摘要
某水电站高拱坝建基岩体地质构造复杂,以陡倾的辉绿岩脉穿插发育于黑云二长花岗岩岩体内为典型特征,而规模较大、分布较广的辉绿岩脉类地质缺陷是高拱坝坝基主要的工程地质问题。浅成的辉绿岩脉力学性质差,且具有明显的各向异性,辉绿岩脉对坝基应力变形影响较大,会造成大坝基础的不均匀变形,并进一步恶化坝体的横缝开度。为满足建基岩体质量要求,提出了针对辉绿岩脉类地质缺陷采取机械开挖、刻槽以及混凝土置换的处理措施。建基岩体辉绿岩脉类地质缺陷经过综合处理后的三维数值分析结果表明:地基的应力分布更加均匀,拱坝变形在许可范围内。
The foundation rock in a high arch dam site is characterized with complex geological structure. The massive and steep dipping diabase dikes, those upgrowth alternately in biotite adamellite granite bedrock, are the main geological defects in die dam foundation. The hypabyssal dia- base dikes, characterized by anisotropy in the strength, greatly affect the stress-strain in the foundation reek. The influence from the diabase dikes would cause inhomogeneous deformation in the dam foundation, and then worsen the transverse joints aperture in the dam. In order to meet the quality requirements of foundation rock, a series of treatment measures were carried out, including machinery excavation, devilling and concrete re- placement. Furthermore, a numerical analysis was put into use to examine the treatment measures. The results show that the treatment measures have improved the uniformity of foundation rock, moreover, the quality of treated foundation can meet the requirements of dam body.
出处
《人民黄河》
CAS
北大核心
2013年第5期109-112,共4页
Yellow River
基金
地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(SKLGP2012K032)
关键词
辉绿岩脉
地质缺陷
基础置换
数值分析
拱坝
diabase dike
geological defect
foundation replacement
numerical analysis
arch dam
