【摘要】 在山区修建隧道时往往会遇到偏压地形，导致衬砌结构受力不均匀。在衬砌结构由部分到闭合时，会因不对称围岩压力而产生裂缝。文中采用数值模拟方法，研究不同工况下施工过程中衬砌结构的内力、安全系数及裂缝发展规律。计算表明，采用CD法开挖时洞周变形较小，裂缝较大。得出当衬砌结构还未闭合时，单元安全系数较低，且会产生一定的裂缝；当衬砌结构达到完整闭合，受力均匀，相同位置处的衬砌单元安全系数明显提高。更多还原

【Abstract】 When building tunnels in mountainous areas, biased terrain is often encountered, leading to uneven stress of lining structures. When the lining structure changes from partial to closed structure, cracks will occur due to the asymmetric surrounding rock pressure. The internal force, safety factor and crack development of lining structure under different construction conditions are studied by numerical simulation. The calculation shows that the CD method has smaller deformation and larger crack around the hole. It is concluded that when the lining structure is not closed, the element safety factor is low and certain cracks will be produced. When the lining structure is completely closed and the force distribution is uniform, the safety factor of the lining unit at the same position will be obviously improved.更多还原