## 5 Results and Discussion
### Mold Model Test Results  
#### 5.2.1 Load-Settlement Curves of the Eight Mold Test Cases  
Figure 10 shows the summary of the basic bearing capacity test results until the 12.5 mm settlement (\(0.25B\)) of all eight mold model test cases. The load-settlement curves were presented in Log2 scale because of the very high bearing capacity exhibited by Case 2. The unreinforced NMC clay (Case 1) represented the raw clay materials expected to be obtained in the field. The OMC clay (Case 2) was included in this study to compare the effects of clay water content on its bearing capacity. The present study also conducted bearing capacity tests for loose sand (Case 3) and dense sand (Case 4) for comparison with both the unreinforced and reinforced NMC clay model cases. We used sand since granular soils are highly desirable as embankment materials because they can facilitate drainage, can prevent saturation, are well-graded, and are capable of being well-compacted. At the same time, the density of sand is considered, in this study, to determine its effects on the bearing capacity. Most importantly, the various reinforcement methods are considered on NMC clay (Cases 5-8) to examine their individual effects on the bearing capacity of NMC clay.  
Figure 9: The locations and plan of the measuring equipment set-up.  
At this point, the results of unreinforced NMC clay (Case 1) and reinforced NMC clays (Cases 5-8) shall be compared with the bearing capacity exhibited by the sand models (Cases 3-4). For a better comparison of each case, analyses of the bearing capacity at SR of 0.05, 0.10, 0.15, and 0.25B are depicted in Figure 11. Unreinforced NMC clay (Case 1) with NMC 30% exhibited low bearing capacity. However, when clayey soil was well-compacted (Case 2) with OMC, it exhibited very high bearing capacity--far higher even than that of dense sand (Case 4).  
Here, the results showed that loose sand (Case 3) and dense sand (Case 4) had higher bearing capacities than unreinforced NMC clay (Case 1). This implied that unreinforced clayey soil is too weak to be utilized as an embankment material, and thus, reinforcements are needed. Hence, when composite geotextiles were added to the NMC clay (Case 7), it showed an equal bearing capacity with loose sand--75 kPa at 0.15B (Case 3)--and that bearing capacity increased by 17% at 0.25B. However, Case 7 showed less bearing capacity than Case 4 by 220% (max) at 0.05B and 0.10B. This implied that composite geotextiles alone are not enough as reinforcements for NMC clay. Therefore, when crushed  
Figure 11: The bearing capacity analysis at 2.5, 5, 7.5, and 12.5 mm penetration.  
Figure 10: The load-settlement curve of mold test results.  
gravel was combined with NMC clay (Case 5), it obtained a higher bearing capacity than loose sand (Case 3). At the same time, Case 5 showed, at first, that the bearing capacity was lower than dense sand (Case 4), but it later became stronger than dense sand by 36% at 0.25\(B\). When crushed gravel and composite geotextiles were combined with the NMC clay (Case 6), it obtained a higher bearing capacity than both loose sand (Case 3) and dense sand (Case 4) at 0.15 and 0.25\(B\). Likewise, adding one more layer of composite geotextiles to the top (Case 8) showed an even higher bearing capacity--higher than that of dense sand (Case 4) at 0.15 and 0.25\(B\).  
To this point, Case 8 exhibited a favorable bearing capacity, which could be desirable for field application. It can be inferred that adding reinforcements to the NMC clay enhanced its bearing capacity--making it exhibit a high bearing capacity, showing better strengths than dense sand. This result is very promising, wherein NMC clay, despite having a high water content, can be used as an efficient material for embankments.