胶东白垩系泥岩崩解特性试验研究

Experimental Study on Disintegration Characteristics of Cretaceous Mudstone in Jiaodong Area

泥岩遇水后物理力学性质变差,易出现不同类型的工程地质灾害。选取胶东白垩系泥岩开展不同初始含水率条件下的静态干湿循环崩解试验,然后对每次循环后的崩解产物进行颗粒分析,同时研究各循环的耐崩解指数。研究结果表明:含水率对胶东白垩系泥岩的崩解速率影响极大,完全干燥的泥岩崩解速率最快,而天然含水率的泥岩崩解速率最慢;胶东白垩系泥岩崩解完全后以细微颗粒为主,颗粒粒径主要分布在0.25~0.075mm区间,级配不良;随着标准循环次数的增加,胶东白垩系泥岩的物理力学性质出现显著劣化,耐崩解性指数持续减小,并且表现出前期剧烈减小,后期逐渐变缓的特点,呈现幂函数衰减规律。研究结论对于指导胶东地区岩土工程防护具有重要意义。

The physical and mechanical properties of mudstones deteriorate when encountering water which will prone to occur different types of engineering geological disasters. A series of wet-dry cycle tests under different water content are conducted on Cretaceous mudstone samples in Jiaodong area. After each cycle,every groups of particle analysis of disintegration is studied,and the disintegration resistance index for each cycle is also researched. The research results show that the water content greatly affects the disintegration rate of Cretaceous mudstones,and the completely dry mudstone disintegrates the fastest,while the natural moisture disintegrates the slowest. The fine particles are the main particles after the disintegration of the Jiaodong Cretaceous mudstone,and most of the particles are mainly distributed in the range of 0. 25 ~ 0. 075 mm,which are poor grading. With the increase of the number of standard cycles,the physical and mechanical properties of the Jiaodong Cretaceous mudstones changes significantly,and the disintegration resistance index continues to change. It shows a characteristic of time shift in the early stage and then gradually slowing down,showing a law of power function decay. The research is of great significance in guiding geotechnical engineering protection in the Jiaodong area.