黄土中的构造斜节理及其对黄土隧道稳定性的影响

本文根据野外调查与隧道施工的资料,论证了在老黄土中存在构造斜节理,它们是构造地应力造成的,与岩石中的构造节理相似。文中对黄土某些构造斜节理的产状及其形成原因进行了力学分析,并对这些构造斜节理的节理面和因开挖洞室导致局部应力集中而产生的土体中破裂面的特征作了总结与对比。文中通过实例说明黄土中的这些构造斜节理构成了黄土中的软弱结构面,这些软弱结构面与地下洞室开挖的临空面可能将土体切割成不稳定结构体。这就成了坍方或影响洞室稳定性的主要原因。因此,在黄土地下工程设计及其施工中,不仅要应用土力学的基本原理与方法,而且还有必要应用岩体力学的基本原理与方法。

Influence of Inclined Tectonic Joints on Stability of Tunnels in the Loess

The inclined tectonic joints in the loess and their influence on stability of tunnels have been investigated. It is found that there are inclined tectonic joints in the loess, just as in the rock mass. They are weak structural faces in the loess. When a tunnel is dug in the loess, the loess is likely to be cut by these weak structural faces and dug face, forming unstable structural parts which might become the primary factor that can influence the stability of the tunnel. It is suggested that the basic principles and method of rock mechanics should be adopted in designing and construction of tunnels in loess.