1. Prof. Akira Asaoka (Former Professor, Nagoya Univerity; Former President, The Japanese Geotechnical Society)
2. Prof. Marcio M. Farias, The University of Brasilia, Brazil
3. Prof. Richard G. Wan, University of Calgary, Calgary, Alberta, Canada
4. Prof. Bujang B.K. Huat, Universiti Putra Malaysia, Malaysia
1. Prof. Akira Asaoka
TITLE: Subsurface Ground Deformation During and After an Earthquake– Simulation and Prediction based on elasto-plastic soil mechanics -
ABSTRACT: Specialization may be an unavoidable accompaniment to development in science, but specialization that runs to excess can actually hinder development. It seems to the authors that soil mechanics/geotechnical engineering is no exception to the rule. We are not just talking about the separate versions of mechanics that exist for sand and for clay, or the fact that dynamics and statics engage different specialists. When it reaches the point that we take it for granted that a model purpose designed to find undrained response in loose sand will have no power to handle compaction in the same loose sand, or that dense sand presents quite separate problems again, or that a computer program devised for consolidation deformation is unable to calculate the bearing capacity of the same foundation, or that one that is capable of computing liquefaction in a soil cannot be expected to compute compaction, and so on and so forth, all that we have left of geotechnology in the end is no more than an assemblage of miscellaneous specialist tools. And if that is the case, it means that when an external force comes to act on a soil foundation there is no system in place at all in geomechanics to allow consistent answers to questions such as: “Will the ground fail or only be deformed?”, “Will liquefaction occur or compaction?” or, more generally, “After an event like an earthquake, what is going to happen to that ground, and how?” Can we be satisfied with that? Questions like these gave the departure point from which the Nagoya University Soil Mechanics Group first set up “GEOASIA Research Society” in 2005.
The purpose of the present paper is to provide a transient analysis of all that occurs in a soil foundation or earth structure, in ALL SOILS, including sand, clay, intermediate, and artificially processed, in ALL STATES, through deformation to failure, and for ALL ROUND applications to static or dynamic problems. The paper will be delivered under the three content heads of “What are the differences between clay and sand?” which will be the introduction of the advanced SYS Cam-clay constitutive model, “The essentials of the pore water-soil skeleton coupled finite deformation analysis” in which rate type equation of motion will be employed, and “Application examples” in which subsurface ground deformation during and after an earthquake. All Calculations in this lecture note have been performed using a single analysis tool, i.e., GEOASIA.
In the course of research into reliability in civil engineering in the 1970s, Prof. Asaoka had the experience of being involved in settlement prediction work on the manmade Port Island in Kobe Bay, where he earned great credit for his proposal of a method of reformulating settlement prediction as an inverse problem of heat equation, allowing future settlement to be estimated by observational procedures under unknown initial and boundary conditions. His work at this time, however, made him painfully aware of the limits of traditional geotechnical engineering, which was highly empirical in tone. Starting in this way, he went on to attain the following principal achievements.
(1) Advancement of geotechnical computation centered on soil-water coupled finite deformation analysis
From an initial insight into one of the essential relations in the mechanics of soils, viz. the fact that the soil skeleton, as an elasto-plastic material, is in endless coupled motion with pore water enclosed in it, Prof. Asaoka traced his way to a computational mechanics capable of handling the whole range of soil behaviors from deformation to failure. Even since his 1987 paper, which shows the loading path dependency of the bearing capacity of a soil foundation, he has asserted a preeminent place in geotechnical computation for a soil-water coupled finite deformation analysis that draws no distinction between treatments of “consolidation” and “bearing capacity.” This line of research won general confirmation at an international symposium on “deformation and progressive failure in Geomechanics” (IS-Nagoya, Chairman Prof. Asaoka) which drew some 50 researchers from 15 European and American countries.
(2) Advancement of elasto-plastic constitutive modeling
Compared with the remolded clay used in laboratory experiments, the mechanical responses of naturally deposited clay, whether alluvial or diluvial in origin, are vastly more complicated. In addition, sand is altogether different from clay. And, to add to the problem, between sand and clay there exists a whole range of intermediate soils, all of which are materials of interest to geotechnical engineering. There is therefore a limit to the applications research that makes use, even multiple integrated use, of “ special elasto-plastic constitutive models” which, for example, fit only a classic sand, only a classic clay, or only a special purpose such as the investigation of undrained responses. Prof. Asaoka contributed a new type of elasto-plastic constitutive model, incorporating three rules of evolution to control overconsolidation, structure and anisotropy. Furthermore, this constitutive model was able not only 1) to explain the difference between sand and clay in the language of elasto-plastic mechanics, but also 2) to show the feasibility of describing all of their compression and shear behaviors including those of the intermediate soils. When this modeling achievement is set alongside the advance in computational technique referred to (1), it becomes clear that their combined use allows almost all the problems of geotechnical engineering, from the bearing capacity of clay to long term continuous consolidation, or from the liquefaction of sand to the compaction and large scale settlement due to vibration, to be discussed together in a single and coherent theoretical framework.
Ten principal career publications:
1) Asaoka, A., “Observational Procedure of Settlement Prediction2< Soils and Foundations, 18(4), pp 87-101, (1978). (Best Young Researcher Award of the Japanese Geotechnical Society)
2) Asaoka, A. and Ohtsuka, S., “Bearing Capacity Analysis of Normally Consolidated Clay Foundations”, Soils and Foundations, 27(3), pp.58-70, (1987). (Best Paper Award of the Japanese Geotechnical Society)
3) Asaoka, A., Ohtsuka, S. and Matsuo, M., “Coupling Analysis of Limiting Equilibrium State for Normally consolidated and Lightly Overconsolidated Soils”, Soils and Foundations, 30(3), pp.109-123, (1990).
4) Asaoka, A., Nakano, M. and Noda, T., “Soil-Water Coupled Behavior of Saturated Clay near/at Critical State”, Soils and Foundations, 34(1), pp.91-106, (1994).
5) Asaoka, A., Nakano, M. and Noda, T., “Soil-Water Coupled Behavior of Heavily Overconsolidated Clay near/at Critical State2”, Soils and Foundations, 37(1), pp.13-28, (1997).
6) Asaoka, A., Nakano, M., Noda, T., Kaneda, K. and Dan Constantinescu, T., “Progressive Failure of heavily Overconsolidated Clays”, Soils and Foundations, 39(2), pp.105-117, (1999).
7) Asaoka, A., Nakano, M. and Noda, T., “Superloading Yield Surface Concept for Highly Structured Soil Behavior”, Soils and Foundations, 40(29, pp.99-110, (2000). (Best Paper Award of the Japanese Geotechnical Society)
8) Asaoka, A., Noda, T., Yamada, E., Kaneda, K. and Nakano, M., “An Elasto-Plastic Description of Two Distinct Volume Change Mechanisms of Soils”, Soils and Foundations, 42(5), pp.47-57, (2002).
9) Noda, T., Asaoka, A. and Yamada, S., “Some bearing Capacity Characteristics a Saturated Naturally deposited Clay Soils”, Soils and Foundations, 47(2), pp.285-301, (2007). (Best Paper Award of the Japanese Geotechnical Society)
10) Noda, T., Asaoka, A. and Nakano, M., “Soil-Water Coupled Finite Deformation Analysis Based on a Rate-Type Equation of Motion Incorporating SYS Cam-Clay Model, Soils and Foundations, 48(6), pp.771-790, (2008) (Best Paper Award of the Japanese Geotechnical Society)
Ten principal presentations at international conferences:
1) CERRA-ICASP, Mexico City, June 1991. (General Report)
2) Int. Symp. On Compression and Consolidation, Hiroshima, Japan, May 1995.
3) The 10th Asian Regional Conference on Soil Mechanics and Foundation Engineering, Beijing, China, August, 1995. (Panel Presentation)
4) The 10th Danube European Conference on Soil Mechanics and Foundation Engineering, Romania, September, 1995. (Keynote Lecture)
5) Int. Symp. On Deformation and Progressive Failure in Geomechanics, Nagoya, Japan, October, 1997. (Keynote Lecture)
6) The 4th European Conference on Numerical Methods in Geotechnical Engineering, Udine, Italy, October, 1998. (Keynote Lecture)
7) Jubilee Congress in University of Peradeniya, Peradeniya, Sri Lanka, July 2000. (Invited Lecture)
8) The 12th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, Singapore, August, 2003. (Keynote Lecture)
9) Jubilee Congress in Housing and Building Research Center, Ministry of Housing, Utilities and Urban Communities, Cairo, Egypt, December, 2004. (Keynote Lecture)
10) The 11th Int. Conference of International Association of Computer Methods and Advances in Geomechanics, Torino, Italy, June 2005. (Overview Lecture)
-Editor in Chief of “Soils and Foundations”, Journal of the Japanese Geotechnical Society, from 1998 to 2002.
-Secretary of the Japanese Geotechnical Society, from 2002 to 2006.
-Vice-President of the Japanese Geotechnical Society, from 2004 to 2006.
-President of the Japanese Geotechnical Society, from 2008 to 2010.
Concise social activities:
Professor Akira Asaoka was born on 10 March 1947, in the city of Osaka, Japan where the 16th ICSMGE was held in September 2005.
Having graduated from Kyoto University in 1970, Professor Asaoka went on his post graduate course in civil engineering and received his master degree of engineering in 1972, and his doctorate of engineering in 1977 in the same university. His first appointment as a research associate in Civil Engineering Department of Kyoto University was to work on civil engineering planning and reliability theory. He also worked as an associate professor at Ressellear Polytechnic Institute, New York, for a period of one year. “Reliability in Civil Engineering Design” was the title of his lectures in the graduate course at RPI. He then returned to Japan, at the early age of 33, he started his research and teaching activities as an associate professor at Nagoya University in the field of soil mechanics and foundation engineering.
1n 1998, Professor Asaoka was granted the title of Full Professor of Civil Engineering by Nagoya University. He was also appointed to the chairmanship of the Civil Engineering Department of Nagoya University and served four times in this position in 1990-1991, 1995-1996, 2002-2003 and 2007-2008.
During this Career, professor Asaoka has published more than 180 technical papers and has ever delivered special lectures in several international conferences including the 12th Asian Regional Conference on SMGE, Singapore 2003. The Japanese Geotechnical Society (JGS) has granted him five awards for his outstanding research work, particularly in consolidation, bearing capacity and constitutive modeling. He was the editor in chief of the “Soils and Foundations,” Journal of the JGS in 2002, a post in which he liaised with Asian and International Geotechnical Societies. From 2004 to 2006, he was Vice-president of the JGS, and from 2008 to 2010, he worked as President of JGS.
In the end of March 2010, Professor Asaoka retired from Nagoya University which granted him the title of Professor Emeritus, and now he is working at Research Division for Earthquakes and Disaster Mitigation, Association for the Development of Earthquake Prediction, as a Senior Research Adviser.
In the beginning of April 2010, Ministry of Education, Culture, Sports, Science and Technology, Japan, granted Professor Asaoka a special prize for his continuous research works on science and technology, particularly in the field of elasto-plasticity including soil mechanics and earthquake engineering, and Professor Asaoka has been given the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology.
1) Best Young Researcher Award of JGS, 1979.
2) Best Paper Award of JGS, 1988.
3) Distinguished Contribution Award of JGS, 2000.
4) Best Paper Award of JGS, 2001.
5) International Association for Computer Methods and Advances in Geomechanics REGIONAL AWARDS: EXCELLENT CONTRIBUTION, 2005.
6) Best Paper Award of JGS, 2008.
7) The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology, Prizes for Science and Technology, Research Category, 2010.
8) Best Paper Award of JGS, 2010.
9) Best Paper Award in Geotechnical Special Publication No. 201, ASCE, 2010.
2. Prof. Márcio Muniz de Farias
TITLE: Use of Recycled Materials for the Construction of Road Pavements
ABSTRACT: The appropriate disposal of industrial wastes is a major environmental concern throughout the world. The industry of civil construction is a major contributor to this problem due to the huge amount of wastes generated during the construction of new buildings and the demolition or reformation of old structures. Construction and demolition wastes (CDW) comprise soils from excavations, asphalt concrete from old pavement surfaces, and a large variety of material from buildings, such as concrete, ceramics, sand and rock chips, gypsum boards, among others. Most of these materials can be recycled to mitigate the waste disposal problem and, at the same time, reduce the exploitation of new raw materials. Despite huge advances in some developed countries, recycling and reuse of wastes is still incipient in many developing countries, such as Brazil. To tackle this problem the author gathered a group of researchers from different Brazilian universities in a joint resource program aiming to investigate the use of industrial wastes in the construction of road pavement layers. This kind of application was chosen taking into account the large amount of materials required and the possible economic impacts. The wastes investigated included CDW, scrap tires and gypsum from the production of agricultural fertilizers (phosphogypsum). The materials were used raw or mixed with other ingredients. Demolition wastes were tested for base pavement course and the results were mostly satisfactory: the positive aspects include gain or strength and stiffness with time; negative aspects include high water absorption and particle breakage. Milled asphalt concrete also showed satisfactory behavior when used together with rejuvenating oils that enhance the properties of oxidized asphalt binders. Granules of rubber recycled from scrap tires are already known for their positive effects on asphalt binders, but this research also showed that they might reduce the breakage of particles when used together with CDW. Gypsum, either from plaster boards or from phosphoric acid, has shown to be the most challenging material: many mechanical properties of soil-gypsum mixes were unsatisfactory, but some promising results were obtained when gypsum was used as filler in hot asphalt mixes, although special attention must be given to problems related to gypsum hydration. Overall the research concludes for the economic, environmental and technical feasibility of recycling most of the materials investigated.
RESUME: Márcio Muniz de Farias
Graduated in Civil Engineering at the Federal University of Ceara, UFC (Brazil, 1983), Master in Geotechnics, at the Catholic University of Rio de Janeiro, PUC-Rio (Brazil, 1986), PhD in Numerical Methods at the University of Wales at Swansea (United Kingdom, 1993), Post-doctoral sabbatical at Nagoya Institute of Technology – NIT (Japan, 1998). Professor at the University of Brasilia (UnB) since 1986, researcher for National Council for Scientific and Technological Development (CNPq), co-editor of the bi-national journal Geotecnia (Portugal/Brazil), member of the editorial board for the Pavements Journal (ABPv-Brazil) and the International Journal for Road Materials and Pavement Design (RMPD, France), referee for several international journals. Major teaching and research experience in the fields of Geotechnics and Pavements. Main research topics are numerical and constitutive modeling, and mechanistic pavement design. More than 250 published papers, supervised 38 master dissertation and 22 doctorate thesis.
3. Prof. Richard Wan
TITLE: Effective stress in unsaturated granular media in the pendular regime
ABSTRACT: Many of the emerging geotechnical problems implicate unsaturated or variably saturated porous media. While the analysis of unsaturated conditions goes beyond Terzaghi’s effective stress, the commonly used Bishop’s effective stress is fraught with its own issues. With this motivation, the paper investigates the mechanical behaviour of a granular material at low moisture content whereby isolated pendular water bridges (menisci) at the interface of particles give rise to capillary forces in addition to existing interparticle contact forces. During an increase in moisture content, the contribution of the capillary forces is lost, which may give way to collapse failure in the absence of any change in mechanical loading. In this connection, we derive a single effective stress tensor that encapsulates evolving liquid bridges, interfaces, particle packing, and water saturation, thus providing a link to failure through a micromechanical analysis of force transport in an unsaturated pendular-state granular material. Apart from the fact that the stress due to contact forces is dependent on fabric, it is found that the so-called suction stress arising from liquid bridges is direction dependent, i.e. anisotropic. The latter is at odds with the common belief that suction stress is isotropic. We demonstrate that suction stress is a function of the distribution of liquid bridges, degree of saturation as well as particle packing, and thus provide an adequate effective stress definition to describe both constitutive behaviour and strength of unsaturated media. Finally, Discrete Element Method (DEM) numerical simulations of triaxial compression tests of pendular-state granular samples at different degrees of saturation are conducted to verify the anisotropic nature of the suction stress and resulting strength contributions.
Prof. WAN Bio:
Richard Wan is a Professor of Civil Engineering with the University of Calgary. He received a Civil Engineering degree from École Nationale des Travaux Publics de l’État, France in 1983, an MSc in Geotechnical Engineering from the University of Ottawa in 1985, and a Ph. D in Geomechanics from the University of Alberta in 1990.
His research is mainly focused on modern analytical, computational and experimental methods for studying the mechanical behaviour of geomaterials. This has involved theoretical work on the description of failure within contemporary approaches that exploit the theory of bifurcation and micromechanics so that various forms of ruptures and material instabilities can be explained coherently. On the other hand, he has also worked on more practical issues in the application of Geomechanics Principles and Computational Mechanics to solve energy resource extraction problems in the oil industry. Another avenue of his research work is in Biomedical Engineering where he has applied basic Geotechnical Engineering knowledge of frost heave and clay swelling to both model prostate cryosurgery and study the cryopreservation of cartilage respectively. He currently has over 100 publications (refereed journals, conference proceedings and edited books) with a successful track record in research grants, as well as graduate student supervision.
He is very much involved with the geomechanics society having organized and led several important technical meetings, including the 8th International Workshop on Birfurcations and Degradations in Geomaterials (IWBDG 2008) and the COMGEO (Computational Geomechanics) new series of conferences. He currently sits on the editorial board of several well known geotechnical engineering/geomechanics journals, and has also served as a scientific reviewer for various organizations including NSERC (Natural Sciences and Engineering Research Council of Canada), among others.
He was the first recipient of the prestigious R.J Melosh medal in finite element modelling, Duke University, USA, and earned several research excellence accolades from his peers. As a distinguished visiting professor, he has also collaborated with several renowned institutions in the UK, France and Japan.
4. Prof. Bujang B.K. Huat
Title: RECENT GEOTECHNICAL RESEARCH ADVANCES IN UNIVERSITY PUTRA MALAYSIA
ABSTRACT: This paper aims to present the recent geotechnical research advances in the field of geotechnical engineering in Universiti Putra Malaysia as follows; (i) Electro-biogrouting method for soft soil stabilization. In this method, the live bacteria or their production are induced by electrical gradient. The soft soil is then stabilized through a physicochemical reaction. (ii) Soil improvement using nano particles, in this method, the effect of nano SiO2 on residual soil treated by cement was investigated. The results showed that nano SiO2 increased the shear strength of the soil effectively. (iii) Effect of coir fiber on flexural strength of the soil was investigated to evaluate the mechanical properties of reinforced marine soft clay as earth structures. The results revealed that the coir fiber increased the flexural strength of the marine soil. (iv) Effect of acid rain on engineering properties of soil was investigated. Significant changes in engineering properties of soils under effect of acid rain were shown.
Dr. Bujang Bin Kim Huat is a Professor at the Department of Civil Engineering, Faculty of Engineering of University Putra He obtained his M.Sc in Soils Mechanics from His special area of interest is in the field of geotechnical and geological engineering, and slope engineering. He has authored and co-authored 18 books, edited 10 conference proceedings, and published more than 100 journal and conference proceedings papers in field of soil mechanics and foundation engineering.
Dr. Bujang Bin Kim Huat is a Professor at the Department of Civil Engineering, Faculty of Engineering of University Putra
He obtained his M.Sc in Soils Mechanics from
His special area of interest is in the field of geotechnical and geological engineering, and slope engineering.
He has authored and co-authored 18 books, edited 10 conference proceedings, and published more than 100 journal and conference proceedings papers in field of soil mechanics and foundation engineering.