高速公路超软土地基的真空预压加固研究

某高速公路采用了真空预压法加固高填方路堤的超软弱土地基。试验表明：与常规堆载预压法相比，采用真空预压法工期节省1/4，路堤实际填高6.2 m的超软弱地基土在预压3个月后，其固结度大于95 %，路基沉降量却减少1/3；地基土强度平均增长1.5倍；路堤填筑期侧向挤出的日均位移量小于0.2 mm/d，路堤地基一直处于稳定状态。预估的路基工后沉降均小于20 cm。由此得到的实践经验，可以在其他类似工程中推广应用。

Study on consolidation of supersoft ground of expressway with vacuum preloading method

The vacuum preloading method is used to consolidate the supersoft ground of an expressway. The test indicated that the improvement effect is very obvious. Compared with the conventional preloading method, the project construction time can be decreased by a quarter; the settlement of roadbed reduces 1/3. The strength of soil increases by 1.5 times. The consolidation degree of soil is larger than 95 % after the embankment of height of 6.2 m was filled and vacuum preloading was constructed for 3 months. The displacement of foundation soil is smaller than 0.2 mm/d during the construction period; the embankment and ground soil are stable. The predicted settlement is less than 20 cm. The experience can also be used in similar engineering.