Abstract
Multi depth pore water pressure in-situ measurement has been carried out in the Kansai international airport second phase island. MP(Multi-level Groundwater monitoring) system was installed in this site in order to observe the behavior of the upper diluvial clay (Osaka bay marine clay Ma12), which was one of the most significant clayey layers in this site due to the thickness of deposits and the large volume of landfill. This system consists of casing, packer, measuring ports and measuring prove, a pore water pressure can be measured as well as a settlement of the port. The construction of the second phase island was started in 1999, the in-situ measurement was installed in 2005. A comparative study of in-situ measurement and elasto-plastic numerical simulation employing “SYS Cam-clay model” with soil-water coupled analysis was mainly discussed in this study.
An elasto-plastic parameter for Ma13, MaDtc and Ma12, which was one of the dominating consolidated layers, was determined referring the results of laboratory tests. A comparison in-situ measurement and numerical simulation considering the landfill construction history, was carried out focusing on the pore water pressure and settlement behavior. A large settlement beyond the pre-consolidated pressure could be described as a loss of soil structure in this model. A comparison exhibited a good agreement, and an accuracy of the second phase island behavior estimated by numerical simulation was verified.
