穿黄隧洞深埋于河床摆幅大、冲淤变化剧烈的黄河河道，地处 7 度地震区，是一个由数百个环拼装联结的非连续变形柔性结构。河床冲淤变化以及地震荷载对隧洞纵向变形以及纵向变形缝的影响问题，是隧洞方案是否可行的关键技术问题之一。为此，采用自编的考虑接触的三维非线性有限元分析程序，计算隧洞结构纵向变形、变形缝张开度、错动位移等。针对隧洞模型计算范围大，接触面多等特点，通过采取多项措施控制计算规模，保证计算精度，结合程序的方程组快速求解方法，解决了穿黄隧洞纵向变形这一技术难题。计算结果表明，在最不利荷载组合作用下，隧洞变形缝的张开度、错动位移和相应跨缝螺栓应力以及混凝土应力均在设计控制的范围内，满足设计要求。

 The Yellow River tunnel, located at 7 degree seismic region, is deeply buried in the reach where the swing of the riverbed is larger and siltation-erosion variation is severe. The tunnel is a discontinuously flexible structure composed of several hundreds rings. The key technique problem in the feasible scheme is the longitudinal deformation caused by erosion-siltation change and earthquake load. So the 3-D nonlinear finite element program is developed to analyze the longitudinal deformation, crack opening, dislocation etc.. According to the characteristics of the large scale model and many contact interfaces ， several approaches are adopted to control calculation scale and to ensure calculation precision, including rapid solution algorithm for the equations. The results show that the crack opening, the dislocation displacement, the bolt stress of span joints, and the concrete stress are all in the design permission range, and can satisfy the design requirement.