真空—堆载联合预压在上海高速公路的应用

On Vacuum Combined with Surcharge Preloading Applied in Shanghai Expressways

真空—堆载联合预压是高速公路软基处理技术。以上海沪青平高速公路为例,通过5个实验段,介绍了真空预压阶段、真空—堆载阶段和联合预压阶段等3个阶段中断面沉降情况。实践证明,该技术提高高速公路软基沉降速率较快,远远超过堆载规划值10mm/d;具有真空预压和堆载预压双重效果,既速度快又不至于失稳;加固深度较大,减少工后沉降;施工管理和质量检验简单易行。因此,该技术施工工艺成熟,可推广应用。最后指出了有待深化完善之处。

Vacuum combined with surcharge preloading method is regarded as the treatment technology to expressway soft ground foundation.Taking Shanghai Huqingping Expressway for instance,the section settlement conditions of 3 stages of vacuum preloading,vacuum surcharge and combined preloading stage are introduced through 5 test sections.The results show that the technology can improve the soft ground settlement rate quickly（more than the planned value 10 mm/d largely）,with the double effect of vacuum preloading and surcharge preloading.The technology also can strengthen the depth and reduce the post-construction settlement with rapid speed and stable station.Moreover,it is easy for construction management and quality test.In conclusion,the method of mature technique should be widely applied,but some disadvantages are also pointed out in the paper.