摘要
煤系地层具有岩层软硬不均,层间胶结较差,风化速度快,遇水易软化,结构易破坏导致强度丧失等特点,特别是夹层中炭质泥岩或页岩具有强度低、易活化、易变性和渗透系数相对较小的特点,这决定了其对整体边坡的稳定性具有控制作用。文章分析了煤系地层边坡饱和、非饱和渗流降雨条件(降雨强度)、土性参数(夹层饱和渗透系数)以及边坡形状尺寸(坡脚、夹层倾角、夹层埋深)等因素对边坡渗流特点及稳定性的影响,发现软弱夹层与上下岩体渗透性差异性对边坡稳定性影响明显;软弱夹层埋置越浅,边坡越易失稳;降雨强度越大,边坡越易沿软弱夹层发生滑坡;并非坡脚越大降雨之后边坡的安全系数降低幅度就大,而是随着夹层倾角的增大,边坡的安全系数逐渐降低,边坡越易沿软弱夹层发生滑坡,这些认识对煤系地层边坡的设计和治理有重要的参考意义。
Coal strata are characterized by uneven soft and hard strata, poor interlaminar cementation, rapid weathering, being easy to soften when exposed to water, loss of strength due to structural damage and so on. In particular, the carbonaceous mudstone or shale in the interlayer has the characteristics of low strength, easy activation, volatility and relatively small permeability coefficient, which determines that it has a control effect on the stability of the overall slope. In this paper, the effects of saturated and unsaturated seepage rainfall conditions （rainfall intensity）, soil property parameters （saturation permeability coefficient of interlayer） and slope shape and size （slope foot, dip angle and buried depth of interlayer） on the seepage characteristics and stability of the slope are analyzed. The results show that the difference of permeability between soft interlayer and upper and lower rock mass has obvious influence on the slope stability. The shallower the soft interlayer is, the more unstable the slope is; the higher the rainfall intensity, the easier the slope along the soft interlayer landslide. It is not that the slope safety factor decreases greatly with the increase of slope inclination, but that the slope safety factor decreases gradually with the increase of interlayer inclination, and the slope is more prone to landslide along the weak interlayer. These findings are significance reference for the design and control of coal measure stratum slope.
作者
李宏儒
张盼
王神尼
赵华鹏
LI Hongru;ZHANG Pan;WANG Shenni;ZHAO Huapeng(Faculty of Civil Engineering and Architecture,Xi＇an University of Technology,Xi＇an 710048,Shannxi,China;Loess Soil Mechanics and Engineering Key Laboratory of Shaanxi Province,Xi＇an 710048,Shannxi,China)
出处
《地质力学学报》
CSCD
2018年第6期836-848,共13页
Journal of Geomechanics
基金
陕西省自然科学基础项目(2017JM5059)
陕西省黄土力学与工程重点实验室项目(13JS073)
西安理工大学基金(256211404)
关键词
煤系地层
软弱夹层
边坡
降雨
安全系数
coal measure strata
soft interlayer
slope
rainfall
safety factor
