中文摘要：

工程岩体根据其受力特性可以分为加载岩体和卸荷岩体,结合三峡工程永久船闸高边坡岩体,利用自行开发的三轴试验设备进行研究,根据几何和重力相似、材料力学性能相似、岩体结构相似、边界力相似、开挖过程模拟相似,由重晶石粉、铁粉、石膏、水等制作尺寸为250 mm×250 mm×250 mm的试件,试件的几何比尺选择为CL=3,9,27,81;并对几何比尺为27的试件制作含有与船闸轴线相垂直的卸荷方向成8°,36°,52°,82°,90°的结构面.对节理岩体的加卸荷应力-应变关系、卸荷岩体(应力-应变关系、抗拉强度、变形模量)的各向异性、卸荷岩体(抗拉强度、抗压强度、泊松比、变形模量)的尺寸效应、卸荷岩体的流变特性、卸荷岩体的强度准则进行试验研究.研究结果表明,不同结构面方向对岩体的卸荷作用明显;岩体的抗压强度、抗拉强度、变形模量、泊松比以及岩体的各向异性等均随着尺寸的加大而降低;岩石受拉的流变特性与岩石所受的拉应力大小直接有关;得出Hoek-Brown准则所描述的岩体强度关系曲线中的岩体材料常数m,s值.

英文摘要：

According to stress characteristics, rock mass may be divided into the loading rock mass and the unloading rock mass respectively. The rock mass of the permanent shiplock of the Three Gorges Project is studied with the self-developed triaxial test equipment based on the geometric similarity and the gravity similarity, the similarity of mechanical properties of material, the similarity of rock mass structure, the similarity of boundary force, and the similarity of excavation process simulation. The 250 mm × 250 mm × 250 mm samples are made by the barite powder, the iron powder, the gypsum, the water and so on; and the geometric scales of the sample are 3, 9, 27, 81 respectively. For the sample with scale of 27, the structural planes are included with dipping angles being 8°, 36°, 52°, 82°, and 90° respectively with the unloading direction vertical to the shiplock axis. Study on the relationship between stress and strain of jointed rock mass under loading and unloading conditions, the anisotropy of unloading rock mass (relationship between stress and strain, tensile strength, deformation modulus), the size effect of unloading rock mass (tensile strength, compressive strength, Poisson's ratio, deformation modulus), the rheological property of unloading rock mass, and the strength criterion of unloading rock mass are also conducted. The research indicates that different structural plane directions affect rock mass unloading evidently. With the size increasing, the tensile strength, compressive strength, deformation modulus, Poisson's ratio and anisotropy of the rock mass decrease. The rheological property of rock has direct relationship with rock mass tensile stress magnitude. Finally, the rock mass material constants m, s of Hoek-Brown criterion are obtained to describe rock mass strength.