摘要：研究目的：在建成兰铁路平安隧道因其复杂的地质构造条件、高构造应力场特征及坚硬完整的围岩条件等，隧道开挖过程中围岩岩爆现象较为普遍。本文在现场调绘及地应力测试、岩块物理力学试验等资料分析的基础上，根据岩爆现象 及其破坏特征，从工程地质环境、地质构造、地应力场及地层岩性等方面，以工程地质的视角，对复杂构造高应力场中质坚性脆围岩岩爆的成因机制进行分析，并对类似工程地质条件下隧道其他段的岩爆等级进行预测。 研究结论： (1)区域构造上，平安隧道3#斜井工区处于较场山字形构造带之前弧部位，褶曲及断层等新老构造叠加，构造条件极其复杂；(2)隧道内岩爆主要呈现为围岩爆裂松脱、剥落、弹射等现象，对工程破坏主要表现为初支喷混凝 土剥落、开裂、拱架扭曲、断裂、垮塌等现象；(3)在时间上，测段岩爆主要表现为即时型岩爆特征，其岩爆等级为中等~强烈岩爆；(4)从工程地质的视角，测段岩爆可归纳为强烈复杂地质构造的孕育条件、高构造应力场的力 学条件、坚硬完整围岩条件等主要因素综合影响的成因机制；(5)本文分析方法和结论对山区类似工程地质条件下隧道工程围岩岩爆的设计和施工具有一定的借鉴意义。

Abstract：Research purposes： For its geological background such as the complex geological structure conditions, high tectonic stress field characteristics, hard and intact surrounding rock conditions, which is under construction for the Ping′an tunnel of Chengdu-Lanzhou railway, the rock-burst disasters of surrounding rock generally produced in the process of tunnel construction. According to the phenomenon of rock-burst and it′s failure characteristics of supporting structure, this paper based on the geological survey, the data analysis of geo-stress test and physical mechanics test of rock mass, from several aspects of the engineering geological environment, geological structure, geo-stress field and formation lithology, the formation mechanisms of rock-burst of surrounding rock which is in the environment of complex geological structure and high geo-stress field were analyzed in perspective of engineering geology, and the rock burst level of the other section of tunnel under similar engineering geological conditions were evaluated.  Research conclusions： (1)In regional structure the 3# inclined shaft working area of Ping′an tunnel located in the front arc position of Jiaochang mountain structural belt, new and old structures such as fold and fault were developed and superimposed, with complex construction condition. (2) In tunnel rock-burst was mainly expressed as the phenomenon of rock burst loose, spalling, and ejection, etc., and with the failure characteristics of primary support concrete spalling, fracture, steel distortion, crack and collapse for the engineering structure. (3) Rock-burst was mainly presented as the immediate rock-burst characteristics in time, and rock-burst level is moderate to strong. (4) In perspective of engineering geology, the formation mechanism of rock-burst of tunnel surrounding rock can be summarized as the comprehensive influence of main factors such as the inoculation conditions of strongly complex geological structure, mechanics condition of high geo- stress field and condition of hard and intact surrounding rock. (5) The 〖JP3〗analysis methods and conclusions of this paper have certain reference significance for the design and construction of rock-〖JP〗burst of surrounding rock of tunnel engineering under similar engineering geological conditions in mountainous area. 