## 4 Test Results and Discussion
### Prediction on Number of Transverse Members Considered Bearing Bond Coefficients  
The relationship between bearing-resistance stress and bearing bond coefficient with the number of transverse members and normal stress is shown in Figure 9. The bearing bond coefficient was decreased according to the increment of bearing-resistance stress with the number of transverse members. Bearing-resistance stress did not increase in PS2-1 and PS3 when normal stress was above a certain value. This means that if normal stress is more than a certain level, the bearing bond coefficient and bearing-resistance stress should be considered in the application of the number of transverse members. Therefore, for transverse members, bearing-resistance stress and bearing bond coefficient due to normal stress can be found as follows.  
If normal stress is higher than a certain level, bearing-resistance stress has a high value, but a number of transverse members have little effect on the bearing bond coefficient. However, the result differs for cases of lower normal stress. Meanwhile, the occurrence range of bearing-resistance stress widely varied with the increment of normal stress, but the incremental ratio of the bearing bond coefficient gradually decreased. Therefore, when predicting the number of transverse members, bearing-resistance stress and bearing bond coefficient should be considered.  
In order to predict the number of transverse members needed to satisfy the required bearing resistance, a prediction method is proposed as shown in Figure 10.  
The prediction method is as follows:  
First, the calculated bearing-resistance stress and bearing bond coefficient, which have the same soil condition, can be plotted as shown in lines 1-3. Second, the intersectional point of each tangent line on the two sides, of which minimal and maximal normal stress is applied in lines 1-3, is extended and connected. The incremental ratio of bearing strength was decreased. Lastly, the prediction of a number of transverse members can be used to obtain the crossing point of the tangential line on the plotted line of bearing-resistance stress and bearing bond coefficient.  
For example, if Points A-D for bearing-resistance stress and bearing bond coefficient are as shown in Figure 10, each point is presented as follows:  
In cases marked on the plotted line (Point A) and unmarked on the plotted line or in the nonoverlap zone (Point B), a number of transverse members are selected from the plotted line and that of shift point B to B', considering stabilization.  
Figure 9: Relationship between bearing-resistance stress and bearing bond coefficient.  
In the cases within the unmarked area on the plotted line and in the marked area on the overlap zone (C and D), evaluation is classified in the lower and upper zone of the solid line, which uses an extended line by the intersectional point of each tangent line in the overlap zone. That is, if the plotted point is marked on the lower zone, the prediction could be selected after the shift from C to C'; if the plotted point is marked on the upper zone, the selection could be decided after the shift from D to D'.  
Therefore, the number of transverse members can easily be predicted in the nonoverlap zone. However, if the selection is within the overlap zone, the above-mentioned rational methods can be used for evaluation. That is, the stability and economic efficiency of a reinforced earth wall used in improved reinforcement can be reasonably predicted.