IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 3 Ver. I (May. - Jun. 2015), PP 68-76 www.iosrjournals.org DOI: 10.9790/1684-12316876 www.iosrjournals.org 68 | Page Numerical Modeling for Prediction of Compression Index from Soil Index Properties R. Nesamatha 1* , Dr. P.D.Arumairaj 2 , PG Scholar, Department of Geotechnical Engineering, Government College of Technology, Coimbatore-13. Associate Professor, Department of Civil Engineering (Soils), Government College of Technology, Coimbatore-13. Abstract: Expansive Clays known for its vulnerability pose numerous problems to builders. Compression index is a clay dependant parameter which can be evaluated from the consolidation test data. Evaluation of compression index from the consolidation test is time consuming and laborious. Prediction of compression index from the index properties of soil is attempted. In this study, a correlation between compression index (C c ) with liquid limit (W L ) and plasticity index (I P ) is aimed at. Remoulded clay samples were collected from twenty locations of Coimbatore for experimental study. Clay was for its liquid limit, plastic limit and consolidation properties in the laboratory. Correlations of compression index in terms of liquid limit and plasticity index was arrived from Regression model and Artificial Neural Network (ANN). From these correlations, the best fit linear equation is found to be ANN which is having higher accuracy. This correlation will be helpful for the geotechnical engineer to predict the compression index value of clay from index properties. Keywords: Regression model, Artificial Neural Network, liquid limit, plasticity index, compression index, correlation I. Introduction Compressibility of soil is an important engineering properties and is related to settlement of the foundation or structures. If the compressibility was high, settlement will also be high. Settlement was calculated from the compression index. Compression index was a clay dependent parameter computed from the consolidation test .The process of consolidation test take longer durations. So it was beneficial if the value of compression index can be related with index properties such as liquid limit and plasticity index. Atterberg’s Reliable correlations between the engineering and index properties of soils will reduce the work load of a soil investigation program, in case of urgency. Study Area was Coimbatore city, covered with black cotton soils.. In this work, twenty locations namely Government College of Technology (GCTCampus), Rathinapuri, Sitra and Government Polytechnic College (GPT), Peelamedu, Thudiyalur, Pudhur, Saravanampatti, Vadakovai, Vadavalli, Agri University(campus), Forest college quarters, Telungupalayam, Saibabacolony, Venkittapuram, GCT(girls hostel), Periyanaikenpalayam, Sivanantha colony , Neelambur, Veerakeralam in the city were identified for soil sampling and laboratory .Samples collected from the twenty locations are analyzed for its grain size distribution, Atterberg’s limit, Standard Proctor Compaction, Consolidation and Diff erential Free Swell. An attempt was made to establish a correlation between compression index Vs plasticity index and compression index Vs liquid limit. In these investigations the observed value of the compression index compared with predicted value of the compression index using MATLAB with the help of Artificial Neural Network and Regression analysis. Amith Nath and S.S Dedalal was collected clay samples from West Bengal and artificially mixed soil samples were prepared. A correlation was achieved to determine the compression ratio in terms of liquid limit, plastic limit,void ratio. Arpan Laskar and Sujit Kumar Pal (2008) carried out a detailed study on Geotechnical Characteristics of two different soils and their mixture and relationships between parameters. The two soil samples collected from NIT Agartala campus and Howrah were investigated and the particle size distribution of NITA sample was determined. Then NITA sample was replaced with different proportions of the Howrah soil. The mixture of both the soils (Mixed Soil) was also investigated to study the variations in properties and to establish correlations of soil parameters. Slamet Widodo and Abdelazim Ibrahim collected 20 samples in Supadio Airport in Pondianak, Indonesia.The soil specimens were tested in the laboratory and proposed three different equations to estimate the compression index of the soils. The summary equations of the literature was given below in the table 1