摘要
研究目的:河流高阶地冲积成因中等压缩性黏土是京沪高速铁路广泛分布的一种地基土,具有较高的天然地基强度,通常不存在填土稳定性问题,天然条件或经浅层处理即可满足沉降控制不十分严格工程的要求。而高速铁路无砟轨道对路基工后沉降有严格的控制要求,对该类土的总沉降和工后沉降分析采用常规的理论计算方法其计算精度无法满足设计的要求。本文通过京沪高速铁路地基土基本特性分析和天然地基的现场填筑试验,研究该类土的沉降分析方法。研究结论:总结了河流高阶地中等压缩性黏土的基本特性,特别是强结构性和高屈服强度的特性;分析了该类地基土在低荷载水平作用下的变形规律;提出了总沉降采用"弹性理论法",以及工后沉降采用基于弹性理论的"沉降完成比例"的计算方法,通常荷载稳定放置6个月后,沉降完成比例可达90%以上。
Research purposes: Mluvial mid -compressible clay on fluvial high terrace is widely distributed at the BeingShanghai high speed railway, which has a characteristic of high natural strength. Generally, there is no stability problem of filling and it can meet the need of engineering with no strict requirement for settlement when it at natural condition or after shalow layer treatment. However, ballastless track in high speed railway has strict requirements for subgrade residual settlement; Furthermore, current theoretical methods for calculating total and residual settlement of this type of soil can not meet the design requirement. So, through analysis of the basic characteristics of foundation soil and in - suit filling experiment on natural ground of Beijing - Shanghai high - speed railway, the settlement analysis method of this type of soil is studied. Research conclusions: Basic characteristics, especially strong structural characteristic and high yield strength characteristic of mid - compressible clay on fluvial high terrace are summarized in this paper. Deformation law of this kind of foundation soil under low loading level is analyzed; At last, different calculation methods are proposed to calculate different settlement, that is, elastic theory method and proportion of settlement - completion method based on elastic method can be used in total settlement and residual settlement calculation respectively. Generally speaking, after the load stable for 6 months, completion of the settlement ratio can be up to 90%.
出处
《铁道工程学报》
EI
北大核心
2011年第11期30-35,共6页
Journal of Railway Engineering Society
关键词
高速铁路
中等压缩性黏土
地基沉降
弹性理论法
high speed railway
mid -compressible clay
ground settlement
elastic theory method