欧标ESCS与国标土壤分类差异性研究

Research on Difference Between European Standard ESCS and National Standard(Railway Standard)Based on Soil Classification

勘察设计人员在从事境外铁路勘察设计时,往往会遇到规范和标准差异化问题,为更好地运用欧洲标准从事勘察工作,了解欧洲标准与国内标准的异同,从土壤分类角度,采用对比分析方法,对欧洲标准、国标、铁标中土壤分类的依据、标准、方法、适用性以及差异进行对比分析。研究表明,欧标、国标与铁标在土壤分类上存在部分差异:对于粗粒土,除粒组粒径存在部分差异外,欧标粉土分类更细致;对于细粒土,塑性A线斜率一致,但欧标根据液限范围对黏性土进行更详细地划分;在细粒土含量在5%~15%时,欧标更加详细;铁标中土的划分未能很好反映土的工程特性,而欧标通过土类代号将次要成分和次次要成分进行标识说明,并引入百分比含量和级配特征,能更好地反映土的工程特性。在实验仪器与试验方法比较方面,国标液塑限试验方法种类更多,也更高效快捷。

There are differences between the specifications and standards which may confuse surveyor and designer when conducting overseas railway survey and design.In order to help designers use European standards efficiently for survey work,and help them get acquainted with the difference and unification between the standards,the angle of soil classification was analyzed by using the comparative analysis method in terms of standard,method,applicability and the difference of soil classification.The analysis result shows that,there are some differences in soil classification between the European standard,the national standard and the railway standard.For coarse-grained soils,except for the difference in particle size,the European standard silt classification is more detailed;for fine-grained soils,the slope of line A of the plasticity diagram is the same,but the European standard provides more detailed information on cohesive soils based on the liquid limit range.The classification of coarse-grained soil is more detailed in the European standard when the content of fine-grained soil is between 5%and 15%;the classification of railway standard soil does not reflect the engineering characteristics of the soil,and the European standard can use the soli code to describe the soil the secondary components and the thirdary components.The percentage content and gradation characteristics are introduced,which can better reflect the engineering characteristics of the soil;compared with the test method,the national standard has more types of liquid-plastic limit test methods which tends to be more efficient and faster.