Lateral Earth Pressure Against the Facing of Segmental GRS Walls

Current design methods "borrowed" from the design concepts for externally stabilized retaining walls and adopted the Rankine or Coulomb earth pressure theories for design of segmental Geosynthetic-Reinforced Soil (GRS) walls. The earth pressure is used to determine the minimum reinforcement strength, minimum reinforcement length, and required connection strength between facing blocks. There is a myth that the connection strength of the wall facing needs to be sufficiently high in order to resist the Rankine or Coulomb lateral earth pressure. Such a design procedure has encouraged the use of heavy facing blocks and the use of pins and lips to increase resistance to lateral earth pressure on the wall face. This paper addresses the lateral earth pressure against the facing. Case studies on the subject of facing lateral earth pressure are presented and discussed. The "bin pressure" concept is introduced and recommended for evaluation of facing connection strength requirements in design.