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1

Convolutional neural networks in the SSI analysis for mine-induced vibrations

Zając Maciej, Kuźniar Krystyna

Computer Assisted Methods in Engineering and Science

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2024

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Vol. 31, no. 1

3--28

EN

Deep neural networks (DNNs) have recently become one of the most often used softcomputational tools for numerical analysis. The huge success of DNNs in the field of imageprocessing is associated with the use of convolutional neural networks (CNNs). CNNs,thanks to their characteristic structure, allow for the effective extraction of multi-layerfeatures. In this paper, the application of CNNs to one of the important soil-structureinteraction (SSI) problems, i.e., the analysis of vibrations transmission from the free-field next to a building to the building foundation, is presented in the case of mine-induced vibrations. To achieve this, the dataset from in-situ experimental measurements,containing 1D ground acceleration records, was converted into 2D spectrogram imagesusing either Fourier transform or continuous wavelet transform. Next, these images wereused as input for a pre-trained CNN. The output is a ratio of maximal vibration valuesrecorded simultaneously on the building foundation and on the ground. Therefore, the lastlayer of the CNN had to be changed from a classification to a regression one. The obtainedresults indicate the suitability of CNN for the analyzed problem.

2

The Effect of Soil-Structure Interaction (SSI) on Structural Stability and Sustainability of RC Structures

Krishnan Ragi, Sivakumar Vidhya Lakshmi

Civil and Environmental Engineering Reports

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2024

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Vol. 34, no. 1

116--136

EN

The issue of SSI involves how the ground or soil reacts to a building built on top of it. Both the character of the structure and the nature of the soil have an impact on the stresses that exist between them, which in turn affects how the structure and soil beneath it move. The issue is crucial, particularly in earthquake regions. The interaction between soil and structure is an extremely intriguing factor in increasing or reducing structural damage or movement. Structures sitting on deformable soil as opposed to strong soil will experience an increase in static settlement and a decrease in seismic harm. The engineer must take into account that the soil liquefaction problem occurs for soft ground in seismic areas. A reinforced concrete wall-frame dual framework's dynamic reaction to SSI has not been sufficiently studied and is infrequently taken into consideration in engineering practice. The structures’ seismic performance when SSI effects are taken into account is still unknown, and there are still some misconceptions about the SSI idea, especially regarding RC wall-frame dual systems. The simulation study of the soil beneath the foundations significantly impacts the framework's frequency response and dynamic properties. Therefore, the overall significance of SSI in the structural aspect and sustainability aspects will be reviewed in this research.

3

Vertical and horizontal dynamic response of suction caisson foundations

Bouneguet Soumia, Messioud Salah, Dias Daniel

Studia Geotechnica et Mechanica

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2023

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Vol. 45, nr 1

1--13

EN

In this article, the dynamic response of suction caisson foundations is studied using a three-dimensional finite element model with an absorbing boundary. The adopted formulation is based on the substructuring method. This formulation has been applied to analyze the effect of soil–structure interaction on the dynamic response of the suction foundation as a function of the kind of load. The suction caisson foundations are embedded in viscoelastic homogenous soils and subjected to external harmonic forces. For each frequency, the dynamic impedance connects the applied forces to the resulting displacement. The constitutive elements of the system are modeled using the finite element volumes and shell elements. The numerical results for the dynamic response of the suction foundations are presented in terms of vertical and horizontal displacements as well as vertical and horizontal dynamic impedances. The results indicated that the overall dynamic response is highly affected by the suction caisson diameter, the soil stiffness variation, and the suction caisson length.

4

Behaviour of soil-steel composite structures during construction and service: a review

Legese Alemu Mosisa, Sobótka Maciej, Machelski Czesław, Różański Adrian

Archives of Civil Engineering

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2023

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Vol. 69, nr 4

263--292

EN

In this paper, existing knowledge on the behaviour of soil-steel composite structures (SSCSs) has been reviewed. In particular, the response of buried corrugated steel plates (CSPs) to static, semistatic, and dynamic loads has been covered. Furthermore, the performance of SSCS under extreme loading, i.e., loading until failure, has been studied. To investigate the behaviour of the type of composite structures considered, numerous full-scale tests and numerical simulations have been conducted for both arched and box shapes of the shell. In addition, researchers have examined different span lengths and cover depths. Furthermore, to enhance the load-bearing capacity of the composite structures, various stiffening elements have been applied and tested. The review shows that the mechanical features of SSCSs are mainly based on the interaction of the shell with the soil backfill. The structures, as a composite system, become appropriately stiff when completely backfilled. For this reason, the construction phase corresponds to the highest values of shell displacement and stress. Moreover, the method of laying and compacting the backfill, as well as the thickness of the cover, has a significant impact on the behaviour of the structure at the stage of operation in both the quantitative and qualitative sense. Finally, a limited number of studies are conducted on the ultimate bearing capacity of large-span SSCS and various reinforcing methods. Considerably more works will need to be done on this topic. It applies to both full scale tests and numerical analysis.

PL

W artykule podsumowano dotychczasową wiedzę na temat zachowania się mostowych konstrukcji gruntowo-powłokowych. W szczególności przeprowadzony przegląd dotyczy mechanicznej odpowiedzi obiektów z blach falistych na obciążenia statyczne, quasi-statyczne i dynamiczne. Ponadto, studium literaturowe obejmuje badania konstrukcji gruntowo-powłokowych przy ich ekstremalnym obciążeniu, tj. do poziomu obciążenia niszczącego. W tym zakresie zachowanie rozpatrywanego typu konstrukcji badano w licznych testach obciążeniowych w pełnej skali jak również na drodze symulacji numerycznych zarówno dla kształtów łukowych, jak i skrzynkowych powłoki. Analizom takim poddano obiekty o różnych rozpiętościach I przy różnych grubościach zasypki. Ponadto, w celu zwiększenia nośności obiektów inżynierskich z blach falistych zastosowano i przetestowano różnego rodzaju elementy usztywniające. Z przeprowadzonego przeglądu wynika, że najważniejsze cechy mechanicznego zachowania się konstrukcji gruntowo-powłokowych opierają się głównie na wzajemnej współpracy powłoki z gruntową zasypką inżynierską. Obiekty takie, jako swego rodzaju układy zintegrowane, nabierają odpowiedniej sztywności dopiero po całkowitym zasypaniu powłoki. Z tego powodu największe deformacje oraz wytężenie powłoki występują w fazie budowy. Sposób układania i zagęszczania zasypki oraz jej minimalna wysokość ponad powłoką mają ponadto istotny wpływ na zachowanie się konstrukcji pod obciążeniem użytkowym na etapie eksploatacji, zarówno w sensie ilościowym, jak i jakościowym. Podsumowując przegląd, wskazano na fakt, że liczba badań, w których określano nośność graniczną, jest ograniczona w przypadku obiektów o dużej rozpiętości i przy zastosowaniu różnych sposobów wzmocnienia konstrukcji. W tym zakresie temat badań obiektów inżynierskich z blach falistych powinien zostać rozszerzony. W opinii autorów w najbliższych latach pojawią się nowe prace w tym zakresie. Dotyczy to zwłaszcza pełnoskalowych testów obciążeniowych ale także analiz numerycznych.

5

Modulus of Laterally Loaded Pile in Cohesionless Slope Crest with Varying Condition

Sivapriya Vijayasimhan, Ganesh Kumar Shanmugam

Civil and Environmental Engineering Reports

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2022

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Vol. 32, no. 3

133--142

EN

Soil - structure interaction behaviour of pile foundation is complex for heavier structures which suffer large lateral load due to wind, wave action etc., in addition to the large vertical and oblique load. The parameters involved in determining the lateral capacity of the foundation are its structural geometry, soil properties and ground condition. The behaviour is different for horizontal ground compared to the sloping ground; it is even different under loading and unloading conditions. In this study, the modulus of single pile is studied under various lengths, diameters, slope angles and loading directions. An equation is generated is developed to obtain the modulus with varying length and diameter.

6

Calculating the Dynamic Impedances of Foundations and their Effect on the Seismic Response of Structures: Analytical and Numerical Study

Boulkhiout Radhwane, Messast Salah

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 2

178--217

EN

This study evaluates the movement of a frame built on soft soil under seismic excitation taking into account soil-structure interaction. First, the study was evaluated using the finite element method, then, by using a substructure method which modelled the soil using springs and dampers in a linear and nonlinear study. Rheological models were determined using impedance functions, calculated using a numerical program CONAN. These dynamic impedances are shown in the displacement vector of a three-degrees-of-freedom frame, which was calculated on the basis of lateral forces distributed over the structure height using the equivalent static method. In this regard, two different calculation norms were chosen; RPA2003 and UBC97. Finally, a parametric study was carried out, based on the effects of soil densification and the foundation geometry on the response of the RC frame.

7

A Study on Dynamic Behavior of Natural Draft Cooling Tower Considering the Effect of Soil-Structure Interaction

Chitrahalli Lingaraju Mahesh Kumar, Kotagi Girisha Shwetha, Bhaktanakatte Channabasappa Shanthappa, Karigowda Manjunatha

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 4

17--32

EN

In this present era, the technology in advanced construction has developed to a very large extent. Some parts of the constructions are still in the improving stage which includes cooling tower construction. Hyperbolic cooling towers are large, thin shell reinforced concrete structures which contribute to power generation efficiency, reliability, and to environmental protection. Cooling towers use evaporation of water to eject heat from processes such as cooling the circulating water used in oil refineries and in power plants. Nowadays in many thermal power plants, we can see the cooling tower. So, preserving this industrial structure is an effort to save the cooling tower from dangerous earthquakes. The present-day cooling towers are exceptional structures in view of their sheer size and complexities. Present paper deals with the study of dynamic response that is modal analysis, seismic analysis of the two different cooling towers varying the H/t ratio and thicknesses with fixity at the base boundary condition, and the soil is modelled as raft for the effect of soil-structure interaction using the direct approach. In this paper, hyperbolic cooling towers are modelled using ANSYS software, which is a finite element software. Results show that the soil-structure interaction effect significantly modifies the earthquake behavior of hyperbolic cooling towers.

8

Accuracy assessment of linear elasticity solution for interaction of cylindrical tank with subsoil

Lewiński Paweł Marek

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 1

art. no. e136039

EN

The subject of this paper is an assessment of the accuracy of a solution based on the linear theory of elasticity describing the interaction of a cylindrical reinforced concrete tank with the subsoil. The subsoil was modelled in the form of an elastic half-space and Winkler springs. The behaviour of the shell structure of the RC cylindrical tank, and particularly of the ground slab interacting with the subsoil, depends largely on the distribution of the reactions on the foundation surface. An analysis of this structure with the shell fixed in a circular ground slab was carried out taking into consideration the elastic half-space model using the Gorbunov-Posadov approach and, for comparison, the two-parameter Winkler model. Although the results for both subsoil models proved to be divergent, the conclusions that follow the accuracy assessment of a solution based on the theory of elasticity are fairly important for engineering practice.

9

An application of reinforced concrete vaulted slabs and rafts in deep excavation works

Kacprzak Grzegorz, Daktera Tomasz, Stańczyk Andrzej, Tomczak Urszula, Bodus Seweryn, Werle Michał

Archives of Civil Engineering

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2021

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Vol. 67, nr 3

61--75

EN

The overall efficiency of a construction of a deep excavation urban project does not depend only on the duration of the construction but also on its influence on the urban environment and the traffic [9, 10]. These two things depend greatly on the excavation method and the construction stages defined during the design process. This paper describes the construction stages of three metro stations (two stations in Warsaw and one in Paris) and discusses their advantages and disadvantages including among other things its impact on neighbouring infrastructure and the city’s traffic. An important conclusion drawn from this analysis is that the shape of the slabs used can considerably affect the design and the construction stages. For example, a vaulted top slab allows an almost immediate traffic restoration and a vaulted bottom raft allows a much shorter dewatering period.

PL

Ogólna efektywność budowy miejskiej inwestycji głębokiego wykopu nie zależy tylko od czasu trwania budowy, ale także od jej wpływu na środowisko miejskie i ruch drogowy [9, 10]. Te dwie rzeczy zależą w dużej mierze od metody wykopów i etapów budowy określonych w procesie projektowania. W niniejszym opracowaniu opisano etapy budowy trzech stacji metra (dwóch w Warszawie i jednej w Paryżu) oraz omówiono ich zalety i wady, w tym m.in. wpływ na sąsiadującą infrastrukturę i ruch w mieście. Ważnym wnioskiem wynikającym z tej analizy jest to, że kształt zastosowanych płyt może mieć istotny wpływ na projekt i etapy budowy. Na przykład, górna płyta sklepiona pozwala na niemal natychmiastowe przywrócenie ruchu, a dolna płyta sklepiona pozwala na znacznie krótszy okres odwadniania. W rezultacie powstała bardziej globalna dyskusja na temat interakcji konstrukcji z gruntem, gdzie wykorzystywane są sklepione elementy konstrukcyjne. Gdy nacisk gruntu jest wywierany na sklepione górną płytę lub płytę denną, tworzenie się sił obręczowych w betonowych przekrojach poprzecznych pozwala na dodatkowe przenoszenie obciążeń i tym samym oferuje znaczne korzyści i szerokie możliwości projektowe.

10

Piles system securing road against landslide. 2D/3D method of numerical modeling and design problems

Urbański A., Grodecki M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 6

1433--1442

EN

The main objective of this work is to present an innovative method of numerical modeling of anchored piles system acting as a road protection against landslide, called the “2D/3D method”. Firstly, short description of the problem and “state of the art” review are included. An effective methodology of the design supported by the numerical analysis, solving the problem of interaction of a periodic system of piles and the unstable soil mass is presented, for which some detailed information about proposed numerical approach is given. The key idea of 2D/3D method is to join the pile with the 2D plane strain continuum by fictitious connectors of Winkler type with P-Y properties identified during the analysis of a subsidiary 3D problem. Practical example of usage of proposed approach to a real case of a road endangered by a landslide then protected by the piles system is presented. On the base of this example, a discussion about important design issues like internal forces in piles (mainly bending moments) and anchors (tensile forces) or overall stability of the soil-structure system is done.

11

Soil-structure interaction of cylindrical tank of variable wall thickness under the constant thermal loading

Lewiński P. M., Rak M.

Archives of Civil Engineering

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2020

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Vol. 66, nr 4

269--285

EN

An effective method for the analysis of soil-structure interaction including the behaviour of cylindrical storage tank with varying wall thickness under the action of constant thermal loading is presented. Elastic half-space and the Winkler model have been used for the description of subsoil. The soil-structure interaction is described by using the power series. A computational example of reinforced concrete tank loaded with constant temperature is given. The analysis of a hydrostatically loaded cylindrical tank performed for the model incorporating elastic half-space shows decrease of radial displacements as well as substantial changes in the distribution of bending moments when compared to the Winkler foundation. Additionally, local increase of subsoil reaction around the slab circumference is observed for the case of elastic half-space, in contrast to the Winkler model. However, in the case of a tank loaded with constant temperature, the solutions for both subsoil models do not differ significantly.

PL

W pracy rozważana jest metoda obliczania naprężeń termicznych w zbiornikach cylindrycznych o zmiennej grubości ścianki, zamocowanych u podstawy w płycie dennej i poddanych osiowo-symetrycznemu równomiernemu obciążeniu termicznemu (rys. 1). Schemat wzajemnego oddziaływania konstrukcji z podłożem pozwala opisać zachowanie konstrukcji zbiorników kołowych o zmiennej grubości ścianki, stosując takie modele podłoża, jak półprzestrzeń idealnie sprężysta i model Winklera. Przyjęta tu metoda (por. Borowicka [1], Gorbunow-Posadow [4]) umożliwia analizę wzajemnego oddziaływania płyty dennej zbiornika z izotropową półprzestrzenią sprężystą obciążoną prostopadle na pewnym obszarze płaszczyzny granicznej, z uwzględnieniem równania różniczkowego opartej na niej płyty kołowej. Analizę współpracy konstrukcji z podłożem przeprowadzono metodą szeregów potegowych [11]. Zaletą tego podejścia jest jest stosunkowo prosty i dokładny opis wzajemnego oddziaływania konstrukcji z podłożem w porównaniu z innymi metodami.

12

Interaction of RC and PC cylindrical silos and tanks with subsoil

Lewiński P. M.

Archives of Civil Engineering

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2020

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Vol. 66, nr 4

249--267

EN

The subject of this paper is an analysis of the influence of circumferential prestressing on the interaction of cylindrical silos and tanks with the subsoil. The behaviour of the shell structures of RC and PC cylindrical silos or tanks (with circumferential pre-tensioning), and particularly of the ground slab interacting with subsoil, depends largely on the function graphs of the subsoil reactions on the foundation surface. Distributions of the subbase reactions on the ground slab in such structures as silos and tanks have a significant impact on the behaviour of not only the slab itself, but also the interacting shell structure. An analysis of these structures with walls fixed in a circular ground slab and foundation ring was carried out taking into consideration the elastic half-space model using the Gorbunov-Posadov approach and the two-parameter Winkler model. In the computational examples of RC and PC silos and tanks with walls fixed in the circular ground slab or foundation ring, the eventual effects of prestressing obtained as a result of the superposition of internal forces were examined. Although the results for both subsoil models proved to be divergent, the conclusions that follow are fairly important for the engineering practice.

PL

Przedmiotem niniejszej pracy jest analiza wpływu obwodowego sprężania na oddziaływanie silosów i zbiorników cylindrycznych z podłożem. Podłoże zamodelowano w postaci półprzestrzeni sprężystej i modelu Winklera. Zachowanie konstrukcji powłokowych żelbetowych i sprężonych silosów i zbiorników cylindrycznych, zwłaszcza płyt dennych oddziałujących z podłożem, zależy w dużej mierze od rozkładu reakcji podłoża na powierzchni fundamentu. Analizę tych konstrukcji ze ścianami zamocowanymi w kołowej płycie dennej i pierścieniu fundamentowym przeprowadzono z uwzględnieniem modelu półprzestrzeni sprężystej na podstawie metody Gorbunowa-Posadowa i dwuparametrowego modelu podłoża Winklera.

13

Slurry shield tunneling in soft ground. Comparison between field data and 3D numerical simulation

Beghoul Mohammed, Demagh Rafik

Studia Geotechnica et Mechanica

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2019

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Vol. 41, nr 3

115--128

EN

In urban areas, the control of ground surface settlement is an important issue during shield tunnel-boring machine (TBM) tunneling. These ground movements are affected by many machine control parameters. In this article, a finite difference (FD) model is developed using Itasca FLAC-3D to numerically simulate the whole process of shield TBM tunneling. The model simulates important components of the mechanized excavation process including slurry pressure on the excavation face, shield conicity, installation of segmental lining, grout injection in the annular void, and grout consolidation. The analysis results from the proposed method are compared and discussed in terms of ground movements (both vertical and horizontal) with field measurements data. The results reveal that the proposed 3D simulation is sufficient and can reasonably reproduce all the operations achieved by the TBM. In fact, the results show that the TBM parameters can be controlled to have acceptable levels of surface settlement. In particular, it seems that moderate face pressure can reduce ground movement significantly and, most importantly, can prevent the occurrence of face-expected instability when the shield crosses very weak soil layers. The shield conicity has also an important effect on ground surface settlement, which can be partly compensated by the grout pressure during tail grouting. Finally, the injection pressure at the rear of the shield significantly reduces the vertical displacements at the crown of the tunnel and, therefore, reduces the settlement at the ground surface.

14

Effect of Tunnel Progress on the Settlement of Existing Piled Foundation

Al-Omari Raid Ramzi, Al-Soud Madhat Shakir, Al-Zuhairi Osamah Ibrahim

Studia Geotechnica et Mechanica

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2019

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Vol. 41, nr 2

102--113

EN

Tunnel construction below or adjacent to piles will affect the performance and eventually the stability of piles due to ground deformation resulting in the movement of piles and changes in the axial force distribution along the piles. A three dimensional finite element analysis using PLAXIS 3D (2013) was performed to study the behaviour of a single pile and 3 x 3 piles group during the advancement of shield tunnelling in ground. The 10-node tetrahedral elements were used to model both the soil and the tunnel lining. The Hardening Soil (HS) model was used to simulate the soil structure interaction at the tunnel-soil interface. An isotropic elastic model was used for the pile, piles cap, tunnel lining and tunnel boring machine shield (TBM). Several parametric studies were attempted including the longitudinal, lateral, and vertical tunnel location relative to pile embedded in different types of soil (clay or sand). The results showed that the pile head settlement increases during the tunnelling advancement in larger values than that for ground surface settlement. A zone of influence was determined in the range of twice the tunnel diameter in the longitudinal direction (forward and backward of the pile), and transverse direction (left and right of the tunnel centreline). If the tunnel boring is kept off this zone then there is no fear of pile collapse.

15

On consistent nonlinear analysis of soil-structure interaction problems

Truty A.

Studia Geotechnica et Mechanica

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2018

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Vol. 40, nr 2

86--95

EN

Nonlinear soil-linear structure computational strategy is commonly accepted in the community of geotechnical engineers using advanced finite element software for solving complex soil-structure interaction problems. However, further design procedure of the structural elements is carried out using increased values of the computed elastic stress resultants. It is absolutely not clear whether this method is conservative and, therefore, whether safe or not. To tackle this problem, a fully consistent nonlinear analysis of a deep excavation protected by the diaphragm wall is analysed here. The subsoil is modelled using the Hardening Soil model, while reinforced concrete is modelled using the modified Lee-Fenves model enhanced by the Eurocode 2 (EC2)-compatible creep module, developed by the author. It is shown that the commonly used nonlinear soil-linear structure computational strategy may yield insufficient amount of reinforcement from the ultimate limit state (ULS) and serviceability limit state (SLS) points of view. A consistent and conservative method of combining fully nonlinear analysis and the rules imposed by the EC2 is proposed.

16

Shakedown analysis of “soil-pile foundation-frame” system under seismic action

Alawdin P., Bulanov G.

Civil and Environmental Engineering Reports

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2018

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Vol. 28, no. 1

100--114

EN

In this article, the seismic shakedown FEM analysis of reinforced concrete and composite spatial frame structures on the deformable foundation, taking into account the elastic-plastic and brittle behavior of structures elements, is presented. A foundation consists of group of the piles in the soil. The behavior of soil is described here using and the elastic half-space theory. The pile deformation model is assumed to be elastic-perfectly plastic, where the bearing capacity is determined by the results of testing the soils or the piles themselves. An example of seismic shakedown limit analysis is presented.

PL

W niniejszym artykule za pomocą metody elementów skończonych przedstawiona analiza przystosowania sejsmicznego przestrzennych układów ramowych na podłożu odkształcanym, biorąc pod uwagę sprężysto-plastyczne i kruche zachowanie elementów układu. Podłoże składa się z grupy pal w gruncie. Grunt zachowuje się jako sprężyste ciało półprzestrzenne. W modelu odkształcenia pali założono zachowanie idealnie sprężysto-plastyczne, a nośność graniczna pali określa się na podstawie wyników badań podłoża lub samych pal. Przedstawiono przykład przystosowania sejsmicznego dla opisanego wyżej układu ramowego.

17

On the mechanics and modeling of interfaces between granular soils and structural materials

Saberi M., Annan C. D., Konrad J. M.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1562--1579

EN

The behavior of interfaces between granular soils and structural construction materials has an important impact on the monotonic and cyclic response of many soil–structure interaction (SSI) systems. Understanding the mechanics and modeling of these interfaces is an important step towards a safe and effective design and analysis of SSI problems. An extensive literature search for a ‘one-stop shop’ providing a comprehensive exposition on the mechanical characteristics and numerical modeling approaches of granular soil–structure interfaces yielded less than encouraging results. This paper seeks to bridge this knowledge gap in as concise manner as possible. To this end, the effects of the essential elements of the SSI problem, including soil and structural features as well as loading conditions, on the deformation and stress transformation mechanism of the interface are critically examined. Simple and advanced interface constitutive modeling methods are discussed, and implementation techniques of interface elements in finite element codes are explained. Additionally, a method to incorporate the effect of particle breakage to improve the capabilities of an elasto-plastic constitutive simulation of the cyclic accumulative contraction in granular interface modeling is introduced.

18

Analiza numeryczna zmian naprężeń w konstrukcji ściany wywołanych nieciągłymi deformacjami podłoża górniczego

Szojda L.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2017

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z. 64, nr 3/I

511--522

PL

Efektem podziemnej eksploatacji kopalin na powierzchni terenu są osiadania powierzchni. W większości przypadków są to deformacje tzw. ciągłe, które ujawniają się w postaci łagodnej niecki obniżeń, jednak w określonych przypadkach mogą się pojawić deformacje nieciągłe. Ich sposób ujawniania się jest gwałtowny, a zabezpieczenie konstrukcji znajdującej się na powierzchni terenu jest trudne. W referacie przedstawiono analizę numeryczną układu budowla-podłoże obciążonej ujawniającymi się nieciągłymi deformacjami podłoża. Analizę przeprowadzono z wykorzystaniem niekomercyjnego oprogramowania MAFEM3D, które zostało opracowane przez prof. Majewskiego. Program stosuje przyrostowo-iteracyjną procedurę MES z wykorzystaniem sprężysto-plastycznego modelu materiałowego z izotropowym wzmocnieniem i osłabieniem. Zastosowanie tego modelu materiałowego umożliwiło opracowanie modelu konstrukcji muru ceglanego oraz podłoża, który został obciążony nieciągłą deformacją terenu. Analizę przeprowadzono dla jednego geometrycznego modelu ściany z różnymi wykorzystanymi materiałami konstrukcyjnymi i elementami wzmacniającymi. Obciążenia zostały zaimplementowane jako próg terenowy, który obejmował różną długość fundamentu. W trakcie analizy wyników brane pod uwagę były zmiany naprężeń w konstrukcji i podłożu. Poziom wytężenia każdego elementu skończonego przedstawia strefy wyczerpania nośności, co może wskazywać na powstanie zarysowań w konstrukcji lub uplastycznień w podłożu. Wyniki analiz numerycznych dają obiecujące rezultaty, które jednak należy ograniczyć do konkretnej konstrukcji ściany. Dalsze etapy analiz powinny zostać rozszerzone na pełną analizę trójwymiarową i przestrzenną współpracę elementów konstrukcyjnych (ściany, płyty stropowe). Należy również rozważyć różny rodzaj parametrów gruntowych oraz lokalizacji progu w stosunku do fundamentów. Przedstawiona analiza jest wstępna, a wyniki mają charakter jakościowy.

EN

Non-continuous mining deformations appear in mining activity regions. They are not so common as continuous ground deformations. The process of their appearing is violent and a protection of the structure is difficult. The paper presents a numerical approach to a soil-structures interaction during the activity of ground fault – non-continuous ground deformation. The analysis was carried out by a noncommercial software MAFEM3D created by prof. Majewski. This software uses incrementaliterative procedure of FEM with elastic-plastic material model and isotropic hardening/softening of a material. It allowed to create model of brick-wall structure and the ground which was loaded by the non-continuous ground deformation. The analysis was carried out for one geometric wall shape but with different material parameters and strengthening elements. The loads were implemented as a ground fault which comprised different length of structure footing. The results of calculation were considered for stresses variability of structure and the subsoil. The effort level for finite element showed areas at risk of cracks in structure as well as the ground plasticization process on the edge of the fault. The numerical analyses gave promising results but they were checked only for one wall structure. The further steps of analyses should be extended to real 3D structures and considered on spatial cooperation of the structural elements like walls, plates etc. In addition the different kind of ground parameters and location below the foundation should be taken in consideration.

19

Analyses of soil-structure interaction based on vertical load tests of displacement piles

Martinkus V., Norkus A.

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2015

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nr 18(4)

261--270

EN

The current paper presents a research based on experimental and numerical analysis of three different frame supported by displacement pile groups embedded in sand. The vertical load tests performed under lab conditions have shown different responses of single piles installed at the same pile group, and a densification effect was named as a key player taking the main roll in explaining this phenomenon. A numerical analysis based on experimental data revealed unfavourable changes on deformation and internal forces of three different frame types caused by densification phenomenon. Performed research has emphasised the significance of soil structure interaction analysis, especially when displacement pile groups embedded in sands are used.

20

Zastosowanie przybliżonych modeli SSI w przypadku wstrząsów górniczych

Kuźniar K., Tatara T.

Przegląd Górniczy

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2015

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T. 71, nr 10

25--30

PL

W pracy dokonano przeglądu wybranych, proponowanych w literaturze, przybliżonych, prostych modeli uwzględniających zjawisko współpracy podłoże-budynek (j. ang.: soil-structure interaction – SSI) podczas trzęsień ziemi. Analizowano przydatność tych modeli do prognozowania różnic między jednocześnie zachodzącymi drganiami gruntu obok budynku i fundamentu budynku, których źródłem były wstrząsy górnicze w Legnicko-Głogowskim Okręgu Miedziowym (LGOM). Skupiono się na ocenie dokładności modeli w przypadku ich stosowania do wyznaczania relacji odpowiednich spektrów odpowiedzi: bezwymiarowych przyśpieszeniowych spektrów odpowiedzi (β) oraz wymiarowych przyśpieszeniowych spektrów odpowiedzi (Sa) od drgań poziomych. Pod uwagę wzięto różnego typu budynki.

EN

This paper presents the selected, proposed in the literature, approximate, simple models which take into account the phenomenon of soil-structure interaction (SSI) during earthquakes. The usefulness of these models for the prediction of the differences between mine-induced vibrations in the Legnica-Glogow Copperfield (LGOM) occurring at the same time on the ground near the buildings and building foundations is analysed. The focus is on the evaluation of the accuracy of the models in the case of their application for the estimation of the relation (ratio) between the corresponding response spectra: non-dimension acceleration response spectra (β) as well as dimension averaged acceleration response spectra (Sa) from the horizontal vibrations. Various types of buildings are taken into account.