超软地基排水固结联合轻质土路堤处理技术及其简易算法

New technology of preloading combined with light-soil for embankment on ultra-soft ground and simplified calculation method

深厚超软地基采用复合地基存在不少缺陷,排水固结路堤的适用高度常低于路堤设计高度。排水固结+轻质土路堤技术利用轻质土的轻质性和应力补偿原理,显著提高排水固结路堤的适用高度,有效减少工后沉降、规避泡沫轻质土路堤在不均匀沉降下易于开裂的缺点。该技术先对路堤进行排水固结,然后根据计算卸除部分填土,之后填筑轻质土至路床顶面。基于软土地基承载力、沉降和固结、应力补偿等理论提出堆载预压+轻质土路堤、真空联合堆载预压+轻质土路堤简易计算分析方法,最后给出工程算例。分析表明,排水固结+轻质土路堤往往比复合地基路堤经济,真空联合堆载预压+轻质土路堤的适用高度远大于堆载预压+轻质土路堤的适用高度。

There are many defects for the composite foundation with thick super soft soil.The applicable height of the drainage-consolidated embankment is often lower than the design height of the embankment.Utilizing its light weight and stress compensation principle,drainage consolidation combined with lightweight soil embankment technology can significantly improve the applicable height of drainage consolidation embankment,effectively reduce post-construction settlement,and avoiding the shortcomings of foam lightweight soil embankment which is easy to crack under uneven settlement.The technology starts with drainage and consolidation of the embankment,and then removes part of the fill according to the calculation.Finally,the lightweight soil is filled on the surface of the road bed.Based on the theory of soft soil foundation bearing capacity,settlement and consolidation,stress compensation,etc,a simple analysis method of preloading combined with lightweight soil embankment,vacuum combined preloading and lightweight soil embankment is proposed.The analyses show that the drainage consolidation combined with lightweight soil embankment is more economical than the composite foundation embankment,and the applicable height of the vacuum combined preloading and lightweight soil embankment is much higher than the applicable height of the preloading combined lightweight soil embankment.