Ma Anliang tunnel of Ⅵ class of surrounding rock on Baoji-Lanzhou high-speed dedicated passenger line is located in loose strata with rich water, passing shallow valley and facing very complex engineering mechanics conditions and great construction risks. The selection of tunnel designing scheme may bring big impact not only on engineering construction safety, progress and investment but also on future operational safety. The aim of the paper is to study the characteristics of Ⅵ class rock railway tunnel and to put forward reasonable scheme. By means of numerical simulation and comparison analysis, all inclusive waterproofing concept supplemented with well point dewatering and grouting reinforcement measures is proposed to protect the safety of the Ⅵ class rock tunnel construction. The scheme is applicable and economical.%宝兰客运专线马鞍梁隧道Ⅵ级围岩地段处于富水的松散地层中，下穿浅埋沟谷，工程力学条件差、施工风险大，隧道设计方案的选择不仅对工程施工安全、进度和投资影响较大，甚至会对工程的运营安全带来影响。通过工程实例研究客运专线隧道Ⅵ级围岩地段主要工程特点，提出Ⅵ级围岩隧道设计的合理方案。通过工程类比法及数值分析确定结构支护参数，采用全包防水理念，并辅以井点降水及注浆加固等措施改善地层，保障了Ⅵ级围岩隧道工程的施工安全，方案经济合理。
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