I am currently involved in the design of several long retaining walls. One option under consideration is the use of soil nails with shotcrete reinforced by welded wire fabric (WWF) and the other is the use of mechanically stabilized earth (MSE) reinforcement (geogrids) with shotcrete reinforced by WWF. What is the best method (or product) to anchor each system to the shotcrete, and how are shotcrete-to-shotcrete (gunite) anchors treated in an MSE wall?

There are many ways to attach a shotcrete facing to a soil nail shoring system or an MSE wall system. For the attachment to a soil nail wall system, you could review the Federal Highway Administration’s “Manual for Design & Construction of Soil Nail Walls.” For MSE wall systems, you should consult with the MSE wall system vendors. Shotcrete facing systems are commonly used on both types of walls, but it is beyond the scope of our association to provide further guidance.