滇中泥质粉砂岩崩解特性试验研究

Research on the experiment of disintegration characteristics of siltstone in Central Yunnan Province

为了研究滇中泥质粉砂岩的崩解特性,对不同风化程度的泥质粉砂岩进行了静态崩解试验、室内环境崩解试验和耐崩解试验。试验结果表明:岩石风化程度越高,崩解越剧烈;强风化状态的泥质粉砂岩在第四次循环后基本崩解完全,耐崩解系数Id2为46.2～61.8;弱风化和微风化泥质粉砂岩在第二、第三次循环崩解开始加剧,耐崩解系数Id2分别为61.1～73.6和79.5～85.4;崩解物以0.5～2mm和小于0.25mm颗粒物为主。泥质粉砂岩的崩解是由岩石浸水膨胀、胶结物溶解和干湿循环产生的拉应力与张应力共同引起的。

To study the disintegration characteristics of siltstone in the central of Yunnan,the static rock disintegration test,the indoor environment rock disintegration test and the rock slake-durability test have been carried out for the intensely weathered argillaceous siltstone,the weakly weathered argillaceous silt-stone and the slightly weathered argillaceous siltstone.The test results show that the more intense the weather degree of the argillaceous siltstone,the more violent of the disintegration.The disintegration of the intensely weathered argillaceous siltstone ends at the fourth dry-wet cycle,its slake-durability index（Id2） is 46.2 ～ 61.8.The disintegration of the weakly weathered and the slightly weathered argillaceous siltstone is violent at the second and the third dry-wet cycle.Their slake-durability index（Id2） are 61.1 ～ 73.6 and 79.5 ～ 85.4.The collapse things of the rock disintegration are mainly 0.5 ～ 2 mm and smaller than 0.25 mm particulates.The reasons of the argillaceous siltstone disintegration are the expansion of water,the dissolution of cement,the tension stress and the tensile stress caused by the dry-wet cycle of the rock.