岷江上游某水电站工程边坡软岩的崩解特性研究

炭质岩层常作为主要岩层或者夹层频繁出现在广西各时代地层单元中，因其易风化裂碎、崩解软化及工程性质对环境敏感，给广西地区公路工程建设带来诸多复杂问题。通过既有地质资料搜集、野外地质调查、取样测试等研究手段，对广西地区炭质岩的分布及组合特征、矿物组成、有机质特征开展研究，并对炭质岩崩解的影响因素及相应工程措施进行了探讨。研究表明：(1)广西地区炭质岩从新元古界至古近系均有分布，主要包括24个地层单元，其基本物质组成以黏土矿物、石英和碳酸盐岩矿物为主，且有机质含量较高，属于中-高级烃源岩的炭质岩类；(2)炭质岩所含黏土矿物中的伊利石和伊/蒙混层、高含量有机质以及硫化物是炭质岩在自然暴露状态下发生崩解的主要物质因素；(3)炭质岩边坡发生崩解的主要原因可分为4类：构造活动、黏土矿物的吸水膨胀性和受热脱水性、有机质和还原性矿物氧化分解反应、自然因素的影响。相关研究成果可为炭质岩地区边坡工程、隧道工程及路基工程的设计施工及处治工作提供重要参考。

Slaking characteristics of soft rock of the engineering slope in a hydroelectric station in the southwest of China

Carbonaceous rock formation frequently appears as the main rock layer or interlayer in the stratigraphic units of different ages in Guangxi Province. Due to its easy weathering, cracking, disintegrating, softening, and the environmental sensitivity of engineering properties, it has brought many complex problems to the highway construction in Guangxi Province. Multiple research methods were adopted to investigate the geochemical characteristics and influence factors of disintegration for carbonaceous rocks. They include existing geological survey data collection, field geological survey and sampling tests. Researches on the distribution and assemblage characteristics of carbonaceous rocks, mineral composition and geochemical characteristics of organic matter were carried out. Meanwhile, influence factors of disintegration for carbonaceous rock and corresponding engineering measures were discussed. The research showes that carbonaceous rocks are distributed from Neoproterozoic to Paleogene in Guangxi Province. 24 major stratigraphic units containing carbonaceous rocks were identified. Its basic material composition is mainly composed of clay minerals, quartz and carbonate minerals. And the organic matter content of carbonaceous rocks in Guangxi Province is high, which belongs to the carbonaceous rocks of middle-high level source rocks. The illite and illite-smectite mixed-layer mineral in clay minerals, high content of organic matter and sulfide are the main material factors for the disintegration of carbonaceous rocks under natural exposure. Tectonic activity, water swelling and thermal dehydration of clay minerals, oxidation and decomposition reactions of organic matter and reducing minerals, and natural factors are the four main reasons for the disintegration of carbonaceous rock slopes. Related research findings can provide important references for the design, construction, prevention and treatment of slope engineering, tunnel engineering and subgrade engineering in carbonaceous rock areas.