Design and Performance of a Permanent Anchored Secant Pile Wall Adjacent to an Existing Structure-PPT Presentation

PPT Presentation

Pdf Summary

The Virginia War Memorial expansion in Richmond required a permanent anchored secant pile wall to retain soil and support the adjacent museum building. Design criteria limited movement of the existing building wall to 0.25 inches horizontally and 0.5 inches vertically.<br /><br />The project considered both Allowable Stress Design (ASD), based on factor-of-safety checks, and Performance-Based Design (PBD), which evaluates predicted wall movement against specified limits. The team used PLAXIS finite-element analysis for PBD, initially estimating soil stiffness from DMT data. Wall and building movements were monitored during excavation, and the PLAXIS soil model was recalibrated as inclinometer measurements became available at successive excavation stages.<br /><br />A contingency plan was prepared in advance, including retensioning installed anchors or adding a second row of anchors if movement exceeded thresholds. The project was completed successfully, with a maximum measured outward wall movement of 0.1 inch. The calibrated PLAXIS model predicted a maximum of 0.25 inch, providing a conservative estimate.<br /><br />The presentation emphasizes that numerical models cannot perfectly predict actual behavior. They are useful tools for informed engineering decisions, but should be paired with construction-stage monitoring, clear movement thresholds, and contingency measures. Engineers must also understand the wall system and construction sequence rather than relying on model results alone.

Keywords

Virginia War Memorial

Richmond

secant pile wall

anchored retaining wall

finite element analysis

PLAXIS

performance-based design

allowable stress design

construction monitoring

wall movement