Soil-structure Interaction Response Research Articles

A comprehensive numerical analysis of EQ-induced lateral earth pressure on structures basement walls

Due to soil-structure interaction, dynamic lateral earth pressures on building embedded walls affect the dynamic performance of the building. Classic relations such as Mononobe-Okabe (M − O) and Seed & Withman (S–W) are applied to determine these dynamic lateral earth pressures in conventional design methods. Considering these relations' assumptions and their neglect of soil-structure interactions during an earthquake, using these relations may result in erroneous and inaccurate estimation of dynamic earth pressure. This paper attempts to understand this phenomenon better and estimate dynamic earth pressure on basement walls. Structure and soil mass are simulated simultaneously, using numerical models. Numerical (finite element) dynamic analyses are carried out for qualitative and quantitative evaluation of dynamic earth pressures on buildings with basements. Different excavation depths, ground topography, geotechnical parameters, and building stories above ground have been considered in these analyses. Finally, the soil-structure interaction response has been discussed using the obtained results, and approximate relations are derived to estimate the dynamic earth pressure.

Soil-structure interaction response considering drift analysis due to three orthogonal components of near-field ground motions

Soil-structure interaction analysis is one of the most challenging problems in the field of structural engineering. In this paper, two aspects less discussed in the literature, namely: (ⅰ) the effect of considering all three components of near-field earthquake excitations instead of just one horizontal component, and (ⅱ) elimination of the part of inter-story drifts caused by the foundation rocking, have been investigated. Theoretical aspects of both phenomena have been considered, and useful considerations have been proposed. To provide a more comprehensive description of the suggested modifications, the seismic behavior of a 15-story steel moment-resisting frame building subjected to four near-field earthquake excitations has been studied. To that end, 3D nonlinear time-history analysis was conducted using ABAQUS finite element software. The structure is supported by a shallow raft foundation on soft-clayey soil. The results indicate that the two mentioned points are of prime importance and should be considered in the soil-structure interaction analysis due to near-field excitations to evaluate the seismic structural responses more accurately.

Sensitivity Analysis of Uncertain Material RC Structure and Soil Parameters on Seismic Response of Soil-Structure Interaction Systems

In seismic performance based design context, engineers are faced to a difficult task to estimate the response of soil-structure interaction (SSI) systems. To accomplish this task successfully, all sources of random and epistemic uncertainties should be taken into account. However, the uncertain parameters have not the same influence on the model response; a sensitivity analysis is therefore required. This article treats the two following aspects: the first one is to perform a sensitivity analysis on all the parameters in order to study their influence on the structural response. The uncertainties effect is done by studying the sensitivity of the maximum structure displacement towards the used materials parameters variation (fc’, εc0, εcu, Es, fsy, α, εsu, A, ξ) and soil properties (ξg, ν) on the SSI seismic response. This study consists of determining, quantifying and analyzing how the outputs of the N2-SSI model are affected by input variables fluctuations. The second aspect is analysing the SSI system response by considering the correlation between the parameters (shear wave velocity and soil damping) and the influence of the lack knowledge of the uncertainties due to this correlation. The results of the sensitivity analysis indicate that the response of the structure is very sensitive to the concrete and steel parameters for larger values of the shear wave velocity. While, the soil damping and Poisson's ratio in the case of soil with shear wave velocity of 90 m/s, are the main inputs with the greatest influence on the maximum displacement output.

Soil Structure Interaction in High-Rise Buildings for Dynamic Loads

Soil-structure interaction(SSI) analysis is the study of the dynamic response of a structure as influenced by the interaction with the surrounding soil. The SSI response is sensitive to the characteristics of the soil, structures, and ground motion, as well as the depth of embedment. The concept of soil-structure interaction was introduced , and the research methods were discussed. This report presents a synthetic of the body of knowledge contained in SSI literature, which has been distilled into a concise narrative and harmonized under a consistent set of variables and units. Specific techniques are described by which SSI phenomena can be simulated in engineering practice, and recommendations for modeling seismic soil-structure interaction effects on building structures are provided. An attempt was made to summarize the all terms in this area of study.

Seismic response of nonlinear soil-structure interaction systems through the Preisach formalism: the Messina Bell Tower case study

In this paper the seismic response of linear behaving structures resting on compliant soil is addressed through the application of the Preisach formalism to capture the soil nonlinearities. The novel application of the Preisach model of hysteresis for nonlinear soil-structure interaction problems is explored through the study of the seismic response of a real structure. Through a harmonic balance procedure, furthermore, simplified nonlinear springs and dashpots are derived in closed form for a ready and accurate evaluation of the nonlinear soil-structure interaction response. The selected case study is the bell tower of the Messina Cathedral in Italy. The Bell Tower hosts the largest and most complex mechanical and astronomical clock in the world and it has been recently equipped by a permanent seismic monitoring system. A pertinent finite element (FE) model including the superstructure and the soil underneath, has been defined using authentic drawings and engineering design reports. The modal properties of the FE model have been compared with the experimental ones, identified from environmental noise recorded through the seismic monitoring system. Furthermore, the FE model has been validated by means of acceleration time histories recorded at different floors during two independent seismic events. A nonlinear incremental dynamic analysis of the Bell Tower has been also performed. The seismic response obtained by the complete FE analysis, has been compared with the proposed Preisach lumped parameter model, assembled with nonlinear springs and nonlinear dashpots. The results are well in agreement, offering an alternative promising strategy for the nonlinear soil-structure interaction studies.

Effect of Turbine Weight on the Seismic Response of a Wind Turbine-Monopile System Located in Liquefied Multilayer Soil

The core objectives of sustainable development are to develop access to renewable, sustainable, reliable, and cost-effective resources. Wind is an essential source of renewable energy, and monopile wind turbines are one method proposed for harnessing wind power. Offshore wind turbines can be vulnerable to earthquakes and liquefaction. This numerical study defined the effects of wind turbine weight on the seismic response of a wind turbine-monopile system located in liquefied multilayered soil with layer thicknesses of 5, 10, 15, and 20 m using four far-field records. OpenSees PL analysis indicated that if the liquefied sand had a lower density or a thickness of more than 10 m, then an increase in the earthquake acceleration beyond 0.4 g caused the pile to float like liquefied soil and to lose its vertical bearing capacity. Moreover, increasing the wind turbine power from 2 to 5 kW had no significant effect on the soil-structure interaction response. As the earthquake acceleration increased, the bending moment of the pile-column also increased as long as liquefaction did not occur and the pile-column deformation remained rotational-spatial in shape. As the acceleration and liquefaction increased and the pile began to float in response to its transverse motion, there was no significant difference in the pile-column displacement along the length, but there was a decrease in the pile-column bending moments. As this phenomenon increased and the pile continued to float, transformation of the pile increased the difference between the displacement of the pile-column along its length and further increased the bending moments. These results were derived from multiple correlation analysis, the bending moment relations, and lateral displacement of the pile-column of the wind turbine.

Nonlinear Inelastic-Degrading Structural Modeling Approach to Assess the Seismic Soil–Structure Interaction Response of Tall Buildings

Oversimplifying structural modeling in the analysis of the seismic performance of tall buildings introduces variability and biases in the computed seismic response. Engineering demand parameters (EDPs) from coupled soil–structure interaction (SSI) systems can only be realistically determined when nonlinear constitutive soil and structural behaviors are adopted in the numerical formulation. Large-magnitude earthquakes mobilize soil and structural demands that are beyond the elastic response of both materials. This paper aims at evaluating the influence of the structural modeling assumptions in the computed soil response due to seismic excitations using a direct fully coupled nonlinear SSI approach. Numerical analyses are conducted on elastic and nonlinear inelastic-degrading tall building models supported on a mat foundation-to-soil continuum domain using a multiple-yield surface plane-strain constitutive model. The models were subjected to multiple ground motion scenarios representative of broadband frequency content. Large discrepancies occur between linear and nonlinear inelastic tall buildings in terms of interstory drifts, peak horizontal accelerations, structural displacements, hysteretic energy, foundation rotation, and soil settlements. The results show how using nonlinear inelastic-degrading structural models of tall buildings largely affect the computed seismic response of the entire SSI system relative to linear elastic structural modeling approaches. More realistic responses are obtained using nonlinear degrading building models including SSI effects, because energy distribution and tradeoff among both the supporting soils and structure vary significantly as the seismic demands induce stresses and strains in the building beyond the onset of structural yielding.

Seismic Response of Double Metro Tunnels Built in Deep Soft-Soil

Rapid development and urbanization have led to the use of underground structures along the world for a wide range of applications including tunnel for subways, railways, highways, material storage, sewage and water transport. The safety of these facilities during seismic events such as recent earthquake in Japan, Taiwan and Turkey becomes more and more problematic due to the complex soil-structure interaction (SSI). The major factor causing severe damages to metro structures is the large deformations imposed by surrounding soils. Thus, for a subway tunnel structure embedded in the soft soil, the study of nonlinear dynamic response of soil-structure interaction during earthquake is important. Nowadays, numerous tools of Finite Element (FE) analysis has been developed to simulate and analyse the tunnel behaviour in order to mitigate its damages during seismic events. In this paper, the displacement response of double metro tunnels under two different earthquake waves is investigate using a Finite Element program (ABAQUS) in 2D plane strain condition, by means of nonlinear dynamic behaviour of soil and tunnels in three different working conditions by varying the embedded depth of the tunnels in soil. The results show that the displacement response of double tunnels built in soft soil is related to the characteristics of the input ground motion, the nature of surrounding soil and the buried depth of the tunnel structures, the peak ground acceleration (PGA) and the SSI effect has an important influence on the displacement response of tunnel structures. Keywords: double metro tunnels, soft soil, nonlinear, dynamic analysis, ground motion, displacement response, SSI, FE, PGA, ABAQUS DOI: 10.7176/ISDE/12-2-04 Publication date: June 30 th 2021

Experiments of an atrium-style metro station under harmonic excitation

The atrium-style station is one of the favourite choices in underground railway systems, as it can provide a larger and clearer space for passengers and commercial clients at the hall level of the station. With such style, as hall slabs are replaced with flat-beams, the station's capabilities to withstand lateral action like seismic action become one of the main concerns. Shaking table tests were conducted to investigate the dynamic response of soil-structure interaction of atrium-style station model under harmonic excitations covering the full frequency range, with comparison to free-field tests. The experimental results confirm that the influence of the structure on the dynamic response of the ground surface begins when the frequency of input motions is greater than 10 Hz. The predominant frequencies of the ground corresponding to the second and third modes both show an increase of 10% from the FF model to the SS model due to the presence of an atrium-style metro station. For atrium-style station: (i) the discontinuous structural elements such as beams and columns are more severely strained than the continuous ones like slabs and side walls, (ii) the peak dynamic soil normal stresses along the side wall follow an approximate L-shaped distribution and the maximum stress occurs at the side wall bottom, and (iii) the spectral characteristics of both dynamic structural strain and dynamic soil normal stress reflect the amplification function of the ground.

Probabilistic Approach to Account for Soil-Structure Interaction in Seismic Design of Building Structures

AbstractThis paper proposes a novel probabilistic approach to account for soil-structure interaction (SSI) in the seismic design of building structures. In this approach, an SSI response modificati...

Influence of various parameters in the seismic soil-structure interaction response of a nuclear power plant

This paper presents a numerical study of the influence of various parameters on the seismic response of the CAREM-25 nuclear power plant (NPP) located in Argentina. The influence of soil stiffness, structure-soil-structure interaction (3SI), and infill soil stiffness are studied. Considering the available analysis capabilities, a full 3D methodology was adopted (direct method). Two soil profiles were used in order to quantify the influence of the soil on the structural response. An engineered rockfill was also used in order to study the influence of infill soil stiffness. Three artificial records with three components each were used as free field input. These records were obtained from the site design spectra. The turbo-group building was approximately modelled in order to consider 3SI. Finally, all live loads as well as the water in pools were included in the model. Design guides for this type of problem are given for all the elements of the model.When comparing flexible soil with stiff soil, important reductions of the maximum absolute acceleration value are obtained by flexible soil. Moreover, the horizontal maximum accelerations are remarkably amplified in height in the case of stiff soil. The influence of the proximity of the turbo-group building (3SI) on the dynamic response of the reactor building is negligible. Finally, the influence of infill soil stiffness is also negligible.

Evaluation and numerical simulation of soil type effects on seismic soil-structure interaction response of RC structures

The present study is aimed at determining the effect of variability in soil type and structure height on soil-structure system responses. In order to explore this innovative idea, a wide range of soil types and structure heights are assumed, and the responses are analyzed with respect to changes in soil type and structure height. It is intended to address the three-fold problem of determining under what circumstances soil-structure interaction (SSI) exerts significant effects on the results, on what condition it could be ignored, and whether taking account of SSI leads to conservative results. To verify the numerical models, the results are compared with those derived from the NEHRP method. Five planar concrete frames are examined under the action of thirty earthquake records. Seven types of soil are considered. For modeling the soil-structure system, the direct method is employed. The plastic behavior of the soil is formulated based on the multi-surface (nested surfaces) concept; the yield surfaces of sand are of the Drucker-Prager type, and those of clay are of the Von Mises type. The exact Incremental Dynamic Analysis (IDA) is adopted for analyzing the soil-structure system. The results indicate that, for sandy soils, the SSI impact is greater for looser sub-soils. For clayey soils, the medium clay has the most powerful SSI effect. For low and medium rise buildings, the SSI effect is more profound as the structure becomes taller, but for high rise buildings, the SSI effect wears off with increasing height.

Seismic response of soil-structure interaction using the support vector regression

In this paper, a different technique to predict the effects of soil-structure interaction (SSI) on seismic response of building systems is investigated. The technique use a machine learning algorithm called Support Vector Regression (SVR) with technical and analytical results as input features. Normally, the effects of SSI on seismic response of existing building systems can be identified by different types of large data sets. Therefore, predicting and estimating the seismic response of building is a difficult task. It is possible to approximate a real valued function of the seismic response and make accurate investing choices regarding the design of building system and reduce the risk involved, by giving the right experimental and/or numerical data to a machine learning regression, such as SVR. The seismic response of both single-degree-of-freedom system and six-storey RC frame which can be represent of a broad range of existing structures, is estimated using proposed SVR model, while allowing flexibility of the soil-foundation system and SSI effects. The seismic response of both single-degree-of-freedom system and six-storey RC frame which can be represent of a broad range of existing structures, is estimated using proposed SVR model, while allowing flexibility of the soil-foundation system and SSI effects. The results show that the performance of the technique can be predicted by reducing the number of real data input features. Further, performance enhancement was achieved by optimizing the RBF kernel and SVR parameters through grid search.

Neighborhood structure effects on the Dynamic response of soil-structure interaction by harmonic analysis

For realizing the variation of structural dynamic characteristics due to neighbor structure in buildings group, the surface structure is idealized as an equivalent single degree of freedom system with rigid base whose site consists of a single homogeneous layer. Based on the model, a equivalent method on the equivalent seismic excitation is proposed. Then, the differences of seismic response and equivalent seismic input between soil - structure interaction (SSI) system and structure -soil-structure interaction (SSSI) system are investigated by harmonic analysis. The numerical results show that dynamic responses would be underestimated in SSSI system when the forcing frequencies are close to the Natural frequency if the effects of neighborhood structure were ignored. Neighborhood structure would make the translational displacement increase and rocking vibration decrease. When establishing an effective seismic input, it is necessary to consider the impact of inertia interaction.

Modeling Using Coupled FEM-SBFEM for Three-Dimensional Seismic SSI in Time Domain

AbstractFor soil-structure interaction (SSI) problems, accurate modeling of the unbounded domain is an important issue. This paper deals with the three-dimensional seismic SSI analysis based on the substructure method by coupling the FEM and the scaled boundary FEM (SBFEM) approaches. The entire analysis is performed in the time domain making the proposed approach capable of dealing with nonlinearity of soil. To verify the developed program, the results from the present analysis are compared with those available in the literature. This verification has been performed for both externally applied dynamic load and seismic load. The effect of boundary conditions on the SSI response is evaluated. The numerical study performed indicates that the SBFEM can act as a computationally efficient boundary when compared with the conventional viscous dashpots. Next, application of the FEM-SBFEM for SSI problems is demonstrated. A dam-foundation interaction analysis is carried out, and the effect of the inhomogeneity of ...

Layered high-performance concrete plates interacting with granular soil under blast loads: an experimental investigation

A new-layered precast tunnel segment made of different fibre-reinforced cementitious composites is here proposed. The article aims to study the effect of impulsive distributed pressure over tunnel rings under blast loads for the development of this new design solution. Shock tube experiments have been carried out to investigate a small portion of tunnel segment interacting with soil subjected to a plane shock wave. A set of accelerometers mounted on the specimen and placed inside the soil, as well as strain gauges mounted on the ad hoc chamber containing the specimen and the soil, have provided valuable information on the soil–structure interaction response. A careful investigation on the possible delamination between concrete layers is also carried out by UPV measurements. The experimental results have pointed out the great potential of this new design solution for precast tunnel segments subjected to internal explosions.

Influence of structure plane size on seismic response of soil-structure interaction

The influence of the change of structure plane size on seismic response was studied for a soil-structure interaction system. Based on the finite element method, a soil-structure interaction calculation model was established to analyze the seismic response by changing the structure plane size and choosing different earthquake waves for different soil fields. The results show that when the natural periods of vibration for different structure plane sizes are close, under the same earthquake wave, the total displacement on the top layer of the structure and the foundation rotation displacement decrease with the increase of structure plane size, and the proportion of superstructure elastic self-deformation displacement to the total displacement increases with the increase of structure plane size. While for different types of sites and seismic waves, under the horizontal and vertical seismic waves, the seismic responses of different plane sizes have a similar change rule.

Seismic soil-structure interaction response of inelastic structures

We analyze the effects of soil-structure interaction (SSI) on the response of yielding single-story structures embedded in an elastic halfspace to a set of accelerograms recorded in California and to a set of records from Mexico City. We find that, for nonlinear hysteretic structures, SSI may lead to larger ductility demands and larger total displacements than if the soil were rigid. This behavior differs from that envisioned in current seismic provisions, which allow designers to ignore SSI altogether or to reduce the base shear force with respect to that of the fixed-base structure. To overcome this deficiency, we examine an approach to incorporate SSI in determining the seismic design coefficient, C˜y, of systems with non-structural degrading elastoplastic behavior and target ductility μt. In this approach, C˜y is obtained as the unreduced seismic coefficient, C, of an equivalent fixed-base structure with natural period T˜, the natural period of the elastic SSI system, and with inelastic reduction factor equal to the λ-root of the fixed-base reduction factor, where λ=T˜/T, and T is the elastic natural period of the structure ignoring SSI. The peak relative displacement of the structure can be evaluated as the yield displacement u˜y times the target ductility μt. The peak total displacement, including SSI, is closely approximated by u˜y(μt+λ2–1).

Strength reduction factor for MDOF soil-structure systems

In most of the seismic design provision, the concept of strength reduction factor has been developed to account for inelastic behavior of structures under seismic excitations. Most recent studies considered soil–structure interaction (SSI) in inelastic response analysis are mainly based on idealized structural models of single degree-of-freedom (SDOF) systems. However, an SDOF system might not be able to well capture the SSI and structural response characteristics of real multiple degrees-of-freedom (MDOF) systems. In this paper, through a comprehensive parametric study of 21600 MDOF and its equivalent SDOF (E-SDOF) systems subjected to an ensemble of 30 earthquake ground motions recorded on alluvium and soft soils, effects of SSI on strength reduction factor of MDOF systems have been intensively investigated. It is concluded that generally, SSI reduces the strength reduction factor of both MDOF and more intensively SDOF systems. However, depending on the number of stories, soil flexibility, aspect ratio and inelastic range of vibration, the strength reduction factor of MDOF systems could be significantly different from that of E-SDOF systems. A new simplified equation, which is a function of fixed-base fundamental period, ductility ratio, the number of stories, structure slenderness ratio and dimensionless frequency, is proposed to estimate strength reduction factors for MDOF soil–structure systems. Copyright © 2012 John Wiley & Sons, Ltd.

Effects of slip and separation on seismic SSI response of nuclear reactor building

The seismic soil–structure interaction response of a nuclear reactor building requires modeling of the soil–structure interface. It allows slip and separation at the interface that affects the behavior and response of the reactor. The joint elements used to model the soil–structure interface, require incorporation of appropriate joint stiffness so that slip and separation phenomena take place under the warranted conditions. This slip and separation causes change in the response of the structure. This paper duly addresses the related aspects through comparative study of responses and draws important conclusions useful for design of nuclear reactor building.