A New Elasto-Viscoplastic Damage Model Combined with the Generalized Hoek-Brown Failure Criterion for Bedded Rock Salt and its Application
A New Elasto-Viscoplastic Damage Model Combined with the Generalized Hoek-Brown Failure Criterion for Bedded Rock Salt and its Application
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DOI：
10.1007/s00603-012-0256-8
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发表时间：
2013-01-01
影响因子：
6.2
通讯作者：
Li, Wen-pei
中科院分区：
文献类型：
--
作者：
Ma, Lin-jian;Liu, Xin-yu;Li, Wen-pei
根据中国西气东输工程的要求，江苏金坛层状盐岩组溶采空洞将用于储气库。由于层状盐岩地层的非均质性，这一任务比传统的盐丘洞室的施工和运营更具挑战性。建立了与广义Hoek-Brown模型相结合的三维蠕变损伤本构模型，并通过一系列层状盐岩的强度和蠕变试验进行了验证。粘塑性模型考虑了蠕变损伤的耦合和不同应力状态下的破坏行为，可以同时计算蠕变的三个阶段以及由恶性损伤和塑性流动引起的变形。在有限差分软件FLAC(3D)中实现了该模型，对薄层盐穴快速抽放瓦斯进行了进一步的地质力学分析。对洞室的体积收敛、破坏和破坏扩展以及洞室周围盐类的应变率进行了详细的计算和讨论。最后，在模拟研究的基础上，提出了保证金坛层状盐穴结构稳定的最小内压为7 Mpa。这些调查结果为洞穴工程的设计和施工提供了必要的投入。
According to the requirement of the West-East Gas Transmission Project in China, the solution-mined cavities located in the Jintan bedded salt formation of Jiangsu province will be utilized for natural gas storage. This task is more challenging than conventional salt dome cavern construction and operation due to the heterogeneous bedding layers of the bedded salt formation. A three-dimensional creep damage constitutive model combined with the generalized Hoek-Brown model is exclusively formulated and validated with a series of strength and creep tests for the bedded rock salt. The viscoplastic model, which takes the coupled creep damage and the failure behavior under various stress states into account, enables both the three creep phases and the deformation induced by vicious damage and plastic flow to be calculated. A further geomechanical analysis of the rapid gas withdrawal for the thin-bedded salt cavern was performed by implementing the proposed model in the finite difference software FLAC(3D). The volume convergence, the damage and failure propagation of the cavern, as well as the strain rate of the salt around the cavern, were evaluated and discussed in detail. Finally, based on the simulation study, a 7-MPa minimum internal pressure is suggested to ensure the structural stability of the Jintan bedded salt cavern. The results obtained from these investigations provide the necessary input for the design and construction of the cavern project.