Monitoring of double-row piles and high buildings adjacent to deep foundation pits

The existing buildings adjacent to a deep foundation pit will be damaged seriously or additionally deformed when the foundation pit is excavated, and it will lead to motion of soils. The double-row piles as one of shielding measures are studied. Based on a deep foundation pit adjacent to high buildings in Beijing, the key design parameters of double-row piles such as distance of row piles, distance of piles, link of top beam, and strength of soils between the piles are analyzed. Through the numerical simulation and in-situ monitoring, the displacement field grouped by the double-row piles, soils after the piles and high buildings is analyzed. The deformation laws of the double-row piles, soils after the piles and high buildings are concluded. At the same time, it is proved that the double-row piles can reduce the displacement field obviously by comparing the double-row piles to the single-row ones. The horizontal displacement of soils after the piles decreases from 17 mm to 8 mm, with a percent of about 53%. The maximum differential settlement of high buildings is 6.9 mm and the angle variance is 0.33‰. In a word, the safety of buildings is ensured by monitoring during the excavation of the deep foundation pit. It may be useful reference to the similar engineering in future.