Fully grouted bolts are a key component of the support system for underground openings. Although considerable effort has been made in the simulation of the reinforcement effect of the fully grouted bolts on the rock masses surrounding underground openings, most of the work has limited significance since the structural element approach is used. This study proposes a local homogenization approach (L-H approach) that integrates elastoplastic mechanics, composite mechanics, and analytical approaches with numerical simulation to effectively simulate the reinforcement effect of the fully grouted bolt on deep surrounding rock masses. In the L-H approach, the representative volume of bolted rock mass (RVBRM) with a fully grouted bolt is established based on the original mesh model utilized in the rockbolt element approach. The RVBRM is a regular quadrangular prism with a cross-sectional size equal to the bolt spacing and a length equal to the bolt length. The RVBRM is homogenized by the L-H approach from a unidirectional bolt-reinforced composite into a homogeneous transversely isotropic medium whose mechanical properties are described by a new transversely isotropic elastoplastic model. The L-H parameters for the RVBRM are obtained using analytical approaches, composite mechanics, and known parameters of the rock mass and bolt. Using the L-H approach, the reinforcement effect of the fully grouted bolt on the bolted rock specimen and the surrounding rock mass in Jinping II Diversion Tunnel #2 with a depth greater than 2000 m is simulated. The results show that the predictions of the L-H approach are more in agreement with the physical model results of bolted rock specimen and provide a more realistic response of the bolted surrounding rock mass. The L-H approach demonstrates that fully grouted bolts with common bolt spacings and diameters substantially enhance the elastic modulus, shear strength, and tensile strength of the rock mass in the direction of the bolt axis.

全灌浆螺栓是地下洞口支撑系统的关键部件。尽管在模拟完全灌浆螺栓对地下洞口周围岩体的加固效果方面已经做出了相当大的努力，但由于使用了结构元件方法，大部分工作的意义有限。本研究提出了一种将弹塑性力学、复合力学、解析方法与数值模拟相结合的局部均匀化方法（LH方法），以有效模拟全灌浆锚杆对深部围岩体的加固效果。在 LH 方法中，基于锚杆单元方法中使用的原始网格模型，建立了具有完全灌浆锚杆的锚杆岩体的代表体积 (RVBRM)。RVBRM 是一个正四棱柱，其横截面尺寸等于螺栓间距，长度等于螺栓长度。RVBRM 通过 LH 方法从单向螺栓增强复合材料均匀化为均匀的横向各向同性介质，其机械性能由新的横向各向同性弹塑性模型描述。RVBRM 的 LH 参数是使用分析方法、复合力学以及岩体和锚杆的已知参数获得的。采用LH法，模拟了锦屏Ⅱ引水隧道#2深度大于2000m的全灌浆锚杆对锚杆岩样及围岩体的加固效果。结果表明，LH法的预测结果与锚杆岩石试件物理模型结果更加吻合，提供了更真实的锚杆围岩响应。LH 方法表明，具有相同螺栓间距和直径的全灌浆螺栓显着提高了岩体在螺栓轴线方向上的弹性模量、剪切强度和抗拉强度。