京沪高速铁路阳澄湖段软土的蠕变特性和次固结特性试验研究
Study on Creep Behaviour and Secondary Consolidation Characteristics of Soft Soil in Yangcheng Lake District of High-speed Beijing-Shanghai Railway
刘浩 1李亮 2赵炼恒 2王曙光3
作者信息
- 1. 中铁工程设计咨询集团有限公司,北京100055
- 2. 中南大学土木工程学院,湖南长沙410075
- 3. 贵州省交通规划勘察设计研究院,贵州贵阳550001
- 折叠
摘要
基于京沪高速铁路阳澄湖地区原状软土的一维固结试验,探讨该地区软土非线性蠕变变形特性.研究先期固结压力、应力水平、加荷比、加载时间以及超载预压对次固结系数Ca值的影响,得到该地区软土Ca与Cc值之间的关系.试验结果表明:该地区软土在相同的应力水平条件下,加荷比大的土样蠕变变形更小,增大加荷比可以减小次固结系数；经预压处理后,土样的次固结系数Cα与预压力p和预压时间密切相关,超载预压可以减小软土的次固结系数,进而能够有效减少工后次沉降；加载的时间间隔对次固结系数有较大影响,加载时间间隔越长,次固结系数越小,主固结和次固结的区分越不明显；次固结系数与先期固结压力无明显相关,Ca和固结压力p可用双曲线拟合；试样的次固结系数Ca与压缩指数Cc之间呈现良好的线性关系,Ca/Cc值的范围在0.018～0.035之间.
Abstract
Onedimensional consolidation tests of undisturbed samples of soft soil in the Yangcheng Lake. District of the Highspeed BeijingShanghai Railway were conducted to study the nonliner creep behaviour of soft soil in that district. The influence of preconsolidation pressures, stress levels, stress ratios, loading time and overload prepressures on Secondary Consolidation Coefficient Ca was studied and the ratios of Ca/Cc of soft soil in that district were found. The results show as follows:Creep deformation diminishes with increasing of loading ratios at the same stress level,therefore,increasing loading ratios can reduce secondary consolidation coefficients;after preloading theatment,Ca is closely connected with Prepressure p and Prepress time, surcharge preloading can decrease the value of Ca and thereby surcharge preloading is propitious for reduction of settlement after construction;loading intervals have great effect on Ca ,the longer the loading interval,the smaller the Ca and the more difficult to distinguish between primary consolidation and secondary consolidation ;Ca has no significant correlation with preconsolidated pressures,Ca and Consolidation Pressure p can be fitted with the hyperbolic curve;a good linear relationship is shown between Ca and Compression Index Cc ,and Ca/Cc ranges from 0. 018 to 0. 035.
关键词
软土/蠕变/次固结/一维固结/非线性/双曲线拟合Key words
soft soil/creep/secondary consolidation/onedimensional consolidation/nonlinear/hyperbolic fitting引用本文复制引用
基金项目
铁道部科技研究开发计划重点项目(2008G032-3)
西部交通建设科技项目(2006318802111)
湖南省交通厅科技项目(2007-29)
出版年
2012
NETL
NSTL
维普
万方数据