本文通过对隧道施工过程监测项目进行监测，然后对监测所得数据进行整理和线性回归分析，找出围岩在开挖支护后变形的内在规律，反演出隧道洞室围岩的综合物理力学参数，以此来进行隧道施工方案等方面的研究，主要内容如下： ⑴本文结合岩石力学理论计算方法和现场监控量测的特点，立足于隧道典型断面观测点模拟所得数据，从隧道围岩的稳定性定量评价方法着手，进行隧道围岩稳定方面的探讨。隧道在不同的断面形式情况下，围岩应力分布不尽相同。隧道断面形式为五心圆时，其围岩应力状态更接近实际工程中对隧道结构受力均匀性方面的要求。 ⑵基于现场监控量测数据，及时运用围岩参数反演程序进行分析，可以比较准确的反演隧道围岩等效力学参数，以此能够快速、准确地对隧道施工中围岩稳定性做出合理的评价，及预测未开挖段隧道在开挖支护后围岩的稳定性。然后利用参数反演得出的岩体物理力学参数建立三维数值模型，通过计算对比得出，大断面小净距隧道使用三台阶七步开挖法进行施工时相对于CD工法的施工组织设计复杂，施工速度缓慢等缺点，施工成本降低，具有广泛地推广价值以及应用前景，在国内同类大断面小净距隧道施工方面提供一定的参考依据。 ⑶通过数值模拟研究了净距在10m、12m、15m、18m、20m等5种工况下，隧道围岩典型观测点处应力应变特征等，得出大断面小净距隧道在使用三台阶七步开挖法，埋深为30m、围岩等级为Ⅴ级的情况下，和本文地形及地质等限制条件相似地段，隧道双洞净距选用12～15m的范围较为合适。 ⑷通过数值模拟研究了掌子面间距为3m、6m、9m、12m、15m共五种工况进行数值模拟，得出当施工间距为12m时，隧道围岩稳定性相对较差，但在安全可控范围，另外也有利于缩短施工工期。

In this paper, based on the the monitoring of the monitoring project of tunnel construction process, and then the data from the monitoring analysis and linear regression, to find out the inherent law of surrounding rock in the excavation deformation, the comprehensive physical and mechanical parameters of surrounding rock of tunnel invert, in order to carry out the research of tunnel construction project, the main contents are as follows. ⑴In this paper, combined with the theory of rock calculating mechanics and characteristics of field monitoring measurement, based on the typical cross-section tunnel observation point simulation data, starting from the quantitative evaluation method of the stability of tunnel surrounding rock, to study the stability of tunnel surrounding rock. In the situation of tunnel section under the different surrounding rock stress distribution, are not the same. Morphology of tunnel section five circles, the stress state is more close to the actual engineering of tunnel structure stress uniformity requirements in terms of its surrounding rock. ⑵Based on the measured data of site monitoring, timely use of parameter inversion procedure to carry on the analysis, the equivalent mechanical parameters of surrounding rock of tunnel can be retrieved accurately, quickly and accurately, which can make a reasonable evaluation on stability of surrounding rock in tunnel construction, and the prediction of excavation tunnel on the stability of surrounding rock after excavation. Then the three-dimensional numerical model is established by use of physical and mechanical parameters of rock mass parameters obtained by calculation, comparison, large section and small spacing tunnel using three step and seven step excavation method of construction compared to the CD method of construction organization design is complex, the construction speed is too slow to reduce the construction cost, and wide popularization value and application prospect, provide the reference in the large section of domestic small spacing tunnel construction. ⑶Through the numerical simulation to study the spacing in 10m, 12M, 15m, 18m, 20m and other 5 kinds of working conditions of tunnel surrounding rock, a typical stress strain characteristics of the observation point, the large section tunnel with small spacing in the use of three step and seven step excavation method, the depth is 30m, surrounding rock grade V case in this paper, and the terrain and geological conditions such as lots of similar tunnel, double hole spacing of 12 ~ 15m range selection is more appropriate. ⑷By numerical simulation of the tunnel face interval of 3M (0.25D), 6m (0.5D), 9m (0.75D), 12m (1.0D), 15m (1.25D) numerical simulation of five kinds of conditions, when the construction of the space of 12M, the stability of tunnel surrounding rock is relatively poor, but in the safety control scope, there are also to shorten the construction period.