ABSTRACT
At the preparation for the construction of transformer station, prevention works by steel pipe pilings and control works by weep hole were designed and constructed to prevent the further sliding by the crystalline schist sliding surface existing under the excavation slope. At the design stage of the prevention works, design parameters were determined by direct shear test, X-ray diffraction method, and piston-type borehole loading test on site after the clear inspection of the sliding surface. Also, long-term field observation of the excavation slope movement was performed by borehole inclinometer, which was installed the vicinity of the prevention works. In this report, we summarize the design parameters, which were derived from the result of the field observation. The excavation slope has been stabilized in spite of the severe rainy conditions, which proves the applied design parameters and design of prevention works to be reasonable.
