宜巴高速公路三里花岩堆形成机理与破坏模式研究

Study on Formation Mechanism and Failure Mode of Sanlihua Talus Slope at Yiba Highway

宜巴高速公路沿线穿越多达几十处地质条件复杂的岩堆,给宜巴高速公路的建设和运营提出了严峻的考验。为此,以宜巴高速公路典型的三里花岩堆为研究对象,从地层岩性、岩堆岸坡、气候变化和其他各种因素的综合影响作用,对岩堆形成机理与破坏模式进行深入的研究。三里花岩堆的形成是由于第四纪新构造运动使地壳大面积的强烈抬升,造成河流的剧烈下切,使山谷高差达数百米,自然山坡出现临空面产生的,在其形成过程中,内动力作用引起了地形地貌的差异并为岩堆的形成提供了物质基础,外动力作用则进一步改造了岩堆的地表形态,造成岩堆的地质结构发生变化。三里花岩堆存在浅层失稳(或局部失稳)和深层失稳(或整体失稳)两种可能的破坏模式。这些研究结论为宜巴高速公路岩堆的稳定性评价、治理措施设计与施工提供了重要依据。

Talus slope is a kind of typical geo-hazard. Along the Yiba highway it crosses up to dozens of complicated geological conditions of talus slope which lead to a severe test to the construction and operation of the Yiba highway. To this end, we take the typical Sanlihua talus slope at Yiba highway as the research object to study on formation mechanism and failure mode of talus slope by considering the combined effects of formation lithology, embankment slope, climate change and other various factors. The formation of Sanlihua talus slope is due to the reason of the large area of strong crustal uplift in Quaternary neotectonic movement which causing a severe undercut of the river along with making the height difference of the valley up to several hundred meters that finally appearing a free face on the natural hillslide. In the process of formation, within the power induced differences in topography and provided the material basis for the forma- tion of the talus slope. On the other hand, the exogenic role made a further transformation of the surface morphology of the talus slope which changed its geological structural. The Sanlihua talus slope exists two possible failure modes of shal- low instability （or local instability） and deep instability （or overall instability）. These research conclusions provide the important basis for the stability evaluation, design and construction of the control measures of the talus slope at Yiba highway.