## 3 Results and Discussion
### Stress Distribution Characteristics  
The angle between the boundary line formed by the points with zero vertical stress on both sides of the retaining wall and the vertical direction is the stress-distribution angle. The stress-distribution angle can more intuitively reflect the influence range of the external load on GRSW. Since it is difficult to obtain the magnitude of the stress-distribution angle directly by calculation in practical engineering, the triangular linear interpolation method is used to calculate the coordinates of the points with zero stress at different wall heights by the center-of-gravity coordinate formula and connect them to obtain the stress-distribution range of the retaining wall. The principle of triangle linear interpolation is that, given a triangle vertex coordinates and values, as shown in Figure 7, the weight influence of each vertex on a specific point inside the triangle is calculated by the center-of-gravity coordinate formula. Then the coordinates and values of a specific point inside the triangle are obtained. See Equations (1)-(3). In this paper, assuming that the value of the stress zero point is known, the coordinates of the additive stress zero point can be obtained by the trial algorithm. \[\text{P(x)}=(1-\text{m}-\text{n})\times\text{P1(x)}+\text{m}\times\text{P2(x)}+ \text{n}\times\text{P3(x)} \tag{1}\]  
\[\text{P(y)}=(1-\text{m}-\text{n})\times\text{P1(y)}+\text{m}\times\text{P2(y)}+ \text{n}\times\text{P3(y)} \tag{2}\]  
\[\text{P}=(1-\text{m}-\text{n})\times\text{P1}+\text{m}\times\text{P2}+\text{n }\times\text{P3} \tag{3}\]  
where: \(1-\text{m}-\text{n}\) is the weight of point P1, m is the weight of point P2, and n is the weight of point P3. Figure 6: Distribution of vertical peak earth pressure along the length of reinforcement at a wall height of 6.9 m.  
Due to the small number of dynamic earth pressure boxes placed in the field test, it is not enough to obtain the stress-distribution law of the retaining wall by this method. To solve this problem, according to the vertical earth pressure value obtained from field monitoring, a contour map of vertical earth pressure was drawn using drawing software. Take the vertical earth pressure at 300,000 load cycles, as shown in Figure 8, to obtain the required coordinates and the value of earth pressure. Then the calculation is performed by linear interpolation inside the triangle, and finally, the stress distribution line is premeditated, as shown in Figure 9.  
Figure 9 shows the stress-distribution range in the GRSW caused by the top cyclic load under different load cycles. The specific distribution angle is shown in Table 4. It can be seen that the stress caused by an external load is gradually attenuated from high to low, so the stress-distribution range is gradually expanded and then gradually contracted. The  
Figure 8: Contour diagram of vertical dynamic earth pressure in the retaining wall when the number of load cycles is 300,000. Figure 7: Triangle linear interpolation diagram. Figure 9: Diagram of the measured stress distribution of GRSW. difference between positive and negative values is caused by the dispersion and decay of stress. The stress-distribution angle of the upper retaining wall ranges from 35\({}^{\circ}\) to 79\({}^{\circ}\), which is larger than that of the unstiffened body. Under the interaction of reinforced soil, the reinforced soil is denser, the stress-distribution range is more extensive in the upper part of the retaining wall, and more soil bears the stress, so the stress decays faster, and the upper part of the retaining wall bears most of the stress. The influence range of the stress on the wall panel is concentrated in the upper part, so the upper part of the GRSW is prone to sizeable horizontal deformation. On the side near the wall panel, the stress-distribution angle at the upper part of the retaining wall is the same as that at the side away from the wall panel, but there will be noticeable fluctuation at the middle and upper parts.