ABSTRACT
Abstract: This chapter provides an overview of the major excavation response experiments conducted at AECL’s Underground Research Laboratory (URL) between 1982 and 2010. Excavation response research was initially conducted as part of shaft construction. An excavation response test at the 240 Level of the URL involved a horizontal tunnel excavated through a subvertical water-bearing fracture. These precursor studies led to a series of experiments in themore highly stressed rock at the 420Level of the URL to investigate the formation of rock damage around tunnels, and to assess the factors that influence the stability of underground excavations. These experiments included the Mine-by Experiment, the Heated Failure Tests, studies of borehole breakouts, the Excavation Stability Study, and the Tunnel Sealing Experiment. The excavation response experiments at the URL culminated in the Thermal-Mechanical Stability Study (TMSS), a comprehensive study to link characterization, numerical modeling, monitoring, and design of underground excavations. As part of decommissioning of AECL’s URL, underground openings were flooded and the shaft was sealed. The facility was closed in 2010.
1 INTRODUCTION
