Modeling of urban geological attributes based on conditional simulation: A case study of Guang'an City.

Urban Geological Modeling (UGM) is a crucial approach for implementing visualization of the underground space and recognizing the complex geological conditions of a city, and it is the top priority task of urban geological survey. Previous UGM studies, assuming homogeneous geological characteristics, have resulted in deviated modeling results and applications. In the case of Guang'an city, a conditional simulation interpolation method is used to establish an attributes distribution model with rock samples as the modeling unit. Combined with field surveys, data collection (topographic, boreholes, profile diagrams, stratigraphic columns, etc.) and data analysis, this methodology is capable of presenting the geological discreteness and heterogeneity of the study area. In this paper, the structure, lithology and attributes distribution model were constructed for the study area. Meanwhile, a rating of tunnel country rock was done using Analytic Hierarchy Process (AHP) as a development method. The results indicate that there are four geotechnical zones in the southwest, west, middle and south of the modeling area with significant zonation characteristics. And the ratings of tunnel country rock demonstrate favorable features for utilization by means of tunnel excavation method from deep to shallow, which provides three-dimensional reference for the planning and utilization of urban underground space in Guang'an city. Additionally, future research directions of UGM are being discussed.