SUMMARY
This paper presents the preliminary research works on a potential seismic isolation method that makes use of scrap rubber tires for the protection of low-to-medium-rise buildings. The method involves mixing shredded rubber tire particles with soil materials and placing the mixtures around building foundations, which provides a function similar to that of a cushion. Meanwhile, the stockpiling of scrap tires is a significant threat to our environment, and the engineering community has been looking for long-term viable solutions to the recycling and reuse of rubber. A finite element program has been developed for modeling the time-domain dynamic responses of soil–foundation–structure system, by which the effectiveness and robustness of the proposed method have been evaluated. In general, the structural responses, in terms of acceleration and inter-story drift, can be reduced by 40–60%. Copyright © 2012 John Wiley & Sons, Ltd.

Seismic isolation for low‐to‐medium‐rise buildings using granulated rubber–soil mixtures: numerical study

This study examines the small-strain dynamic properties of mixtures composed of sandy and gravelly soils with granulated tire rubber in terms of shear modulus (GO), and damping ratio in shear (Dmin). Torsional resonant column tests are performed on dry, dense specimens of soil-rubber mixtures in a range of soil to rubber particles size 5:1–1:10 and rubber content from 0 to 35% by mixture weight. The experimental results indicate that the response of the mixtures is significantly affected by the content of rubber and the relative size of rubber to soil particles. Concering the small-strain shear modulus, an equivalent void ratio is introduced that considers the volume of rubber particles as part of the total volume of voids. Based on a comprehensive set of test results a series of equations were developed that can be used to evaluate the shear modulus and damping ratio at small shear strain levels if the confining pressure, the content of rubber by mixture weight, the grain size of soil and rubber particles, and the dynamic and physical properties of the intact soil are known.

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Small-Strain Shear Modulus and Damping Ratio of Sand-Rubber and Gravel-Rubber Mixtures

Effect of rubber size on the behaviour of sand-rubber mixtures: A numerical investigation

This paper presents studies on use of recycled tire shreds in sand–tire chips (STC) mixture for retaining wall applications. Small-scale physical model tests were performed on rigid retaining wall with different STC mixtures. Rigid retaining wall model of 600 mm height was constructed in a Perspex container. The wall was made with hollow rectangular steel sections. STC mixtures with different tire chips proportions, such as 10, 20, 30, 40, and 50 % along with pure sand were considered as backfill materials. Static surcharge load, up to 10 kPa, was applied using concrete blocks. Model wall behaviour in terms of displacements and earth pressures has been discussed for sand alone (control case) and STC mixtures as backfill materials. The experimental results indicate that the horizontal displacements and lateral earth pressures are reduced to about 50–60 % of that of control case by using STC mixtures which functioned as light weight backfill materials.

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Recycled Tire Chips Mixed with Sand as Lightweight Backfill Material in Retaining Wall Applications: An Experimental Investigation

Multifaceted potentials of tire-derived three dimensional geosynthetics in geotechnical applications and their evaluation

A series of large-scale underwater shaking table tests was performed on a gravity type model caisson protected by a cushioning technique using tire chips (scrap tire derived recycled product). The function of the tire chips cushion is to reduce the load and restricting the permanent displacement of such waterfront retaining structures during earthquakes by exploiting the compressibility, the ductility and the energy absorbing capacity of tire chips. The seismic performance of such earthquake resistant techniques was evaluated by subjecting the soil-structure system into three different earthquake loadings (two actual earthquake records and one synthetic earthquake), and measuring the respective responses. The results demonstrated that the seismic load against the caisson quay wall could be substantially reduced using the proposed technique. In addition, the presence of the protective tire chips cushion could significantly reduce the earthquake-induced residual displacement of the caisson quay wall.

Underwater Shake Table Tests on Waterfront Structures Protected with Tire Chips Cushion

Strong-motion earthquake observation of pile-supported wharves and a container crane during the 2011 off the pacific coast of tohoku earthquake

A shake table test of breakwater which paid its attention to power spectrum intensity as an earthquake motion evaluation index

本研究は，既設重力式岸壁前面に新設矢板を打設する増深改良を対象とし，有限要素法による地震応答解析の簡略化のための既設ケーソンとその築堤過程の省略の影響について検討し，その変形挙動のメカニズムを考慮した考察を行った．既設ケーソンの築堤過程の省略においては，ケーソン設置時の海底地盤への応力伝達が評価できなくなり，増深改良後の矢板前面海底地盤の拘束圧を小さく評価した．このことにより矢板根入れ部の変位に対する地盤の抵抗が小さくなり，改良岸壁の全体的な変位挙動を大きく評価するなど，その影響は小さくなかった．既設ケーソンのモデル化の省略においては，ケーソン底面付近での矢板への局所的に大きい土圧が表現されなくなり，矢板の曲げ変形の評価が小さくなった． 

Effect of existing structure modeling in seismic response analysis of an improved and deepened gravity-type quay wall by sheet piles with anchor piles

Pile model penetration tests were conducted in a transparent plane strain container filled with granular mechanoluminescent-coated particles. The pile models were constructed with flat and cone-shape tips. Load transmission through the analogue granular soil was captured by taking images of the light emissions from one side of the container that were triggered by inter-particle force-induced mechanoluminescence during pile penetration. Time-coincident images were taken from the other side of the container using a second camera and the corresponding displacement fields computed using the digital image correlation (DIC) method. Particle contact force chains at peak loads are shown to be in reasonable agreement with particle displacement fields. Differences in both displacements fields and patterns of particle contact force chains were detectable between pile models with flat and cone shape pile tips. The orientations of the particle contact force chains generated at the base of the flat tip pile model at peak pile load were in reasonable agreement with the geometry of the wedge of soil assumed from classical bearing capacity theory.

Visualization of localized deformation and load transmission during pile penetration using mechanoluminescent-coated particles and digital image correlation

Eiji Kohama

Papers

Underwater Shake Table Tests on Waterfront Structures Protected with Tire Chips Cushion

Strong-motion earthquake observation of pile-supported wharves and a container crane during the 2011 off the pacific coast of tohoku earthquake

A shake table test of breakwater which paid its attention to power spectrum intensity as an earthquake motion evaluation index

Effect of existing structure modeling in seismic response analysis of an improved and deepened gravity-type quay wall by sheet piles with anchor piles

Visualization of localized deformation and load transmission during pile penetration using mechanoluminescent-coated particles and digital image correlation