Three Hinge Buckling Stability of Laminated Rock Masses

9月份，在安大略省金斯敦的伍兹砂和砾石采石场发生了屈曲(弹出)故障(克罗斯利，1991年)。这导致采石场洪水泛滥，并对当地地下水状况造成重大影响(例如，邻近的水井干涸)。屈曲破坏通常发生在安大略省南部和美国中西部，通常是在坚硬的叠层近地表岩石中高水平地应力的驱动下，在几乎没有预警的情况下突然发生的。因此，安大略省环境和气候变化部(OMECC)要求根据基本工程原则和场地具体条件，为未来的采石场开发对岩石缓冲厚度(采石场底部和地下含水层之间的分隔)进行量化评估(Kinney，2013)。 弹出式屈曲，也被称为三铰屈曲(THB)，在含有频繁交叉接合的层合岩板中往往会发生剧烈的屈曲，从而形成一个中心铰链和两个支座铰链。对于岩坡、隧道施工和地下采矿，THB也是一个重要的稳定性问题：在靠近自由面的地方，高应力下的层状岩石会出现很大的跨度。尽管许多作者(Civers，1981；Diederichs Roorda，Thompson，&White，1982)在岩石力学中的屈曲行为研究方面取得了进展，但仍有几个关键问题尚未解决。目前，还没有明确的工程方法来评估采石场底板的稳定性。 这项拟议的研究计划将研究THB稳定性，短期关注采石场底板稳定性，长期关注采矿和土木工程中广泛的相关应用，如岩坡和地下洞穴。这将需要详细了解THB的破坏机制、地应力条件、岩石性质的空间分布以及任何潜在的“触发”机制(例如，孔压)。该研究计划将利用物理模型(实验室规模的THB物理模型)、高级数值模型(间断)和最新的岩石力学发展来研究THB的稳定性。研究结果将对加拿大采矿业、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.