袋装砂井加固处理珠江三角洲某高速公路软基效果分析

珠江三角洲某高速公路路基采用７．０ｃｍ砂井排水堆载预压加固处理，测试资料分析表明加固效果显著。土体固结度达到８０％时所需的预压时间约为原设计时间的１／３倍；合理加密砂井间距对孔压消散，加快土体固结是十分有利的；排水砂井除排水作用外，还起到竖向加筋抗滑作用。但施打砂井后，土体扰动引起土体抗剪强度降低是非常可观的，工程学术界和广大现场施工人员应予以重视。

Analysis on an expressway soft ground improved by packed drains in Pearl River delta

This paper discussed the result of soft ground improvement of an expressway located in Pearl River delta and its foundation was treated by preloading combined with packed drain of a diameter of 7 cm. Testing and monitoring results showed that the adopted method of ground treatment was very effective, so the preloading time when degree of consolidation reach 80% was reduced by 1/3 as compared with the design anticipation. Moreover, appropriate decrease of packed drain spacing was useful to the pore pressure dissipation and soil consolidation. Packed drains also have a vertical reinforcement and anti slide effect besides the drainage. Soil shear strength has a significant decrease due to disturbance after construction of the packed drains, which should be seriously considered for practice technicians and academic authorities.