Monitoring and analysis of synchronized excavation of extra large-scale adjacent riverside deep foundation pits in soft soil

Based on the field data of two extra large-scale riverside adjacent deep foundation pits in soft soil, the mutual impact of synchronized excavation of adjacent deep foundation pits, such as deformation characteristics of retaining walls, mutual impact on the axial forces of struts and the settlement of pillars were analyzed. The results show that the deformation of the retaining wall in the adjacent central position of foundation pits tends to increase, while those in the corner and in the positions away from the adjacent location are less affected by the adjacent pits excavation. The vertical displacement at the top of the retaining wall in the adjacent area is affected by the adjacent foundation pits excavation; and the horizontal displacement at the top of the retaining wall in the adjacent area increases when the distance between the foundation pits reduces. It is also concluded that the axial force of struts tends to decrease after reaching the peaks, while the vertical displacement of pillars keeps increasing. Comparing the deformation of retaining wall and settlement outside the pits with the classical theory, the retaining walls' deformation in the adjacent area is different from that of a single one.