پويا جوان بخت

Stone Column is considered one of the most useful improvement options for soft soil and loose sand to increase the bearing capacity and reduce settlement. Another goal of the Stone Column is to reduce the excess pore water pressure and reduce soil liquefaction potential. Various vibro stone curtain of jet grout and DSM type have been implemented. Among the advantages of the diaphragm wall, we can mention the reduction of settlement and the reduction of liquefaction potential. The soils of the coastal areas of the Caspian Sea and the Persian Gulf can be at risk of liquefaction. Investigating the Stone Column as one of the solutions to deal with liquefaction seems necessary. Using Vibroflot is one of the options for Stone Column installation. Understanding how the soil components change during the installation of the Stone Column by vibroflot can be beneficial and play a role in the Stone Column design. Also, induced liquefaction due to vibroflot vibration seems probable. In most of the conducted laboratory studies, the behavior and process of the stone curtain installation have not been investigated, so the effect of the vibro stone curtain and soil changes during the installation process is not well known. In this research, in order to investigate the implementation process of the vibro stone curtain and their behavior during implementation, an experiment was conducted with the vibro stone curtain including two rows of walls, and to investigate the settlement improvement, a static loading was also performed on the unimproved soil.. Physical modeling with a scale of 1:10 was done in the laboratory. The model soil was Firouzkoh161 and D3 sand. Six Stone Columns were installed utilizing a miniature vibroflot. Acceleration and pore water pressure sensors recorded the data. In the end, a D3 blanket was implemented on the model, and the model was loaded to eva‎luate the soil improvement performance. With the installation of the vibro stone curtain by Vibroflot, pore water pressure in the soil increased. In some cases, liquefaction occurred even more than a radius of 14 cm from the axis of the columns. By moving away from the installation place, the excess pore water pressure created also decreased. As the number of installed Stone Columns increased, the depreciation rate of excess pore water pressure increased, and the excess pressure of pore water was depreciated earlier. The recorded accelerations showed the high frequencies caused by the vibration of the vibroflot were damped in the soil. The settlement results of the improved and unimproved soil indicated the positive effect of the Stone Columns.

بهسازي خاك , روانگرايي , فشار آب حفره‌اي

soil improvement , liquefaction , pore water pressure

Pouya Javanbakht

Dr. Mohsen Sabermahani