Undrained shear and stiffness degradation of intact marine clay under monotonic and cyclic loading

Pan, Kun; Yuan, Zonghao; Zhao, Chao-Fa; Tong, Junhao; Yang, Z. X.

doi:10.1016/j.enggeo.2021.106502

Cited by 26 publications

(5 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Likewise, The G si,N of specimen J7-3 decreased with N from the 1 st stage, while that of specimens J7-4 and J12-1 decreased from the 2 nd and 3 rd stages, respectively. The decrease of G si , N with N can reflect the stiffness degradation of soils (Pan et al, 2021;Jin et al, 2022). Hence there is a cyclic threshold shear strain for stiffness degradation (g td ) of marine clays in the Yangtze estuary, that is, there exists a g td so that when g c < g td , there is no noticeable stiffness degradation and the microstructure of the soils hardly changes at this stage, and while g c > g td , the microstructure is destroyed causing the apparent stiffness degradation.…”

Section: Test Proceduresmentioning

confidence: 99%

“…earthquakes), they may suffer cyclic degradation, which will trigger stability problems of marine structures and reduce their service life. Hence the dynamic properties of marine clays under marine geology disasters have received extensive attention from the scientific and engineering communities (Fattah and Mustafa, 2016;Fattah et al, 2017;Yang et al, 2018;Zhu et al, 2020;Fattah et al, 2021;Pan et al, 2021;Jin et al, 2022;Lei et al, 2022;Tsai, 2022;Wu et al, 2023). The cyclic threshold shear strain for pore water pressure generation (g tp ) [when the cyclic shear strain amplitude (g c ) is below g tp , negligible pore water pressure generated, and while g c > g tp , pore water pressure accumulates significantly.]…”

mentioning

confidence: 99%

See 1 more Smart Citation

Cyclic threshold shear strain for pore water pressure generation and stiffness degradation in marine clays at Yangtze estuary

et al. 2023

View full text Add to dashboard Cite

Cyclic threshold shear strain is a fundamental property of saturated soils under cyclic loading. To investigate the cyclic threshold shear strain for pore water pressure generation (γtp) and stiffness degradation (γtd), a series of strain-controlled multistage undrained cyclic triaxial tests were carried out on in-situ saturated marine clay in the Yangtze estuary with different plasticity index Ip. The test results show that both γtp and γtd increase with increasing Ip, and γtp is larger than γtd for the same marine clay tested under the same conditions, with γtp = 0.017 ~ 0.019%, γtd = 0.008 ~ 0.012% for Ip of 17, γtp = 0.033 ~ 0.039%, γtd = 0.020 ~ 0.025% for Ip of 32, and γtp = 0.040 ~ 0.048%, γtd = 0.031 ~ 0.036% for Ip of 40. Moreover, the development of stiffness degradation may not necessarily require the generation of pore water pressure but can be aggravated by it. Furthermore, the γtp and γtd of marine clay are compared with terrestrial soils and marine clays cited from the published literature, the results indicate that the special marine sedimentary environment and the combined action of flow and tidal wave system cause the γtp and γtd of marine clay in the Yangtze estuary to be smaller than that of the terrestrial clays and marine clays in other sea areas.

show abstract

Section: Test Proceduresmentioning

confidence: 99%

mentioning

confidence: 99%

Cyclic threshold shear strain for pore water pressure generation and stiffness degradation in marine clays at Yangtze estuary

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Earthquakes are among the most destructive geological hazards, with the resulting ground motion characteristics being closely related to the dynamic parameters of the rock mass [1], including shear modulus [2] (modulus of elasticity) and damping ratio [3], which are essential for exploring the intrinsic connections between earthquakes and rock behavior. Shear modulus measures a rock mass's resistance to deformation under seismic forces, and this relationship is proportional; that is, a larger shear modulus indicates higher material stiffness [4][5][6]. Theoretical analyses indicate that seismic waves propagate with reduced energy attenuation in materials of higher stiffness, consequently increasing the amplitude of vertical ground fluctuations [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Damping and Stiffness Responses of Silica Rock under Constant Amplitude and Variable Rate Cyclic Loading

Wu,

Wang,

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

In this paper, the shear modulus and damping ratio of silica rock under cyclic loading were experimentally analyzed using two loading modes, constant amplitude and increasing amplitude, combined with three increasing loading rates. Observations have indicated a decrease in the shear modulus of specimens as the number of cycles increased during the loading and unloading phases and an overall increase with larger amplitude intervals. The change in loading rate significantly affects the damping ratio of the specimens, leading to a stepwise decrease within the same cyclic group, while the damping ratio of a single specimen exhibits a ‘concave’ distribution throughout the cyclic interval. Based on the axial strain and dissipation energy, this paper develops two damage models that can effectively predict the damage accumulation process in rocks under cyclic loading. These findings have significant implications for a deeper understanding of the mechanical behavior of rocks under dynamic loading and offer theoretical guidance and technical support for rock engineering.

show abstract

“…However, the lateral stiffness stopped degrading when the number of cyclic loadings was larger and showed the stability of the pile-soil system. An in-depth study of the shear strength, critical state, and cyclic response of highly compressible marine-phase soft clays was conducted by Pan et al [33]. Recently, some researchers have proposed a simple method to analyze the cyclic stiffness degradation of clay through numerical studies [34,35].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Mechanical Behavior of Skirt–Pile Foundations in Saturated Clay under Horizontal Load

Fan,

Duan,

Wang

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

Skirt–pile foundations have gained widespread attention in the field of offshore engineering due to their ease of installation and high bearing capacity. In this study, the ultimate bearing capacity, pile bending moment distribution and development, cumulative deformation characteristics, and cyclic stiffness development of skirt–pile foundations were investigated using physical model tests. The experimental results indicate that the ultimate bearing capacity and deformation resistance of the foundation can effectively be improved by increasing the skirt diameter. The cumulative deformation of the skirt–piles exhibited rapid development during the initial stages of cyclic loading, eventually stabilizing. Under long-term cyclic loading, the existence of the skirt can share the bending moment, which then affects the internal force distribution of the pile foundation along the axis. The pile foundation’s cyclic stiffness reduces as the loading cycles increase and increases as the skirt diameter and length grow. Meanwhile, the horizontal cyclic stiffness decreases as the number of cycles increases, stabilizing after 3000 cycles. This study can not only deepen the understanding of the deformation laws of skirt–pile foundations in clay soil but also offers some references for the design of offshore pile foundations.

show abstract

Undrained shear and stiffness degradation of intact marine clay under monotonic and cyclic loading

Cited by 26 publications

References 55 publications

Cyclic threshold shear strain for pore water pressure generation and stiffness degradation in marine clays at Yangtze estuary

Cyclic threshold shear strain for pore water pressure generation and stiffness degradation in marine clays at Yangtze estuary

Damping and Stiffness Responses of Silica Rock under Constant Amplitude and Variable Rate Cyclic Loading

Experimental Study on Mechanical Behavior of Skirt–Pile Foundations in Saturated Clay under Horizontal Load

Contact Info

Product

Resources

About