摘要
鉴于传统的软土地基超载预压设计未考虑软土的流变特性,无法解释预压中沉降过大、预压期末沉降速率难以稳定等现象,采用弹粘塑性模型,运用有限元方法,计算分析高速公路软土地基上路堤的沉降,对不同预压荷载和预压时间下的路堤超载预压效果进行了研究。计算结果与实测沉降对比显示,在软土地基路堤沉降分析中考虑流变是必要的。研究发现,存在一个与最小工后沉降相对应的最佳预压荷载量;增加预压时间有利于减小工后沉降,但超过一定范围后效果并不显著。
In the conventional preloading design methods the soft soil＇ s rheological characteristics are not con sidered, and thus it is unable to explain the over - settlement and the unexpected high settlement rate at the end of preloading stage. In this paper the finite element method is adopted using a new elastic - visco - plastic constitutive model, to investigate the effects of the loading level and the loading time of surcharge preloading on the settlement. Compared with the elastic - plastic analysis results and measured data, the validation of considering the soft soil＇ s rheological characteristics in settlements prediction is proved. The research results showed the existence of an optimum surcharge load according to the minimum pest -construction settlements. And the increase of preloading time is advantageous to reducing pest-construction settlements, but the effect would not be remarkable over a certain scope.
出处
《地下空间与工程学报》
CSCD
2008年第2期355-360,共6页
Chinese Journal of Underground Space and Engineering
关键词
流变
超载预压
有限元
沉降
rheology
surcharge preloading
finite element method
settlements
