低黏土矿物含量泥岩的自由膨胀率试验研究  

Experimental study on free expansion rate of mudstone with low clay mineral content

作　　者：王冲[1] 王起才[1,2] 张戎令 崔晓宁[1] 李进前 祁强[1] WANG Chong;WANG Qicai;ZHANG Rongling;CUI Xiaoning;LI Jinqian;QI Qiang(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;Road and Bridge Engineering Disaster Prevention Technology Local Joint National Engineering Laboratory, Lanzhou 730070,Gansu,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]道桥工程灾害防治技术国家地方联合工程实验室,甘肃兰州730070

出　　处：《水利水电技术》2018年第5期123-128,共6页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(51768033);教育部长江学者和创新团队滚动支持发展计划(IRT_15R29);中国铁路总公司科技研究计划(Z2015-G001);青年人才托举工程(2015QNRC001);甘肃省基础研究创新群体(145RJIA332);兰州交通大学(201606)优秀平台资助;飞天学者特聘计划;陇原青年创新人才扶持计划

摘　　要：针对现有规范中自由膨胀率试验方法存在的不足之处,为了在规范基础之上得到更为精准且具有代表性的自由膨胀率试验结果,在满足规范试验要求的基础之上,将某工程地基中的低黏土矿物泥岩碾碎,把0.5~0.25 mm、0.25~0.1 mm、<0.1 mm三种粒径范围的碾碎泥岩按照不同的质量比例组合搭配完成自由膨胀率试验。结果表明:对于同一种土样,依据规范完成的自由膨胀率试验可能会因为试验人员、操作过程等原因导致级配不同,进而出现千差万别的试验结果,且结果符合正态分布。通过分析建议使用以上三种粒径范围质量比为60∶40∶0、40∶20∶40、20∶20∶60的级配进行自由膨胀率试验。验证发现,建议级配的试验结果能够与各指标更加同步、准确地判别膨胀土。试验成果可为进一步完善工程地质相关规范提供借鉴。Aiming at the deficiencies of the methods for the experiment on the free expansion rate prescribed in the existing criteria concerned,the mudstone with low clay mineral content got from the foundation of a project is crushed on the basis to meet the experiment requirement prescribed in the relevant criteria,from which the experiment on the free expansion rates of the crushed mudstones with three particle sizes,i. e. 0. 5 - 0. 25 mm,0. 25 - 0. 1 mm and 0. 1 mm are made in accordance with various combinations of mass proportions,so as to obtain more accurate and representative experimental result of free expansion rate. The result indicates that for the same kind of mudstone sample,the experiments on the free expansion rate finished according to the criteria concerned can possibly lead to different gradations due to different experiment personnel and operation processes,and then produce quitedifferent experimental results,while the results accord with the normal distribution as well. Through analysis,it is suggested to carry out the experiment of free expansion rate with the gradations of 60 ∶ 40 ∶ 0,40 ∶ 20 ∶ 40 and 20 ∶ 20 ∶ 60 of the mass proportions for the three ranges of particle size mentioned above. The relevant verification finds out that the experimental result from the suggested gradations can be more synchronized with all the indexes concerned and then accurately judge the expansive soil. The experimental results can provide references for further improving the relevant engineering geological criteria.

关 键 词：自由膨胀率 泥岩 膨胀土 级配 正态分布 

分 类 号：TU443[建筑科学—岩土工程]