A key issue in the field of porous rock geomechanics is finding suitable suites of samples in which petrophysical characteristics systematically vary, in order to determine the controlling factors on the mechanical behavior. To resolve this problem a new methodology has been developed, whereby high-porosity synthetic sandstone samples are produced from initially incohesive sand, by using the chemical reaction between sodium silicate and hydrochloric acid to generate amorphous quartz cement and thus provide cohesion. This enables the production of sandstone samples for laboratory testing which have reproducible petrophysical properties that can be systematically controlled, including porosity, grain size, cement content, grain shape and grain size distribution. Here, poorly-sorted, high-porosity (36–38%) sandstones were produced and subjected to a range of geomechanical tests, including uniaxial and triaxial experiments, to see if their microstructure and mechanical response was similar to equivalent natural samples. The 36–38% porosity synthetic sandstones have realistic and reproducible uniaxial compressive and tensile strengths of 5.18 (± 0.76) MPa and 0.167 (± 0.117) MPa respectively, as well as hydrostatic yield strengths (P*) of 67–69 MPa. They also exhibit yield curves with a comparable geometry to natural sandstones of similar porosity and grain size and display elastic moduli within the expected range for natural sandstones. The methodology outlined in this contribution allows for the production of sandstones for laboratory testing with reproducible behavior, that can be utilized in future studies to systematically investigate how different petrophysical properties control the mechanical response of sandstone to elastic and inelastic deformation.

多孔岩石地质力学领域的一个关键问题是找到合适的岩石物理特征系统变化的样品套件，以确定力学行为的控制因素。为了解决这个问题，开发了一种新的方法，即通过使用硅酸钠和盐酸之间的化学反应，从最初的非粘性砂中生产高孔隙度合成砂岩样品生成无定形石英胶结物，从而提供内聚力。这使得能够生产用于实验室测试的砂岩样品，这些样品具有可系统控制的可重现的岩石物理特性，包括孔隙度、粒度、水泥含量、颗粒形状和粒度分布。在这里，生产了分选不良的高孔隙率 (36-38%)砂岩，并进行了一系列地质力学测试，包括单轴和三轴实验，以查看它们的微观结构和力学响应是否与等效的天然样品相似。孔隙率为 36-38% 的合成砂岩分别具有 5.18 (± 0.76) MPa 和 0.167 (± 0.117) MPa 的真实且可再现的单轴抗压和抗拉强度，以及静水屈服强度 (P*) 67–69 兆帕。它们还显示出与具有相似孔隙度和粒度的天然砂岩具有可比几何形状的屈服曲线，并显示出天然砂岩预期范围内的弹性模量。本贡献中概述的方法允许生产具有可重复行为的实验室测试砂岩，可用于未来的研究，以系统地研究不同的岩石物理特性如何控制砂岩对弹性和非弹性变形的机械响应。