江西白垩系泥质粉砂岩崩解试验研究

Experimental Study on Disintegration of Cretaceous Argillaceous Siltstone in Jiangxi Province

对南昌地区泥质粉砂岩典型出露地段开展现场调研并取样测试其基本物理力学性质,同时进行了静态崩解试验和岩石的耐崩解试验,从能量耗散原理的角度分析了泥质粉砂岩静态崩解过程中吸收的能量向表面能转化的规律。试验结果表明:水和温度岩的相互作用是加快泥质粉砂岩风化的主要外部营力;泥质粉砂岩的静态崩解由碎块状过渡到粒渣状、泥糊状,可按崩解物形态划分为剧烈崩解、细微崩解和崩解稳定三个阶段,崩解过程中其表面能累计增加量随崩解次数增加而增加,而单次表面能增量趋于减小;耐崩解试验中,泥质粉砂岩耐崩解性指数随循环次数的增大呈负指数关系递减。试验结果对于工程实践中如何抑制红层软岩崩解并保持其完整承载能力、或对其预崩解处理促进其快速崩解达到稳定的颗粒级配状态具有一定的参考价值。

Field investigations were conducted on typical exposed areas of argillaceous siltstones in Nanchang,and samples were taken to test their basic physical and mechanical properties.At the same time,static disintegration test and rock anti-disintegration test were carried out.From the perspective of the principle of energy dissipation,the law of the energy absorbed during the static disintegration of argillaceous siltstone to surface energy was analyzed.The test results show that the temperature and water-rock interaction are the main external forces for rapid weathering of argillaceous siltstone;the static disintegration test of argillaceous siltstone can be divided into three stages:severe disintegration stage,slight disintegration stage and stable disintegration stage,and the disintegration morphology changes from fragmentary to granular and slushy.In the process of disintegration,the cumulative increase of surface energy increases with the increase of disintegration cycles,while the increase of single surface energy tends to decrease;In the anti-disintegration test,the disintegration resistance index of argillaceous siltstone decreases with a negative exponential relationship as the number of disintegration cycle increases.The test results have certain reference value for how to restrain the disintegration of red-bedded soft rock and maintain its complete bearing capacity,or for its pre-disintegration treatment to promote its rapid disintegration to achieve stable particle size distribution in engineering practice.