工程地质学报2017，Vol.25Issue(5)：1220-1229,10.DOI:10.13544/j.cnki.jeg.2017.05.006
岩腔后退近水平砂-泥岩互层危岩稳定性研究
STABILITY OF UNSTABLE ROCK IN NEARLY-HORIZONTAL SANDSTONE-MUDSTONE STRATUM DUE TO ENLARGED ROCK-CELL
摘要
Abstract
The retreated rock-cell is a key factor of change in stability of unstable rocks in nearly-horizontal sandstone-mudstone in the part of Chongqing of the Three Gorges Reservoir.Based on parallel retreating rock-cell theory,this paper proposes the mechanical mechanism of shear failure and tension failure under retreating mudstone-cell,and stability calculation method for three kinds of unstable rocks in consideration of retreating rock-cell parameters.Pursuant to stability calculation outcome of Taibai unstable rocks in Wanzhou District,Chongqing, it is concluded as follows using the method proposed in this paper.Unstable sliding rock W12,unstable toppling rock W22 and unstable dropping rock W4 are stable.Unstable toppling rock W59 is sub-stable.Unstable dropping rock W16 is almost stable.They are identical with the field monitoring data from 2008 to 2013.Against unstable sliding rock W12,this paper discusses and concludes that the minimum principal stress decreases linearly over time. With the continuously decreased minimum principal stress,the shear failure firstly occurs to mudstone.Then the mudstone is broken with tension.The angle of rupture of mudstone unceasingly decreases with the decreased minimum principal stress.With enlarged rock-cell,stability coefficient decreases in concave curve.So enlarged rock-cell is the root cause of unstable rock failure.It exists one critical rock-cell depth.Unstable rock would break under this critical rock-cell depth.It can forecast the failure time of unstable rock.关键词
工程地质/后退力学机制/稳定性计算方法/砂-泥岩互层危岩/岩腔Key words
Engineering geology/Retreating mechanical mechanism/Stability calculation method/Unstable rock existing in sandstone-mudstone/Rock-cell分类
天文与地球科学引用本文复制引用
周云涛,石胜伟,张勇,蔡强,梁炯,程英建..岩腔后退近水平砂-泥岩互层危岩稳定性研究[J].工程地质学报,2017,25(5):1220-1229,10.基金项目
国土资源部公益性行业科研专项项目(201511051),中国地质调查项目(DD20160278)资助. （201511051）
