大直径土压平衡盾构隧道下穿既有高速公路施工影响分析

Analysis on the influence of large diameter earth pressure balanced shield tunnel under the existing expressway construction

通过对大直径土压平衡盾构隧道下穿既有高速公路的施工影响进行分析,研究了当前阶段高速公路变形沉降控制标准和采用不同加固措施情况下既有高速公路施工影响变化。研究结果表明,在未加固工况中路基变形的最大值为28.6mm,加固工况中路基的沉降变形最大值为17.3mm。对比分析表明,洞内的注浆加固对于地表的沉降变形控制效果是极为显著的,所以在盾构隧道开挖过程中对于盾构隧道洞内进行注浆加固十分必要。

By analyzing the construction impact of a large-diameter earth pressure balance shield tunnel crossing an existing expressway,the current deformation and settlement control standards of the expressway and the changes in the construction impact of the existing expressway under different reinforcement measures are studied.The research results indicate that the maximum deformation of the roadbed under unreinforced conditions is 28.6 mm,the maximum settlement deformation of the roadbed in the reinforcement condition is 17.3 mm.Comparative analysis shows that the grouting reinforcement inside the tunnel has a significant effect on controlling surface settlement and deformation,so it is necessary to carry out grouting reinforcement inside the shield tunnel during the excavation process.