International Concrete Abstracts Portal

Editors: Kyuichi Maruyama and Andrew W. Taylor

The First American Concrete Institute (ACI) and Japan Concrete Institute (JCI) joint seminar was conceived as a vehicle for promoting collaboration and cooperation between two organizations that are dedicated to the global advancement of concrete technology. In September 2012 ACI President James Wight, and ACI Executive Vice President Ronald Burg, visited the headquarters of JCI and discussed ways to promote collaboration between ACI and JCI with JCI President Taketo Uomoto and JCI Executive Directors. A joint ACI and JCI technical seminar was proposed as a way to share knowledge and foster collaboration between the two organizations. Subsequent discussions between Ronald Burg and JCI Executive Director Kyuichi Maruyama led to a joint seminar planning meeting, held at the ACI convention in Minneapolis, Minnesota, in April 2013.

This volume contains the technical papers presented at the First ACI & JCI Joint Seminar, held in Waimea, Island of Hawaii, Hawaii, July 16 to 18, 2014. The theme of the joint seminar was “Design of Concrete Structures Against Earthquake and Tsunami Disasters.” Five papers were presented by authors from ACI, and five papers from JCI. Three papers are related to tsunami loads and structural design requirements, and seven are related to seismic analysis and design.

The three papers on tsunami effects included a summary by Nakano of structural design requirements for tsunami evacuation buildings in Japan; an overview by Chock of the new tsunami load and design requirements in the United States; and a study by Maruyama et al. on the evaluation of tsunami forces acting on bridge girders.

The seven papers on seismic effects addressed topics ranging from seismic design standards to innovative methods of construction for seismic retrofit. Parra-Montesinos et al. presented the results of experiments on fiber-reinforced coupling beams, as well as design guidelines. Teshigawara discussed JCI contributions to the ISO Standard for seismic evaluation and retrofit of existing concrete structures. A summary of a project on the use of high-strength reinforcement for seismic design was presented by Kelly et al., including findings that are based on extensive prior research on high-strength reinforcement in Japan. Shiohara described the results of a study that supports the new Architectural Institute of Japan (AIJ) Standard for Seismic Capacity Calculation, with a focus on beam-column joints and collapse simulation. Matamoros presented a study of factors that affect drift ratio at axial failure of nonductile reinforced concrete buildings. A study of the seismic response of reinforced concrete bridge piers, including the effects of interaction between piles and soil, was presented by Maki et al. Finally, French et al. discussed an overview of lessons learned from laboratory testing of reinforced concrete shear walls.

The day after the joint seminar a meeting was held between ACI and JCI officials to discuss future collaboration and joint seminars. Representing ACI were President William E. Rushing, and the ACI Executive Vice President, Ronald Burg. Representing JCI were President Hirozo Mihashi, and Chair of the JCI Committee on JCI-ACI Collaboration, Kyuichi Maruyama. It was resolved to hold a second joint seminar, to be hosted by JCI in Tokyo, in conjunction with the 50th anniversary celebrations of the founding of JCI on July 13, 2015. In addition, subsequent discussions between ACI and JCI led to plans for the third joint seminar, to be hosted by ACI at the ACI Convention in Anaheim, California, in October 2017.

It is hoped that this collection of papers will serve to advance the state of analysis and design of concrete structures against earthquakes and tsunamis in both the United States and Japan, and that it will serve as a model for future collaboration between ACI and JCI.

Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-313

The Tsunami Loads and Effects Subcommittee of the ASCE/SEI 7 Standards Committee has developed a new Chapter 6 - Tsunami Loads and Effects for the 2016 edition of the ASCE 7 Standard, Minimum Design Loads for Buildings and Other Structures. Chapter 6 provides loads and other requirements for tsunami and its effects. The 2016 edition of the ASCE 7-16 Tsunami Loads and Effects chapter will be applicable initially to the states of Alaska, Washington, Oregon, California, and Hawaii, which are tsunami-prone regions that have probabilistically quantifiable hazards resulting from tsunamigenic earthquakes of subduction mechanism. The International Building Code (IBC) references design provisions that are given in American Society of Civil Engineers Standard 7. The ASCE 7 Standard becomes part of an enacted building code law through adoption of the model International Building Code by the local authority having jurisdiction (such as a state, county, or city). The IBC would incorporate ASCE 7-16 in 2018. Therefore, it is anticipated that the first national tsunami design provisions of ASCE 7-16 would be utilized as a part of mandatory building codes of U.S. jurisdictions after 2020. In these five western states, it is recognized by federal, state, and local governments that mitigation of tsunami risk to public safety requires emergency preparedness for evacuation, in addition to structural resilience of critical facilities necessary for immediate response and economic and social recovery. The public safety risk has been only partially mitigated through warning and preparedness of evacuation; there are many areas where complete evacuation cannot be assured. The lesson of recent catastrophic tsunami is that historical records alone do not provide a sufficient measure of the potential heights of future tsunamis. Engineering design must consider the occurrence of events greater than scenarios in the historical record, based on the underlying seismicity of subduction zones. For U.S. national tsunami design provisions to achieve a consistent reliability standard of structural performance for community resilience, Probabilistic Tsunami Hazard Analysis (PTHA) consistent with source seismicity is performed in addition to consideration of historical event scenarios.

The design of reinforced concrete coupling beams in regions of high seismicity typically includes the use of diagonal bars designed to resist the entire shear demand, along with closely spaced transverse reinforcement to provide concrete confinement and diagonal bar support. While results from experimental investigations indicate that this design leads to stable behavior under large displacement reversals, the required reinforcement detailing is labor intensive and time consuming. One alternative that has been proven successful to simplify reinforcement detailing in coupling beams is the addition of discontinuous, deformed steel fibers to the concrete. Test results indicate that elimination of diagonal reinforcement, along with substantial reductions in confinement reinforcement over most of the beam span, are possible in coupling beams with span-to-depth ratios greater than or equal to approximately 2.2 when a tensile strain-hardening fiber reinforced concrete is used. Given the advantages of eliminating diagonal reinforcement in coupling beams, this new design was incorporated in high-rise structures in the State of Washington, USA, starting in the early 2010s. In this paper, a brief summary of relevant experimental results and the implementation of fiber reinforced concrete coupling beams in high-rise earthquake-resistant construction is provided.

This paper deals with what tsunami force acted on bridge girders by Great East Japan Earthquake broken out in March 11, 2011. First of all, a lot of efforts were conducted to collect almost all data of bridge girders in the inundation area. Satellite images in internet websites proved very effective to make a quick survey of any bridge in the inundation area. Detailed data on the bridges were obtained from authorities for use in damage analysis. The method proposed by Prof. Kosa was introduced to see whether bridges were washed away or not by tsunami. The resistance of each bridge is expressed as a function of the self-weight of bridge girder, and the tsunami force is defined by hydro-dynamic equation. More than two hundred bridges, including both washed away bridges and survived ones, were analyzed. Motion pictures taken by digital camera during the attack of tsunami were examined to evaluate the velocity and height of tsunami. As far as bridges in a local area were taken into account, the method was good to see whether bridges were survived or not. Field survey of the bridges washed away indicated that the failures would have been by tsunami uplift force. Experimental investigation was done using a water channel to examine what forces acted on bridge girders and to develop a proper simulation model.

A new concept of joint hinging developed in Japan is presented, which will be implemented in a new draft provision for beam-column joints in the New AIJ (Architectural Institute of Japan) Standard for Seismic Capacity Calculation. This paper discusses the key issues of the new draft provisions, with background, test data verification, theory and analyses with emphasis on why such a concept is necessary. The factors affecting joint hinging failure are discussed for seismic design consideration. Seismic collapse simulation were made by non-linear time history analysis for moment frames with BC joints failing due to joint hinging, to demonstrate the challenge of simulated strength degradation and severe pinching hysteretic behavior inherent to joint hinging. Draft equations to calculate the strength of joint hinging strength of BC joints are also introduced.