Abstract To evaluate the shear strength of rock mass containing non-persistent joints, a comprehensive knowledge of the shear mechanism of both joint and rock bridge is required. In this study, different joint configurations were initially designed, then the 3D printed and plaster specimens were made applying 3D printing technology and casting process, respectively. A novel procedure was applied to build plaster specimens embedding finite (closed/open) joints surrounded by intact material from all sides. Subsequently, joint persistence (rock bridge ratio) and joint dispersion effects of both single joint and coplanar intermittent joints on the shear strength of the specimens were experimentally examined by conducting several direct shear tests under constant normal load (CNL) condition. The experimental results obtained from the plaster and 3D printed specimens were compared to assess the applicability of powder-based 3D printing technology to shear behavior analysis of weakness planes containing non-persistent joints. Moreover, the joint friction contribution to the shear strength of the plaster specimens containing a single non-persistent joint was investigated thanks to the proposed casting procedure. It was found that the embedded joints of the specimens with greater rock bridge ratios have less contribution to the shear strength.

中文翻译：

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粉末基 3D 打印技术在非持久节理岩体剪切行为分析中的适用性

摘要 为了评价含非持久节理岩体的抗剪强度，需要全面了解节理和岩桥的剪切机理。在这项研究中，最初设计了不同的接头配置，然后分别应用 3D 打印技术和铸造工艺制作了 3D 打印和石膏标本。应用了一种新程序来构建石膏标本，该标本嵌入有限（闭合/开放）接头，四周被完整材料包围。随后，通过在恒定法向载荷 (CNL) 条件下进行多次直接剪切试验，实验检验了单节和共面间断节理对试样剪切强度的节理持久性（岩桥比）和节理分散效应。比较从石膏和 3D 打印标本获得的实验结果，以评估基于粉末的 3D 打印技术对包含非持久性接头的薄弱平面的剪切行为分析的适用性。此外，由于所提出的铸造程序，研究了接头摩擦对包含单个非持久接头的石膏试样的剪切强度的贡献。发现岩桥比较大的试件的嵌缝对抗剪强度的贡献较小。由于建议的铸造程序，研究了接头摩擦对包含单个非持久接头的石膏试样的剪切强度的贡献。发现岩桥比较大的试件的嵌缝对抗剪强度的贡献较小。由于建议的铸造程序，研究了接头摩擦对包含单个非持久接头的石膏试样的剪切强度的贡献。发现岩桥比较大的试件的嵌缝对抗剪强度的贡献较小。