裂隙砂岩力学特性颗粒流数值模拟

为了研究裂隙砂岩力学特性,利用颗粒流(PFC)软件构建含不同几何状态的裂隙试样模型,分析裂隙几何状态对裂隙试样力学特性和变形特性的影响。结果表明:相比于完整试样,裂隙试样的峰值强度、弹性模量、峰值轴向应变均有所降低,泊松比明显提高;裂隙试样峰值强度、弹性模量随着岩桥宽度的增加逐渐增加,随着岩桥倾角增加,裂隙试样弹性模量呈现先减小后增大的变化规律,当岩桥倾角与裂隙倾角相同时,裂隙试样的弹性模量、峰值强度最小;裂隙试样泊松比随着岩桥宽度、围压的增加逐渐降低,随着围压增加,裂隙试样峰值强度、峰值轴向应变逐渐增加;裂隙的存在弱化了试样的力学特性,改变了试样的变形特性,岩桥宽度越小,弱化能力越强,相比于岩桥宽度对裂隙试样的影响程度,岩桥倾角对试样的影响程度较小。

材料力学课堂教学创新改革研究

为适应新时期环境下高等教育对培养人才的要求,从材料力学课程的课堂教学入手,讨论了在学时较少的现状下如何通过转变教学观念和精炼教学内容提高课堂教学的效率和培养学生的学习能力;讲述了如何用提高教学趣味性的手段激发学生学习的积极性;同时也对力学模型和"云课堂"两种实用性强、可行性高的课堂教学方法进行了探讨。

Numerical investigation on the sensitivity of jointed rock mass strength to various factors

The mechanical properties of jointed rock masses, such as strength, deformation and the failure mechanism, can be understood only by studying the sensitivity of jointed rock mass strength (both the peak and residual strengths) to the factors that affect it. An orthogonal design of uniaxial compression tests was simulated on eighteen groups of jointed rock specimens having different geometric and mechanical properties using RFPA2D (Rock Failure Process Analysis) code. The results show that the peak strength is controlled by the geometric parameters of the joints, but that the residual strength is controlled by the mechanical prop- erties of the joint interfaces. The failure mode of jointed rock specimens is mainly shear failure. Joint quantity, or density, is the most important index that affects jointed rock mass strength and engineering quality.

预制裂隙细砂岩裂纹扩展过程及宏观破坏模式单轴压缩试验研究

为研究裂隙的存在对岩体破坏模式的影响,本文对含有不同几何状态的裂隙细砂岩进行了单轴压缩试验,分析了单轴压缩条件下,岩桥倾角和岩桥宽度对裂隙细砂岩试样裂纹起裂、扩展过程以及破坏模式的影响;结果表明:从整体来看,在单轴压缩条件下,裂隙细砂岩试样的破坏模式主要有拉伸破坏、剪切破坏、拉剪组合破坏3种;随着岩桥宽度的增加,裂隙细砂岩试样裂纹发育的起始位置从1条裂隙的尖端转化为2条裂隙的尖端,裂隙细砂岩试样的破坏模式由剪切破坏模式经过拉剪组合破坏模式后向拉伸破坏模式过渡;随着岩桥倾角的增加,裂隙细砂岩试样裂纹发育的起始位置从2条裂隙的尖端转化为1条裂隙的尖端,裂隙细砂岩试样的破坏模式由拉剪破坏逐渐向剪切破坏过渡;裂纹的发育和扩展在应力-应变曲线上都有所体现,应力-应变曲线的每一次波动都对应裂纹的发育或扩展;试验结果为裂隙岩体工程提供了一定的指导意义。