Mechanical behaviour and failure mode of bentheim sandstone under triaxial compression

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• 作者：Klein ; E. ; Baud ; P. ; Reuschl&eacute ; T. ; Wong ; T-f.
• 刊名：Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy
• 出版年：2001
• 出版时间：2001
• 年：2001
• 卷：26
• 期：1-2
• 页码：21-25
• 全文大小：624 K

文摘

Hydrostatic and triaxial compression tests have been conducted on nominally dry samples of Bentheim sandstone, a homogeneous quartz-rich sandstone with porosity of about 23 % . A broad range of confining pressures were used to observe the transition from the brittle faulting to cataclastic flow regime. Mechanical data for the brittle strength and compactive yield stress can be fitted with empirical envelopes that have been shown to be applicable to other porous sandstones. However, the Bentheim sandstone is somewhat unusual in that quasi-ductile failure (characterized by an overall hardening trend punctuated by episodic strain softening and compaction band formation) was observed over a wide range of confining pressures from 120 MPa to 300 MPa. Since this failure mode is similar to observations in honeycombed cellular solids, it is speculated that the prevalence of quasi-ductile failure in the Bentheim sandstone arises from its relatively homogeneous mineralogy and grain size. Compaction band formation may be inhibited in other sandstones with higher fractions of feldspar and clay, as well as more disperse grain sizes.