随着我国对高速公路建设的加大投入，有些公路隧道不可避免的穿过煤系地层和采空区。但我国在类似的工程地质条件下建成的隧道实例较少，缺乏可借鉴的设计施工经验。本文以山西祁（县）至临（汾）高速公路灵石至霍州段常家山隧道项目为依托，在系统分析该隧道的工程地质特征和采空区岩体变形破坏特征的基础上，采用数值模拟方法，详细分析了在Ⅰ～Ⅳ类围岩和采空区条件下所采用的施工方法和支护方案对隧道围岩稳定性的影响，得出对于选定的支护方案，在不同的工程地质条件下各个施工步骤的隧道围岩应力场特征图、应变（位移）场特征图和塑性区分布图。经分析和研究这些模拟结果，认为： （1）Ⅰ、Ⅱ和Ⅲ类围岩塑性区面积及其分布范围与施工步骤密切相关，其稳定性容易受到隧道开挖的扰动。在分断面开挖中，下断面的开挖对围岩的扰动最大，对隧道的稳定性影响也最大。Ⅳ类围岩稳定性好，尽管采用全断面开挖，但出现的塑性区面积则很小，且支护后塑性区消失。 （2）在本文设定的条件下，模拟的Ⅰ至Ⅳ类围岩的施工步骤和支护方案均为可行有效的； （3）采空区段，本文先模拟采煤，后模拟采空区注浆回填，接着模拟隧道的施工过程。从模拟结果可以看出：①采空区注浆后仍存在复杂的应力应变场，在煤柱附近仍存在较大的应力集中；②采空区注浆后，不管采空区是处于隧道上方还是下方，各施工步骤对隧道稳定性的影响与I类围岩段的相似。③采空区位于隧道上方时，其对隧道的影响远复杂于位于下方的影响。由于煤柱附近存在明显的应力集中，其与隧道的空间位置关系对隧道稳定性有较大影响，当位于隧道拱腰上方时，会使隧道产生扁压。

As the enlarging investment of highway building in our country, some of highway tunnels are inevitable to cut through the coal strata and gob. But there are a little of tunnels that have been built under the similar engineering geology condition, and the experience of design and construction of them is lack. Based on the Changjiashan tunnel which is an important project of the highway from Qixian to Linfen in Shanxi province, this thesis systemically analyzed the character of engineering geology and the rock’s deformation of the coal gob, and analyzed the effect of the excavation and support to the stability of the tunnel in differ classification of surrounding rock from I to IV and in coal gob condition using numerical simulation method. For the selective support scheme, the character of the stress field and the deformation field, and the distributing of the plastic field of each excavation procedure in differ engineering geology condition is worked out.The analyzing result of the numerical simulation can conclude as follows: (1) The plastic field area of the I 、II and III surrounding rock are colsely correlated with the excavation procedure, and the stability of the I 、II and III surrounding rock are easy to be disturbed. Among the excavation procedure, the excavation of the lower section has the biggest impact on the stability of the tunnel. Because of the good the stability of the IV surrounding rock, although the tunnel was fully excavated the plastic field area was few, and the plastic field area is disappeared when the tunnel is supported. (2) On the premise of the thesis, the excavation procedure and the support scheme of Changjiashan tunnel are both feasible. (3) In the coal gob field, the mining is simulated firstly, and then the backfilling of the gob, next the excavating of the tunnel. From the result of the simulation it can be seen: ① there still has complex stress field after the backfilling of the gob and bigger stess concentration nearby the coal column; ② after backfilling the gob, no matter the gob is above or beneath the tunnel,the effect on the stability of the tunnel of each excavation procedure is similar to the effect of the I surrounding rock; ③ when the gob above the tunnel, it has more complex effect on the tunnel than beneath it. Because of the obvious stess concentration nearby the coal column, the relation between the coal column and the tunnel has great effect on the stability of tunnel. It can produce unsymmetrically load when it is nearby the arch of the tunnel.