随着国家西部大开发战略部署的实施，西部地区的基础建设也得到了火速发展，黄土地区公路、铁路、输水输气隧道也在逐年增多，所面临的施工与运营安全问题越来越多。所以说对黄土地区隧道结构体系受力特征的研究是非常严峻的，因为大多数的黄土地区的隧道并非只处于黄土地层中，黄土地区的隧道处于土岩变层中的情况较多，因此对该地区的研究应当引起足够的重视。 本文在对国内外黄土地区隧道研究现状及存在的问题大量总结的基础上，择取适合于黄土地区隧道研究的方法理论，即地层—结构计算模型，并根据工程实例，将黄土地区隧道分为处于黄土地层中的隧道和处于土岩变层中的隧道两大类，依托工程实例，应用ANSYS有限元大型计算软件，通过建立隧道洞室的有限元模型，对多种不同工况下的黄土地区隧道结构体系受力特征进行对比分析。 通过对黄土层中两种不同衬砌厚度隧道结构体系受力特征的研究，且对这两种工况下黄土层中隧道结构体系受力特征进行了分析比较。得到衬砌厚度的增加对隧道周围黄土是有影响的，在一定范围内，衬砌厚度小时，隧道结构发生的位移较大，衬砌的应力较大，而当衬砌厚度较厚时，隧道结构发生的位移较小，衬砌所的应力较小，隧道结构体系也就比较稳定。 分别从土岩变层作用位置在隧道洞室墙脚处、拱脚处、拱上对黄土地区土岩变层中的隧道结构体系进行受力特征分析，对黄土层中的工况与土岩变层中的工况进行隧道结构体系受力特征的比较。得到土岩变层位置对土岩变层中的隧道结构体系是会产生一定影响的，当其他各项条件一定时，土岩变层位置越接近地表，衬砌所须要承受的应力也就减小，隧道结构体系也就比较稳定。黄土地区土岩变层中的隧道结构体系下部岩体负担了一部分的力，阻止了隧道结构体系产生更大的变形。

With the implementation of the strategic plan of the country's western development, infrastructure construction in the western region has also been rushed development, loess highway, railway, water gas tunnels are increasing year by year, construction and operational security issues faced by more and more . So the study of loess region architecture tunnel stress characteristics is very serious, because most of the loess tunnel area not only in the loess formations, tunnels loess area in soil and rock layers become in many cases, so the Research in the area should be taken seriously enough. Methods In this paper, the status of the tunnel theory loess areas and problems at home and abroad on the basis of a large number of summary, choose to take the tunnel in the loess region for that stratum - structure model, and according to engineering example, the Metro Tunnel into Only in loess strata in tunnels and in two categories become layers of soil and rock tunnels, relying on engineering example, large-scale application of ANSYS finite element calculation software, through a finite element model of the tunnel cavern, a variety of different conditions loess area architecture tunnel stress characteristics were analyzed. Through the study of loess layers of two different structural systems tunnel lining thickness characteristics of the force, and these two conditions loess tunnel architecture force characteristics were analyzed and compared. The thickness of the lining around the loess obtained to increase tunnel is influential, in a certain range, lining thickness h, the tunnel structure has a larger displacement, stress is large lining, and when the lining thickness is thick, the displacement of the tunnel structure smaller, less stress lining the tunnel structural system will be more stable. Respectively, from the interface of the soil and rock effect change position in the corners of the tunnel excavation, arch of the foot, the arch interface of the soil and rock architecture tunnel stress characteristics. Loess layers and interface of the soil and rock conditions compare tunnel structural system characterized by force. Obtain interface of the interface of the soil and rock location change in the structure of the tunnel system will have some impact, when all other conditions constant, the interface of the soil and rock location closer to the surface position change layer lining the need to reduce the stress on it tunnel structural system will be more stable. Interface of the soil and rock of loess area in the lower part of the rock tunnel architecture part of the burden of power, preventing the tunnel structure system have a greater deformation.