泥岩的崩解性是我国西南地区岩土工程中重要的岩石特性之一。通过室内耐崩解试验,从崩解物形态变化、耐崩解指数和颗粒分析3个方面对泥岩的崩解特性进行了详细描述;根据耐崩解指数将泥岩的崩解强度分为强、中、弱3个等级;并以此将其崩解机制分为3类:吸水膨胀崩解机制、楔裂压力崩解机制、混合崩解机制。研究表明:随着崩解标准循环次数的增加,泥岩的耐崩解性指数呈负指数关系降低;强崩解性泥岩、弱崩解性泥岩、中崩解性泥岩分别表现为吸水膨胀崩解机制、楔裂压力崩解机制、混合崩解机制;崩解性的强弱与崩解产物的粒径、崩解机制有较好的对应关系,强、弱崩解产物颗粒粒径具有两极分化的趋势,而中崩解颗粒则主要位于中间粒径。

Disintegration of mudstone is important in geotechnical engineering of southwest China. By indoor disintegration resistance test, disintegration features of mudstone are described in detail from three aspects, including morphological changes of disintegration products, disintegration resistance index and particle size analysis. On the basis of disintegration resistance index, disintegration intensity is divided into three levels: strong disintegration, middle disintegration and weak disintegration, and the disintegration mechanism is also classified into three types: swell disintegration after absorbing water, disintegration under wedging pressure and disintegration under mixed factors. Results show that as standard cycle times of disintegration increase, disintegration resistance index of mudstone decreases in negative exponential distribution. Furthermore, strong disintegration mudstone belongs to the mechanism of swell disintegration after absorbing water, weak disintegration mudstone and middle disintegration mudstone belong to that of disintegration under wedging pressure and disintegration under mixed factors, respectively. Finally, disintegration intensity is obviously relevant to the particle size and disintegration mechanism of disintegration product. Particle size of strong or weak disintegration product has a polarization trend, yet that of middle disintegration product is mainly middle-size.