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基材土-岩接触面剪切力学性能是生态护坡体系长久稳定的关键,相关研究可为解决基材脱落难题、完善生态防护技术体系提供必要依据和指导。采用自制的原位剪切仪对4种不同粗糙起伏的基材土-岩接触面进行了原位剪切试验,结果表明,基材土-岩接触面剪切应力-位移表现出典型的软化特性,具有明显的初始线弹性变形、弹塑性变形、峰后软化以及残余剪切变形4个阶段。分析发现,文中试验条件下凸起高度算数平均偏差Ra在4 mm以下时,峰值剪切强度增加速度较快,随后呈逐渐减弱趋势;残余剪切强度、峰值剪切位移以及进入残余阶段的剪切位移与粗糙凸起高度算数平均偏差呈近线性正相关关系。可见实施生态护坡时合理地控制坡面粗糙起伏,有助于提高土-岩接触面峰值剪切强度和残余剪切强度,改善其变形性能,对防护体系的长期整体稳定具有促进作用。
Shear mechanical properties of the substrate soil-rock contact surface is the key to long-term stability of the ecological slope protection system. Related research can provide the necessary basis and guidance for solving the problem of substrate falling off and perfecting the ecological protection technology system. Home-made in-situ shear was used to conduct in-situ shear tests on four soil-rock interfaces with different roughness. The results show that the shear stress-displacement at the substrate-rock interface shows typical softening Characteristics, with obvious initial linear elastic deformation, elastic deformation, post-peak softening and residual shear deformation of four stages. The analysis shows that the peak shear strength increases rapidly when the average deviation Ra of the height of convexity under the test condition is below 4 mm, and then decreases gradually; the residual shear strength, the peak shear displacement and the shear force entering the residual stage The tangent displacement and the arithmetic average deviation of the height of rough bump have a nearly linear positive correlation. It can be seen that it is reasonable to control the roughness of slope during the implementation of ecological slope protection, which is helpful to improve the peak shear strength and residual shear strength of soil-rock contact surface and improve its deformation performance, which can promote long-term overall stability of the protection system.