泥岩耐崩解性和颗粒粒径相关性的试验研究

Correlation Between Disintegration Resistance and Particle Size of Mudstone

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 g eo tech n ica l e n g in e e rn g of southwest C h in a. By indoor d is in te-gration resistance test, disintegrat ion fea tu re s of mudstone a re d e s c r ib ed in d e ta i l from th re e a s p e c t s, in c lu d in g mor-phological changes of disintegrat ion p ro d u c ts ,d isintegrat ion re s is tan c e index an d p a r t ic le size an a ly s is. On th e basis of disintegration resistance index,disin teg rat io n in ten sity is divided into th re e le v e l s： strong d is in te g ra t io n ,middledisintegration and weak disintegrat ion, an d th e disin teg rat io n me chanism is also classified into th re e ty p e s： swelldisintegration after absorbing wa te r ,d isintegrat ion u n d e r wedging p re s su re an d d isintegrat ion u n d e r Results show that as s tandard cyc le times of d isintegrat ion in c r e a s e ,disintegrat ion re s is tan c e index creases in negative exponentia l d is t r ib u t io n. F u r th e rm o re ,strong d isintegrat ion mudstone of swell disintegration af te r ab so rb in g wa te r, weak d isintegrat ion mudstone an d middle d isintelong to that of disintegrat ion unde r wedging p re s su re an d disintegrat ion u n d e r mixed fa c to r s, re sp e c t iv e ly. F in a l ly,disintegration intensity is obviously relev an t to th e p a r t ic le size an d disin teg rat io n me chanism of d isintegrat ion p ro d-uct. Particle size of strong or weak d isintegrat ion pro d u ct has a p o la rz a t io n t r e n d ,yet th a t of middle disintegrat ionproduct is mainly middle- s ize.