【摘要】 盾构始发是盾构法修建隧道过程中易出现风险事故的重要环节,盾构直接切削始发基坑的围护结构实现始发的新工艺要求对围护结构的强度、刚度等参数进行充分研究。本文以某地铁工程为背景,对盾构始发基坑中的玻璃纤维筋桩即围护结构在开挖施工过程中变形进行了研究。通过采用数值模拟计算方法和现场监测的方法对基坑开挖过程中玻璃纤维筋桩的变形和基坑周边地表沉降进行分析,得出了玻璃纤维筋桩桩体以及桩后地表位移的变化特征。通过玻璃纤维筋灌注桩与普通钢筋灌注桩桩体变形的对比分析表明:由于玻璃纤维筋桩的刚度小于钢筋桩的刚度,玻璃纤维筋桩体的水平位移比钢筋桩的水平位移会增大,但均能满足盾构始发基坑顺利开挖和盾构直接切削始发的要求。总之,对局部玻璃纤维筋桩的围护结构变形的研究,确保了盾构直削始发的成功完成,并为今后的类似工程提供了有益参考。更多还原

【Abstract】 As an important construction link of shield tunnel, shield-driven maybe lead to risk. Particularly as a new construction technology, it is so necessary to adequately research the design parameters of enclosure structure cut by shield machine directly. Based on subway engineering, the deformation of enclosure structure composed of GFRP pile is researched. By numerical analysis and monitoring in-site, the deformation of GFRP pile and ground settlement in the process of excavation of deep shield-driven pit is analyzed. The variation characteristics of deformation of GFRP pile and ground settlement are concluded. By the comparative analysis, the horizontal displacement of GFRP pile is more than that of reinforced concrete pile. The GFRP pile meet the requirement of excavation safely and cutting directly. In a word, GFRP piles are applied in shield-driven pit successfully. It may be useful for similar engineering in future.更多还原