the geography teachers, India. Vol 2 No.1 pp.7-21. 6.\tAkram Javed (2000), Geomorpholigical study of Bulandshahir district (U.P) using remotely sensed data. Tata energy research Institute (TERI), New Delhi, Journal of the Indian society of Remote Sensing, Vol. 28, No. 2 & 3. 7.\tAlam Singh: Modern Geotechnical Engineering 2nd Edition: CBS Publishers & Distributors (P) Ltd."]}

The Core logging frequency for most structures in first core logging per substructure unit under 100 feet long and 2nd core logging for footings longer than 100 feet. The important properties to be consider are permeability, compacted density, shear strength, compressibility, flexibility, grain size, distribution and resistance to internal erosion. The earthquake prone areas thicker core is desirable core thickness with 30% to 50% of water head has proved satisfactory for any type of soil and any Dam height provided the soil is reasonable impervious,