# Dynamic Response of Non-Yielding Wall Supporting Over-Consolidated Sand
## 4 Results
### Effect of Backfill Over-Consolidation Ratio  
The effect of compaction effort on the seismic response of the non-yielding wall is examined by varying the OCR of the backfill. Changing the backfill OCR alters the lateral earth pressure to be applied for compaction in accordance with Equation (1), which simulates soils with different degrees of compaction. Figure 16 shows the dynamic, incremental lateral deflection of the wall at mid-height, normalized to the height of the wall. Maximum and residual deflections are shown. The figure shows that increasing the OCR ratio of the backfill results in a consistent decrease in the maximum and residual deflection increments  
Figure 14: Variation in maximum and residual lateral earth forces with backfill friction angle. Figure 15: Variation in maximum, minimum, and residual resultant force elevation with friction angle. of the wall. This suggests that a higher compaction effort, which yields a larger OCR ratio in the backfill, leads to lower wall deflections during and after ground shaking. The effect of backfill OCR on the dynamic deflection increments is more pronounced for OCR values less than 3. Figure 17 shows the maximum and residual total lateral earth pressures subjected to the wall during base shaking at different backfill OCR values. Static earth pressures prior to dynamic loading for each case are also shown for comparison. Figure 17a shows that for all OCR values, the base excitation significantly increased the lateral earth pressure beyond the static conditions within the top half of the wall. This increase was less significant within the bottom half of the wall. The large increase in pressures in the upper half of the wall may be attributed to the amplification of response as waves travel upward along the soil-wall system. Figure 17a also shows that the total earth pressure increased with increasing backfill OCR. Figure 17b shows that within the top half of the wall, all cases retained pressures larger than the static condition at the end of the excitation. Within the bottom third of the wall, backfill soils with OCR = 1 and 4 retained earth pressures larger than their corresponding static values. Backfill soils with OCR = 2 and 3 retained pressures lower than their corresponding static values within the bottom third of the wall. Figure 16: Variation in maximum and residual lateral wall deflection at mid-height with backfill OCR. Figure 17: Variation in critical lateral earth pressure with backfill OCR. (**a**) Maximum pressure, (**b**) residual pressure. Figure 18 shows the maximum and residual forces acting on the wall due to base excitation for different backfill OCR values. The lateral earth force on the wall in static conditions is also shown. It is clear from the figure that the total maximum and residual forces increased with increasing backfill OCR. However, this increase in total pressure corresponds to the increase in static earth pressure due to compaction [6]. The dynamic force increment is more representative of the effect of OCR on the dynamic response of the wall. It can be seen in Figure 18 that the dynamic maximum and residual force increments decreased with increasing OCR values. This suggests that a higher compaction effort causes the non-yielding wall system to develop larger lateral static forces but lower dynamic lateral forces during and after seismic events. Finally, the dynamic amplitude was found to increase with an increasing backfill OCR. An increase in dynamic amplitude of 13% was observed from the case of OCR = 1 to the case of OCR = 4. The location of the total maximum, minimum, and residual forces on the wall are shown in Figure 19. It can be observed that the elevation of the maximum and residual forces increased from the static value of approximately 0.5H to the range of 0.54 H-0.7 H. As the backfill OCR increased, the location of the total maximum and residual forces became closer to the middle of the wall.