高地应力下深埋隧洞软岩段围岩时效特征研究

“引大济湟”调水总干渠输水隧洞埋深大，地应力较高，其中穿越的洞段Ⅳ、Ⅴ类围岩占有较大的比例，在高地应力作用下围岩开挖卸荷后极可能出现大变形失稳、垮塌等，这些都极大地影响着TBM的掘进效率及施工进度。根据洞室开挖过程中实际揭示的围岩地质条件及变形特征，采用三维黏弹塑性数值方法，对围岩的流变特性与时效变形进行研究；在对实测地应力场进行分析基础上，结合围岩现场变形规律，对围岩蠕变力学参数进行了反演，进而对隧洞开挖区域的软弱围岩进行黏弹塑性数值分析，获得了规律性认识，为动态调整设计提供科学依据。

Study of aging characteristics of soft surrounding rock in deep tunnel with high ground stress

The deep diversion tunnel for Yinda-Jihuang water transfer project is under high ground stress. Along the tunnel axis, the Ⅳ and Ⅴclass of surrounding rocks occupies a larger proportion. Under the action of high geostress, the surrounding rocks likely appear in large deformation instability to collapse after excavation unloading; these affected greatly TBM tunneling efficiency and construction schedule. According to the practical geological conditions and the surrounding rock revealed deformation characteristics, this paper adopts three-dimensional visco-elastoplastic numerical method to research aging deformation characteristics of the surrounding rocks. Based on the measured geostress field, and combining site deformation law of the surrounding rock, the creep mechanical parameters of rock is obtained by back analysis, then for weak rock visco-elastoplastic numerical analysis of excavation areas is caned out. Regularity conclusion is obtained, so as to provide the scientific basis for dynamic adjustment design