土工排水网在超软土加固中的应用

针对超软土真空预压加固中砂垫层铺设困难、造价高等难题，提出以可循环使用的土工排水网替代砂垫层作为水平排水垫层。对比了砂垫层和土工排水网作为水平排水垫层的异同。通过现场试验，对采用土工排水网时的膜下真空度、地基土的竖向排水效果进行了检验，并对土工排水网的作用机理、铺设工艺和循环利用方法进行了探索。结果表明，在超软土的真空预压加固中，用土工排水网替代砂垫层，施工更为简单，加固效果良好，是可行的。

Application of geotechnical drainage net to improvement of ultra-soft soil

In order to solve the laying problem of the sand cushion on ultra-soft soil, and to decrease the cost in vacuum preloading projects because of the increasing price of the natural sand, the recyclable three dimensional drainage net made of polythene is used to replace the sand cushion. A comparison has been carried out between the sand cushion and the three dimensional drainage net when they act as horizontal drainage cushion. Field tests are conducted to verify the vacuum degree under the sealing film and the vertical drainage effectiveness of soil under the drainage net. The action mechanism, the laying method and the recyclable utilization method are studied in the tests. The tests results show that it is feasible to replace the sand cushion with geotechnical drainage net and this technology is more convenient and effective for the improvement of ultra-soft soil.