Application of Depth-measurable Prefabricated Vertical Drains for Soft Ground Improvement

摘要

A kind of depth-measurable prefabricated vertical drains (PVD) was applied for soft ground improvement in Tianjin, China. Test was conducted to check the effectiveness of impulse method for detection of installation depth of PVD. The PVD were set into two groups in length: 20 m and 8 m. The installation depth of PVD was checked in 24 hours since they were installed. The tests result revealed that the measuring precision of impulse method is fairly good but it can be effect by the installation depth. The measuring precision can be controlled in 2% for most PVD when the installation depth was about 20 m. There is a fall down of precision when the installation depth was about 8 m. There is no need for additional construction measures when the PVD for impulse method are installed. All of the PVD installed can be checked for installation depth easily, so the apparatus and measuring method are good in operability and stability.