新型防淤堵真空预压法室内与现场试验研究

 针对目前直排式真空预压法的真空应力难以到达深部土体，排水板淤堵严重，加固效果欠佳，难以满足工程实际应用需要的问题，提出一种新型真空预压吹填土地基处理技术--新型防淤堵真空预压法，是对直排式真空预压法的技术改进和创新，该真空预压技术采用防淤堵排水板，其滤膜为无凹凸结构亲水性材料，滤膜与芯材轧在一起，提高排水效果；此外采用无孔真空管、密封接头直接与竖向防淤堵塑料排水板密闭连接，形成水平密闭排水系统，缩短真空传递路径，减少真空度的沿程损失，真空度直达土体深部，加快土体孔压的消散，防止淤堵，提高加固效果。通过不同排水板真空预压试验，以及室内模型试验和现场试验对直排式真空预压法与新型防淤堵真空预压法加固吹填淤泥地基加固效果进行对比研究，获得不同排水板的加固效果和新型真空预压防淤堵加固机制，并证明新型防淤堵真空预压法的有效性，为该技术的应用和发展提供理论依据。

INDOOR AND FIELD EXPERIMENT ON VACUUM PRELOADING WITH NEW ANTI-CLOGGING MEASURES

The difficulties of pumped vacuum pressure to reach the deep soil and the severe clogging of drainage board in the current method of vacuum preloading lead to unsatisfactory effect in soil reinforcement and are unable to meet the needs of engineering applications. The vacuum preloading technology for the treatment dredged ground with anti-clogging measures was thus proposed. The anti-clogging drainage boards used the filtering membranes of hydrophilic material without concave and convex structures. The membrane and core material were rolled and bonded together to improve the effect of draining. Moreover，the vacuum tubes connected with the PVDs directly and airtightly formed a closed anti-clogging drainage system. As a result，the flow path of vacuum was shortened，the loss of the degree of vacuum along the path was reduced；the vacuum pressure reached the deeper soil layers，the dissipation of pore pressure in soil was accelerated and the effect of soil consolidation was improved. Field and laboratory model tests on the vacuum preloading with and without anti-clogging were carried out；and then the comparison of the experimental results confirmed the effectiveness of the new measures.