某强倾倒变形体内浅埋偏压洞口段的隧道变形分析及处治技术研究

以处于强倾倒变形体内并在施工过程中出现过2次变形的浅埋偏压隧道进口段为研究对象，针对实际工程地质条件及变形情况，应用新奥法原理及拱效应理论，以变形观察及监控量测为信息化施工手段，及时采用堆（填）碴反压、注浆加固、网喷补强支护等一系列有针对性的补救措施，在洞内成功地加固变形隧道，制止过大变形可能诱发隧道塌方及山体滑坡的险情; 并在后续施工中，通过调整支护参数和利用创新的“三台阶八步法”施工方法，安全、顺利地完成后续不良地质段的隧道施工任务。

Analysis on Deformation of a Shallow-covered Asymmetrically-pressured Tunnel Portal Section Located in Toppling Deformed Ground and Its Treatment

The entrance portal section of a tunnel is located in toppling deformed ground and is shallow covered and asymmetrically pressured. Two deformation incidents occurred during the construction of the portal section of the tunnel. In the paper, the causes for the deformation incidents are analyzed, and countermeasures such as muck piling, grouting and additional wiremeshing and shotcreting are taken. In the end, the deformation of the tunnel portal section has been brought under effective control and the possible tunnel collapse and landslide have been avoided. In the construction of the remaining tunnel section, the support parameters have been adjusted and the “three bench eight step” construction method has been used innovatively. Finally, the tunnel has been completed successfully. 