Geological and geotechnical observations from the Niagara Tunnel Project

作者：Perras Matthew A^*; Diederichs Mark S; Besaw David

来源：Bulletin of Engineering Geology and the Environment, 2014, 73(4): 1303-1323.

DOI：10.1007/s10064-014-0633-5

• Niagara Tunnel Project
• Tunnel boring machine (TBM)
• Sedimentary rock
• Hard rock tunnel
• Overbreak

The Niagara Tunnel Project is a water diversion tunnel that was constructed in Niagara Falls, ON, Canada. The tunnel was excavated by a 14.4-m-diameter tunnel boring machine that passed through 11 geological formations. The rock types included limestone, sandstone, siltstone, shale, and mudstone. The overbreak was divided into four zones, evaluated by observations as the tunnel excavation progressed. Overbreak within the Rochester, Neagha, and Grimsby Formations was %26lt; 0.6 m deep typically, measured perpendicular to the designed excavation perimeter. The Power Glen Formation had overbreak as deep as 2.7 m. The deepest overbreak was measured in the Queenston Formation, where 3-4 m was typical and associated with the tunnel alignment. Maximum overbreak occurred when the tunnel was aligned perpendicular to the maximum horizontal stress. The overbreak was focused in the crown and inverted, with only minor volumes of sidewall overbreak occurring. The deep overbreak within the Queenston was overcome by utilizing spiles and adjusting the tunnel alignment to minimize the duration of excavation in the Queenston Formation. The tunnel went into operation in March, 2013.

• 出版日期2014-11