为研究川藏铁路深埋隧道超长水平钻探实施的可行性及复杂地质条件下水平钻探对隧道施工的影响程度，在川藏铁路隧道勘察设计中开展大量调研工作及地表超长深埋水平钻探试验，并结合隧道掘进指标、钻探速度，研究钻爆法及TBM施工中超长超前水平钻探对隧道掘进效率的影响程度。研究结果表明： 1）在单位长度内，围岩地质条件越好，钻探深度越大，隧道掘进速度越快，超前水平钻探对施工影响越大。2）在Ⅱ、Ⅲ级围岩地段，在TBM设备后方180 m处实施超前水平钻探时，水平钻探进度难以追赶TBM施工进度，钻探对施工指导意义相对较小； 在Ⅳ、Ⅴ级围岩地段，水平钻探进度可以很快追赶上TBM施工进度，在TBM施工受阻等复杂地质条件下，采取水平钻探技术对指导隧道施工有一定意义。3）在护盾处开展长距离连续水平钻探时，对隧道施工的影响程度最大可达85.11%，影响较大。综合分析表明，超前水平钻探在断层破碎带、强富水及高压富水、岩溶等不良地质地段实施较为合适。

A substantial amount of research work and superlong and deepburied horizontal drilling tests have been conducted on the survey and design of the SichuanTibet railway to study the feasibility of implementing superlong horizontal drilling in the deepburied tunnel of the SichuanTibet railway and the influence of horizontal drilling on tunnel construction under complex geological conditions. According to the tunneling index and drilling speed, the influence of superlong advance horizontal drilling on the construction period by drilling and blasting and tunnel boring machine (TBM) methods is studied. The results reveal the following: (1) In unit length, the better the geological conditions of surrounding rock, the deeper the drilling depth and the faster the tunneling speed, and the greater the influence of advance horizontal drilling on the construction. (2) When advance horizontal drilling is carried out 180 m behind TBM equipment in the surrounding rock of grades Ⅱ and Ⅲ, horizontal drilling progress is difficult to keep up with the TBM′s construction speed, and the significance of drilling for construction guidance is relatively small. Whereas in the surrounding rock of grades Ⅳ and Ⅴ, it can catch up with the TBM construction tunnel face by a certain distance, making it crucial to guide the tunnel construction in complicated geological conditions such as when TBM construction is interrupted. (3) Longdistance continuous horizontal drilling at the shield has the greatest impact on the tunnel construction, accounting for up to 85.11% of the total. Comprehensive analysis shows that advance horizontal drilling is better suited in the fault fracture zone, strong and highpressure waterrich, karst, and other unfavorable geological sections.