Wai Lin Aung creator Avirut Puttiwongrak Chairperson Chao, Kuo Chieh Examination Committee Taweephong Suksawat Examination Committee AIT Scholarships Scholarship Donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2025 continuing eng

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76 leaves : ill.+ 1 online resource Building in mountainous areas poses considerable challenges in geotechnical engineering, especially due to the unforeseen occurrence of hard rock layers. This study investigates the integration of Two-dimensional Electrical Resistivity Imaging and Multichannel Analysis of Surface Waves to assess subsurface conditions at a bridge construction site in Chiang Rai, Thailand. Although the site was initially expected to consist of soft soils, borehole data revealed the presence of a granite layer at a depth of 10 to 15 meters, which was not anticipated based on preliminary geophysical surveys. The research aims to explore the relationship between Rock Quality Designation (RQD), electrical resistivity, and shear wave velocity to assess subsurface changes after the discovery of the granite layer. Results indicate that RQD is inversely proportional to electrical resistivity but directly proportional to shear wave velocity. The granite layer, which is highly weathered and behaves like soil (resulting in low resistivity), retains a high shear wave velocity due to its rock nature. This study demonstrates that the combined use of 2D ERI and MASW provides valuable insights into subsurface conditions and offers a reliable method for evaluating ground properties in areas with unexpected hard rock layers, contributing to more informed geotechnical decision making in bridge construction projects. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Geotechnical and Earth Resources Engineering Thesis (M. Eng.) - Asian Institute of Technology, 2025 Rocks Classification Geotechnical engineering Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B23576 http://203.159.5.9/ait-thesis/detail.php?q=B23576 260209 20260817162923.0