An engineering site suitability index (ESSI) for the evaluation of geological situations based on a multi-factor interaction matrix

The aim of this study is to determine how to evaluate the suitability of engineering sites quantitatively with the aid of multi-disciplines. This paper presents an engineering site suitability index (ESSI) system based on a multi-factor interaction matrix. This system was designed to define the principal causes related to suitability of engineering sites, quantify factor interactions, obtain the weight ratios and calculate the index of suitability. Recently, the ESSI system has been used successfully in the site selection for the China Spallation Neutron Source (CSNS) project. Firstly, the geomorphology, lithology, geological structure, hydrogeology, rock weathering and land use were selected as evaluation indices to compare the suitability of the five potential sites. Secondly, the relationship matrix was established, and then the weight ratios of six influential factors were computed comprehensively after the analysis of relationship among these six factors. The third site was selected for the suitability of CSNS as the most favorable engineering site after the evaluation of five potential sites for the engineering excavation and construction. This case study shows that the ESSI system is scientific, reasonable and applicable to provide a reference for similar large-scale geo-engineering sites.