# Dynamic Response and Geogrid Strain Analysis of GRS Retaining Wall
## 3 Test Results and Analysis
### Acceleration Response  
As shown in Figures 11 and 12, the acceleration response of soil under dynamic load was measured by a dynamic accelerometer in the test, and the peak value of dynamic response was taken to study the influence of average load, peak value, amplitude and frequency on dynamic characteristics of soil under dynamic load. The preliminary study found that the peak acceleration in the soil decreases from top to bottom. Reinforced soil structure has a better acceleration weakening effect on high-frequency loads than on low-frequency loads. This is because the soil under dynamic load is equivalent to a damper, and the frictional collision of soil particles causes the energy to be consumed as a way to reduce the acceleration response in the soil. The farther away from the vibration source, the more obvious the damping effect was.  
It can be found from Figures 11 and 12 that increasing the load amplitude and frequency both increase the peak acceleration. In the case of constant amplitude loading (Figure 11), by keeping the peak load unchanged and increasing the frequency, the acceleration peak will increase, while by keeping the load frequency unchanged and increasing the peak, the peak acceleration changes little. In the case of constant frequency loading (Figure 12), by keeping the average value unchanged and increasing the amplitude, the acceleration peak will increase, while by keeping the amplitude unchanged and increasing the average value, the acceleration peak will decrease. This shows that the different load factors influencing the peak acceleration of the GRS retaining wall under traffic load are the load frequency, amplitude, peak and average value. The reason for this is that the  
Figure 11: Variation in acceleration peak and frequency.  
Figure 12: Distribution pattern of acceleration peaks at different depths.  
acceleration response is different from the dynamic response, and the peak acceleration does not affect the deformation of the retaining wall. The greater the acceleration, the faster the energy consumption. [PERSON] et al. [49] proposed in their study that the geogrid will produce a \"stretching effect\" and the \"dynamic tension membrane effect\" under traffic load, and this mechanism will increase the action area of the geogrid and soil particles, and the greater the frequency and magnitude of the traffic load, the more obvious the effect.  
It thus appears that the acceleration response in the soil is a mechanism for coordinating deformation in a reinforced soil structure. Under dynamic load, the soil particles move irregularly. During the movement, the direct collision friction of soil particles and the friction between the geogrid and soil particles transfer and dissipate the energy in the soil. In this process, the compactness of the reinforced soil structure is improved. Taking equal frequency loading as an example (Figure 12), with the increase in the number of load cycles, C3-1 and C5-1 show an increasing decay of the acceleration peak compared to C1-1. This indicates that as the number of load cycles increases, the compactness of the upper reinforced soil structure gradually becomes higher than that of the surrounding soil, and thus the range of acceleration propagation in the soil becomes smaller.