This study is about the changing in the soft soil properties after improved using a combina-tion between prefabricate vertical drains, PVD and surcharge. The data is from case study for a mega pro-ject in Egypt, where the soft soil is extended up to 50m depth. A vertical drains is 25m deep were used with 6.5m of surcharge. The dissimilarity in the soil profile from area to other offered a wide variation in the improved parameters. The built trail area – including several types of instrumentations for intensive monitoring- was not enough to understand the whole behavior, which needed more instrumentations and CPTu`s in different locations from the site. The challenge was how to connect all these measurements to-gether for better understanding to the occurred improvement. Several models were built and calibrated us-ing the collected data to predict the soil behavior and the development of the settlement. Laboratory tests were performed using boreholes samples from the site and the measured parameters used as well for the soil models. Pre and post CPTu tests were combined in building model – especially the horizontal soil pa-rameters from dissipation tests – and used after for the verification. An acceptable agreement was found based on the developed numerical model where also used after to expect the long term settlement which was the key function from this model. The combination between surcharge and vertical drains can be suc-cessfully used to improve the soft soil, where the improved parameters can be evaluated numerically and back calculated to be used later on.
Menu