Soil-structure Interaction Research Articles

Investigation of torsion in asymmetric mid-rise structures on the pile-raft system considering soil-structure interaction

The adverse conditions of the soil such as soft soil can have seismic consequences that may either amplify seismic response or render the structure vulnerable. On one hand, the design and construction of asymmetric structures have become prevalent due to aesthetic considerations and structural space limitations. Studies indicate that structures with geometric irregularities are susceptible to seismic forces, leading to non-uniform distribution of floor drifts, excessive torsional behavior, and more, depending on the degree of irregularity. In this research, the main goal was to investigate the effect of soil and structure interaction on the torsion of asymmetric Mid-Rise Structures. To achieve this goal two asymmetric Steel moment frame system 15-story structures aim to address the effect of interaction between soil and structure on the seismic performance, one with a rigid base and the other with a flexible base, one with a rigid base and the other with a flexible base. To mitigate the settlement of soil-associated structures, a pile-raft system is employed, considering the softness of the soil. Additionally, to study the torsional behavior of these structures, their planes are asymmetrically designed in L-shape and C-shape configurations, subjected to four ground motion excitations in both far and near-field scenarios. Three-dimensional finite element numerical simulations are performed using Abaqus software. Various configurations of the pile-raft system for the asymmetric C-shape structure are examined to assess the effects of pile diameter and length on the torsional irregularity coefficient. The results show that the soil-structure interaction increases the maximum floor rotation angle, placing these structures in critical conditions concerning torsional irregularity under near-field and far-field seismic excitations.

Optimising synthetic datasets for machine learning-based prediction of building damage due to tunnelling

Assessment of tunnelling-induced building damage is a complex Soil-Structure Interaction (SSI) probelm, influenced by numerous geometric and material parameters of both the soil and structures, and is characterised by strong non-linear behaviour. Currently, there is a trend towards developing data-driven models using Machine Learning (ML) to capture this complex behaviour. Given the scarcity of real data, which typically comes from specific case studies, many researchers have turned to creating extensive synthetic datasets via sophisticated and validated numerical models like Finite Element Method (FEM). However, the development of these datasets and the training of advanced ML algorithms present significant challenges. poses significant challenges. Reliance solely on parameter domains and ranges derived from case studies can lead to imbalanced data distributions and subsequently poor performance of models in less populated regions. In this paper, we introduce a strategy for designing optimal high-confidence datasets through an iterative procedure. This process begins with a systematic literature review to determine the importance of parameters, their ranges, and dependencies as they pertain to building damage induced by SSI. Starting with several hundred FEM simulations, we generate an initial dataset and assess its quality and impact through Sensitivity Analysis (SA) studies, statistical modelling, and re-sampling in statistically significant regions. This evaluation allows us to refine the model’s input space, seeking scenarios that mitigate output distribution imbalances. The procedure is repeated until the datasets achieve a satisfactory balance for training metamodels, minimising bias effectively. Our findings highlight the success of this approach in identifying an optimal and feasible input space that significantly reduces imbalanced distributions of output features. This approach not only proves effective in our study but also offers a versatile methodology that could be adapted to other disciplines aiming to generate high-quality synthetic datasets.

Seismic evaluation of BRBF steel structures with L-shaped irregular plan considering soil-structure interaction

Seismic evaluation of BRBF steel structures with L-shaped irregular plan considering soil-structure interaction

Influence of soil‐structure interaction on the behavior of the tower‐foundation system of a horizontal‐axis wind turbine

AbstractThe ongoing advancement of wind turbines, aiming for taller towers to harness more intense winds, poses substantial structural challenges. Soil‐structure interaction (SSI) assumes fundamental importance, necessitating precise analysis, and mathematical modeling. This study focuses on examining how SSI influences horizontal‐axis wind turbine tower‐foundation systems. Six numerical models, varying from simplified to more complex representations, are created using the finite element method (FEM) in ANSYS software. The analysis reveals significant sensitivity to support conditions, particularly elastic supports, causing the greatest displacement at the tower's top (1.899 m), highlighting the substantial influence of SSI and second‐order effects. Incorporating SSI and second‐order effects results in a 30.11% increase in von Mises stress at the base flange (73.4 MPa), compared to models excluding these factors. Stress variation along the tower height notably increases with second‐order effects; however, the structure maintains a 13.32% safety margin relative to steel load‐bearing capacity. Foundation analyses indicate stresses exceeding concrete's allowable stress by 24.3%, underscoring the need for foundation optimization. These results stress the importance of considering SSI and geometric nonlinearity for wind turbine development. The lack of comparable studies in literature underscores the significance of this research in advancing the field's knowledge.

Validation and Parametric Study of a Soil–Structure Interaction Nonlinear Simplified Model

This paper established a numerical model for the structure system in a soil–structure interaction using MATLAB 23.2 and ANSYS 24.1 software and validated the effectiveness and accuracy of a simplified nonlinear calculation model for soil–structure interaction through the numerical simulation results. Meanwhile, a list of key parameters was identified according to their influence on the simplified model, including the free field area, site soil parameters, equivalent soil area, superstructure size and number of stories, and input seismic waves. On this basis, a series of parametric investigations were carried out with the validated simplified model, by varying the selected key parameters. The research findings demonstrated that the simplified calculation model exhibited excellent accuracy and efficiency, and was capable of reflecting the nonlinear response of the structural system. It is applicable to the field of dynamic response analysis of the superstructure, considering soil–structure interaction.

The role of the foundation flexibility on the seismic response of a modern tall building: Vertically incident plane waves

The soil-structure interaction (SSI) is an integral part of the seismic response of structures. The knowledge about its effects is based largely on numerical simulations involving simplified models. In this paper, we examine the consequence of several assumptions in SSI models of buildings, with emphasis on the rigid foundation assumption. To this end, we analyze several variants of a linear three-dimensional finite element model of the structure and soil corresponding to a uniquely instrumented 50-story skyscraper, with a basement on a pile foundation, located in southwest China. The models are excited by triaxial motion due to a vertically incident plane wave. The most realistic model (with basement and piles, both with bond contact with the soil), predicted an 8 % reduction of the apparent frequency and a 30 %–50 % increase in the apparent damping ratio of the 1st mode of vibration, relative to the model with fixed basement. The model with a rigid foundation (basement) embedded in the soil underestimated the reduction in apparent frequency by a factor of two. The SSI effects were the most pronounced for the model with flexible basement and no piles (16 %–19 % reduction in apparent frequency and 73 %–86 % increase in apparent damping ratio). The basement-structure interaction reduced the apparent frequency by 5 %–8 % depending on the direction. It is concluded that, for such a building, a detailed model of the structure and its foundation is needed to predict reliably the SSI effects.

Seismic mitigation performance of a periodic foundation for nuclear power structures considering soil-structure interactions

Periodic structures may be designed as periodic foundations to reduce the seismic response of engineering structures. The periodic foundation is more suitable for the seismic mitigation of nuclear power structures because of its wide attenuation domain. Based on the dispersion relationship of infinite periodic structures, this research constructs a one-dimensional layered periodic foundation using rubber and concrete materials, determines the attenuation domain frequency band gap that meets the seismic design requirements of nuclear power structures, and optimizes the raft design of nuclear power structures. At the same time, with the scarcity of bedrock sites, the site selection of nuclear power structures is inevitably shifted to soft rock sites. Therefore, this paper also considers the influence of the soil-structure interaction (SSI) on the seismic response of nuclear power structures. A three-dimensional finite element model of the nuclear power structure-periodic foundation-site system was established, and a detailed parameter analysis of the seismic performance of the periodic foundation of nuclear power structures considering the SSI effect was carried out. The results show that the seismic response of nuclear power structures can be significantly reduced by designing the attenuation domain of the periodic foundation.

Efficiency evaluation of single and double tuned mass dampers on building response reduction by considering soil-structure interaction

Efficiency evaluation of single and double tuned mass dampers on building response reduction by considering soil-structure interaction

Estimating Hardening Soil-Brick model parameters for sands based on CPTU tests and laboratory experimental evidence

The Hardening Soil-Brick model for soils is designed to carry out complex numerical analyses of soil-structure interaction problems taking into account strong stiffness variation in the range of small strains. However, to calibrate its parameters advanced triaxial and oedometric tests are required. In case of uncemented sands laboratory testing is usually difficult. Therefore, to facilitate calibration procedures, a CPTU based method, enhanced by an experimental evidence derived from advanced triaxial drained and oedometric tests, has been proposed and verified. It is shown in the paper that using exclusively the CPTU test results one can calibrate most important model parameters for sands with accuracy that is sufficient for solving real life problems. The major goal of this paper is to identify correlations between all reference stiffness moduli, then verify them, and finally link with the CPTU based identification procedures. It is shown in the paper that such correlations exist and they exhibit very high coefficients of determination. Moreover, as the seismic version of the CPTU test is not often available in the practice, an enhanced procedure for identification of very small strain shear stiffness modulus has been proposed and then verified, using set of the SCPTU tests conducted in Gdańsk sands (Poland).

A Review on Seismic Response Analysis Methods for Underground Structures

Seismic safety of underground structures is of paramount importance. This paper reviews the current research status of seismic response analysis methods for underground structures, focuses on the basic principles, advantages and disadvantages, and applicability of the proposed static method and dynamic time course analysis method. It also analyses their applications in engineering. It is shown that the seismic coefficient method, although simple, may have relatively large calculation errors due to oversimplification. The free-field deformation method is simple in form and easy to implement, but ignores soil-structure interaction. The flexibility coefficient method is simple in form and considers soil-structure interaction, but ignores many factors. The reaction displacement method directly reflects the soil-structure interaction, but the foundation spring parameters are difficult to value. The reaction acceleration method has the same advantages as the reaction displacement method, but there is a certain error. The dynamic time-course analysis method is accurate but computationally intensive.

Comparison between seismic analysis of twisting and regular 52-story towers considering soil-structure interaction

Comparison between seismic analysis of twisting and regular 52-story towers considering soil-structure interaction

Numerical investigation of the effects of soil-structure and granular material-structure interaction on the seismic response of a flat-bottom reinforced concrete silo

Numerical investigation of the effects of soil-structure and granular material-structure interaction on the seismic response of a flat-bottom reinforced concrete silo

An optimal design approach for steel space frames with T-stub semi-rigid connections considering soil-structure interaction

An optimization technique for designing the steel space frame with T-stub semi-rigid connections and interaction between soil and structure is presented in this article. A three-parameter-based elastic foundation model is utilized to investigate soil-structure interactions (SSI). To enable two-way data transfer for all optimization methods, computer software was developed using C# version 17.8.6, which connects to SAP2000-OAPI version 22. Particle swarm optimization (PSO) and teaching-learning-based optimization (TLBO) are employed for optimal designs. These optimization techniques choose profile sections from a list, including 64W discrete sections from the American Institute of Steel Construction (AISC). The Load and Resistance Factor Design-American Institute of Steel Construction (LRFD-AISC) strength constraints, geometric constraints, inter-storey drift constraints, and displacement constraints are considered during optimization. The first phase entails creating optimal designs for two unique steel space frames that consider SSI but do not include T-stub semi-rigid connections. Following that, the same optimization procedures are carried out with T-stub semi-rigid connections. The parameters needed for the foundation model are obtained through soil surface displacements. Utilizing T-stub semi-rigid connections while considering the interaction between the structure and the soil produces increased structural weight.

Influence of soil structure interaction on G + 11 storied RC frame against unconfined surface blast loads

All Nuclear power plants consist of several structures of varying importance that have to be designed for dynamic loading like earthquakes and impacts that they might be exposed to. Research on the influence of dynamic loading from blast events is still crucial to address to guarantee the general safety and integrity of nuclear plants. Conventional structural design approaches typically ignore the Soil-Structure Interaction (SSI) effect. However, studies show that the SSI effect is significant in structures exposed to dynamic loads such as wind and seismic loads. The present study is focused on evaluating the Soil-Structure Interaction effects on G + 11 storied reinforced concrete framed structure exposed to unconfined surface blast loads. The SSI effect for three flexible soil bases (i.e., Loose, Medium, and Dense) is evaluated by performing a Fast Non-linear (Time History) Analysis on a Two-Dimensional Finite Element Model developed in (Extended Three-Dimensional Analysis of Building System) ETABS software. Unconfined surface blast load of three different charge weights (i.e., 500 kg TNT, 1500 kg TNT, and 2500 kg TNT) at a standoff distance of 10 m are applied on the structure. Blast wave parameters are evaluated based on technical manual TM-5–1300. The blast response of the structure with and without the SSI effect is studied. It is concluded from this study that, there is a significant variation in dynamic response parameters of the structure with flexible soil bases compared to rigid or fixed base. For all magnitudes of surface blasts and soil base conditions, the ground floor is the most vulnerable floor against collapse. The study recommends measures to mitigate the damage due to unconfined surface blasts on multi-storey reinforced concrete structures.

A novel hybrid framework based on modified continued-fraction for pile-soil dynamic interaction of large-scale nuclear power structures

Accurate unbounded domain radiation damping and ground motion input in the near field are important for analyzing the dynamic safety of large-scale nuclear power structures (NPSs). The scaled boundary finite element method (SBFEM) can automatically satisfy the abovementioned radiation condition. However, owing to the coupling of time and space, conventional SBFEM is not competent to the analysis of large-scale structures. In this investigation, a novel coupled method is developed to improve the computational efficiency of unbounded domain dynamic stiffness using a modified continued-fraction technique. Furthermore, a set of systematic and efficient computational procedures for soil-structure interaction (SSI) are implemented based on parallel programming using a special preprocess. The proposed method is verified using three numerical examples, and another numerical application is analyzed for large-scale NPSs with a pile-raft foundation (PRF). The results show that the innovative method has wide engineering applicability with high numerical accuracy and stability, indicating that this method can be applied to the SSI dynamic seismic analysis of large-scale NPSs.

Response Mitigation of Building Isolated by Shape Memory Alloy Rubber Bearing Considering Soil Structure Interaction Effect

Response Mitigation of Building Isolated by Shape Memory Alloy Rubber Bearing Considering Soil Structure Interaction Effect

Derivation and Application of Analytical Coupling Loss Coefficient by Transfer Function in Soil–Building Vibration

Vibrations generated by railways may undergo amplification or reduction while traversing the foundations, floors, and spans of adjacent structures. This fluctuation in the vibration intensity, identified as a building’s coupling loss, is commonly considered in vibration forecasts through the utilization of universal frequency-independent adjustment parameters. This article employs a theoretical analytical approach to investigate the propagation characteristics of Rayleigh waves in elastic foundation soil, as well as the variations at the contact surface of buildings’ foundations. Analytical expressions for the coupling loss coefficient are derived to explore the displacement transfer relationship in the soil–structure interaction. To accurately and efficiently analyze the proposed buildings and site, the entire vibration propagation system is decoupled into substructure systems for independent analytical calculations. Theoretical analytical methods are utilized to obtain the displacement transfer functions between the soil and the structures through the refraction and transmission of waves. From a theoretical perspective, a thorough understanding of the interaction between soil and buildings is achieved. The influence of various variables related to railways and foundations on the building responses is analyzed. By comparing with measured data, the correctness of the analytical form of the coupling loss coefficient is validated, filling a gap in the literature due to the lack of analytical research on displacement transfer losses in soil–structure interactions.

Effect of tunnel-building separation distance on the dynamic soil-structure interaction response

Understanding how buried structures respond to cyclic loading is crucial for designing earthquake-resistant underground infrastructure. The complexity of the dynamic response of these underground structures is accentuated when accounting for their interaction with adjacent buildings. This study focuses on the impact of the lateral distance between a shallow rectangular tunnel and an adjacent residential structure on dynamic soil-structure interaction, employing two dynamic centrifuge tests. Particle Image Velocimetry technique was adopted to observe the developed mechanisms of liquefied soil deformation, tunnel uplift, and foundation settlement. Results show the pronounced effects on soil deformation above the tunnel crown with a reduction in the tunnel-building separation distance. The distribution of excess pore pressure along the tunnel lining will be presented. Tunnel manifested additional lateral movement and reduced uplift when the adjacent building was in close proximity. A decrease in the tunnel-building distance contributed to a reduction of building rotation, primarily due to the significant mitigation of non-uniform settlement under the footing. Overall, the soil deformation mechanism around the tunnel and the building will be shown to change depending on the separation distance between them.

Numerical simulation and parametric analysis on a shallow tunnel in liquefiable ground subject to multiple shakings

In active earthquake zones, it is very likely that the structures would experience multiple shakings in major seismic events. For underground structures, the soil-structure interactions and the resultant dynamic responses could vary significantly according to the characteristics of the shakings. In this paper, the scenario of a shallow tunnel in liquefiable ground subject to multiple shakings is studied. The OpenSees platform and the PM4Sand constitutive model are employed to construct a plane-strain numerical model, where a rectangular tunnel is buried in saturated Hostun sand. Its validity is verified by the data from a centrifuge test of four consecutive shakings. The numerical soil-structure system is then configured for further investigation on the subject matter. Firstly, the liquefaction-induced uplift is identified as the main threat to the integrity of the tunnel in a seismic event of multiple shakings. Then, the pertinent soil-structure interactions are intensely discussed in a parametric analysis considering the influences of the permeability coefficient, the tunnel self-weight, and the shaking sequence.

A 2D equivalent linear inversion model of bedrock motions in a layered transversely isotropic half-space

Inversion is the process that evaluates input motion on the bedrock from surface motions, primarily for use as input excitation for site seismic response or soil-structure interaction analyses. The paper presents a two-dimensional (2D) equivalent linear inversion model for bedrock motion in a multi-layered transversely isotropic (TI) half-space. Based on the exact dynamic stiffness matrices of TI soil layer and bedrock half-space, an inversion objective function is established from both horizontal and vertical surface acceleration records, and the optimization method is adopted to update the control parameters for the inversion process. Moreover, an equivalent linear method is used to account for the TI soil nonlinearity, thus realizing the nonlinear inversion for bedrock motion and incident angle. The inversion procedure is verified by using a single-layered TI soil profile model with three different materials. The numerical results demonstrate that the bedrock motion and the incident angle in the TI medium can be accurately inversed according to the surface motions and the TI site characteristics, indicating that the inversion method can be used for reliable engineering applications in the TI medium.