淋雨对桂林鲕粒灰岩溶蚀机理的实验研究  

EXPERIMENTAL STUDY ON DISSOLUTION MECHANISM OF OOLITIC LIMESTONE IN GUILIN UNDER ATTACK OF SIMULATED RAIN

作　　者：陈晓鹏 张中俭[1] 张彬[1] CHEN Xiaopeng;ZHANG Zhongjian;ZHANG Bin(Department of Civil Engineering,School of Engineering and Technology,China University of Geosciences(Beijing),Beijing 100083)

机构地区：[1]中国地质大学(北京)工程技术学院土木工程系

出　　处：《工程地质学报》2019年第3期516-524,共9页Journal of Engineering Geology

基　　金：国家自然科学基金(41602329);中央高校基本科研业务费资助~~

摘　　要：灰岩在自然环境下易发生溶蚀,其中水是引起灰岩发生溶蚀的重要因素。在淋雨试验箱内利用纯净水冲刷鲕粒灰岩表面,研究动力水对鲕粒灰岩溶蚀的机理。实验共进行1200h,每隔120h(即为1个循环)后,测试试块的表面微观形貌、质量和波速等参数,并基于起伏度变化计算溶蚀速率。微观形貌的测试结果表明,淋雨可以导致试块表面的方解石基质溶解与鲕粒脱落。其中,第1~4次循环间,试块表面方解石基质缓慢溶解,溶蚀速率为0~0.05μm·h^-1;第5次循环时,试块发生鲕粒脱落,溶蚀速率增大到0.08~0.47μm·h^-1;第6~10次循环间,方解石基质缓慢溶解,溶蚀速率为0~0.06μm·h^-1。同时,弹性波速在整个淋雨循环过程中没有变化,表明灰岩试块的内部没有发生劣化。Carbonate rock can be easily corroded in natural environment.Water is an important factor that causes carbonate rock erosion.The pure water was used to wash the surface of oolitic limestone specimens in the experimental tank.The mechanism of rain or dynamic water on the dissolution of oolitic limestone was studied.The experiment of simulated rain was carried out for 1200 h.After each 120 h(i.e.a cycle),specimens were dried and the surface mico-topography,weight and ultrasonic wave velocity of specimens were measured,and the dissolution rate was calculated based on the change of the micro-topography.The results show that rain can cause calcite matrix dissolution and oolitic detachment on the surface of specimens.During the first to the fourth rain cycles,the calcite matrix on the surface of specimens slowly dissolved and the dissolution rate was 0~0.05μm·h^-1.During the fifth rain cycle,oolitic detachment occurred on the surface of specimens and the dissolution rate was 0.08~0.47μm·h^-1.During the sixth to the tenth rain cycles,the calcite matrix on the surface of specimens slowly dissolved and the dissolution rate was 0~0.06μm·h^-1.Elastic wave velocity did not change during the whole cycling process,indicating that there is no degradation inside specimens.

关 键 词：桂林 鲕粒灰岩 淋雨循环 微观形貌 溶蚀机理 溶蚀速率 

分 类 号：P642.25[天文地球—工程地质学]