隧道中缓倾层状岩体工程性状研究

Study on Engineering Characteristics of Slow Dip Layered Rock Mass in Tunnel

通过研究缓倾围岩变形机理，提出围岩破坏或失稳的力学模型，结合现行隧道围岩分级标准，利用力学模型计算对比，分析了围岩稳定的影响因素。研究结果：缓倾围岩与非缓倾围岩相比，其变形机理和力学模型有明显不同；破坏形式主要是洞顶冒落；围岩稳定性不仅与层理产状有关，还与层理厚度、岩层抗拉强度和隧道跨度有关，因此对其组成的围岩分级应适当调低。

Through study on the deformation mechanism of slow dip layered rock mass, this paper puts forward the mechanical model of rock mass damage or failure and analyzes the influence factors of rock stability through calculation comparison with mechanical model. It is indicated that compared to non-slow dip rock mass, the deformation mechanism and mechanical model of slow dip rock mass are quite different indeed and the main failure mode is falling from the upper tunnel. Surrounding rock stability is not only involved with bedding occurrence but also with stratification thickness, tensile strength and tunnel span, of which rock mass classification should be lowered.