Long-term creep of water-saturated tuff under uniaxial compression
Long-term creep of water-saturated tuff under uniaxial compression
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DOI：
10.1016/j.ijrmms.2010.03.012
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发表时间：
2010-07
影响因子：
7.2
通讯作者：
S. Okubo;K. Fukui;K. Hashiba
中科院分区：
文献类型：
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作者：
S. Okubo;K. Fukui;K. Hashiba
地面建筑物和其他结构对环境施加负荷。减轻这些影响的一种方法是利用地下空间。目前的技术水平使我们能够在地下建造隧道和圆顶等结构，并建造废物处置库。然而，一旦地下结构建成，人们必须考虑如何维护它们多年，而且似乎不太可能允许业主在某个时间点后简单地放弃它们，因为它们“已经过时”。地下建筑物的建造必须非常小心地计划，并且谨慎地假设它们将尽可能长时间地使用。例如，隧道的最低使用寿命通常为几百年，废物处置库的最低使用寿命通常为几千年或几万年。然而，迄今为止的表现表明，设计师，不仅在土木和采矿工程，假设使用寿命不到世纪的大多数地下结构。因此，对相对较短的使用期内的岩石或岩体特性进行了大量研究，但对较长使用期的数据积累相对不足。伊藤和Sasajima [1]对花岗岩和辉长岩梁的挠度进行了多年的观测。他们的结果表明，尽管由于温度的波动，偏转会发生很大的变化，但随着时间的推移，偏转会无可否认地增加。Bé rest等人[2]在岩盐中进行了650天的蠕变测试，并报告蠕变应变率为7 10013 sq 1。本文作者参与的研究包括Nishimatsu和Yamaguchi [3]对拉伸应力下的蠕变的研究; Yamaguchi等人对压缩应力下的蠕变和松弛的研究。[4]，Okubo et al. [5]，Chu [6] and Cho et al. [7]。然而，由于各种限制，测试期从未超过三个月。作者进行的唯一长期研究是一项为期三年的现场调查，测量收敛性[8]。我们在这里报告两组在水饱和的塔格凝灰岩中收集的数据，这两组数据是在1994年春季开始的两次长期蠕变试验中收集的，持续了2.5年和12年。本报告是对数据的解释，并与早期短期蠕变试验的结果进行了比较。
Above-ground buildings and other structures exert loads on the environment. One way to mitigate these effects is to use underground space. Current levels of technology allow us to construct structures such as tunnels and domes underground, and to construct repositories for waste disposal. Once underground structures have been built, however, one must consider how to maintain them for many years, and it seems unlikely that owners will be allowed to simply abandon them after some point in time for being ‘‘past their usefulness’’. The construction of underground structures must be planned with great care, and it is prudent to assume that they will be used for as long as possible. For example, typically, minimum useful lives are several centuries for tunnels and several millennia or several tens of millennia for waste disposal repositories. However, performance to date suggests that designers, not only in civil and mining engineering, assume a useful life less than a century for most underground structures. Accordingly, there has been much research into rock or rock-mass properties over relatively short-use periods, but accumulation of data about use over longer periods is comparatively inadequate. Ito and Sasajima [1] conducted observations of the deflection of granite and gabbro beams over many years. Their results showed that although there were large changes in deflection due to fluctuations in temperature, there was an undeniable increase in deflection with the passage of time. Bé rest et al.[2] performed a 650-day creep test in halite and reported a creep strain rate of 7 Â 10À13 sÀ1. Research in which the present authors have been involved includes studies of creep under tensile stress by Nishimatsu and Yamaguchi [3]; and creep and relaxation under compressive stress by Yamaguchi et al.[4], Okubo et al.[5], Chu [6] and Cho et al.[7]. However, test periods were never greater than three months, due to various limitations. The only longer-term study performed by the authors was an in-situ survey measuring convergence carried out over three years [8]. We report here on two sets of data gathered on water-saturated Tage tuff in two long-term creep tests initiated in the spring of 1994 [9] and continued for 2.5 and 12 years. This report is an interpretation of the data and a comparison to the results of the earlier shorter-term creep tests.