真空联合堆载预压真空泵功率影响对比试验

Comparison Experiments on Impact of Pump Power of Vacuum Preloading Method

真空联合堆载预压作为一种能快速、有效改善地基土性质的地基处理方式,广泛应用于工程实践当中。然而真空预压的加固机理并不十分清楚,实际操作的施工参数往往依靠经验选取,如真空泵功率大小等。有鉴于此,采用5.5 k W·h与7.5 k W·h的真空泵进行现场对比试验,并埋设大量监测仪器进行监控,利用监测数据分析探讨了真空泵功率对真空联合堆载预压加固效果的影响。结果表明使用7.5 k W·h功率的真空泵仅能在早期较快传递真空度,而超过18天后地层真空度分布与使用5.5 k W·h基本相同。因此,相比于较长的加固时间,沉降量几乎相等。试验所揭示的现象与相关结论为该处理方式的相关理论研究与应用提供了重要资料与参考。

Vacuum preloading method is widely used in the ground improvement projects. It can improve the strength of the ground rapidly and efficiently. However, the reinforcement mechanism is not very clear to us. Some construction parameters of this method are chosen by experience without evaluating the actual influence, such as the power of vacuum pump. In order to find the impacts of the power of the vacuum pump, 5. 5kW＆#183;h and 7. 5 kW·h vacuum pumps were used separately in two experiment fields. A lot of sensors and instruments, such as settlement plates, pore water sensors, vacuum sensors, were used to monitor during the preloading process. It was shown that bigger power pump （ 7. 5 kW· h ） can only transmit the vacuum in the early days during the preloading. The distribution of vacuum became the same with the field using 7. 5 kW·h pumps after 18 days. The settlements were almost the same using different pumps with the same working time. The data and the results obtained from the experiments provide an important reference to this kind of method.