The mechanical properties of deep rocks change nonlinearly in an in situ pressure environment, so standard cores cannot be used as real samples for deep rock mechanics research. Therefore, obtaining an in situ pressure core is essential. However, the existing pressure-maintaining cores cannot overcome the sealing capacity limit, largely due to the lack of consideration of sealing theory and experimental verifications of pressure-maintaining controllers. Therefore, this paper explores the sealing form and failure mechanism of pressure-maintaining controllers. The sealing state transition, pressure leakage, deformation failure theory, and test method for a pressure-maintaining controller are determined. Through theoretical analysis and experiments, (1) a seal-form discrimination method based on the chimeric curve is proposed to obtain the pressure seal conversion trend; (2) the leakage rate is exponentially related to the initial pressure, which confirms the pressure leakage principle of the pressure-maintaining controller; and (3) based on deformation failure theory for pressure-maintaining controllers, the failure mode and deformation trend are obtained through a destructive limit pressure experiment. The research results provide a theoretical basis and experimental support for improving pressure coring in deep rock and obtaining pressure cores at deep positions to construct a new conceptual system of deep in situ rock mechanics.

中文翻译：

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深层原位岩心保压控制器的密封形式及失效机理

深部岩石的力学性质在原位压力环境下呈非线性变化，因此标准岩心不能作为深部岩石力学研究的真实样本。因此，获得原位压力岩心至关重要。然而，现有的保压芯无法克服密封能力极限，主要是由于缺乏对密封理论的考虑和保压控制器的实验验证。因此，本文探讨了保压控制器的密封形式和失效机理。确定了保压控制器的密封状态转变、压力泄漏、变形破坏理论和测试方法。通过理论分析和实验，(1)提出了一种基于嵌合曲线的密封形式判别方法，得到压力密封转换趋势；(2)泄漏率与初始压力呈指数关系，证实了保压控制器的泄压原理；(3)基于保压控制器的变形失效理论，通过破坏性极限压力实验得到失效模式和变形趋势。研究成果为改进深部岩石压力取心、获取深部压力取心、构建深部原位岩石力学新概念体系提供了理论依据和实验支持。确定了保压控制器的泄压原理；(3)基于保压控制器的变形失效理论，通过破坏性极限压力实验得到失效模式和变形趋势。研究成果为改进深部岩石压力取心、获取深部压力取心、构建深部原位岩石力学新概念体系提供了理论依据和实验支持。确定了保压控制器的泄压原理；(3)基于保压控制器变形失效理论，通过破坏性极限压力实验得到失效模式和变形趋势。研究成果为改进深部岩石压力取心、获取深部压力取心、构建深部原位岩石力学新概念体系提供了理论依据和实验支持。