Figure 1.
Stabilized soil blocks division
Table 1.
Material properties of Nanjing soil [18]
| Soil properties | Values |
| USCS Classification | CL |
| Specific gravity | 2.7 |
| Liquid limit | 36.4% |
| Plasticity index | 17.8% |
| Optimum moisture content | 16.5% |
| Maximum dry density | 1.7 g/cm3 |
| D60 | 0.0117 mm |
| D30 | 0.0048 mm |
| D10 | 0.0011 mm |
Table 2.
Index and strength parameters of PP-fiber [18]
| Behavior parameters | Values |
| Fiber type | Single fiber |
| Unit weight | 0.91 g/cm3 |
| Average diameter | 0.034 mm |
| Average length | 12 mm |
| Breaking tensile strength | 350 MPa |
| Modulus of elasticity | 3500 MPa |
| Fusion point | 165°C |
| Burning point | 590°C |
| Acid and alkali resistance | Very good |
| Dispersibility | Excellent |
Table 3.
Material properties of different cases considered in this study [18]
| Sample no. | Cement content (%) | Fiber content (%) | Modulus of elasticity E (MPa) | Poisson’s ratio | Unit weight (kN/m3) | Cohesion c (kPa) | Angle of internal friction ϕ (degrees) |
| 1 | 0 | 0 | 5.8 | 0.2 | 16.7 | 75.1 | 27.3 |
| 2 | 0 | 0.05 | 5.6 | 0.2 | 16.7 | 95.3 | 28.2 |
| 3 | 0 | 0.15 | 5.5 | 0.2 | 16.7 | 102.5 | 30.1 |
| 4 | 0 | 0.25 | 5.3 | 0.2 | 16.7 | 114.3 | 31.6 |
| 5 | 5 | 0 | 39.5 | 0.3 | 16.7 | 152.1 | 34.2 |
| 6 | 8 | 0 | 50.7 | 0.3 | 16.7 | 171.8 | 35.3 |
| 7 | 5 | 0.05 | 39.2 | 0.3 | 16.7 | 169.4 | 35.1 |
| 8 | 5 | 0.15 | 38.8 | 0.3 | 16.7 | 186.7 | 36.3 |
| 9 | 5 | 0.25 | 38.5 | 0.3 | 16.7 | 193.4 | 36.7 |
| 10 | 8 | 0.05 | 50.4 | 0.3 | 16.7 | 181.4 | 37.0 |
| 11 | 8 | 0.15 | 49.9 | 0.3 | 16.7 | 193.3 | 37.5 |
| 12 | 8 | 0.25 | 49.3 | 0.3 | 16.7 | 229.8 | 39.3 |
Figure 2.
Typical 3D FE mesh of the one-quarter model
Figure 3.
Soil, pile-raft material properties and load configuration for validation [30]
Figure 4.
Comparison of the load-settlement curves from different analysis methods
Table 4.
Comparison of the settlement from centrifuge test [33] and present study
| Model | Average settlement (mm) | Load taken by piles (%) |
| Horikoshi and Randolph [33] | 22 | 19 |
| Present study | 21 | 20 |
Figure 5.
The variation of maximum settlement of pile-raft with the width of reinforced block
Figure 6.
The variation of maximum settlement of pile-raft with the width of stabilized block
Figure 7.
The variation of maximum settlement of pile-raft with the depth of reinforced block
Figure 8.
The effect of pile spacing on the differential settlement (between the corner and center of raft) of pile-raft system
Figure 9.
The effect of the number of piles on the maximum bending moment of the foundation for various amounts of cement content
Figure 10.
The influence of pile length and reinforced soil block dimensions on the resulting maximum bending moment at the center of raft surface
Figure 11.
The variation of pile-raft maximum settlement with cement content for various pile lengths and block sizes
Figure 12.
The relationship between the (a) maximum (b) differential settlement (between the corner and center of the raft) of pile-raft and fiber content
Figure 13.
The combined effect of adding fibers and cement on the maximum and differential settlement (between the corner and center of the raft) of the foundation for (a) 5% cement and (b) 8% cement