Seite - 114 - in Book of Full Papers - Symposium Hydro Engineering

4. EXECUTION OF EXPLORATION PROGRAM The initial exploration program was outlined by a team of engineers, geologists, and construction specialists between March 6 and 12, 2017. The first drill rigs were mobilized on March 13, 2017, and drilling began on March 14, 2017. The initial exploration program consisted of 60 rock-core borings, 16 seismic lines, 10 inclinometers, and 10 vibrating-wire piezometers. As design efforts progressed and changed, the exploration program was modified to accommodate those design changes. By the end of July 2017, the exploration program had been expanded to 104 rock-core borings (over 2800 m [9180 ft] of rock core), 22 seismic lines, 15 inclinometers, 15 vibrating-wire piezometers, and 11 piezometers (both open standpipe piezometers and observation wells; Fig. 6). In order to successfully execute a large amount of exploration in a short amount of time (about 4 months), an exploration workplan was prepared to establish the project protocols, a wide variety of resources was identified and mobilized, a field QA/QC program was implemented, a team of geologists and geotechnical engineers was stationed in the office to analyze the incoming data, and regular consultations with the design team were held to ensure that design needs were being met. 4.1. EXPLORATION METHODS Several methods were utilized to explore the subsurface conditions in and around the FCO Spillway chute and the Emergency Spillway, including the following: concrete and rock-core borings, packer and falling head permeability testing, downhole televiewer surveys – optical and acoustic, borehole geophysical suspension logging, grouted-in-place vibrating-wire piezometers (VWPs), open standpipe piezometers, observation wells, inclinometer casings and instrumentation, P-wave surface geophysics, concrete coring, test pits and bulldozer trenches, laboratory testing of rock and soil for index properties and 114