Dynamic Response of Saturated Soil - Foundation System Acted upon by Vibration

Fattah, Mohammed Y.; Al-Mosawi, Mosa J.; Al-Ameri, Abbas Fadhil Ibrahim

doi:10.1080/13632469.2016.1210060

“…These results are compatible with those found by Fattah et al (2016) who concluded that the maximum displacement amplitude of footing is reduced to half when the size of footing is doubled for dry and saturated sand. The final settlement of the foundation increases with increasing the amplitude of dynamic force, operating frequency and degree of saturation.…”

Section: From Figures Andsupporting

confidence: 93%

Liquefaction Potential of Sandy Soil from Small Laboratory Machine Foundation Model

Fattah

¹

,

Salim

²

,

Haleel

³

2018

IRECE

Self Cite

7

1

0

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Liquefaction is a phenomenon that occurs during earthquakes, and leads to ground failure. Water-saturated, well sorted, fine grain sands and silts behave as viscous fluid as a result of liquefaction. This behavior of fluids is very different than solids behavior. This paper presents and discusses the results of 54 experimental model tests, all of them were performed on saturated sand under vertical dynamic traffic load using different relative densities (medium and dense), different shapes of footing (square and circular), and different embedment depths (at surface and at depth B) where B is the width of footing. It was concluded that by increasing the relative density of sand, the surface settlement decreases; when sand's relative density increases from 60% to 80%, the reduction of the surface settlement for surface footing condition was about 26 to 72 % at (0.5 ton, 0.5 Hz -2 ton, 1 Hz), and 27 -74 % at (0.5 ton, 0.5 Hz -2 ton, 1 Hz) reduction for embedded footing condition models. Also the embedment of footing in dense sand reduces the settlement more than medium sand, because the dense soil is the stiffest. The amplitude of displacement (Az) decreased at both depths B and 2B, when soil relative density increased, the percentage of reduction in (Az) was about (4-93) % at depth B, and about (37-77) % at depths 2B, when soil relative density increased from (60%) to (80%). Also the displacement amplitude (Az) of the surface square footing is less than that of circular footing at both depths B and 2B.

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“…Experimental and numerical studies for the effect of harmonic dynamic loading on a shallow foundation of different sizes and depth of embedment in dry and saturated sand with different relative density was performed [12]. It was found that displacement amplitude for dry dense sand is less than of dry loose sand.…”

Section: Introductionmentioning

confidence: 99%

Vertical and Lateral Displacement Response of Foundation to Earthquake Loading

Al-Ameri

¹

,

Jawad

²

,

Fattah

³

2020

IJE

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“…rough the light compaction test, the maximum dry density ρ dmax of loess is 1.69 g/cm 3 , and the optimal moisture content ω op is 20.1%. e construction of building foundations and road subgrades often takes compactness as the standard of design and evaluation of engineering quality, so this test selects 0.96ρ dmax , 0.90ρ dmax , and 0.85ρ dmax for comparison of three dry densities, namely, 1.62 g/cm 3 , 1.52 g/ cm 3 , and 1.44 g/cm 3 . Loess taken from the construction site was air-dried, crushed, and passed through a 2 mm sieve.…”

Section: Test Materials and Sample Preparationmentioning

confidence: 99%

“…e dynamic modulus and damping ratio are the basis of foundation engineering seismic design, seismic stability evaluation, settlement prediction, and other works. Researchers also attach great importance to this research work and carry out a series of studies on various types of soil through field tests, indoor resonant column tests, dynamic triaxial tests, and dynamic torsional shear tests [1][2][3][4]. In actual engineering, dynamic loads such as earthquakes, traffic, waves, and other dynamic loads produce vertical dynamic stress and horizontal dynamic stress in foundation soil.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Dynamic Modulus and Damping Ratio of Compacted Loess under Circular Dynamic Stress Paths

Yang

¹

,

Shao

²

,

Zhi

³

2021

Advances in Civil Engineering

2

0

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Dynamic loads such as earthquakes and traffic will simultaneously generate vertical dynamic stress and horizontal shear stress in the foundation soil. When the vertical dynamic stress amplitude is twice the horizontal shear dynamic stress amplitude, and the phase difference between them is 90°, a circular dynamic stress path is formed in the τ z θ d ∼ σ zd − σ θ d / 2 stress coordinate system. To simulate the stress state of soil in the area of the circular dynamic stress path caused by bidirectional dynamic stress coupling, a series of tests of compacted loess under the action of a circular dynamic stress path were carried out using a hollow cylindrical torsion shear apparatus. The effects of the mean principal stress, dry density, and deviatoric stress ratio (the ratio of deviator stress to average principal stress) on the dynamic modulus and damping ratio of compacted loess were mainly studied. The test results show that, under the action of the circular dynamic stress path, the larger the mean principal stress is, the larger the dynamic compression modulus and dynamic shear modulus are. The dynamic compression modulus increases obviously with increasing dry density, but the dynamic shear modulus increases only slightly. When the deviator stress ratio increases from 0 to 0.4, the dynamic compression modulus and dynamic shear modulus increase to a certain extent. In addition, the greater the dry density and deviatoric stress ratio are, the greater the initial dynamic compression modulus and initial dynamic shear modulus of the compacted loess. The dynamic compression damping ratio of compacted loess increases with increasing mean principal stress, but the dynamic shear damping ratio decreases with increasing mean principal stress. Dry density basically has no effect on the dynamic compression damping ratio and dynamic shear damping ratio of compacted loess. When the dynamic strain exceeds 1%, the greater the deviatoric stress ratio is, the smaller the dynamic compression damping ratio and the dynamic shear damping ratio are. The research results can provide reference for the study of dynamic modulus and damping ratio of loess under special stress paths.

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Dynamic Response of Saturated Soil - Foundation System Acted upon by Vibration

Cited by 33 publications

References 6 publications

Liquefaction Potential of Sandy Soil from Small Laboratory Machine Foundation Model

Liquefaction Potential of Sandy Soil from Small Laboratory Machine Foundation Model

Vertical and Lateral Displacement Response of Foundation to Earthquake Loading

Experimental Study on the Dynamic Modulus and Damping Ratio of Compacted Loess under Circular Dynamic Stress Paths

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