【摘要】 四车道隧道的跨径较大,施工过程复杂,国内可借鉴的经验不多。该文以平潭牛寨山大跨度扁平隧道为工程背景,其南线出口浅埋段偏压严重,在对左右导坑上台阶进行开挖支护后,山体及初支出现裂缝。在工程病害分析处理中得出:围岩参数在连续暴雨的影响下降低,山体形成潜在滑裂面,研究拟采用内侧设置Φ108微型钢管桩注浆加固,外侧设挡墙反压回填的处理方案;通过FLAC 3D软件模拟加固过程来验证方案的正确性,按照计算成果指导施工,成功解决了工程实际问题,为今后类似工程病害提供可借鉴的技术资料。更多还原

【Abstract】 Due to the long span of four-lane tunnel and the complexity of construction process,in domestic,it has few experiences to be used as references. This paper takes the large-span flat tunnel of Niuzhaishan located in Pingtan as the engineering background. The unsymmetrical loading in south exit of shallow buried section is serious. After excavating and supporting the steps of the right and left headings,the cracks occur in the mountain and the first branch. During the analyzing and processing of engineering disease,the results show the surrounding rock parameter is decreased by the effects of continuous heavy rain. It has potential slip and crack surface on the mountain. It intends to adopt the scheme such as setting the diameter Φ108 micro steel pipe pile to groute and reinforce inside,and setting the retaining wall to reverse pressure backfill outside; The correctness of the scheme is verified by simulating the reinforcement process by FLAC 3D software,and the construction is guided according to the calculation results,the practical engineering problems are solved successfully. It can provide reference data for similar engineering diseases in the future.更多还原