Large‐scale field testing of geotechnical seismic isolation of structures using gravel‐rubber mixtures

Earthquake Engineering & Structural Dynamics, Journal Year: 2021, Volume and Issue: 50(10), P. 2712 - 2731

Published: May 31, 2021

Abstract We present the results of a large‐scale experimental campaign performed on prototype structure EuroProteas in Thessaloniki, Greece, to assess effectiveness gravel‐rubber mixture (GRM) layers underneath shallow foundations as means geotechnical seismic isolation (GSI). found that GSI structures is optimized by increasing rubber content soil‐rubber up 30% per weight. The systems has been investigated numerically and small‐scale experiments. This article seeks fill gap lack full‐scale studies this subject. Three soil pits were excavated backfilled with GRM different weight serve foundation soil. A large number instruments installed structure, foundation, surface, inside beneath fully monitor GSI‐structure systems’ response three dimensions. investigation included ambient noise, free‐ forced‐vibration tests. Our showed layer composed effectively isolates structure. Even 0.5 m thickness (ie, B /6 width) system successfully cuts off practically all emitted waves at (horizontal or vertical) distance from foundation. significant reduction system's stiffness was apparent, leading rocking‐dominant response. rise damping substantial energy dissipation highlight its system.

Language: Английский

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Seismic fragility assessment of geotechnical seismic isolation (GSI) for bridge configuration

Bulletin of Earthquake Engineering, Journal Year: 2022, Volume and Issue: 21(8), P. 3969 - 3990

Published: Feb. 24, 2022

Abstract The seismic vulnerability of bridges may be reduced by the application Geotechnical Seismic Isolation (GSI) below foundations columns and abutments. However, role GSI on response has been limitedly examined in literature. Therefore, this research conducted to study effect applying address aforementioned gap knowledge. Advanced nonlinear dynamic three-dimensional finite element analyses have using OpenSees influence GSI. cases traditional isolated subjected earthquakes considered assess effects. results showed that reduces column while its seems less significant for In addition, fragility curves developed compared provide insights with a probabilistic-based approach. paper useful benchmark design considerations regarding use bridges.

Language: Английский

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Seismic resilience of bridges isolated with traditional and geotechnical seismic isolation (GSI)

Bulletin of Earthquake Engineering, Journal Year: 2023, Volume and Issue: 21(7), P. 3521 - 3535

Published: March 7, 2023

Language: Английский

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Seismic isolation effect of rubber-sand mixture cushion under different site classes based on a simplified analysis model

Soil Dynamics and Earthquake Engineering, Journal Year: 2023, Volume and Issue: 166, P. 107738 - 107738

Published: Jan. 9, 2023

Language: Английский

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Analytical design models for geotechnical seismic isolation systems

Bulletin of Earthquake Engineering, Journal Year: 2022, Volume and Issue: 21(8), P. 3881 - 3904

Published: July 25, 2022

Abstract Geotechnical Seismic Isolation (GSI) can be defined as a new category of seismic isolation techniques that involve the dynamic interaction between structural system and geo-materials. Whilst mechanism various GSI systems their performance have already been demonstrated through different research methods, there is missing link fundamental engineering practice. This paper aims to initiate development in this direction. A suite equivalent-linear foundation stiffness damping models under same framework proposed for four configurations, one which novel combination two existing ones. The exact solutions equivalent properties flexible-base also derived explicitly include inertia strain-dependent materials, are both significant systems. application analytical design has illustrated response history analyses detailed hand-calculation procedure outlined demonstrated.

Language: Английский

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Dynamic properties of recycled polyurethane-coated rubber-soil mixtures

Case Studies in Construction Materials, Journal Year: 2023, Volume and Issue: 18, P. e01859 - e01859

Published: Jan. 18, 2023

A large quantity of end-of-life tire (ELT) rubber is being blended with thermoplastic polyurethane to provide a durable and ecologically friendly material for flexible surfaces, while significant elastomeric waste (left-over cut-outs) also generated. These materials can be used efficiently seismic isolation vibration damping at minimal cost, process known as frugal innovation. In this regard, (TPE) material, which polyurethane-coated (PUcR), obtained from the recycling industry, explored in study. Herein, we targeted evaluate stiffness energy dissipation capabilities TPE or PU-coated rubber, which, best our knowledge, has never been reported before. To that end, series cyclic triaxial tests were carried out on rubber-soil mixtures. comparison untreated mixtures, shear modulus mixtures reduces by 5.5–12.7%, ratio increases up 12.6%.

Language: Английский

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Experimental study on sand-tire chip mixture foundations acting as a soil liquefaction countermeasure

Bulletin of Earthquake Engineering, Journal Year: 2023, Volume and Issue: 21(8), P. 4037 - 4063

Published: March 18, 2023

Abstract Soil liquefaction is a phenomenon associated with strong earthquakes and it can affect large areas. High-rise low-rise buildings, residential structures typically of 1–2 storeys, may be equally prone to the destructive consequences liquefaction. For case high-rise expensive solutions like well-designed piles ground improvement used. However, in smaller structures, this not economically viable. To purpose, current research explores effectiveness novel proposed low-cost protection technique, where soil underneath foundation replaced by sand-tire chip mixture base reaching down certain depth. Series triaxial shaking table tests were performed for range parametric scenarios to, mainly mechanistically, assess such mitigation since similar previous studies are extremely limited. The have shown that closest considered surface, thicker higher tire ratio, more effective become on controlling pore pressure rise leads

Language: Английский

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Direct shear behavior of gravel-rubber mixtures: Discrete element modeling and microscopic investigations

SOILS AND FOUNDATIONS, Journal Year: 2022, Volume and Issue: 62(3), P. 101156 - 101156

Published: May 6, 2022

In this paper, a newly developed 3-dimentional discrete element model (DEM) for gravel-rubber mixtures (GRMs), namely DEM4GRM, that is capable of accurately describing the macro-scale shear response (from small to large deformation) GRMs in direct box apparatus presented. Rigid gravel grains are modelled as simple multi-shape clumps, while soft rubber particles modeled by using deformable 35-ball body-centered-cubic clusters. Mixtures prepared with different volumetric content (VRC) at 0, 10, 25, 40 and 100%, statically compressed under 30, 60 100 kPa vertical stress then sheared, closely simulating reference laboratory test procedure. The variation micro-scale factors such fabric, normal tangential force anisotropy carefully examined throughout shearing process described means novel micro-mechanical relationships valid GRMs. Moreover, strong-force chains scrutinized identify transition from rigid granular skeleton gain insights on load transfer deformation mechanisms It shown development fabric during related strength GRMs, strongly depends VRC. Besides, appear be primarily formed gravel-gravel contacts (resulting rigid-like mechanical behavior) up VRC = 30%, rubber-rubber (causing soft-like response) beyond 60%. Alternatively, 30% < 60%, predominant network an intermediate behavior observed. This consistent behavioral trends observed macro- responses.

Language: Английский

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Shaking table experiments on framed structure resting on geogrid reinforced geotechnical seismic isolation system

Bulletin of Earthquake Engineering, Journal Year: 2023, Volume and Issue: 21(8), P. 3823 - 3849

Published: April 26, 2023

Language: Английский

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Serviceability performance of buildings founded on rubber–soil mixtures for geotechnical seismic isolation

Australian Journal of Structural Engineering, Journal Year: 2023, Volume and Issue: 24(4), P. 265 - 278

Published: June 29, 2023

Base isolation is a low-damage seismic design strategy that can be used for constructing resilient structures. Geotechnical (GSI) new category of emerging base techniques has attracted global interest in the past decade. Research on GSI based rubber-soil mixtures (RSM) focused structural performance under earthquake actions, whilst there are concerns over serviceability limit states (SLS) requirements relation to (i) human comfort strong winds and (ii) ground settlement gravity, which may induce cracking durability issues This article presents first study buildings constructed with GSI-RSM system. The finite element model coupled soil-foundation-structure system been validated by data recorded from geotechnical centrifuge testing. numerical estimates have also compared analytical predictions. It concluded satisfactorily fulfill SLS requirements.

Language: Английский

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