研究目的:通过真空—堆载联合预压软基处理技术在某铁路路基试验段的应用实例,详细介绍了该技术的施工工艺要点,并对其沉降估算方法进行了探讨。
研究结论:真空—堆载联合预压处理软基施工中,要以确保排水系统的渗透性和抽真空系统的密封性为原则,从多处细节要点入手,控制好砂垫层、塑料排水板、管网、密封膜、密封沟、真空泵的施工质量。通过验证,目前常用的“等效荷载法”估算沉降量的结果与实测值有一定差距。分析认为未考虑真空度沿竖向的传递深度及土体侧向变形的修正是造成差距的主要原因,如何准确考虑这两个因素还有待进一步探讨。
Research purposes:Based on one example of application of the vacuum-heaped load preloading technology in treating soft subgrade in the experimental section, the introduction is given to the key points of this construction technology and the discussion is made on the method for the settlement estimation.
Research conclusions:During treating the soft subgrade with vacuum-heaped load preloading, it is necessary to follow the principle of guaranteeing good permeability of drainage system and air tightness of vacuum system, and control the construction quality of sand bedding, plastic drainage board, pipe network, sealing membrane, sealing grove and vacuum pump. From verification, it is found the calculated results with the commonly used "equivalent load methods" are different from the actualmeasured results to some extent, and from the analysis, it is thought the main reasons for the differences between the calculated results and the actually measured results are the vertically transferred depth of the vacuum degree and the lateral deformation of soil were not considered. How to accurately consider these two factors needs to be further discussed.