Laboratory investigation of reinforcement spacing effect on geosynthetic-block connection

This study investigates the connection between geogrid reinforcement and modular concrete block facings using a laboratory testing device that simulates the key mechanisms in segmental geosynthetic reinforced structures. The device enables the assessment of various factors influencing connection loads, including vertical spacing effects. A comprehensive instrumentation program was implemented to measure lateral earth pressures, geosynthetic strains, and loads within a geosynthetic-reinforced unit cell subjected to incremental surcharge stages. The findings highlight the significant impact of closely spaced geogrid reinforcements on connection load behavior in segmental geosynthetic walls. Reducing vertical spacing while maintaining S_v/T_ult ratio led to a more uniform distribution of horizontal displacements along the facing wall and a substantial reduction in relative settlements. This reduction suggests that closely spaced reinforcements effectively mitigate the down-drag effect altering the mechanisms governing connection load development and, consequently, influence the appropriate methodology for calculating required connection loads in design analysis.