为同时满足双线行车和右线停车线扩大断面的功能需要，西安地铁一号线枣园北路站—汉城路站区间采用非等大断面小净距黄土地铁隧道。针对断面不等大、盾构法与新奥法组合施工方案、小净距黄土地铁隧道的特点，进行了左线小断面盾构法、右线大断面双侧壁导坑法或CRD法双线依次先后贯通3种施工方案的数值模拟与比选分析。计算结果表明，与先贯通小洞、后开挖大洞的方案相比较，采用先新奥法贯通大断面隧道、后盾构法掘进小断面隧道的施工方案对围岩扰动较小，能更有利于控制地表变形；双侧壁导坑法较CRD法虽更能充分体现围岩的自承能力，有效发挥初期支护的承载能力，提高二次衬砌的安全储备，但若将先贯通的大断面隧道施工方案由双侧壁导坑法改为CRD法，可在确保工程安全的前提下降低施工成本，并加快施工进度，顺利地完成隧道建设。

A portion of the running tunnel from Zaoyuan North Road Station to Hancheng Road Station on No. 1 line of Xi’an Metro is designed as a closelyspaced Metro tunnel with different crosssection dimensions. The parallel tunnel tubes have such features as different crosssection dimensions, dual construction methods (shield tunneling method and NATM) and small spacing. Numerical simulation is made on the construction of the left small crosssection tunnel tube by shield tunneling method and the right large crosssection tunnel tube by double side drift method and CRD method. The calculation results show that: 1) Compared to the scheme that the left small crosssection tunnel tube is broken through before the right large crosssection tunnel tube is excavated, the scheme that the right large crosssection tunnel tube is broken through by NATM before the left small crosssection tunnel tube is bored by shield has smaller disturbance on the surrounding rock mass and is more helpful for ground deformation control; 2) Compared to CRD method, double side drift method is more helpful to making full use of the selfsupport capacity of the surrounding rock mass, is more helpful to making full use of the loadbearing capacity of the primary support, and is more helpful to improving the safety reserve of the secondary lining; however, if CRD method is adopted for the right large crosssection tunnel tube, which is broken through before the left small crosssection tunnel tube, the construction cost can be reduced, the construction progress can be improved and the tunnel can be constructed successfully under safe conditions.