Effective Width Rule in the Analysis of Footing on Reinforced Sand Slope

Abdelmadjid Abdi; Khelifa Abbeche; Djamel Athmania; Mounir Bouassida

Open Access

Effective Width Rule in the Analysis of Footing on Reinforced Sand Slope

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| Apr 08, 2019

Studia Geotechnica et Mechanica

Volume 41 (2019): Issue 1 (April 2019)

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Published Online: Apr 08, 2019

Page range: 42 - 55

Received: Sep 25, 2018

Accepted: Jan 28, 2019

DOI: https://doi.org/10.2478/sgem-2019-0005

Keywords
bearing capacity, eccentricity, footing, geogrid, model test, slope

© 2019 Abdelmadjid Abdi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Schematic view of footing model considering the effective width of footing.

Cross section of model test in the case of reinforced ground by geotextiles.

Tested footing with location of applied load.

Geometry and mesh size of the numerical model.

Outputs of PLAXIS code for e/B = 0.1 opposite to the slope facing. (a) Deformed mesh; (b) contours of total displacement.

Outputs of PLAXIS code for e/B = 0.1 towards the slope facing. (a) Deformed mesh; (b) contours of total displacement.

Relationship between the failure load and the displacements of a strip footing under various eccentricities located towards the reinforced slope face.

Comparison between the experimental and numerical results for reinforced sand (N = 1, m/B = 0.25).

Variation of iB versus e/B of a strip footing under eccentric load located towards the reinforced slope face.

Relationship between the failure load and the displacements of a strip footing under various eccentricities located opposite to the reinforced slope face.

Variation of iB versus e/B of a strip footing under load eccentricity located opposite to the reinforced slope face.

Material properties of the sand used.

Parameters	Values
Cohesion, c (kPa)	0.0
Angle of internal friction (°)	41
Dry unit weight (kN/m³)	16.1
Maximum dry density (kN/m³)	19.1
Minimum dry density (kN/m³)	13.75
D₁₀	0.28
D₆₀	1.20
D₃₀	0.79
Coefficient of uniformity, C_u	4.28
Coefficient of curvature, C_c	1.85

Parameters used in the numerical study.

Material	γ_unsat (kN/m³)	γ_sat (kN/m³)	E (kn)	ν	EA (kPa)	EI (kN.m²)	φ(°)	ψ(°)	R
Sand	16.1	19.12	14,000	0.3	–	–	41	8	0.7
Geogrid		–	–	–	500	–	–	–	–
Foundation	–	–	–	–	2.10E+07	1.75E+03	–	–	–
	–

Geogrid properties.

Description	R6 80/20
Raw material	Transparent polyester
Surface ground (g/m²)	380
Tensile strength (kN/m)	20 ≤ R_T ≤ 80
Elongation (%)	0 ≤ ΔL ≤ 8
Tensile strength for 1% elongation (kN/m)	16
Tensile strength for 2% elongation (kN/m)	28
Tensile strength for 5% elongation (kN/m)	56
Meshes opening (mm ´ mm)	73 ´ 30
Elongation before service (%)	0
Roller dimensions, length and width (m ´ m)	4.75 ´ 100

Parameters and conditions of performed tests.

Test reference	N	μ/B	e/B	d/B
C0	0		0	0.5
T01, F01			0.1
T02, F02			0.2
T03, F03			0.3
C250	1	0.25	0
T251, F251			0.1
T252, F252			0.2
T253, F253			0.3
C500		0.5	0
T501, F501			0.1
T502, F502			0.2
T503, F503			0.3
C750		0.75	0
T751, F751			0.1
T752, F752			0.2
T753, F753			0.3

Ultimate loads of footing under various load eccentricities located towards the slope face.

N	μ/B	e/B	qu(kN/ml)			i_B ;total width	i_B ;effective width
			Experimental results	Numerical results using total width method	Numerical results using effective width method
0		0	2.71	2.81	2.81	1.000	1.000
		0.1	1.78	1.96	2.02	0.698	0.719
		0.2	1.38	1.5	1.54	0.534	0.548
		0.3	0.98	1.06	1.11	0.377	0.395
1	0.25	0	2.81	3.13	3.13	1.000	1.000
		0.1	2.53	2.66	2.75	0.850	0.879
		0.2	1.93	2.06	2.08	0.658	0.665
		0.3	1.22	1.32	1.45	0.422	0.463
		0.4		0.64	0.66	0.204	0.211
	0.5	0	3.08	3.18	3.18	1.000	1.000
		0.1	2.61	2.76	2.81	0.868	0.884
		0.2	1.78	1.88	1.91	0.591	0.601
		0.3	0.95	1.06	1.11	0.333	0.349
	0.75	0	3.11	3.2	3.2	1.000	1.000
		0.1	2.24	2.42	2.55	0.756	0.797
		0.2	1.53	1.42	1.52	0.444	0.475
		0.3	0.88	0.97	1.02	0.303	0.319

Ultimate loads of footing under various load eccentricities located opposite to the slope face.

N	μ/B	e/B	q_u(kN/ml)			i_B ; total width	i_B ; effective width
			Experimental	Numerical results with total	Numerical results with
			results	width method	effective width method
0		0	2.71	2.81	2.81	1.000	1.000
		0.1	2.33	2.46	2.51	0.875	0.893
		0.2	2.08	2.02	2.1	0.719	0.747
		0.3	1.54	1.61	1.7	0.573	0.605
1	0.25	0	2.81	3.13	3.13	1.000	1.000
		0.1	2.55	2.7	2.83	0.863	0.904
		0.2	2.21	2.36	2.44	0.754	0.780
		0.3	1.61	1.82	1.93	0.581	0.617
	0.5	0	3.08	3.18	3.18	1.000	1.000
		0.1	3	3.16	3.22	0.994	1.013
		0.2	2.75	2.87	2.96	0.903	0.931
		0.3	1.98	2.1	2.15	0.660	0.676
	0.75	0	3.11	3.2	3.2	1.000	1.000
		0.1	3.1	3.23	3.27	1.009	1.022
		0.2	2.52	2.66	2.71	0.831	0.847
		0.3	1.28	1.39	1.48	0.434	0.463

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Effective Width Rule in the Analysis of Footing on Reinforced Sand Slope

Article Category: Research Article

Published Online: Apr 08, 2019

Page range: 42 - 55

Received: Sep 25, 2018

Accepted: Jan 28, 2019

DOI: https://doi.org/10.2478/sgem-2019-0005

Keywords
bearing capacity, eccentricity, footing, geogrid, model test, slope

© 2019 Abdelmadjid Abdi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Figure 1

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Figure 15

Material properties of the sand used.

Parameters used in the numerical study.

Geogrid properties.

Parameters and conditions of performed tests.

Ultimate loads of footing under various load eccentricities located towards the slope face.

Ultimate loads of footing under various load eccentricities located opposite to the slope face.

Effective Width Rule in the Analysis of Footing on Reinforced Sand Slope

Article Category: Research Article

Published Online: Apr 08, 2019

Page range: 42 - 55

Received: Sep 25, 2018

Accepted: Jan 28, 2019

DOI: https://doi.org/10.2478/sgem-2019-0005

Keywordsbearing capacity, eccentricity, footing, geogrid, model test, slope

© 2019 Abdelmadjid Abdi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Material properties of the sand used.

Parameters used in the numerical study.

Geogrid properties.

Parameters and conditions of performed tests.

Ultimate loads of footing under various load eccentricities located towards the slope face.

Ultimate loads of footing under various load eccentricities located opposite to the slope face.

Keywords
bearing capacity, eccentricity, footing, geogrid, model test, slope