Article
Chemistry, Multidisciplinary
Pan Gao, Shuai Yuan, Jinghao Chen, Mingjie Li
Summary: This paper proposes a numerical model with a Coupled Eulerian-Lagrangian approach to study spudcan penetration into sand overlying clay. The model is verified and it is found that stress-dependence and strain-softening effects dominate shallow and deep penetrations, respectively.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Marine
Shujin Zhou, Mi Zhou, Yinghui Tian, Xihong Zhang
Summary: In this study, a large deformation finite-element (LDFE) model is established to investigate the penetration behavior of helical piles, considering the strain rate effect and strain softening effect in soil. The numerical model is validated by comparing with centrifuge results. Parametric studies show that the penetration behavior of helical piles is significantly influenced by the strain rate and strain softening of soil. The theoretical model for predicting torque requirements is extended to account for the strain rate and strain softening effect.
Article
Engineering, Ocean
Lindong Fan, Pan Gao, Fei Wang, Menglan Duan
Summary: This study investigates the penetration process of large scale rectangular spudcans in clay using centrifuge experiments and finite element analysis. The back-flow sequence of soil near the spudcan is affected by geometric characteristics, and a new equation for predicting the stable cavity depth is proposed for engineering applications. The conclusions of the study provide theoretical support for the application of rectangular spudcans.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Marine
Teng Ma, Zhong Xiao, Wei Zhang, Pan Hu, Xian Wei
Summary: This study investigates the influence of the external beveled tip angle on the soil plug, soil softening, and penetration resistance of a bucket foundation in clay. By using the Coupled Eulerian-Lagrangian approach, the study establishes penetration resistance models for the bucket foundation considering soil large deformation and strain softening. The results show that increasing the angle of the external beveled tip reduces the soil plug height and the degree of softening inside the bucket, while increasing the soil amount and the coefficient of the outer side wall. However, the overall penetration resistance of the bucket foundation remains unchanged.
Article
Computer Science, Interdisciplinary Applications
Chunlei Li, Long Yu, Xianjing Kong, Heyue Zhang
Summary: This study simulated the continuous penetration of a spherical penetrometer (ball) into softening and rate-dependent soil, revealing three stages from shallow failure mechanism to deep flow-round mechanism. The effects of strain rate and softening parameters on the failure mechanism and the evolved bearing factor profile were investigated. The dimensionless soil strength sum /gamma ' D and the frictional condition of the soil-ball interface were explored as well. Empirical formulas were developed to estimate the critical depths of the ball penetration test. A practical interpretation framework, incorporating the effects of strain rate and softening, was developed to assess the soil undrained shear strength using the ball penetrometer.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Ocean
Chunlei Li, Long Yu, Xianjing Kong, Yunrui Han
Summary: Pipe-soil interaction is crucial for deep-water pipeline systems as it affects their structural behavior and integrity. The pipe embedment plays a significant role in determining the boundary conditions and subsequently influencing the pipe-soil interaction. In this study, a robust finite-element model using the Remeshing and Interpolation Technique with Small Strain (RITSS) method was developed for vertical penetration of pipelines in clay. The model discussed the development mechanism of soil shear bands during pipeline penetration and explored the effects of pipeline roughness on shear strength degradation and enhancement. Parametric analysis also examined the effects of soil buoyancy, soil strength gradient, strain softening, and strain rate on penetration resistance. A validated evaluation framework for penetration resistance was developed based on the sensitivity of each parameter, which can provide valuable guidance for designing vertical penetration of pipelines in deep-water engineering.
APPLIED OCEAN RESEARCH
(2023)
Article
Engineering, Marine
Yifei Fan, Jianhua Wang, Shilun Feng
Summary: This study proposes a new method for analyzing pile group interactions that can evaluate the effect of spudcan penetration, based on the modified Poulos method commonly used in ocean engineering practices. The method calculates additional pile head deflection induced by pile group interaction through elastic analysis and nonlinear foundation beam method, with the Y multiplier indicating the impact of spudcan penetration on pile group interaction. Predicted results were validated against centrifuge model tests and numerical simulations.
Article
Construction & Building Technology
Wonjun Shin, Hwisan Park, Jihoon Han
Summary: The study proposes a modified concrete material model that accurately represents the dynamic response and fracture behavior of concrete by considering strain rate-dependent parameters. The model is validated by comparing the numerical simulations with experimental results, showing good agreement.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Ocean
Yifei Fan, Jianhua Wang
Summary: A method is developed to calculate the response of piles subjected to spudcan penetration-induced load near adjacent jacket platforms. Centrifuge model tests are conducted to verify the validity of the proposed method. The study finds that factors such as rotation stiffness at the pile head, lateral pile head load direction, and spudcan-pile clearance size affect the penetration effect of spudcans.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Marine
Kailin Ding, Shuntao Fan, Sheng Dong
Summary: The bearing capacity of spudcan foundations under various loading conditions, including vertical, horizontal, and moment loading, must be effectively assessed before the operation of jack-up platforms. However, limited studies have focused on the combined loading effects of spudcan foundations in soft-over-stiff clays, considering the influence of installation processes. This study utilizes two-dimensional remeshing and interpolation with small strain method for simulating large deformations during spudcan installation and employs a three-dimensional model for small strain analysis of bearing capacity.
Article
Engineering, Ocean
Shujin Zhou, Mi Zhou, Yinghui Tian, Xihong Zhang
Summary: In this study, a numerical model is established to investigate the soil flow mechanism of caissons with pad-eye stiffeners. The soil strain softening effect is considered. The study finds that the soil failure mechanisms and penetration resistances of locally stiffened caissons at the pad-eye are significantly different from unstiffened caissons or caissons with interval rings. A simplified flow mechanism is proposed and approximating expressions are derived for predicting the penetration resistance of the caisson.
APPLIED OCEAN RESEARCH
(2022)
Article
Engineering, Geological
Mi Zhou, Shujin Zhou, Xihong Zhang, Yinghui Tian
Summary: This study utilized LDFE analyses to investigate the impact of spudcan penetration on an adjacent skirted foundation. It was concluded that the behavior of the impacted skirt is closely related to soil flow mechanisms around the skirted foundation induced by spudcan penetration. The clearance distance between the spudcan and the skirt was identified as the key factor. Approximating expressions for estimating the maximum rotation of the skirt during spudcan penetration were proposed based on intensive numerical modeling results.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Hang Zhou, Hanlong Liu, Zengliang Wang, Longyong Tong
Summary: This paper incorporates the rate-dependent and strain-softening behaviors of clay into a theoretical framework based on cavity expansion, using the modified Tresca model proposed by Einav and Randolph. By simplifying the models and conducting parametric analyses, closed-form solutions for cavity expansion responses were obtained, demonstrating relatively accurate results compared to numerical integration solutions. This study provides insights into the influence of rate dependency and strain softening on the cone penetration test results, allowing for a modified expression of the cone penetration resistance factor to capture clay properties more appropriately.
JOURNAL OF ENGINEERING MECHANICS
(2021)
Article
Engineering, Geological
Nurhan Ecemis, Mustafa Sezer Arik, Hazal Taneri
Summary: The influence of drainage conditions on cone penetration test (CPT) resistance and excess pore pressure in sand and silty sand was investigated through field and physical model tests. Drainage is possible in saturated clean sand and silty sand under certain conditions. The effect of drainage conditions on CPT resistance and pore pressure was explained in terms of the coefficient of consolidation (c(h)) and penetration rate (v). The physical model tests showed that excess pore pressure and its dissipation rate significantly affect cone resistance, depending on the coefficient of consolidation and penetration rate. For the same relative density, normalized CPT resistance decreases with a decrease in c(h) or an increase in penetration rate. The difference in CPT resistance in silty sand is attributed to drainage conditions. A drainage equation for excess pore water pressure and CPT resistance was developed based on the results from this study and field test data reported in the literature.
Article
Engineering, Industrial
Hongchun Shang, Pengfei Wu, Yanshan Lou, Jizhen Wang, Qiang Chen
Summary: This research characterizes and models the dynamic hardening behavior of an aluminum alloy under the coupling effect of strain rate and temperature. The study shows that the ANN model accurately predicts the behavior with high accuracy and better computational efficiency compared to other models.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
