期刊名称：IOP Conference Series: Earth and Environmental Science
印刷版ISSN：1755-1307
电子版ISSN：1755-1315
出版年度：2019
卷号：304
期号：3
页码：1-9
DOI：10.1088/1755-1315/304/3/032008
出版社：IOP Publishing
摘要：The geological conditions of tunnel entrance section are complex, and the hazards of landslide and collapse are easy to occur, which makes the selection of construction methods of tunnel entrance section particularly important before tunnel construction. Therefore, it is of great significance to study the transformation of construction methods between tunnel body section and tunnel entrance section for the safety construction of tunnel entrance section. Taking a tunnel of Meida Expressway as an example, the geological characteristics of the tunnel body and the tunnel entrance section of Meida Expressway are analyzed. Based on the comprehensive consideration of the construction period, safety and advantages and disadvantages of the construction method, the CD method is adopted to construct the tunnel outlet section. Through numerical simulation of tunnel body and outlet section, it is concluded that CD method is superior to bench method in tunnel body section, and can ensure construction safety; and the steps of conversion from bench method to CD method are summarized. Finally, through monitoring and measuring the surrounding rock and surface deformation near transition section, it is concluded that the maximum cumulative deformation at vault top is 78.6 mm, and the maximum cumulative deformation at surface is 94.6 mm, which meets the requirements of specifications and ensures the safety of the tunnel entrance. Therefore, reasonable transformation of tunnel construction method can ensure construction safety, at the same time, it can also speed up construction progress and save funds.
