Dynamic Soil-structure Interaction Research Articles

Dynamic responses of reinforced concrete silo considering pile–soil‐structure–granular solid interaction

SummaryThe columned‐supported reinforced concrete silo models with different filling conditions considering soil‐structure dynamic interaction (SSI) are established based on the finite element program ANSYS to thoroughly investigate the complex interaction mechanism of the soil–pile–silo structure with granular solid. The dynamic characteristics and seismic responses of the SSI system and fixed‐base condition are analyzed and compared when the filling conditions are empty‐filled state, half‐filled state and full‐filled state. The numerical results reveal that the SSI effect reduces the seismic acceleration response of columned‐supported silos effectively. However, in terms of displacement, the SSI effect often amplifies the relative deformation of the supporting column and the cylindrical silos. Furthermore, the SSI effect often increases the relative dynamic lateral pressure of the storage material in the half‐filled silo condition. In the full‐filled silo condition, the relative dynamic lateral pressure at the top and bottom of the storage material is increased by the SSI effect; while it is decreased in the middle part of the granular solid, demonstrating that the SSI effect could change and increase the seismic responses of the silo structure in certain areas. Therefore, the investigation provides a comprehensive insight into the interaction mechanism of the pile–soil–silo structure with different filling conditions.

Effect of Soil-Structure Interaction on the Response of Machine Foundation Subjected to Seismic Loading: A Review Study

This review provides a detailed look at the current knowledge and approaches related to Dynamic Soil-Structure Interaction (DSSI) in machine foundation design, focusing on its substantial impact on seismic response and structural stability. The significance of this interaction in structural design, especially in areas prone to seismic activity, is pivotal. The paper begins by exploring various modeling methods, like the Finite Element Method (FEM), highlighting their importance in understanding the intricate aspects of DSSI, such as energy loss and interface behavior. It is evident from the studies that FEM is particularly effective in analyzing settlement under reciprocating loads. Soil-structure interaction (SSI) is a complex phenomenon that can positively and negatively affect the seismic performance of machine foundations. Several factors, including embedment depth, soil stiffness, and foundation properties, govern the influence of SSI. This review discusses the dual nature of SSI and highlights the importance of considering the interaction between soil properties, foundation design, seismic loads, and interaction effects. In addition, it identifies the limitations of the current research and advocates for more accurate and inclusive models and extensive empirical studies to address real-world complexities and uncertainties. In conclusion, this review offers crucial insights and foundational knowledge for future innovative design solutions and advanced research methodologies and significantly contributes to developing resilient and reliable structural designs in seismic-prone regions. The emphasis is on the need for more nuanced and comprehensive studies to further the understanding and application of DSSI in machine foundation design.  

On the Numerical Investigation of the Absorbing Boundaries Influence to the Dynamic Soil Structure Interaction

On the Numerical Investigation of the Absorbing Boundaries Influence to the Dynamic Soil Structure Interaction

Importance of higher modes for dynamic soil structure interaction of monopile‐supported offshore wind turbines

AbstractOffshore wind turbines (OWTs) have emerged as one of the most sustainable and renewable sources of energy. The size of OWTs has been increasing, which creates more challenges in the design of foundations due to the potential higher‐mode effects involved in the dynamic soil‐structure interaction (DSSI) response. Several foundation modeling techniques are available for calculating the OWT fundamental frequency; however, their capability to predict the higher modes by considering real geometric configurations is unclear. The main aim of this study is to perform a rigorous modal analysis of the NREL 5MW reference OWT to investigate the higher mode effects using the 3D finite element method. A detailed parametric analysis is also performed to study the effects of soil inhomogeneity, initial soil modulus, and the monopile dimensions (diameter, thickness, and embedded pile depth) on higher modes' natural frequencies and effective mass participation ratios. The study shows that dynamic soil‐structure interaction has a significant role in modal response and the simplified foundation models are not accurate enough. Given the significant contribution from higher modes, they should not be simply ignored in the OWT design, particularly in earthquake‐prone zones.

Dynamic soil–structure interaction of a three-span railway bridge subject to high-speed train passage

In this study, the influence of Soil-Structure Interaction (SSI) on the dynamic behavior of a three-span concrete slab railway bridge with integrated retaining walls is investigated. The bridge is subjected to controlled excitations using a hydraulic actuator with different frequencies and load amplitudes. A 3D model of the railway bridge-soil system is implemented and calibrated using the experimental frequency response functions at each sensor location. A soil-free model is also created to compare with the calibrated model. It is observed that the dynamic behavior of the railway bridge is substantially altered by the presence of the surrounding soils, and neglecting SSI can lead to underestimation and inaccurate results. Additionally, the calibrated model is used for further train-passage analyses. For the studied bridge, neglecting SSI increases the maximum acceleration response of the bridge during high-speed train passages from 5.5 m/s2 up to 14.5 m/s2. It is also shown that the response of the bridge during train passage is predominantly influenced by its first bending mode, with higher modes inducing no discernible effect. Finally, parametric studies are performed in order to study the uncertainties related to the soil properties.

Large‐scale seismic soil–structure interaction analysis via efficient finite element modeling and multi‐GPU parallel explicit algorithm

AbstractAs urban population increases, integrated underground–aboveground complexes are being constructed at growing paces in major cities. The seismic analysis of such complexes is crucial for the safety and functionality in the threat of potential earthquake disasters. However, fine‐grained numerical modeling and analysis of such large and complex structures are still inefficient due to the consideration of the soil–structure interaction (SSI). To address this challenge, an efficient approach for numerical modeling of large‐scale seismic SSI analysis is presented in this paper to overcome the limitations of existing finite element analysis (FEA) software. Moreover, a multi‐graphic processing unit (GPU) parallel explicit algorithm is implemented for the nonlinear dynamic SSI problems to further increase the computational efficiency. A large underground–aboveground complex project in China is used as an example to demonstrate the capability of the integrated method. The accuracy and reliability of the multi‐GPU parallel explicit finite element algorithm for SSI analysis (GFEA‐SSIA) are verified through a comparative analysis of the linear‐elastic and nonlinear dynamic response of the building calculated by GFEA‐SSIA and common FEA software. Finally, the structural response and structural damage of the underground–aboveground complex are analyzed under multidirectional seismic motions, and the damage distributions of the structures are provided.

Implementation and verification of direct infinite elements in axisymmetric problems

In the field of dynamic soil-structure interaction, the simulation of geotechnical massifs under non-vanishing time-averaged loads is often challenging, depending on factors such as load variations, the 3D model representation and the chosen model boundaries. This study aims to evaluate the effectiveness of the method developed recently by the authors under non-vanishing time-averaged loads. The evaluation involves comparing the results of a homogeneous axisymmetric model at two control points and the simulation of an axisymmetric bilayer. The aim is to demonstrate the robustness of the method in contrast to widely used dissipative devices in scenarios involving sudden loading. Using an implicit integration scheme in the time domain, the method is shown to be effective and correlations with reliable solutions and comparisons with common dissipative devices for sudden-load models are presented. This analysis leads to the conclusion that the proposed procedure adeptly addresses the challenges associated with the simulation of geotechnical masses under non-vanishing time-averaged loads.

A State-of-the-Art Review on Computational Modeling of Dynamic Soil–Structure Interaction in Crash Test Simulations

The use of nonlinear, large-deformation, dynamic finite element analysis (FEA) has become a cornerstone in crash test simulations, playing a pivotal role in evaluating the safety performance of critical civil infrastructures, including soil-embedded vehicle barrier systems. This review paper offers a detailed examination of numerical modeling methodologies employed for simulating dynamic soil–structure interactions in crash test simulations, with a particular focus on dynamic impact pile–soil interaction. This interaction is a critical determinant in assessing the effectiveness of soil-embedded barrier systems during vehicular impacts. Our extensive review methodically categorizes and critically evaluates four prevalent modeling methodologies: the lumped parameter method, the subgrade reaction method, the modified subgrade reaction approach, and the direct or mesh-based continuum method. We explore each methodology’s underlying philosophy, strengths, and shortcomings in accurately simulating the dynamic interaction between soil and piles under impact loading. This technical review aims to provide a thorough understanding of the critical and distinctive aspects of modeling soil’s dynamic responses under impact loading conditions. Moreover, this paper is envisioned to serve as a foundational reference for future research endeavors, steering the advancement of innovative simulation techniques for tackling the dynamic impact soil–structure interaction problem.

Assessment of liquefaction effects on dynamic soil-structure interaction for the 1908 Messina and Reggio Calabria scenario earthquake

Earthquake-induced liquefaction can significantly modify the dynamic response of a soil deposit and interacting structures. In this study, dynamic soil-structure interaction analyses have been performed for a strategic building resting on liquefiable soil. The structure, located in the city of Messina (Sicily, Italy), was built after the strong earthquake of 1908 that caused severe ground shaking and also liquefaction phenomena. Numerical analyses have been conducted with the finite element code PLAXIS3D that adopts the UBC3D-PLM model to simulate the seismic response of liquefiable soils. The advanced UBC3D-PLM model has been calibrated by means of the simulation of cyclic direct simple shear tests (CDSS) using PLAXIS3D software. The seismic behaviour of the soil-structure system on liquefiable soil has been analysed in terms of liquefaction potential, accelerations, response spectra and displacements under three seismograms of the 1908 earthquake. Findings of this study can be of great significance and interest for the prevention and mitigation of seismic liquefaction hazards in areas with high seismic risk.

Dynamic soil-structure interaction analysis for base-isolated nuclear island building based on the method of external source wave motion

Soil-structure interaction (SSI) is crucial to the dynamic response of nuclear power plants (NPPs), and should be properly considered when analysing the seismic isolation performance of base-isolated NPPs. In this study, a three-dimensional numerical simulation program is developed for the time-domain dynamic analysis of base-isolated NPPs considering SSI effects. The seismic input is realised using the method of external source wave motion, and the nonlinear behavior of isolators is fully considered. Using this program, the SSI effects of the base-isolated nuclear island building under different sites are analysed and compared, including the acceleration, displacement, and floor response spectra. The numerical results show that the SSI effects change the spectral characteristics of the actual seismic input. When the shear wave velocity of the site is relatively large, the SSI effects can increase the dynamic response of base-isolated NPPs. Additionally, the isolation performance of the base-isolated NPPs is weakened when SSI effects are considered, and with a decrease in the shear wave velocity of the site, the isolation capacity is further reduced. The influence of the SSI effects should be fully considered in the base isolation design of NPPs.

Seismic fragility analysis of subway station structure subjected to sequence-type ground motions

As a critical urban infrastructure, the subway station damaged in an earthquake not only leads to interruption of underground transportation, but may also result in serious casualties and economic losses. The current seismic design of underground structures only considers the mainshock effects but ignores the potential hazards of aftershocks. However, most mainshocks are often followed by aftershocks in a short period of time. In the past earthquakes, it was reported that the mainshock-damaged engineering structures suffered more serious structural damage and even complete collapse when subjected to aftershocks before restoration. This paper proposes a framework for the development of seismic fragility curves of underground structures subjected to sequence-type ground motions. Finite element models of a two-story, three-span subway station considering nonlinear dynamic soil-structure interaction (SSI) was established in this study. A comprehensive assessment of the seismic performance of the subway station structure under the sequence-type ground motions was conducted on the SSI model. Both the mainshock-aftershock fragility analysis of the intact structure and the aftershock fragility analysis of the mainshock-damaged structures were performed by combining the traditional seismic probability demand model and the back-to-back mainshock-aftershock probability demand model. The numerical results indicated that the impact of aftershocks on the seismic performance of subway station structures cannot be ignored. The aftershock fragility of the structure is highly dependent on the mainshock-damaged state. The failure probability of a severely mainshock-damaged subway station structure is much higher in the aftershocks than structures in other damage states. Besides, the probability of the mainshock-damaged structure transferring to a more severe level of damage state increases with the increase of the intensity of aftershock motions. For the subway station under sequence-type ground motions, the transition probability of one severer level of damage state is greater than 40 % for the 1.0 g peak ground acceleration of aftershocks and the transition probability of more than two severer level of damage state is less than 10 %.

Equivalent fundamental period of bridge piers on caisson foundations from dynamic centrifuge testing

Dynamic soil-structure interaction is typically decomposed in kinematic and inertial effects. Inertial interaction generally results in an increase in the fundamental period and damping of the system, which, for slender structures, corresponds to a decrease of the inertial forces transmitted to the superstructure. Relations to estimate the period increase are mainly available in the literature for shallow foundations.In this paper, the fundamental period of bridge piers on compliant caisson foundations was obtained from dynamic centrifuge tests. A rigid and a flexible bridge pier were subjected to trains of sinusoidal waves and real ground motions. The interpretation of the experimental results permitted to (i) evaluate the increase of period with respect to fixed-base conditions; (ii) assess the dependency of the compliant-base period on the motion intensity. The second aspect sheds light on the role played by non-linearity of soil behaviour and emphasises the importance of performing preliminary soil response analyses.

Variable cross-sectional effect on bi-directional blades–tower–soil–structure dynamic interaction on offshore wind turbine subject to wind–wave loads

BackgroundThis study introduces a numerical model designed to simulate interactions occurring between a wind turbine's tower and the surrounding soil, as well as between the nacelle, blades, and the surrounding environment. This simulation accounts for both fore–aft and side-to-side movements. To describe these interactions, the model leverages the Euler–Lagrange equations. It calculates wave loads utilizing the Morison equation, with wave data generated based on the JONSWAP spectrum. Furthermore, aerodynamic loads are determined using the blade element moment theory, and the wind spectrum is generated using the Von Karman turbulence model. The tower is represented as a variable cross-sectional beam, employing a two-noded Euler beam element with two degrees of freedom: transverse displacement and rotation, and utilizing Hermite polynomial shape functions.ResultsIn a comparative analysis against experimental data, this modified model demonstrates significant enhancements in accurately reproducing the dynamic behavior of wind turbines with variable cross-sectional towers, outperforming models that approximate the tower with a constant cross section. Our findings reveal that the modified model achieves a remarkable improvement of 15% in replicating the tower's dynamic response when compared to the constant cross-sectional models. As a case study, a 5 MW monopile wind turbine with a flexible foundation, specifically the one provided by the National Renewable Energy Laboratory (NREL), is employed to simulate its dynamic response.ConclusionsThis research presents a robust numerical model for simulating wind turbine behavior in various environmental conditions. The incorporation of variable cross-sectional tower representation significantly improves the model's accuracy, making it a valuable tool for assessing wind turbine dynamics. The study's findings highlight the importance of considering tower flexibility in wind turbine simulations to enhance their real-world applicability.

Thermodynamically consistent effective stress formulation for unsaturated soils across a wide range of soil saturation

We outline an extension of Biot’s theory of dynamic wave propagation in fluid-saturated media, which can be used to model dynamic soil-structure interaction in frictionless conditions across a wide range of soil saturation levels. In this regard, we present a comprehensive analysis of experimental evidence, the thermodynamic, and the theoretical basis of using the degree of saturation as Bishop’s parameter in unsaturated soils. The analysis highlights the limitations of using this parameter to accurately model unsaturated soil behaviour, particularly as the soil approaches dryness. Based on the analysis, a new definition of effective stress is proposed, and the associated work-conjugate pairs are identified. Recommendations are made for constitutive modelling using the new definition of effective stress. Finally, we introduce a fully coupled finite element contact model that utilises the new effective stress definition. Through numerical examples, we demonstrate the model’s capability to control the vanishing capillary effect on soil-structure interaction as the soil dries.

The effect of foundation–soil–foundation interaction on the response of continuous, multi-span railway bridges

This paper focuses on the effect of dynamic soil–structure interaction (SSI), including foundation–soil–foundation interaction (FSFI), on the dynamic response of multi-span railway bridges, which constitute an important part of high-speed rail networks around the world. We consider an infinitely long box girder bridge on piled foundations and use periodic structure theory to restrict the computational domain to a reference cell. The superstructure is modeled with finite elements, while a periodic finite element-boundary element (FE-BE) model is used to compute the dynamic stiffness of the piled foundation, taking into account FSFI. It is demonstrated that (1) the natural frequencies of the in-phase torsional and bending modes are significantly lowered due to the flexibility of the foundation–soil system; (2) the effect of FSFI on the bridge response is limited for typical span lengths and soil stiffness; and (3) the peak bridge deck acceleration is lower if SSI is taken into account, as is the resonant train speed.

Time-domain deconvolution procedure for elastoplastic materials: Application to the Treasure Island site during the 1989 Loma Prieta earthquake

When dynamic soil-structure interaction (DSSI) analyses are performed, e.g. using the finite element (FE) method, the input signal is required at the base of the model. Nevertheless, acceleration records are usually available at the surface and, therefore, the desired motion must be deconvolved to the base. The latter is usually performed through the solution of one-dimensional propagation of shear waves in an elastic medium, in the frequency domain. Herein, nonlinear behavior is generally incorporated through the equivalent-linear method, by iteratively reducing the stiffness and increasing the critical damping ratio as a function of the maximum strains attained in each iteration. However, if complex material models are adopted to characterize the soil, the input motion derived with the equivalent linear method will not be compatible due to the simplified approach used to represent the nonlinear behavior. In this article, the use of a procedure to perform a time-domain deconvolution in non-linear elastoplastic materials is demonstrated. The goal is to generate input accelerograms at the base of a FE model to perform DSSI analyses. The procedure is based on the iterative modification of the motion at the base according to the relative differences between the propagated and target surface spectra. To illustrate the use of the methodology, it was applied to a FE model of the Treasure Island site (San Francisco, US), to derive the required motion at the base from a record of the Loma Prieta earthquake.•This article provides a useful guideline to optimize the use of the deconvolution procedure to derive input motions for dynamic FE analyses considering nonlinear elastoplastic materials.

Seismic Response of High-Rise Frame–Shear Wall Buildings under the Influence of Dynamic Soil–Structure Interaction

Seismic Response of High-Rise Frame–Shear Wall Buildings under the Influence of Dynamic Soil–Structure Interaction

Study on the Seismic Response Characteristics of Shield Tunnels with Different General Segment Assembly Methods and Widths

Shield tunnels assembled with general ring segments are widely used in urban areas. Segment assembly methods and widths cause changes in the mechanical properties of the structure and influence the seismic response of shield tunnels. To investigate the influence of the assembly method and width of the general ring segment on the seismic performance of a shield tunnel, a three-dimensional refined soil–structure dynamic interaction finite element model of the shield tunnel was established based on ABAQUS, and the mechanical response and joint deformation of the general ring lining under seismic loads were studied. The simulation results show the following: (i) The overall deformation of the tunnel lining is not significantly affected by the assembly method, and the difference is only 5.24% under a 0.4 g earthquake. (ii) The seismic responses of general ring tunnels with different assembly methods are quite different, and the mechanical properties of the shield tunnel assembled with the straight assembly method are better than those of the shield tunnel assembled with staggered joints, but the deformation of the structure is larger. Under the action of a 0.1 g earthquake, the radial force, circumferential force, and bending moment of the staggered 90° assembly tunnel are respectively reduced by 13.6%, 11.1%, and 17.8% compared with the staggered 45° assembly structure, but the maximum intra-opening deformation increases by 0.19, 0.58, and 2.4 mm, respectively. (iii) The internal force distribution of the bolts is controlled by the deformation of the joint; compared with the CF90 and TF assembled tunnels, the mechanical properties and deformation characteristics of the CF45 and CF90 assembled tunnels are more reasonable. (iv) The extrados and intrados joint opening deformation and shear dislocation of the 1.2 m wide general ring segment under the staggered assembly increase by 1.2 mm and 1.03 mm, respectively, compared with the 1.5 m wide segment, while the radial force, circumferential force, and bending moment are reduced by 24.4%, 36.5%, and 41.7%, respectively, indicating that the seismic performance of the shield tunnel with a segment width of 1.5 m is better than that of the shield tunnel with a width of 1.2 m.

Dynamic Soil-Structure Interaction of Multi-Story Buildings using the Finite Element Method and Minimax Probability Machine Regression

Soil-Structure Interaction (SSI) issues are some of the most critical problems encountered in the design of structures prone to earthquake shaking. The damage caused by an earthquake mainly depends on the interaction between soil and structure. In this study, the effect of dynamic SSI on a multi-story building is examined using two methods, Finite Element Method (FEM) and Minimax Probability Machine Regression (MPMR). The MPMR was used to develop a model based on the input and output database generated from the FEM model. The performance comparison of these two models shows a good correlation. The MPMR model significantly reduced the computational time and can thus be utilized as a substitute for determining the response quantities.

EFFECTS OF NEAR-FAULT ON DYNAMIC RESPONSE OF A STRUCTURE EXCITED BY EARTHQUAKE WAVES

The goal of this study is to concentrate on the near-fault effects on the structure behavior of underground excitation. To figure out the exact behavior of the structure, a simple model is chosen. During the solution process, dynamic soil-structure interaction is taken into account. The physics of the problem is very complicated owing to the reflection of the waves from the free surface and fault boundary, and the scattering of the waves from the foundation and transmission of the energy into the structure. The materials of the soil and the structure are considered as homogeneous and isotropic, and the foundation is assumed as a rigid body. Response of the structure in the frequency domain is derived using Wave Function Expansion Method and Image Method. Numerical results show that when the structure approaches the fault, the amplitudes of the foundation and relative displacements of the structure are getting bigger. The incident angles of the waves have a big influence on the response of the structure close to the fault, therefore the standard design code should not be applied in the analysis of the structures. It is concluded that near-fault effects should be considered carefully.