Cover
Vol. 20 No. 1 (2026)

Published: April 29, 2026

Pages: 60-76

Research Article

Experimental Investigation of Lateral Displacement Behavior of Contiguous Pile Walls in Staged Excavation

Mohammed Burhan Mikael 1 Ahmed Hasan 2
1 SU: Salahaddin University - Erbil
2 Salahaddin University-Erbil
History
  • Received: September 25, 2025
  • Revised: January 13, 2026
  • Accepted: March 1, 2026
  • Available Online: June 30, 2026
DOI

https://doi.org/10.37650/IJCE200105

Abstract

Deep excavations in urban areas require reliable retaining systems to ensure stability and prevent damaging adjacent infrastructure. Contiguous pile walls (CPWs) are widely used in space-constrained projects, although their behavior in silty soils under staged excavation conditions is less well explored. This study experimentally investigates the lateral displacement behavior of CPWs using a physical model, focusing on four governing parameters: pile spacing, surcharge load, soil unit weight, and moisture content. A rigid model chamber was constructed with instrumented CPWs, where dial gauges measured the lateral displacement during sequential excavation. Results show that surcharge load and moisture content are the most adverse parameters: lateral displacement increased by up to 200% under a 50 kPa surcharge and by more than 50% with higher moisture content. In contrast, increased soil unit weight had a substantial effect on decreasing lateral displacement by more than 50%. Pile spacing regulated the efficiency of soil arching with the closer spacing mobilizing stronger load transfer and limiting deflection and wider spacing weakening the arching and increasing movement. These findings offer practical recommendations for the design and monitoring of excavation support systems in urban settings, where displacement control is critical for maintaining the stability of the walls and preventing damage to adjacent infrastructure.

Keywords

References

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