PLAXIS 3D Tutorial 07: Rapid drawdown analysis

This example concerns the stability of a reservoir dam under conditions of drawdown. Fast reduction of the reservoir level may lead to instability of the dam due to high pore water pressures that remain inside the dam. The dam to be considered is 30 m high. The top width and the base width of the dam are 5 m and 172.5 m respectively. The dam consists of a clay core with a well graded fill at both sides. The geometry of the dam is depicted in the image below. The normal water level behind the dam is 25 m high. A situation is considered where the water level drops 20 m. The normal phreatic level at the right hand side of the dam is 10 m below ground surface. The sub-soil consists of overconsolidated silty sand.

This requires the PlaxFlow module in order to be able to perform (transient) groundwater flow calculations.

The attached *.p3dlog file contains all the commands to generate the models up to calculation (without point for curves selection). With a Bentley Geotechnical SELECT Entitlement [GSE] (former PLAXIS-VIP) licence you can use the commands runner to open the *.p3dlog file and to execute all commands in one go. Without a VIP licence, you can open the *.p3dlog file with any text editor, like Notepad, and then execute the commands via the command line command by command.