Underground hydrogen energy storage (UHES) in lined rock caverns (LRCs) represents a crucial solution to the challenge of unstable and uneven clean energy generation. Nevertheless, the attainment of enhanced storage efficiencies frequently necessitates the utilization of elevated hydrogen storage pressures. Consequently, a comprehensive understanding of the elastic-plastic mechanical response of surrounding rock under hydrogen pressure is of paramount importance for ensuring the safety of UHES. In this study, an elastoplastic solution of LRCs during construction and operation phases is established. Two essential phenomena affecting the post-peak mechanical responses of surrounding rock, strain softening and dilatancy, are coupled into the plastic solution. A computational process is developed and its accuracy is validated through comparison with numerical models. The influence of surrounding rock quality parameters, strain softening and dilatancy parameters, concrete quality parameters and hydrogen pressure on the radius of the plastic softening zone (Rs) and plastic residual zone (Rr) were analyzed. Results show that higher surrounding rock quality can effectively reduce both Rs and Rr. Nevertheless, when the surrounding rock quality already reaches a high standard, such as c1 > 3.5 MPa, φ1 > 65°, or E > 55 MPa, it becomes inefficient to overly pursue further improvements in the surrounding rock quality. Furthermore, the strain softening and dilatancy phenomena only affect Rr. Additionally, the concrete lining with higher stiffness can share a larger portion of the hydrogen pressure, thus reducing both Rs and Rr. Notably, When the elastic modulus of concrete increases from 20 MPa to 40 MPa, Rr decreases by 31.98 % and Rs decreases by 20.96 %. Moreover, the critical hydrogen pressure (PHcr) at which the surrounding rock begins to enter a plastic state is proportional to the ground stress (P0). Specifically, when P0 is increased sequentially from 2.5 MPa to 3.0 MPa and 3.5 MPa, PHcr sequentially becomes 2.4 MPa, 4.0 MPa, and 5.0 MPa. The findings presented in this study contribute to improving the safety of LRCs during construction and operation.

中文翻译：

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考虑应变软化和膨胀的开挖和运营阶段用于衬砌储氢腔的弹塑性解决方案


衬砌岩洞 （LRC） 中的地下氢能储存 （UHES） 是应对清洁能源生产不稳定和不平衡挑战的关键解决方案。然而，实现更高的存储效率通常需要利用较高的储氢压力。因此，全面了解氢压下围岩的弹塑性力学响应对于确保 UHES 的安全性至关重要。在本研究中，建立了 LRC 在施工和运营阶段的弹塑性解决方案。影响围岩峰后机械响应的两个基本现象，应变软化和膨胀，耦合到塑性溶液中。开发了一种计算过程，并通过与数值模型进行比较来验证其准确性。分析了围岩质量参数、应变软化和膨胀参数、混凝土质量参数和氢压力对塑性软化区 （Rs） 和塑性残余区 （Rr） 半径的影响。结果表明，较高的围岩质量可以有效降低 Rs 和 Rr。然而，当围岩质量已经达到高标准时，如 c1 > 3.5 MPa、φ1 > 65° 或 E > 55 MPa，过度追求围岩质量的进一步改进会变得效率低下。此外，应变软化和剪胀现象只影响 Rr，此外，刚度较高的混凝土衬砌可以分担更大部分的氢压力，从而降低 Rs 和 Rr。值得注意的是，当混凝土的弹性模量从 20 MPa 增加到 40 MPa 时，Rr 降低 31.98 %，Rs 降低 20.96 %。 此外，周围岩石开始进入塑性状态的临界氢压 （PHcr） 与地应力 （P0） 成正比。具体来说，当 P0 从 2.5 MPa 依次增加到 3.0 MPa 和 3.5 MPa 时，PHcr 依次变为 2.4 MPa、4.0 MPa 和 5.0 MPa。本研究中提出的研究结果有助于提高 LRC 在施工和运营过程中的安全性。