无砂垫层真空预压法处理湖相吹填淤泥效果评价

Evaluation on the effect of vacuum preloading method with sand-free cushion to treat lacustrine dredging sludge

经过对新近吹填的超软淤泥土场地进行无砂垫层真空预压后,进行了平板荷载试验、十字剪切试验、静力触探试验等一系列原位测试和分析,得到了如下结论:经过无砂垫层真空预压后,吹填超软淤泥土场地的地基承载力、不排水抗剪强度均有明显提高,其物理力学性能均有了明显改善,说明无砂垫层真空预压法处理加固大面积高压缩性淤泥土行之有效,可以为进一步的施工提供作业面;由贯入曲线可知,在表层1m内加固效果良好,随着深度的加大,加固效果显著减弱;由十字剪切板测试可知,无砂垫层真空预压后土体为低灵敏度土体,表明处理后的土体结构性并不显著。这些测试结果可以为湖相吹填超软淤泥土区域地基处理的设计、施工、检测等提供支撑或参考。

The conclusions are shown as follows based on a series of in-situ tests and analysis,such as plate load test,cross shear test,static penetration test,etc.after vacuum preloading of the sand-free cushion on newly filled ultra-soft silt soil sites:the foundation bearing capacity and undrained shear strength of the hydraulic reclamation ultra-soft silt soil sites are prominently improved after vacuum preloading of the sand-free cushion.The physical and mechanical properties are obviously improved.It is obvious that the vacuum preloading method with the sand-free cushion is effective to reinforce large area high compressibility silt soil.It can provide the operation surface for further construction.It can be seen from the penetration curve that the reinforcement effect is excellent within 1m of the surface layer.However,the effect is decreased significantly with the increase of the depth.The soil belongs to low-sensitivity soil after vacuum preloading of sand-free cushion according to the cross shear plate test.It indicates that the soil structure is not significant after treatment.These test results can provide support or reference for the design,construction and inspection of the foundation treatment in the ultra-soft silt soil area of lacustrine reclamation.