Author Contributions
Conceptualization, G.G.; methodology, G.G.; software, K.C.; validation, K.C; formal analysis, G.G. and K.C.; investigation, K.C.; resources, G.G.; data curation, K.C.; writing—original draft preparation, K.C.; writing—review and editing, G.G.; visualization, K.C.; supervision, G.G.; project administration, G.G.; funding acquisition, G.G. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Schematic graph of Combination Splice: (a) Splice plates; (b) Clamp ring.
Figure 1.
Schematic graph of Combination Splice: (a) Splice plates; (b) Clamp ring.
Figure 2.
Combination Splice.
Figure 2.
Combination Splice.
Figure 3.
Force analysis.
Figure 3.
Force analysis.
Figure 4.
Parameters of various parts of the clamp ring: (a) side and front view, (b) sectional drawing.
Figure 4.
Parameters of various parts of the clamp ring: (a) side and front view, (b) sectional drawing.
Figure 5.
Schematic diagram of reinforcements in pile test specimens: (unit: mm).
Figure 5.
Schematic diagram of reinforcements in pile test specimens: (unit: mm).
Figure 6.
Schematic diagram of the bending test setup and instruments.
Figure 6.
Schematic diagram of the bending test setup and instruments.
Figure 7.
Bending test setup and instruments photograph.
Figure 7.
Bending test setup and instruments photograph.
Figure 8.
Failure modes of pile test specimens: (a) concrete crushing; (b) anchorage failure.
Figure 8.
Failure modes of pile test specimens: (a) concrete crushing; (b) anchorage failure.
Figure 9.
Relationship between the load and the midspan displacement: (a) P4A-CS-I/P4B-CS-I, (b) P5A-CS-I/P5B-CS-I, (c) P5C-CS-II/P5D-CS-II, (d) P6A-CS-I/P6B-CS-I.
Figure 9.
Relationship between the load and the midspan displacement: (a) P4A-CS-I/P4B-CS-I, (b) P5A-CS-I/P5B-CS-I, (c) P5C-CS-II/P5D-CS-II, (d) P6A-CS-I/P6B-CS-I.
Figure 10.
Crack distribution of Specimens: (a) P4*-CS-I, (b) P5*-CS5-I, (c) P5*-CS5-III, (d) P6*-CS6-I.
Figure 10.
Crack distribution of Specimens: (a) P4*-CS-I, (b) P5*-CS5-I, (c) P5*-CS5-III, (d) P6*-CS6-I.
Figure 11.
Strain development of specimens: (a) Clamp strain of P4B-CS-I, (b) Concrete strain of P4B-CS-I, (c) Clamp strain of P5A-CS-I, (d) Concrete strain of P5A-CS-I, (e) Clamp strain of P5C-CS-I, (f) Concrete strain of P5C-CS-I, (g) Clamp strain of P6A-CS-I, (h) Concrete strain of P6A-CS-I.
Figure 11.
Strain development of specimens: (a) Clamp strain of P4B-CS-I, (b) Concrete strain of P4B-CS-I, (c) Clamp strain of P5A-CS-I, (d) Concrete strain of P5A-CS-I, (e) Clamp strain of P5C-CS-I, (f) Concrete strain of P5C-CS-I, (g) Clamp strain of P6A-CS-I, (h) Concrete strain of P6A-CS-I.
Figure 12.
Constitutive law of material: (a) uniaxial compression of concrete, (b) uniaxial tension, (c) uniaxial tension for rebar.
Figure 12.
Constitutive law of material: (a) uniaxial compression of concrete, (b) uniaxial tension, (c) uniaxial tension for rebar.
Figure 13.
Schematic diagram of the finite element model.
Figure 13.
Schematic diagram of the finite element model.
Figure 14.
Comparison of load–displacement curves between FEA and experimental results: (a) P4B-CS-I, (b) P5B-CS-I, (c) P5C-CS-II, (d) P6A-CS-I.
Figure 14.
Comparison of load–displacement curves between FEA and experimental results: (a) P4B-CS-I, (b) P5B-CS-I, (c) P5C-CS-II, (d) P6A-CS-I.
Figure 15.
Crack distribution of numerical and experimental results for specimens: (a) P4-CS-I, (b) P5-CS-I, (c) P5-CS-II, (d) P6-CS-I.
Figure 15.
Crack distribution of numerical and experimental results for specimens: (a) P4-CS-I, (b) P5-CS-I, (c) P5-CS-II, (d) P6-CS-I.
Figure 16.
Assembly gap of Combination Splice.
Figure 16.
Assembly gap of Combination Splice.
Figure 17.
Load –Displacement curves of different gap distances.
Figure 17.
Load –Displacement curves of different gap distances.
Figure 18.
Uniform corrosion of clamp rings.
Figure 18.
Uniform corrosion of clamp rings.
Figure 19.
Load–displacement curves of different corrosion thicknesses.
Figure 19.
Load–displacement curves of different corrosion thicknesses.
Table 1.
Mechanical properties of the steel.
Table 1.
Mechanical properties of the steel.
Steel | Ds(mm) | Area(mm2) | Es(GPa) | fy(MPa) | fu(MPa) | Fmax(kN) | δ(%) |
---|
HSSS | 11.1 | 74.2 | 165 | 1920 | 2170 | 161.014 | 6 |
Stirrup | 6 | 19.6 | 197 | 534 | 562 | 11.0152 | 2.6 |
Table 2.
Mechanical properties of Concrete using Empirical formulas.
Table 2.
Mechanical properties of Concrete using Empirical formulas.
Parameter | Empirical Formulas | Result | Parameter | Empirical Formulas | Result |
---|
fcu | fcu = 0.91fcu,10 + 1 | 106.7 MPa | Ec | 10,200fc^(1/3) | 44,850.7 MPa |
fc | fc = 0.818fcu | 87.2 MPa | εcu | (1432.88 + 10.423fcu) × 10−6 | 0.00255 |
Table 3.
Detailed dimensions of specimen.
Table 3.
Detailed dimensions of specimen.
Specimen | D*/mm | Dp/mm | t/mm | Prestressed Strands | ρs/% | Stirrup | Length/m |
---|
P4A/P4B | 400 | 308 | 95 | 7ΦD11.1 | 0.57 | Φb4@80 | 4.0 × 2 |
P5A/P5B | 500 | 406 | 100 | 11ΦD11.1 | 0.65 | Φb5@80 | 4.0 × 2 |
P5C/P5D | 500 | 406 | 100 | 11ΦD15.2 | 1.23 | Φb5@80 | 4.0 × 2 |
P6A/P6B | 600 | 506 | 110 | 14ΦD11.1 | 0.61 | Φb5@80 | 4.0 × 2 |
Table 4.
Detailed dimension of Combined Splice (units: mm).
Table 4.
Detailed dimension of Combined Splice (units: mm).
Specimen | Combined Splice | D4 | D5 | D6 | t1 | t2 | t3 | h1 | h2 |
---|
P4A/P4B | CS4-I | 356 | 372 | 404 | 12 | 24 | 8 | 48 | 24 |
P5A/P5B | CS5-I | 456 | 472 | 504 | 12 | 24 | 8 | 48 | 24 |
P5C/P5D | CS5-II | 444 | 464 | 504 | 17 | 30 | 10 | 68 | 34 |
P6A/P6B | CS6-I | 556 | 572 | 604 | 12 | 24 | 8 | 48 | 24 |
Table 5.
Flexural performance parameters of specimens.
Table 5.
Flexural performance parameters of specimens.
Specimens | /kN·m | /kN·m | /
| /kN·m |
/kN·m | / | /mm |
---|
P4A-CS-I | 91 | 93 | 102% | 133 | 142 | 107% | 35.40 |
P4B-CS-I | 91 | 97 | 107% | 133 | 159 | 120% | 58.22 |
P5A-CS-I | 178 | 186 | 104% | 272 | 328 | 121% | 60.11 |
P5B-CS-I | 178 | 180 | 101% | 272 | 302 | 111% | 51.00 |
P5C-CS-II | 241 | 263 | 109% | 477 | 473 | 99% | 39.63 |
P5D-CS-II | 241 | 263 | 109% | 477 | 514 | 108% | 43.07 |
P6A-CS-I | 289 | 299 | 103% | 427 | 461 | 108% | 40.25 |
P6B-CS-I | 289 | 289 | 100% | 427 | 455 | 107% | 42.15 |
Table 6.
Crack number and regions.
Table 6.
Crack number and regions.
Specimen Splice | Crack Numbers | Crack Region (mm) | Max Crack Length (mm) | Max Crack Width (mm) |
---|
P4A-CS4-I | 6 | −1200–1200 | 240 | 0.48 |
P4B-CS4-I | 12 | −1250–1200 | 320 | 1.22 |
P5A-CS5-I | 10 | −1100–1100 | 390 | 1.10 |
P5B-CS5-I | 9 | −1100–1100 | 350 | 0.98 |
P5C-CS5-II | 11 | −1000–1000 | 350 | 0.82 |
P5D-CS5-II | 14 | −1000–1000 | 370 | 0.68 |
P6A-CS6-I | 7 | −1000–1000 | 410 | 0.84 |
P6A-CS6-I | 7 | −1000–900 | 450 | 0.88 |
Table 7.
Key parameters to determine the constitutive law of materials.
Table 7.
Key parameters to determine the constitutive law of materials.
Parameter for uniaxial compression constitutive law |
| | | | |
0.001 | 0.00255 | 0.00458 | 1.434 | 1.650 |
Parameter for uniaxial tension constitutive law |
| | | | |
0.000129 | 0.000129744 | 0.000172993 | 0.000207101 | |
| | | Ec | |
5.847227 | 1.929584977 | 0.58472272 | 45238 | |
Parameter for stirrup and HSSS constitutive law |
| k1 | k2 | k3 | k4 |
ΦD 10.7 | 1 | 4.56 | 5.58 | 1.07 |
ΦD 11.1 | 1 | 5.14 | 5.2 | 1.13 |
d6 | 1 | 12.1 | 12.1 | 1.15 |
Table 8.
Interaction and Constraints.
Table 8.
Interaction and Constraints.
Interaction Parts of FEA Model | Interaction and Constraints |
---|
Pile body–Splice plates | Surf–Surf Contact (Hard Contact and Friction) |
Pile body–Steel strands | Embedded |
Pile body–Stirrup | Embedded |
Steel Strands–Splice plates | Tie |
End plates–End plates | Surf–Surf Contact (Hard Contact and Friction) |
End plates–Combined splice (Connecting ring and welded) | Surf–Surf Contact (Hard Contact and Friction) |
Loading block–Pile body | Tie |
Supporting block–Pile body | Tie |
Table 9.
Element type of FEA model.
Table 9.
Element type of FEA model.
Parts of FEA Model | Element Type |
---|
Concrete pile | C3D8R |
Steel strand | T3D2 |
Stirrup | T3D2 |
Splice plate of pile | C3D8R |
Combination Splice (Clamp ring and welded) | C3D8R |
Loading blocks and Supporting blocks | C3D8R |