Showing papers on "Soil structure interaction published in 2016"
TL;DR: In this article, the Euler-Bernoulli and Timoshenko beam theory is used to obtain the first natural frequency of the whole system using only limited data on the WTG (Wind Turbine Generator), tower dimensions, monopile dimensions and the ground.
146 citations
TL;DR: In this paper, a three-dimensional finite-element analysis of a deep excavation supported by a diaphragm wall, recently constructed in Shanghai, is presented. And the authors investigate the level of detail that is required in the finite element model to obtain results that provide a realistic representation of the wall and ground movements measured during the construction process.
Abstract: The design of deep excavations requires careful consideration of the influence of various soil/structure interaction mechanisms and detailed issues relating to the construction processes and the mechanics of the soil. Finite-element analysis provides a useful design tool for deep excavations, but care needs to be taken to ensure that an appropriate level of detail is included in the model. This paper describes a three-dimensional finite-element analysis of a deep excavation supported by a diaphragm wall, recently constructed in Shanghai. The principal purpose of the study is to investigate the level of detail that is required in the finite-element model to obtain results that provide a realistic representation of the wall and ground movements measured during the construction process. Studies are conducted on (a) the influence of the soil constitutive model on the quality of the results; (b) procedures to model the effect of post-cure shrinkage in the concrete floor slabs; (c) procedures to model the const...
82 citations
TL;DR: In this article, the authors quantify the flexural response of pipelines to normal faulting over a wide range of pipeline stiffness by using continuous functions of pipeline and soil displacement calculated using digital image correlation.
Abstract: Relative ground movement represents a severe seismic hazard to pipelines crossing faults, and the maximum expected pipeline strains are the primary design concern. Past research has documented how stiff steel pipelines respond to permanent ground deformation and has produced calibrated empirical models of pipeline response to strike-slip and normal faulting. However, what little data exist on flexible pipelines illustrate how ‘stiff pipeline’ soil reaction models significantly overestimate peak strains for flexible pipelines. Results for four centrifuge tests conducted on model pipelines are presented to quantify the flexural response of pipelines to normal faulting over a wide range of pipeline stiffness. Continuous functions of pipeline and soil displacement calculated using digital image correlation are used to assess pipeline curvature, soil reaction and relative displacement. Comparisons of peak measured curvatures to current design analysis methods confirm that empirical stiff pipeline soil reaction...
81 citations
TL;DR: In this paper, the results of fully coupled, three-dimensional (3D), nonlinear finite-element analyses of structures founded on liquefiable soils are compared with centrifuge experiments.
Abstract: The results of fully coupled, three-dimensional (3D), nonlinear finite-element analyses of structures founded on liquefiable soils are compared with centrifuge experiments. The goal is to provide insight into the numerical model’s capabilities in predicting the key engineering demand parameters that control building performance on softened ground for a range of structures, soil profiles, and ground motions. Experimental and numerical observations will also guide future analyses and mitigation decisions. The numerical model captured excess pore pressures and accelerations, the dominant displacement mechanisms under the foundation, and therefore building’s settlement, tilt, and interstory drift. Both experimental and numerical results showed that increasing the structure’s contact pressure and height/width (H/B) ratio generally reduces net excess pore pressure ratios in soil but amplifies the structure’s tilting tendencies and total drift. The settlement response of a structure with a greater pressu...
68 citations
TL;DR: In this article, a 3D numerical model of a 15-storey full-scale (prototype) structure was simulated with four different types of foundations: (i) a fixed-based structure that excludes the soil-structure interaction (SSI), (ii) a structure supported by a shallow foundation, (iii) a structural support supported by the pile-raft foundation in soft soil and (iv) a floating (frictiona...
Abstract: In selecting the type of foundation best suited for mid-rise buildings in high risk seismic zones, design engineers may consider that a shallow foundation, a pile foundation, or a pile-raft foundation can best carry the static and dynamic loads. However, different types of foundations behave differently during earthquakes, depending on the soil–structure interaction (SSI) where the properties of the in situ soil and type of foundation change the dynamic characteristics (natural frequency and damping) of the soil–foundation–structure system. In order to investigate the different characteristics of SSI and its influence on the seismic response of building frames, a 3D numerical model of a 15-storey full-scale (prototype) structure was simulated with four different types of foundations: (i) A fixed-based structure that excludes the SSI, (ii) a structure supported by a shallow foundation, (iii) a structure supported by a pile-raft foundation in soft soil and (iv) a structure supported by a floating (frictiona...
64 citations
TL;DR: In this paper, an experimental model consisting of an oscillator connected to a single or a group of piles embedded in a bi-layer deposit was used to study the modal dynamic response of the soil-pile-structure system in terms of period elongation and system damping ratio.
Abstract: Summary
An effective way to study the complex seismic soil-structure interaction phenomena is to investigate the response of physical scaled models in 1-g or n-g laboratory devices. The outcomes of an extensive experimental campaign carried out on scaled models by means of the shaking table of the Bristol Laboratory for Advanced Dynamics Engineering, University of Bristol, UK, are discussed in the present paper. The experimental model comprises an oscillator connected to a single or a group of piles embedded in a bi-layer deposit. Different pile head conditions, that is free head and fixed head, several dynamic properties of the structure, including different masses at the top of the single degree of freedom system, excited by various input motions, e.g. white noise, sinedwells and natural earthquake strong motions recorded in Italy, have been tested. In the present work, the modal dynamic response of the soil–pile–structure system is assessed in terms of period elongation and system damping ratio. Furthermore, the effects of oscillator mass and pile head conditions on soil–pile response have been highlighted, when the harmonic input motions are considered. Copyright © 2015 John Wiley & Sons, Ltd.
62 citations
TL;DR: In this paper, an Euler-Lagrangian wind turbine mathematical model based on an energy formulation was developed for this purpose which considers the structural dynamics of the system and the interaction between in-plane and out-of-plane blade vibrations.
60 citations
TL;DR: In this article, a comprehensive parametric study has been carried out to investigate the seismic performance of multi-storey shear buildings considering soil-structure interaction (SSI).
59 citations
55 citations
TL;DR: In this article, Reinforced concrete buildings being 3, 5, 6, 8, 9 stories high, resting on soft and very soft soil types, once with moment resisting and once with concrete shear walls are considered.
52 citations
TL;DR: In this article, a relatively comprehensive method, full 3D nonlinear time history analysis of soil-structure interaction (SSI) using direct method of configuration, has been employed in this work through the understanding of SSI effect well specifically investigated for a historical masonry stone arch bridge (Mataraci Bridge, Trabzon).
Abstract: Historical masonry arch bridges, which represent the richness of cultural heritage of the country (Anatolia, Turkey), should be protected against detrimental effects and transferred well to next generations with a thorough effort given for the accurate estimations under the seismic responses affected by the nonlinear soil and structural characteristics. In this viewpoint, a relatively comprehensive method, full 3D nonlinear time history analysis of soil–structure interaction (SSI) (using direct method of configuration), has been employed in this work through the understanding of SSI effect well specifically investigated for a historical masonry stone arch bridge (Mataraci Bridge, Trabzon). For this purpose, the SSI model of bridge–substructure soil was built with the finite elements in 3D using the solid element, and then figured out in detail based on the results of seismic responses due to earthquake excitation. It is found from the results that in comparison with the fixed base solution, the influence of SSI becomes relatively prominent on the responses of displacement, acceleration, rotation, frequency (at lower modes of vibration), modal shapes, base shear, and overturning moment, while the stresses almost remain unchanged. The effort given in this study could be beneficial for other historical structures in the country for accurate estimations of the responses when seismically considered.
TL;DR: In this article, an experimental dynamic centrifuge program is presented, where the influences of the base shaking signal and the height of the gravity center of the superstructure are investigated, and the differences in the behavior of batter and vertical piles under seismic soil-pile-superstructure interaction.
TL;DR: In this article, a detailed literature review on soil-structure interaction analysis of laterally loaded piles is presented, which is highly essential for predicting a more accurate structural behavior so as to improve the safety of structures under extreme loading conditions.
Abstract: Soil–structure interaction plays an important role in the behavior of structure under static or dynamic loading. It influences the behavior of soil, as well as the response of pile under loading. The analysis is highly essential for predicting a more accurate structural behavior so as to improve the safety of structures under extreme loading conditions. The soil–pile system behavior is predominantly nonlinear and this makes the problem complicated. In a laterally loaded pile the load is resisted by the soil–pile interaction effect, which in turn depends on soil properties, pile material, pile diameter, loading type and bed slope of ground. The difficulty in the accountability of the influencing factors necessitates a careful study on soil–structure interaction problem. The analysis became easier with the debut of powerful computers and simulation tools such as finite element analysis software. A detailed literature review on soil–structure interaction analysis of laterally loaded piles is presented in this paper.
01 Jan 2016
TL;DR: In this article, the authors carried out a comprehensive critical review on available and well-known research studies in the area of seismic behaviour of braced and unbraced building structures affected by soil-structure interaction (SSI).
Abstract: The current study carries out a comprehensive critical review on available and well-known research studies in the area of seismic behaviour of braced and unbraced building structures affected by soil-structure interaction (SSI). Based on the current review outcomes, it has become apparent that considering effects of SSI in seismic design of braced building structures is not necessary and assuming fixed-base structure is deemed to be conservative. However, SSI effects can amplify the lateral deflections and corresponding inter-storey drifts of unbraced building structures founding on soft grounds, forcing the structure to behave in the inelastic range, resulting in severe damage of the building structures. Consequently, seismic design procedure of unbraced building structures founding on soft soils without taking into account detrimental influences of SSI cannot adequately assure structural sufficiency and safety for the benefit of the community.
TL;DR: In this paper, the authors proposed a grant for the California Geological Survey (CGS) with a grant number: 1014-963 and Grant Number: 65A0450.
Abstract: California Geological Survey. Grant Number: 1014-963 California Department of Transportation. Grant Number: 65A0450
TL;DR: In this article, the authors investigated the impact of different rubber-soil mixtures on the dynamic response of the abutment-backfill system under various seismic excitations, accounting for dynamic soil-abutment interaction.
Abstract: Reuse of the 1.5 billion waste tyres that are produced annually is a one of the major worldwide challenges, as waste tyres are toxic and cause pollution to the environment. In recognition of this problem, this paper introduces the reuse of tyres, in the form of derived aggregates in mixtures with granulated soil materials, as previous studies indicated the potential benefits of these materials in the seismic performance of structures. The objective of the present research study is to investigate whether use of rubberised backfills benefits the seismic response of Integral Abutment Bridges (IABs) by enhancing soil-structure interaction (SSI) effects. Numerical models including typical integral abutments on surface foundation with nonlinear conventional backfill material and its alternative form as soil-rubber mixtures are analysed and their response parameters are compared. The research is conducted on the basis of parametric analysis, which aims to evaluate the influence of different rubber-soil mixtures on the dynamic response of the abutment-backfill system under various seismic excitations, accounting for dynamic soil-abutment interaction. The results provide evidence that the use of rubberised backfill leads to reductions in the backfill settlements, the horizontal displacements of the bridge deck, the residual horizontal displacements of the top of the abutment and the pressures acting on the abutment, up to 55%, 18%, 43% and 47% respectively, with respect to a conventional backfill comprising of clean sand. Considerable amount of decrease in bending moments and shear forces on the abutment wall is also observed. Therefore, rubberised backfills offer promising solution to mitigate the earthquake risk, towards economic design with minimal damage objectives for the resilience of transportation networks.
TL;DR: In this paper, a new ground improvement method is proposed using pervious concrete piles to provide high permeability while also providing higher stiffness and strength, which are independent of surrounding soil confinement.
Abstract: Granular column ground-improvement methods are widely used to improve bearing capacity and provide a drainage path. However, the behavior of granular columns depends on the confinement provided by the surrounding soil, which limits their use in poor soils. A new ground-improvement method is proposed using pervious concrete piles to provide high permeability while also providing higher stiffness and strength, which are independent of surrounding soil confinement. Building on prior research on the behavior of vertically loaded pervious concrete piles and granular columns, this paper investigates the behavior of laterally-loaded pervious concrete piles and the effects of installation on their response. Two fully-instrumented lateral load tests were conducted on a precast and cast-in-place pile using different installation methods. Advanced sensors measured the soil–structure interaction during installation and under lateral loading. Test results confirmed that laterally-loaded pervious concrete groun...
TL;DR: In this article, 3D reinforced concrete (RC) and steel building structures have been considered for studying the effect of soil-structure interaction modelling on the structural fragility assessment of such structures.
TL;DR: In this paper, a practical optimisation technique is introduced to obtain optimum seismic design loads for non-linear shear-buildings on soft soils based on the concept of uniform damage distribution.
TL;DR: In this paper, the effects of fluid viscous damper (FVD) for a cable-stayed bridge under randomly generated earthquake excitation are investigated, where the FVD is modeled as a simplified Maxwell model, which consists of a linear spring in series with a nonlinear dashpot.
Abstract: As a passive energy dissipation device, the fluid viscous damper (FVD) is effective for mitigating wind or seismic load-induced vibrations. In this paper, the effects of FVDs for a cable-stayed bridge under randomly generated earthquake excitation are investigated. The FVD is modeled as a simplified Maxwell model, which consists of a linear spring in series with a nonlinear dashpot. The pile is modeled as a beam on the nonlinear Winkler foundation, and the soil–pile interactions are simulated by using continuously distributed hysteretic springs and viscous dashpots placed in parallel. Three random ground motions are generated from the earthquake risk assessment based on the seismotectonics and seismicity analysis of the bridge location. The seismic response of the cable-stayed bridge with FVD considering soil–structure interactions (SSIs) is obtained by solving the equations of motion in the time domain using a direct integration method. Parametric studies are conducted for the two key parameters ...
TL;DR: In this article, a stationary air pluviation device used to prepare uniform sand specimens in a large-size test chamber with dimensions equal to 900 mm × 900 mm/1000 mm (in length, width, and depth).
Abstract: Relative density is an important state parameter that influences the soil behavior. Preparation of sand specimens with uniform density is critical during large-scale laboratory testing in geotechnical engineering. In this study, the details of a stationary air pluviation device used to prepare uniform sand specimens in a large-size test chamber with dimensions equal to 900 mm × 900 mm × 1000 mm (in length, width, and depth) are provided. The proposed device is found to be simple to construct due to presence of only two diffuser sieves with an ability to produce uniform sand beds in a reasonably quick time. Prior to construction of full-scale pluviation device, a scaled-down model of the device with plan dimensions equal to 300 mm × 300 mm is fabricated to perform calibration studies. The range of densities of two gradations of Indian Standard sand (IS Grade II and IS Grade III) obtained using this device for various heights of fall of sand particles and passing through different opening sizes are provided. Relative density in the range of 53–99 % and 74–99 % is achieved for IS Grade II and III sands, respectively. The spatial uniformity in densities is also assessed, and the coefficient of variation (COV) in the density is found to be less than about 7 %. In addition to pluviation method, uniform sand beds are also prepared using pneumatically-operated vibratory method. The target relative density of sand bed is achieved by adjusting the pressure of compressed air inside the vibrator, and the maximum relative density of IS Grade II and Grade III sands from vibratory method is found to be higher than that from pluviation method for the range of pressures chosen in the study.
TL;DR: In this paper, a six-directional, coupled, linear approach is proposed, which contains an implementation of soil-structure interaction matrices in the system matrices of the whole substructure.
TL;DR: In this article, a mathematical model is developed for calculating the seismic response of an irregular multi-story building equipped with active tendons and the effect of soil-structure interaction (SSI) is considered.
TL;DR: In this article, an approximate procedure for analyzing SSI and evaluating the relative importance of its effects, as well as the influence of the principal parameters involved (performance point, reduction factor, etc.).
TL;DR: In this paper, Luco et al. used Dunkerley's formula to evaluate the lower bounds for structural natural frequencies considering soil-structure interaction (SSI), which was validated by both experimental and numerical results.
Abstract: In order to investigate the influence of soil–structure interaction (SSI) on the dynamic characteristics of buildings, a series of free-vibration experiments were performed on a 1/4-scale steel-frame structure. The structural fixed-base fundamental period was for the first time determined by experiments as to avoid evaluation errors in the conventional SSI analyses, and its numerical counterpart obtained by using SAP2000® was also given for comparison. A total of 34 scenarios, which varied with regard to overall stiffness and mass of the structure, were examined in the experiments and the numerical simulations. In each experimental scenario, the fundamental period of the structure was determined under fixed-base and flexible-base conditions. A newly proposed method by Luco using Dunkerley’s formula to evaluate the lower bounds for structural natural frequencies considering SSI was validated by both experimental and numerical results. This method was found to exhibit excellent accuracy in predicting the fundamental period of the structure with SSI. This experimentally verified formula, having a broader application potential than the Jennings and Bielak and Veletsos and Meek expressions, could apply to a variety of researching areas in earthquake engineering and would be a useful reference for future seismic code revisions in assessing the basic period of the structure with SSI.
TL;DR: In this article, the seismic response of a foundation pile embedded in a saturated coarse-grained deposit is examined through a series of three-dimensional dynamic finite element analyses incorporating an advanced plasticity soil model and implementing a fully coupled interaction between the soil skeleton and the pore fluid.
TL;DR: In this paper, the effect of soil stiffness on the seismic response of reinforced concrete shear wall buildings was investigated. And the authors found that the shear walls placed at the core of the building attracted the least earthquake force.
Abstract: Buildings are subjected to lateral loads caused by wind, blasting and earthquakes. The high stresses developed by these loads literally tear the building components apart, which are in general designed for gravity loads. To resist these lateral forces, shear walls can be introduced in buildings. Present study aims to determine the apt shear wall position which attracts the least earthquake forces in symmetric plan multi-storey buildings. Dynamic response of a structure is significantly influenced by the underlying soil due to its natural ability to deform. Three dimensional finite element soil–structure interaction analyses of reinforced concrete shear wall buildings with shear walls placed at various locations is carried out in time domain using scaled down Elcentro ground motion to determine the seismic response variation in the structure due to the effect of stiffness of soil. Four different soil types based on shear wave velocity and six varying shear wall positions in multi-storey buildings up to 16 storeys are considered to determine the effect of soil–structure interaction. From the study, it is found that structural response as per conventional fixed base condition is very conservative. For buildings founded on soil with Vs ≤ 300 m/s, providing the shear walls at the core is advantageous whereas for soil with Vs > 300 m/s, the shear walls placed at exterior corners of the building attracts the least earthquake force.
TL;DR: In this article, the authors evaluate the commonly used substructuring method for analysis of bridge systems where the bridge is divided into two sub-systems: the bridge superstructure and the substructure including the pile foundations, abutments, and soil.
TL;DR: In this paper, a set of 3D finite-element full dynamic analyses have been carried out, calibrated on the experimental results of a centrifuge test on a model tunnel in a dense dry sand layer subjected to transversal dynamic loading.
TL;DR: In this paper, the authors compared several experimental measurements of reinforced concrete slab - subsoil interaction with numerical analysis of shallow foundation by means of FEM, and compared the results of experimental loading test are compared with soil - foundation interaction analysis based on finite element method (FEM).
Abstract: Several experimental measurements of reinforced concrete slab - subsoil interaction are compared with numerical analysis of shallow foundation by means of FEM. At the Faculty of Civil Engineering VSB - Technical University of Ostrava testing device was constructed so that the phenomena of soil - foundation interaction could be experimentally investigated and compared with numerical models. Results of experimental loading test are compared with soil - foundation interaction analysis based on finite element method (FEM). The purpose of this paper is to compare resulting deformation of the slab, subsidence of the subsoil, bending moments and contact stress calculated by different software based on FEM. Currently there are several software that, can deal with the interaction of foundations and subsoil.