Soil and structure deformation during deep foundation pit excavation in soft clay: case study and sensitivity analysis

• Published in: Arabian journal of geosciences 2022, Vol.15 (9), Article 926
• Main Authors: Tian, Angran, Ju, Jun, Zhang, Haolong, Yin, Peng, Tang, Qiang, Li, Wenwen
• Format: Article
• Language: English
• Subjects: Clay; Construction; Construction accidents & safety; Construction industry; Deep foundations; Deformation; Displacement; Dredging; Earth and Environmental Science; Earth science; Earth Sciences; Excavation; Friction; Internal friction; Mechanical properties; Modulus of elasticity; Occupational safety; Original Paper; Piles; Sensitivity analysis; Soft clay; Soil structure; Underground construction
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-022-10152-z

The construction of underground space in soft clay is becoming more complex, which brings great threats to construction safety. Taking a deep foundation pit in Suzhou as an example, the deformation of the foundation pit and retaining structure was calculated by FLAC 3D, and the main factors were analyzed. The results show that the simulation results fit the data measured in the field very well. The maximum horizontal displacement of pile is 1.79 cm, the maximum foundation pit bottom heave is 3.38 cm, and the maximum ground settlement is 2.39 cm. The increase in cohesion, internal friction angle, elastic modulus, and pile insertion ratio can reduce the horizontal displacement of pile and ground settlement, and the effect of internal friction angle and elastic modulus is better. By comparing different research results, the maximum ground settlement and the maximum horizontal displacement of retaining structure are 0.460–0.040% and 0.068–0.251% of the maximum excavation depth, respectively.