ORIGINAL PAPER Interactions Between Soils and Laboratory Simulated Electrolyte Solution Sitaram Nayak • B. M. Sunil • S. Shrihari • P. V. Sivapullaiah Received: 10 May 2009 / Accepted: 22 April 2010 / Published online: 15 May 2010 Ó Springer Science+Business Media B.V. 2010 Abstract To study the impact of salt water intrusion on two types of soils from west coast region of India were investigated in the laboratory. The key charac- teristics evaluated included Atterberg limits, compac- tion characteristics, hydraulic conductivity and chemical characteristics of selected soils. The sea at this coast receives effluent from different points and hence the characteristics change with time and local- ity. Therefore, to maintain uniform composition, 0.5 N sodium chloride solution (NaCl) was prepared in the laboratory and batch tests were used to determine the immediate effect on soils. Soil specimens were prepared by mixing the soils with 0.5 N NaCl in the increments of 0, 5, 10 and 20% by weight to vary the degree of contamination. Experimental results of soils mixed with 0.5 N NaCl showed that the maximum dry density increases and the optimum moisture content (OMC) decreases with increasing sodium chloride concentration. The study also revealed that the hydraulic conductivity of the soils tested increases with increase in sodium chloride concentration. The Atterberg limits of contaminated specimens show a remarkable change when compared with uncontami- nated specimens. Keywords Soils  Sodium chloride solution  Contamination  Atterberg limits  Hydraulic conductivity  Compaction characteristics 1 Introduction One may think of soil and ground water pollution in the coastal areas is due to salt water intrusion. The objective of the present investigation is to study the impact of salt water intrusion on the properties of the soils encountered in the study region. Such studies may be useful in connection with any possible applications during geotechnical investigation for the construction of structures. The study area is situated in southwest coast of India (Latitude 12852 0 N, Longitude 74849 0 E). It receives very heavy rainfall (3,500 mm annually) during southwest monsoon for 4 months (June to September). Many seasonal rivers in the lower reaches of the region become saline due to salt water ingression during non-monsoon periods. Therefore, soil and groundwater systems are affected by salt water intrusion and seepage of saline water from polluted rivers (Gajendragad 1986). Lateritic soil and shedi soil S. Nayak  B. M. Sunil (&)  S. Shrihari Department of Civil Engineering, National Institute of Technology Karnataka, PO: Srinivasnagara, Surathkal 575025, India e-mail: sunilbm@nitk.ac.in; bmsunil@gmail.com S. Nayak e-mail: snayak65@yahoo.co.in S. Shrihari e-mail: s.shrihari@gmail.com P. V. Sivapullaiah Department of Civil Engineering, Indian Institute of Science, Bangalore 560012, India 123 Geotech Geol Eng (2010) 28:899–906 DOI 10.1007/s10706-010-9333-5