Anomalies of noble gases and self-potential associated with fractures and fluid dynamics in a horizontal borehole, Mont Terri Underground Rock Laboratory

被引：12

作者：

Maineult, Alexis ^{[1
]}

Thomas, Bertrand ^{[2
]}

Nussbaum, Christophe ^{[3
]}

Wieczorek, Klaus ^{[4
]}

Gibert, Dominique ^{[1
,5
]}

Lavielle, Bernard ^{[2
]}

Kergosien, Bruno ^{[5
]}

Nicollin, Florence ^{[5
]}

Mahiouz, Karim ^{[1
]}

Lesparre, Nolwenn ^{[1
]}

机构：

[1] Univ Paris Diderot, Inst Phys Globe Paris, CNRS, UMR 7154, F-75005 Paris, France

[2] Univ Bordeaux 1, Ctr Etud Nucl Bordeaux Gradignan, CNRS, UMR 5797, F-33175 Gradignan, France

[3] Swisstopo, Fed Off Topog, CH-3084 Wabern, Switzerland

[4] Gesell Anlagen & Reaktorsicherheit GRS mbH, D-38122 Braunschweig, Germany

[5] Univ Rennes 1, Geosci Rennes, CNRS, UMR 6118, F-35000 Rennes, France

来源：

ENGINEERING GEOLOGY | 2013年 / 156卷

关键词：

Mont Terri Underground Rock Laboratory; Excavation Damaged Zone; Noble gases; Self-potential; Opalinus clay; EXCAVATION DAMAGED ZONE; OPALINUS-CLAY; RADIOGENIC HELIUM; LOW PERMEABILITY; DISTURBED ZONE; WATER-CONTENT; PORE-WATER; GROUNDWATER; CONDUCTIVITY; TOMOGRAPHY;

D O I：

10.1016/j.enggeo.2013.01.010

中图分类号：

P5 [地质学];

学科分类号：

0709 ; 081803 ;

摘要：

Before the excavation of the new gallery Ga08 in the Mont Terri Underground Rock Laboratory (Switzerland), which joined the existing gallery Ga04 in 2008, the end-face of gallery Ga04 was instrumented in 2007 to characterize the evolution of the rock mass with geochemical and geophysical methods. The noble gas content of a 12-m long horizontal borehole evidenced that desaturation processes occurred in the first 2 m, where pre-existing fractures accommodated the stress change during excavation of gallery Ga04 four years before. These first 2 m are associated with the so-called Excavation Damaged Zone (EDZ). As an inflow of pore water was observed in this borehole few weeks after its drilling, continuous self-potential (SP) measurements were performed to characterize its dynamics. After the drilling of new sub-horizontal boreholes in the end-face, strong localized variations of SP occurred. The comparison with the geological features of the rock mass suggests that these dynamic anomalies have to be associated with fluid circulation in pre-existing tectonic fractures that were primarily reactivated by the excavation of the gallery Ga04 and subsequently by the drilling operations. (c) 2013 Elsevier B.V. All rights reserved.

引用

页码：46 / 57

页数：12