A Critical Review of Full-Scale Shaking Table Tests Conducted on Reinforced Soil Retaining Walls - Reinforced Soil Engineering: Advances in Research and Practice - page 493

Figure 17 Experimental setup instrumentation of PWRI wall. (From Ling et al., 2000.)
A total of 52 strain gauges were used to measure the elongation of the
geogrid, that is, 7 and 2 strain gauges on each layer of primary and secondary
reinforcements, respectively. The horizontal displacement of the wall face was
measured at 11 locations. The lateral load acting on the facing blocks was
measured using 11 load transducers installed in the mid-height of each concrete
block. The vertical and horizontal loads acting at the toe of the facing were also
measured using load transducers. The vertical load due to the backfill soil was
measured at six locations along the base of the soil mass.