为了分析新建隧道开挖过程中,既有隧道的存在及交错间距变化对新建近接隧道围岩形变量的影响,文章以重庆两江隧道交错近接段为依托工程,开展了交错近接隧道相似模型试验和相应的数值模拟研究.研究表明:交错隧道近接距离与新建隧道的拱顶沉降量及左、右拱腰收敛值成反比;新建隧道开挖过程中的拱顶沉降量及左、右拱腰收敛值的变化趋势一致,可归纳为迅速上升、缓慢上升和稳定三个阶段;隧道拱顶沉降量最大且大于拱腰收敛值之和,对于该类隧道,隧道围岩变形设计上限应以拱顶沉降量为主.通过数据拟合,建立了隧道变形量H(mm)及隧道交错间距L(m)的关系式,相关系数均大于0.995,可为类似隧道预留变形量的设计和施工提供参考.%In order to analyze the effects of the approaching distance of an existing tunnel on rock mass deforma-tion during construction of a new adjacent tunnel, a similarity model test and numerical simulation study are con-ducted based on the approaching section of the Chongqing Liangjiang tunnel. The results show that:1) the approach-ing distance between the two tunnel tubes is inversely proportional to the crown settlement and convergence of the left and right tunnel haunches of the new tunnel;2) the change tendency of the crown settlement complies with that of the convergence of the left and right tunnel haunches during construction of the new tunnel, and it can be summa-rized as the three phases of rapid increase, slow increase and stabilization;and 3) the tunnel crown settlement is larg-er than the sum of the haunch convergence, so the designed upper limit of rock mass deformation should be mainly based on the crown settlement for this type of tunnel. A relationship expression regarding the tunnel deformation H (mm)and tunnel approaching distance L(m) is established by means of data fitting, with the correlation coefficients all being more than 0.995, which provides a reference for the design of reserved deformation and the construction of similar projects.
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