Three Hinge Buckling Stability of Laminated Rock Masses

1989年9月，位于安大略省金斯顿的伍兹砂石采石场发生屈曲（“弹起”）故障（Crossley，1991）。 这导致采石场被洪水淹没，并对当地地下水状况产生重大影响（例如邻近的威尔斯井干涸）。 屈曲破坏通常出现在安大略南部和美国中西部，通常是突然发生的，几乎没有警告，由坚硬的层状近地表岩石中的高水平原地应力驱动。 因此，安大略环境和气候变化部（OMECC）要求根据基本工程原则和现场具体条件对未来采石场开发的岩石缓冲厚度（采石场底板和下层含水层之间的分离）进行量化评估（Kinney，2013）。 ** 弹出屈曲，也称为三铰屈曲（THB），倾向于在含有频繁交叉节理的层状岩石板中剧烈发生，从而形成一个中心铰和两个支座铰。 THB也是岩石边坡、隧道和地下采矿的重要稳定性问题：在自由表面附近出现高应力下的层状岩石的显著跨度的地方。 虽然许多作者（Cavers，1981; Diederichs Roorda，Thompson，&白色，1982）在岩石力学屈曲行为的研究方面取得了进展，但仍有几个关键问题没有解决。 目前，还没有明确的工程方法来评估采石场地面THB稳定性。 ** 这项拟议的研究计划将调查THB稳定性，短期重点是采石场底板稳定性，长期重点是采矿和土木工程中广泛的相关应用，如岩石边坡和地下开口。 这将需要详细了解THB破坏机制、原地应力条件、岩体性质的空间分布以及任何潜在的“触发”机制（例如，孔隙水压力）。 该研究计划将利用物理建模（实验室规模的THB物理建模），先进的数值建模（不连续）和最近的岩石力学发展来研究THB稳定性。 研究结果将对加拿大矿业、监管机构和公众产生实际的、直接适用的影响。 **

In September 1989, a buckling ("pop-up") failure occurred at Woods Sand and Gravel Quarry in Kingston, ON (Crossley, 1991). This resulted in flooding of the quarry and significant impact on the local groundwater conditions (e.g. neighbouring wells went dry). Buckling failures have commonly arisen in southern Ontario and the mid-western U.S. and typically develop suddenly, with little warning, driven by high horizontal in situ stresses in the stiff, laminated, near-surface rock. As a result, the Ontario Ministry of Environment and Climate Change (OMECC) has requested quantifiable assessment of rock buffer thickness (the separation between quarry floor and underlying aquifer) for future quarry development on the basis of fundamental engineering principles and site specific conditions (Kinney, 2013). ******Pop-up buckling, also referred to as three hinge buckling (THB), tends to occur violently in laminated rock slabs containing frequent cross-jointing that allows for the formation of a central hinge and two abutment hinges. THB is also a significant stability issue for rock slopes, tunnelling and underground mining: wherever a significant span of laminated rock under high stress occurs near a free surface. Although many authors (Cavers, 1981; Diederichs Roorda, Thompson, & White, 1982) have made progress in the study of buckling behaviour in rock mechanics, several key issues remain unresolved. At this time, there is no clear engineering methodology to evaluate quarry floor THB stability. ******This proposed research program will investigate THB stability with a short-term focus on quarry floor stability, and a long-term focus on a broad range of relevant applications in mining and civil engineering, such as rock slopes and underground openings. This will require a detailed understanding of the THB failure mechanism, the in situ stress conditions, the spatial distribution of rock mass properties, and any potential "trigger" mechanism (e.g., pore water pressure). The research program will utilize physical modelling (laboratory-scale THB physical modelling), advanced numerical modelling (discontinuum) and recent rock mechanics developments to study THB stability. The results will have practical, directly applicable implications for the Canadian mining industry, regulatory agencies, and the general public. **