Discontinuity Measurement for Slope Failure Analysis with Structure from Motion Method Using Drone on A Slope in Hargowilis, Kokap District, Kulon Progo Regency, D.I. Yogyakarta Province

Abstract

Abstract The measurement of the discontinuity area is one of the important data to determine the slope failure kinematics. Discontinuity measurement can be done by geological compass measurements, but only limited to areas that can be reached and safe. Methods that can help measure the discontinuity plane is Structue from Motion techniques. This method uses raw data in the form of outcrop photos that are processed into point clouds to be processed into a 3-dimensional model. This model is used to measuring the position of the discontinuity plane digitally with a FACETS plug-in by CloudCompare software. FACETS plug-in performs a measurements automatically with the Kd-Nearest algorithm for two sides of of the outcrop. Side-1 has a dimension about 60 meter length and 25 meter height with slop face direction to the east an Side-2 has a dimensions about 25 meter length and 20 meter height, facing south. Side-1 kinematic analysis showing 8.97% of falilure mechanism are oblique. Meanwhile, wedge sliding are the most possible slope failure type happen ini Side-2 with 27,05% chance.