浅层真空预压法施工工艺浅析

传统的真空预压法加固含水量极高、承载力低的超软土地基存在较大困难。文章提出浅层真空预压施工工法，通过在地基土上插设不超过6m的短板，初步加固软土地基，形成硬壳层，可满足卖地及工程实施初步需要。施工工艺中提出三维土工排水网替代砂垫层的新思路，结合实际工程在现场试验区加以实施。试验结果表明，三维土工排水网排水效果好，重复使用率高，大大节约工程造价，可替代砂垫层在大面积施工中使用。采用塑料排水板与滤管直接连接的方式，减少了真空度的损失，增强加固效果。该施工工艺可为大面积施工及类似工程作参考。

Analysis on Construction Technology of Surface Soft Clay Improvement by Vacuum Preloading

It is difficult to improve the very soft clay foundation by traditional vacuum preloading, which has very high water content and low bearing capacity. A new method of improvement soft clay named surface soft soil improvement is presented in this paper. The short plastic vertical drain PVD with 6 m in length is used, which can make the soft clay foundation to be improved in preliminary. Once forming the hard coat layer, the foundation are met the needs of engineering construction. In the construction technology, the three-dimension drainage network is used to instead of the sand bedding course, and put into practice in field test area with actual engineering. The result shows that it is effective to drain when the three-dimension drainage network being constructed, the ration of recycle is high, the project cost would be decreased, and the method of the three-dimension drainage network being instead of the sand bedding course is feasible on a large scale engineering construction. Furthermore, the plastic vertical drain PVD is connected with the filter by direct mode, the loss of the degree of vacuum is decreased, and the improvement is increased. Thus, this construction technology is as a reference to the large scale engineering construction and similar projects.