Design and Behaviour of Walls Over Compressive Soil Case Study: Repair of the Vergel Bridge in Mexico

Over the years, the construction of mechanically stabilized earth (MSE) structures has been a practical solution in infrastructure projects; the simplicity in installation and economical benefits are well accepted nowadays. Designing and construction of a structure founded on a compressible soil is one of the major challenges in retaining wall projects; MSE wall is not an exception [1]. In cases that large settlements are expected, special considerations shall be taken into account for the design, site preparation, and construction in order to guarantee a sound performance [2]. The MSE walls of the Vergel Bridge in Northern Mexico were founded on a highly compressible ground. The ground improvement solution consisted of a series of pressure grout injection. Further to poor ground problem, an out-of-spec backfill was used as the reinforced fill in the MSE walls in this project. To overcome this problem, a new supporting retaining wall was constructed in front of the existing wall to stabilize it. Other challenges in this project are regarding construction schedule that should have been carried out without shutting down traffic. This paper summarizes and discusses the design approach and construction process in repairing this structure.