Challenges on Sheeting, Shoring and Underpinning Projects

摘要

It is common knowledge among geotechnical engineers and contractors that most of the uncertainty in the design, price, and schedule of sheeting, shoring, and underpinning projects lies in the ground conditions. Delays and additional costs can accrue quickly when the conditions underground change or if they are ill-defined. Common challenges include soft, loose or wet ground, rock, ground water and dewatering, adjacent construction, undercutting, unapproved modifications, system stiffness/deflection, and cantilevering. Combine any of these with insufficient investigations and poor communication and the project is heading for trouble. As these common challenges are not new, it is troubling that many engineers do not recognize, understand, or communicate these issues to owners and developers. Failing to learn from old lessons will only lead to more problems. Challenges encountered on sheeting, shoring, and underpinning projects around the National Capital Region are highlighted and presented through a collection of case histories.