Abstract: PHC pipe pile is widely used in recent years. The application of PHC pipe pile belongs to soil compaction pile-sinking mode. The compaction effect caused during piles driving would produce adversely effects on the surrounding environment and affects its possibility and bearing characteristics. The study of compaction effect was conducted based on the measurements and statistics of excess pore water pressure and horizontal displacement in the Guang-Qing Expressway Expansion Project. Horizontal displacements were monitored by fixed inclinometer measurements, pore water pressure was measured using vibrating wire, and using the automatic data acquisition system of data acquisition. The studies show that excess pore water pressure which caused by pile-driving in the project presented approximately linearly with the depth increasing and reduced with the distance increasing in the horizontal direction. Soil horizontal displacement of soil compaction effects decreasing as the distance increasing; it also has the significantly of hysteresis which can lead to pile body tilt. Piling on the widened foundation influences the original foundation slightly, while the site conditions have remarkable impaction on pile driving effect. The old embankment restraints horizontal displacement perpendicular to the roadbed direction.

Key words: PHC pipe pile, Guang-Qing Expressway, compaction effect, pore water pressure, horizontal displacement