【摘要】 针对玄武岩岩体施工期围岩的变形、稳定问题,以一赋存于玄武岩岩体中水电站大型地下厂房为背景,以其三大洞室为研究对象,依据开挖施工期围岩位移监测成果,在对围岩的变形量级、空间分布规律分析的基础上,结合施工进度和地质资料分析围岩位移随时间的发展规律及深部发展规律,最后对施工过程中玄武岩岩体的位移特征进行归纳总结,进而探讨层间、层内错动带对围岩位移的影响。研究结果表明:玄武岩岩体结构面虽然发育,但处于镶嵌紧密状态下,结构面对围岩位移整体影响较小;围岩位移基本在20 mm范围内,15 m深度范围以外的岩体位移呈现弹性状态,变形随深度发展具有连续性,该类岩体可视为均匀介质。施工是变形发展的主要影响因素,随着分层开挖进行,围岩位移呈台阶状上升趋势。更多还原

【Abstract】 Aiming at the problem of deformation and stability about rock mass,with underground powerhouse caverns of a hydropower station hosted in basalt rock mass as background,taking three chambers(the generator chamber,the main transformer chamber and the tail water surge chamber) as objects of study,based on monitoring results during construction,surrounding rock mass deformation magnitude distribution and spatial distribution in underground powerhouse chambers are analysed firstly,then by means of geological information combining with excavation and construction progress,the law of in-depth and by-time are analysed,at last the deformation characteristics of basalt rock mass during construction are summarized,and the effect of the inner beddings of the basalt on surrounding rock displacement is analyzed at mean time. The research results show that,with structural surface enriched,but mosaic structure in basaltic,effects of structural surface on surrounding rock mass deformation are not obvious. Most parts of surrounding rock displacements are within 20 mm,and within the scope of 15 m depth the rock mass displacement presents flexibility state,and deformation developed continuity with depth,such kind of rock mass can be considered as a homogeneous medium. Construction is the main factor that affects the development of deformation,and along with excavation carried out,the surrounding rock displacement shows developing trend like step.更多还原