堆载预压下深厚人工填土试验段沉降分析及预测

根据中石油云南某石化装卸场铁路专用线整体道床区域堆载预压现场的测试数据,分析了我国西南地区深厚人工填土地基在堆载预压下沉降变形规律,探讨了人工填土在整体道床沉降控制中的适用性。分析结果表明:堆载作用下,地基沉降变形曲线出现明显的反弯点,以碎石土等粗粒料为主要组成部分的人工填土沉降变形主要分为瞬时沉降和蠕变变形,其中瞬时沉降占比达到66.3%~83.6%;采用《高速铁路设计规范》中的灰色系统理论和双曲线法对地基工后沉降进行预测,预测结果表明:双曲线法比GM(1,1)模型更适合应用于人工填土地基的沉降预测,经堆载预压处理的深厚人工填土地基工后沉降能满足整体道床的沉降控制要求。

Analysis and Prediction on Settlement of Test Section of Deep Artificial Fill under Preloading

Based on the measurements from the preloading site in the area of monolithic track bed for dedicated railway line in a petrochemical loading and unloading field of CNPC in Yunnan,this paper analyzed the settlement deformation rule of deep artificial fill foundation under preloading in the southwest China,and discussed the applicability of artificial fill in the settlement control of monolithic track bed.The results show that,under the action of surcharge,the curve of foundation settlement has significant inflection point;the artificial fill,which takes gravel soil and other coarse-grained material as the main component,is subject to two kinds of settlement deformation,i.e.,immediate settlement and creep deformation,wherein the immediate settlement accounts for 66.3 %-83.6 %.The post-construction settlement of the foundation was predicted by use of gray system theory and hyperbola method specified in the Code for Design of High Speed Railway.The result of prediction shows that the hyperbola method is more suitable than GM(1,1)model to be applied in the settlement prediction of artificial fill foundation,and the post-construction settlement of the deep artificial fill foundation which is treated by surcharge preloading can meet the control requirement about the settlement of monolithic track bed.