黄泛区公路地基压实标准的研究

Research on the compaction standard of highway foundation in the flooding area of the Yellow River

采用有限差分的计算方法，分析了黄泛区公路地基在不同压实度和压实深度条件下的沉降规律，提出了地基的压实标准和处置技术措施．研究认为，对高度〈6m的路基，保证90％的压实度对减少路基的工后沉降变形至关重要．对高度〉6m的路基，提高地基压实度，特别是将压实度由90％提高到93％，对降低地基沉降的作用不大．加大地基的压实深度，与提高压实度表现出相似的规律性，但对降低地基沉降的效果更明显．应根据路基高度提出地基的压实控制标准．路基高度≤2m，地基表层30压实度应≥93％；路基高度2～6m，地基表层30压实度应≥90％；路基高度〉6m，地基表层30压实度应〉185％．指出采用强夯、冲击碾压实地基，是黄泛区经济有效的工程技术措施．

Using the computaional methods of finite difference, the sedimentation law of highway foundation in the flooding area of the Yellow River was analyzed for different degrees of compaction and depths of compaction. The compaction standard and technical measures were put forth. It is proved＇that it is important to reduce the settlement after the completion of the roadbed, when the compaction is more than 90% for the situation with the roadbed height less than 6 m. When the roadbed is heigher than 6 m, the compaction degree raising has little effect on reducing the deformation of the roadbed, especially for the compaction range of 90% - 93 %. It exhibits the same regulation in enhancing the compaction depth as that in raising the degree of compaction, which has evident effects on reducing the foundation sedimentation. Therefore, the compaction standard of highway foundation should be put forth according to roadbed height. When the roadbed height is ≤ 2 m, the degree of compaction should be ≥ 93 % within the scope of 30 cm of the foundation surface layer. When the roadbed height is in the range of 2 - 6 m, the compaction degree should be higher than 90% within the scope of 30 cm of the foundation surface layer. When the roadbed height is more than 6 m, the degree of compaction should be ≥ 85 % within the scope of 30 cm of the foundation surface layer. It is pointed out that dynamic compaction and pound grinding is the most economic and valid engineering technical measure in the flooding area of the Yellow River.