USING BLENDER FOR 3-D MODELING AND GEOLOGICAL ANALYSIS ALONG THE EAST MONTEBELLO FAULT: INTEGRATING ADVANCED EXPLORATION TECHNIQUES INTO A THREE-DIMENSIONAL COMPREHENSIVE GEOLOGIC FRAMEWORK

This study presents a comprehensive 3-dimensional (3-D) fault investigation of a property along the East Montebello Fault (EMF) in the City of Rosemead in Los Angeles, employing diverse exploration methodologies to assess characteristics of the geological environment and test for the presence of a fault. The investigation integrates collected field data such as cone penetrometer testing (CPT), geologic trenching, geotechnical borings, geophysics, elevation data derived from drone aerial photos, along with published data and maps, to establish a comprehensive visualization and analytical framework of the surface and subsurface.

46 CPT logs were collected to provide insight into lateral characteristics of subsurface stratigraphy and soil properties, aiding in the identification of potential fault indicators. Eight geotechnical borings were collected to correlate soil horizons across the property and calibrate the CPT signals for analysis. Four geologic trenches were excavated to provide direct observation of those stratigraphical features that suggested a potential fault in the CPT correlations.

Integration of acquired data into a 3-D geologic model was achieved using Blender, an open source 3-D modeling software allowing geologic modeling within a Geographic Information System (GIS) environment. 3-D geologic modeling is key to ensure internal consistency between the collected geologic datasets, enhancing the accuracy and defensibility of the geological model and facilitates visualization and analysis of the stratigraphy across the site to develop a robust interpretation. The 3-D model allowed correlation of several soil horizons across the property that depict lateral continuity between layers. Although the investigated property is located within the trend of the active EMF, the presence of a Holocene fault was conclusively refuted.

The study contributes to the investigation methodologies and understanding of fault systems in urban settings and demonstrates the efficacy of integrating exploration methodologies and 3-D modeling techniques in subsurface geological studies. The developed geological model provides a valuable framework for engineering geology applications in land-use planning and seismic hazard assessments.