沪昆客专姚家隧道板岩宏观崩解特性及微观机理研究

Macro disintegration characteristics and micro mechanism of slate in the Yaojia tunnel of the Shanghai-Kunming Passenger Dedicated Line

针对板岩遇水软化、崩解的特点,以沪昆客运专线长昆湖南段CKTJ-IX标段姚家隧道DK384+080附近的板岩岩样为研究对象,进行成分、微观结构测试和浸水崩解试验,分析板岩的宏观崩解特性和微观机理。试验结果表明:随着干湿循环次数的增加,粒径大于2 mm的崩解物颗粒逐步向小于2 mm粒径区间过渡;对于不同风化程度的板岩,粒径大于2 mm的崩解物向其它粒径区间过渡的程度不同;风化程度越高,板岩的耐崩解性指数越低,其抵挡软化、崩解的能力越差;板岩的矿物成分、结构构造和充填胶结特征等内部因素对其崩解性起着控制作用,地理气候条件等外部因素是引起板岩崩解的诱发条件,各因素的作用效力和作用时间的不同使板岩的崩解强弱程度不尽相同。

According to the characteristics of slate softening and disintegrating with water, the ingredient and microstructure test and the disintegration experiment were conducted, and macro disintegration characteristics and micro mechanism of slate was analyzed. The rock samples at DK384 ＋ 080 of the Yaojia tunnel of the Chang-Kun Hunan CKTJ-IX Section in the Shanghai-Kunming Passenger Dedicated Line was taken as an example. The results indicate that with the increase in dry-wet cycles, disintegration particles more than 2 mm gradually transit to the particle size range less than 2 mm. For different weathering degrees of slate, the level of which disintegration particles more than 2 mm transit to the particle size range less than 2 mm is different. The higher the weathering degree, the lower the disintegration resistance index and the worse the ability to resist softening and disintegration. Internal factors such as mineral composition, internal structure, filling and cementation characteristics of slate play a controlling role in the disintegration. The geography and climate condition, and other external factors are the inducing conditions causing slate to disintegrate. The difference in action effect and duration of various factors makes the disintegrating degree different.