地下工程三面围合空间中底板注浆对下方隧道衬砌的影响

Influence of Grouting under Bottom Slab of Upper Tunnel on Lower Tunnel Lining in a Three-side Enclosed Space

在盾构法隧道注浆研究领域,关于半无限空间中注浆对隧道和周围环境影响的研究已较为成熟,而关于三面围合空间中盾构法隧道施工后进行底板注浆的相关研究甚少。结合已有研究成果,分析和探讨了在底板下注浆对隧道衬砌结构的影响规律,并确定了合理的注浆压力。结果表明,底板脱空可能使衬砌环出现与半无限空间中符号相反的弯矩;底板下注浆可能导致衬砌环产生比半无限空间中更大的弯矩。

Regarding to the shield tunnel grouting,there have been lots of researches on the grouting influence on tunnel and surrounding environment in a semi-infinite space.However,the research on the grouting under bottom slab of upper tunnel after the construction of the lower shield tunnel in a three-side enclosed space is fimited.Through theoretical derivation,the distribution law of the load on the tunnel fining during shield construction in a three-side enclosed space is obtained.Combined with the existing research results,the influence of grouting under bottom slab of upper tunnel on the lining structure of lower tunnel is analyzed and discussed,and the reasonable grouting pressure is determined.The results show that the bending moment of lining ring in a three-side enclosed space may be opposite to that in semi-infinite space due to the void of bottom slab of the upper tunnel,and the bending moment of lining ring may be larger than that in semi-infinite space due to grouting under bottom slab.