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对隧道围岩与初衬之间的相互作用进行了研究,并对二次衬砌前的围岩和初衬中应力与位移及其释放进行了计算分析。首先利用线性黏弹性理论,导出了隧道开挖后围岩和初衬中的应力与位移;然后选取Maxwell和Poyting-Thomson三参数固体流变模型模拟围岩,研究了隧道围岩与初衬之间的相互作用;最后结合公路隧道施工,计算了二次衬砌前的围岩应力和位移及其释放率、围岩与初衬间相互作用、释放荷载分担系数,并依此探讨了初衬混凝土的最小厚度与释放荷载分担系数之间的关系。结果表明,初衬混凝土的厚度小于最小厚度时,初衬混凝土中会出现拉应力,而初衬混凝土的厚度大于容许厚度时,不利于围岩的载荷和变形释放。
The interaction between tunnel surrounding rock and primary lining is studied, and the stress and displacement in surrounding rock and primary lining before secondary lining are calculated and analyzed. Firstly, using the theory of linear viscoelasticity, the stress and displacement in the surrounding rock and primary lining after tunnel excavation are deduced. Then the Maxwell and Poyting-Thomson three-parameter solid rheological model is selected to simulate the surrounding rock. Finally, combined with the construction of highway tunnel, the stress and displacement of surrounding rock before the secondary lining and its release rate, the interaction between the surrounding rock and the primary lining and the load sharing coefficient are calculated. Based on this, the initial lining concrete The relationship between the minimum thickness and the release load sharing factor. The results show that when the thickness of the initial lining concrete is less than the minimum thickness, the tensile stress will appear in the primary lining concrete. When the thickness of the primary lining concrete is larger than the allowable thickness, the load and deformation release of the surrounding rock are not conducive.