GZA was asked by the manager of the commercial plaza to evaluate approximately 950 feet of rock slope, as high as 70 feet, that bordered the plaza’s rear access, loading docks, and portions of public parking areas. The granite and basalt slope had been cut very steeply with no catchment area and had produced several significant rockfall events in recent years.
In response, GZA completed field bedrock mapping using ropes-access techniques and LiDAR scanning, made rock slope engineering evaluations, prepared a risk matrix, compared alternatives, prepared plans, and observed and documented construction of the rock slope stabilization measures.
GZA developed mitigation measures that included heavy scaling, rock bolting, dowelled shotcrete buttresses, an anchored mesh drape, and an enhanced catchment system. Stabilization measures were constructed that control the risk of rockfall that could endanger personnel and damage facilities.