顺层边坡松动岩层工程特性及工程处治措施

Engineering Characteristics and Treatment Measures of Disturbed Rock Strata in Bedding Rock Slope

通过对松动岩层的形成机制和工程特性深入分析,显示松动岩层和原岩层有本质区别,由于松动岩层孔隙张开、泥质充填等不利因素,其抗剪强度和原岩层相比差异显著;通过极限平衡方法对工程实例中的松动岩层滑坡进行反分析,结果表明松动岩层充分泥化后强度大幅下降,不能简单通过原岩强度折减得到。勘察阶段应将其作为特殊岩体对待,有条件的情况下应进行现场槽探,弄清松动岩层具体情况。边坡开挖后,松动岩层易于软化而导致大面积滑动,因此建议在边坡开挖前采用抗滑桩预先加固、开挖坡面后采用锚杆(锚索)框架加固坡面、并做辅以坡体截排水的综合工程处治措施。

The formation mechanism and engineering characteristics of disturbed rock strata are analyzed. There are essential differences between disturbed rock strata and original rock strata. Because of the unfavorable factors such as pore openings and shale filling of disturbed rock strata, the shear strength is significantly lower than that of original rock strata, which cannot be determined simply by strength reduction of original rock strata. It should be treated as a special rock in engineering survey, trench exploration should be carried out if it is possible. Large area of landslide often occur in disturbed rock strata after slope excavation. It is suggested that the anti-slide pile should be pre-reinforced before slope excavation, bolt （or anchor wire） frame and cutoff drainage should be taken after slope excavation.