真空预压法处理吹填超软地基10 a进展及展望

Review and Outlook in Improvement of Hydraulic Fill via Vacuum Preloading in the Past Ten Years

近十年来,大量围填海等吹填造陆工程相继开展,真空预压是处理吹填超软地基的主要方法。由于吹填超软地基的性质比一般软基更差,真空预压处理中遇到了一系列新问题,研究和解决这些新问题推动了技术的持续发展。总结了真空预压法处理吹填超软地基的进展,各项改进措施及其对加固效果、经济、环境、工期的影响。超软地基表面施工用泡沫浮桥法搭建作业面的成本仅为传统真空预压成本的58.8%、对相邻排水体采取异步真空吸水预压,排水量较传统真空预压法提高了29.3%;采用沉降自适应排水通道连接排水体,降低了排水体的弯折。真空堆载联合预压最终沉降量比传统真空预压增加30%、电渗用在真空预压最后阶段,含水率下降了25%,能耗占真空预压能耗的8%、加入SS-331H试剂真空化学联合预压使抗剪强度增加了4~5倍。建议完善相关技术规程,便于方法推广应用;研发耐腐蚀的电渗阳极,防淤堵排水板,降低成本;对其他如S320等试剂进行研究,提升土体性能的同时,充分考虑对环境的影响。

In the past decade,a large number of land reclamation projects have been carried out,and vacuum preloading is the main method to deal with the reclamation of ultra-soft foundation.As the properties of the base of hydraulic fill are worse than that of general soft ground,a series of new problems occurred in vacuum preloading,calling for the solution to these problems,which promoted the development of technology continuously.The progress of vacuum preloading method of treating overfilled soft foundation was summarized,and various improvement measures and the impacts on the reinforcement effect,economy,environment,and construction timeline were presented.Foam pontoon bridge method was introduced for the construction of ultra-soft foundation surface.The cost of constructing a working surface with this method was only 58.8%of that of traditional vacuum preloading,and asynchronous vacuum preloading was applied to adjacent drainage bodies,so that the drainage volume was increased by 29.3%compared with the traditional vacuum preloading method.Moreover,the settlement adaptive drainage channel was used to connect drainage water body for reducing the bending of the water drainage body.In addition,in the final stage of vacuum preloading,water content was decreased by 25%,and the energy consumption accounted for 8%of the energy consumption of vacuum preloading.With the addition of SS-331H reagent vacuum chemical combined preloading,the shear strength was increased by 4~5 times.At last,it is suggested that first,relevant technical regulations shall be upgraded to promote the application of the method;second,corrosion-resistant electroosmotic anode and anti-blocking drainage board shall be developed to reduce costs;third,other reagents,such as S320,shall be studied to improve soil properties while taking a full account of the impact on the environment.