为进一步探索单臂掘进机在浅埋、近接既有建（构）筑物和铁路大断面隧道开挖中的适用性，以成渝客专新红岩隧道下穿地下商场为工程背景，从隧道非爆法开挖方法的比选、外围环境及围岩岩性的分析、数值模拟计算和现场试验等方面进行了分析研究。主要结论如下： 1）在浅埋、近接既有建（构）筑物环境中应用单臂掘进机切削法进行隧道开挖，在减小对周边围岩及建（构）筑物的扰动、控制沉降方面效果明显，安全性高； 2）在围岩强度为30 MPa左右时，单臂掘进机的开挖掘进效率较高； 3）从经济效益上分析，单臂掘进机开挖的成本由于设备投入、功效等因素，较普通机械开挖成本有比较大的增加，在开挖Ⅳ、Ⅴ级围岩时单臂掘进机的施工成本基本一致； 4）单臂掘进机开挖受大断面隧道尺寸、隧道安全步距控制等方面的制约，影响其功效正常发挥，导致开挖过程工序相对繁多，降低了隧道掘进速度。对于单臂掘进机切削法，建议在特殊环境、敏感工点、短距离隧道掘进中应用，对于长距离隧道掘进还需进一步优化单臂掘进机开挖的工法体系，以及在砂岩、泥岩夹砂岩围岩环境中的降尘措施。

The aim of this study is to analyze the applicability of singlecantilever tunneling machines in shallowcovered tunnels adjacent to existing buildings and largesection railway tunnels. Studies regarding comparison and selection of nonblasting excavation methods are conducted along with investigation of the surrounding environment and lithology of the surrounding rocks, numerical simulation, and field test of New Hongyan tunnel on ChengduChongqing highspeed railway crossing underneath underground shopping mall. Following conclusions are drawn: (1) The singlecantilever tunneling machine can decrease the construction disturbance on surrounding rocks and buildings, considerably affecting the deformation control and construction safety. (2) The excavation efficiency of singlecantilever tunneling machine is high in surrounding rocks with a strength of approximately 30 MPa. (3) The singlecantilever tunneling machine costs much more than the conventional tunneling machine, and it costs almost the same in Grade Ⅳ and Ⅴ surrounding rocks. (4) The excavation of a singlecantilever tunneling machine is subject to restrictions of tunnel crosssection size and safe step pitch control, leading to complex excavation procedures and low tunneling efficiency. The machine is recommended for shortdistance excavation in delicate construction sites of special environments. Longdistance tunneling requires further optimization of the excavation method system of singlecantilever tunneling machine, as well as dust control measures in the environments mixed with sandstone and mudstones.