Coupled thermal-hydraulic-mechanical-chemical modeling for permeability evolution of rocks through fracture generation and subsequent sealing
Coupled thermal-hydraulic-mechanical-chemical modeling for permeability evolution of rocks through fracture generation and subsequent sealing
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DOI：
10.1007/s10596-020-09948-3
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发表时间：
2020-04-06
影响因子：
2.5
通讯作者：
Kishida, Kiyoshi
中科院分区：
文献类型：
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作者：
Ogata, Sho;Yasuhara, Hideaki;Kishida, Kiyoshi
作者提出的THMC耦合模型IPSACC可以描述由于矿物反应引起的岩石渗透率的长期演化，压力溶解和自由面溶解/沉淀）在岩石裂缝内，在本研究中升级，纳入裂缝的启动/扩展的过程。所提出的模型的显着特点是它能够模拟裂缝的生成和生成的裂缝内的矿物反应以及随后的渗透率变化。所提出的模型被应用于预测的长期变化的岩石渗透性位于附近的高水平放射性废物的地质处置库。预测结果表明，裂缝附近的处置腔和损伤区的渗透性增加显着超过的完整的岩石在开挖过程中，而几乎整个损伤区的渗透性下降了约一个数量级，由于压力溶液中的接触粗糙的岩石裂缝后，设置虚拟放射性废物到处置腔。总的来说，它被澄清，所提出的模型是能够计算岩石的渗透率的演变，通过裂缝的产生和随后的密封，由于矿物反应在实际的现场规模。因此，潜在的使用拟议的模型，以审查自然屏障的长期性能，以延迟放射性核素的运输已经显示。
The coupled THMC model, interface for pressure solution analysis under coupled conditions, IPSACC, that was proposed by the authors and can describe the long-term evolution in rock permeability due to mineral reactions (i.e., pressure solution and free-face dissolution/precipitation) within rock fractures, was upgraded in the present study by incorporating the processes of fracture initiation/propagation. The remarkable characteristic of the proposed model is its ability to simulate the generation of fractures and the mineral reactions within the generated fractures as well as the subsequent changes in permeability. The proposed model was applied to predictions of the long-term changes in the permeability of rock located near high-level radioactive waste within a geological repository. The predicted results revealed that fractures were generated near the disposal cavity and that the permeability of the damaged zone increased significantly more than that of the intact rock during the excavation, while the permeability in almost the entire damaged zone decreased by about one order of magnitude due to pressure solution at the contacting asperities within the rock fractures after setting virtual radioactive waste into the disposal cavity. Overall, it was clarified that the proposed model is capable of calculating the permeability evolution of rock through fracture generation and subsequent sealing due to mineral reactions at the actual field scale. Thus, the potential for using the proposed model to examine the long-term performance of natural barriers for delaying the transport of radionuclides has been shown.