4th U.S.-Japan Workshop on Soil-Structure Interaction Tsukuba, Japan

March 28-30, 2007

DEVELOPMENT OF EDUCATION MATERIALS FOR SOIL AND

STRUCTURAL DYNAMICS

Nobuo FUKUWA1

SUMMARY In order to improve the effect of education on structural dynamics and soil dynamics for the university students and structural engineers, a series of educational tools named ‘Bururu’ have been developed by the author. These are composed of the portable shaking table, dynamic test models and the web-based simulation tools. Various types of shaking table which can be easily carried to class-room are developed. These are manual operation type shaking table, electric operation type shaking table and digital controlled bi-lateral shaking table using pulse motor. A lot of dynamic test models are also prepared such as various pendulums, framed structures, dampers, base-isolation, soft soil and liquefaction soil. By showing various dynamic tests just after teaching the formulation of dynamics, students easily understand the dynamic phenomena. In order to support the real experiment, the web-based virtual experiment tools are also developed. This is a real-time dynamic simulator using FLASH action-script. Here the seismic ground motion is controlled by the movement of mouse and various parameters of soil-structure system are interactively input on web pages. Since the students easily control the seismic ground motion by the mouse and actually feel the difference of the soil-structure response, students really understand the importance of dynamics.

INTRODUCTION Soil-structure interaction (SSI) is the most important factor that dominates the behavior of structures when an earthquake occurs. However, the soil-structure interaction is seldom taken into consideration in the aseismic design. On the contrary, aseismic design based on earthquake response analysis is made only for special buildings, such as super high rise buildings and seismic isolated buildings. Because of this, even structural designers who make aseismic design cannot imagine the dynamic response of buildings. University education on structure usually centers on statics, mainly structural mechanics, and there is little time spare for education in dynamics. Generally, lectures on structural mechanics are accompanied with adequate exercises. In the case of statics, because simultaneous linear equations can be solved with consideration for equilibrium of force and displacement compatibility, difficult numerical formulas are not necessary. Moreover, because graphical methods have been developed, answers are easy to express

1 Professor, Nagoya Univ., Nagoya, Japan, Email: fukuwa@sharaku.nuac.nagoya-u.ac.jp

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as illustrations. Because of this, students comparatively well understand equilibrium of force, moment distribution, and deformation behavior. On the other hand, because universities do not have enough time to give lectures on dynamics, and dynamics requires knowledge of mathematics, such as of differential equations and Fourier analysis, it seems hard for students to study dynamics. Because recent students are not good at spending a lot of time in studying basic theories, their stamina cannot hold up for lectures that center on formularization. Dynamic calculation is not suited to written exercises and requires the use of a computer. Therefore, students who do not prepare adequately and do not review are likely to drop out. Because dynamic phenomena cannot be expressed by still images, they are frequently explained with waveforms and spectra. In addition, it is hard to understand dynamic phenomena from graphs. To improve on this, it would seem more effective to use simple model experiments and simple simulators in addition to formularization and graphs. As far as earthquake-resistant design of low damping and long-period structures such as super high rise buildings are concerned, unless designers have a correct understanding of resonance, they will be unable to grasp the importance of period and damping. And unless they understand this, they cannot grasp the basics of design of super high rise building, such as the avoidance of resonance and the addition of damping. In addition, they cannot understand that not only the amplitude but also the period or duration are also important for prediction of strong ground motion. Recently, there have been an increasing number of buildings artificially controlling their dynamic behavior, such as base isolation or vibration control. If the principles of base isolation and vibration control are plainly explained not only to engineers but also to the owners of buildings, base isolated or vibration controlled buildings will become much popular. In Japan, since the beginning of this century, design methods that adopt more dynamics than before have been introduced and the soil amplification and soil-structure interaction can be taken into consideration in the design code. Therefore the importance of dynamics has been increasingly emphasized. Moreover, given recent earthquake disasters and E-Defene’s full-scale collapse experiment, the collapse of buildings cannot be explained without knowledge of dynamic phenomena. With the growing importance of seismic retrofit, model experiments and simulators, which can easily demonstrate collapse experiments, have come to be highly important. It is necessary for many people to understand vibration phenomena correctly and realize how buildings collapse. This will encourage students to study dynamics, engineers to adopt base isolation and vibration control based on dynamic phenomena, building owners to construct buildings with consideration for seismic safety, and residents to take the initiative in improving the countermeasure in their houses. Now is the time to shake off the traditional education style by the formularization of theories and by the use of graphs of waveforms and spectra and grope for new education methods. This will enable the dissemination of soil-structure interaction. In this paper, I will explain several examples of methods I have attempted. These are simple vibration experiment tools usable in classes and a virtual experiment system usable on the Internet. They are teaching materials that can dynamically and plainly explain the dynamic behavior of buildings in case of an earthquake and details of collapse.

VIBRATION EXPERIMENT EDUCATION MATERIALS The vibration experiment education materials explained herein are collectively called “BURURU.” The first one developed was a hand-rotating portable shaking table. This is a duralumin attaché case that contains a shaking table and various experimental materials. Rotating the handle by hand makes the table move translationally.

The hand-rotating simple mechanism is suitable for feeling the period of vibration. The development created a great sensation, and we received many requests to use BURURU. After that, we began to sell it on the request of many persons. At present, about one hundred units are being used by universities, government disaster prevention and construction bureaus, natural and science museums, volunteer groups, house makers and construction companies. Universities use them for lectures on earthquake engineering, museums use them for demonstrating vibration of buildings, and government bureaus use them for the development of public awareness of seismic retrofit. Moreover, units are used by volunteer groups for the development of public awareness of disaster prevention in communities and by house makers and construction companies for explanation of base isolation and vibration control technologies.

Table 1 BURURU series demonstrating actual shaking phenomena

Name Image Operations Characteristics Use Hand-driven BURURU

The handle is rotated by hand, and the rotary motion is converted into translation, which shakes the table.

Many types of miniatures are contained in an attache case easy to carry. Users turn the handle by hand, so they can really feel frequency characteristics.

It can be used at many occasions, such as lectures and events. As it offers visual explanations of dynamic phenomenon, vibration theories can be learned more effectively.

Electric BURURU

It is driven by a motor, powered by a built-in buttery. The table shakes at frequencies specified by the dial.

As its vibration frequencies can be mechanically controlled, the table can be shaken in a constant and repeatable manner. The device is light and easy to carry.

It can easily imitate continuous changes of frequencies, and shorter and longer period motions, which are difficult for a hand-driven device to simulate.

Small BURURU

The shaking machine has a battery in it, and generates horizontal vibrations. The frequency can be changed with a dial.

It can be placed on a small mock, and shake it. The device has the resonance curve understood in an effective manner.

It can be used to explain principles of vibration tests, which are often carried for vibration testing of buildings.

DIC BURURU

Driven by a pulse motor under the digital control of a PC. Possible to change the waveform freely by two horizontal axes.

Possible to reproduce the movement of two horizontal directions by digital control. Possible to make a range of models from desktop to large-sized according to the length of the rail. It can also reproduce a long period vibration.

A desktop model can be used for lectures and TV studios, while a large-sized model can be used for events.

Foldable BURURU

Swing a foldable inverted pendulum right and left by hand. It is possible to change the position and number of masses and the amount of mass.

Possible to convey the vibrations of the particles. Possible to change the mass, the spring constant, and the number of particles and add damping. Interaction experiment is also possible if swinging softly.

Useful for lectures on vibration theories at university. Used together with study of theoretical analysis of particles.

Furniture Falling BURURU

Swing indoor models on ball bearing horizontally by hand.

Indoor models include drawers, bookshelf, desk, TV, bed, etc. They are used for reproducing falling of furniture. There are also tools for preventing furniture falling.

Because this BURURU reproduces furniture falling, it is the most suitable for teaching the importance of preventing furniture falling.

On-cart BURURU

A cart used, ordinarily, to carry goods is equipped with a handle, which is pushed and pulled to shake the cart.

It is applicable to experiments with miniatures similar to wooden building, so it helps users really feel how effective seismic strengthening is. They can also see how eccentricity causes torsion. Children can stand on it to feel shakes.

It is useful in explaining how effective seismic strengthening is for wooden building in ways that ordinary people can easily understand it.

BURURU for collapsing wooden buildings

It has two different models of building on the cart, similar to that of the on-cart BURURU, and shows how different they are in ways they collapse.

Demonstrations can be carried out, for example, with or without braces and/or structural plywood, with different arrangements of walls, with or without metal connectors, with different weight of roofs, on soft or hard ground etc.

It uses 1/10 scale models of conventional framework structure buildings to show how differently they collapse. It is the best tool for education about anti-seismic strengthening.

Temple Collapse BURURU

Put two temple models on a large wooden cart and examine the difference in the form of falling.

A carpenter trained in traditional temple carpentry made wooden temple models on a scale of 1:10. Detailed and elaborate models are used for comparative experiment to examine whether seismic retrofit is necessary or not.

Useful for developing awareness of seismic retrofit necessary for shrines and temples, bases for the spirit and history of communities.

Self-propelled BURURU

It has batteries in it to power a servomotor, and imitates earthquake motions according to waveforms input.

It can replicate longer-period and longer-stroke earthquake motions, which cannot be mimicked by conventional shaking tables. Users can stand on it to feel shakes.

It is useful to have high buildings residents and those concerned feel how they shake and help them improve awareness.

LongLong BURURU

Driven by a pulse motor under the digital control of a PC. Possible to change the waveform freely by a horizontal axis.

Possible to reproduce the movement of one horizontal direction by digital control. Super-long-stroke and long-period shaking table that can reproduce vibrations of 3 m, 5 m/s, and 20 m/s2.

Useful as an ordinary digital-control one-axis shaker and for reproducing the floor response of a long-period building to long-period earthquake vibrations.

Paper BURURU The paper model house is swung by

hand from side to side.

Participants by themselves build mocks and shake them, so that they can personally see how different buildings are in natural periods and what effects braces have.

It is an effective tool at participatory workshops, and a good souvenir at lectures. It can also be used to have children interested in how buildings shake.

ParaPara BURURU Flip through sheets of paper by hand.

A flip book illustrates an experiment on falling by the use of BURURU for collapsing wooden buildings. It is possible to understand the importance of seismic retrofitting of wooden buildings while enjoying cutoff animation.

Because the book can be used without a PC or an experimental model, it is possible to develop various people’s awareness of seismic retrofitting of wooden buildingss.

We have received various requests from these users, both directly and indirectly. In short, they wanted the following type of BURURU: a more portable, lighter, and smaller one; a more inexpensive one; an electric one; a large one that can be used in a gymnasium; a small shaker that can be placed on the top of a building model; and one that can even show the collapse of a house.

Accordingly, we decided to develop various vibration experiment education materials based on the concept of the hand-rotating portable shaking table. Table 1 shows the vibration experiment education materials we have developed up to now. In addition, I will outline each of the materials. Hand-rotating portable shaking table, which contains various models This is the first portable vibration experiment education material. It has a mechanism that changes rotary motion to translational motion via a universal joint. As shown in Figure 1, the shaking table in the container is shaken right and left by turning the handle by hand. The container contains various models, such as an inverted pendulum, two-story and four-story frame models, cross bracing, an earthquake-resistant wall, a base isolation device, a damper, and a liquefaction model. By using them, it is possible to make experiments on seismic retrofit, base isolation, and vibration control as shown in Figure 2, including experiments about replacement of frame model with lumped mass model, changes in period according to the height and weight of lumped mass, difference in period according to the number of building floors, shapes of primary and higher modes, changes in vibration mode and period according to the balance of rigidity of floors and the weight of the roof, the principle of base isolation, and the principle of vibration control. To shake the frame models, we have developed a small shaker that uses eccentric mass. Because it is possible to change frequency, the small shaker is suitable for explanations of resonance curve and vibration mode at lectures on dynamics. This makes it easy to indicate points common to the resonance by seismic ground motion and the resonance by the forced vibration using shaker. There are also a model for experiment on liquefaction, models for soft soil and layered soil, and a model for experiment on fall of furniture. An experiment on liquefaction is carried out by setting up a light

(a) Outer appearance (b) Models contained (c) Shaking table

(a)外観

(g) Small shaker (d) Model for soil amplification

(e) Model for liquefaction experiment

(f) Model for falling of indoor furniture

Figure 1 Outlines of the shaking table of Hand-rotating BURURU and related model

building, a heavy building, a pile-supported building, and buried pipes on liquefied ground made of glass beads. Soft soil is used for experiments on soil-structure interaction, while the layered soil model is used for showing shear vibration and resonance between building and soil. Indoor models are experimental tools for showing the effect of prevention of furniture falling. Because this experimental material has an interesting mechanism, it is effectively used in a wide range of fields from lectures at universities to disaster prevention education at elementary schools. Electric portable shaking table This is an electricity-driven portable shaking table based on the mechanism of the hand-rotating one. The frequency is adjustable by turning a dial. Because it is driven by rechargeable batteries and is light and small, it is easy to carry. It is especially suitable for use in small classes. Folding pendulum This is a folding inverted pendulum used on the hand. Two or more weights that contain magnets are attached to a leaf spring, and the pedestal folds. Because of this, the folding pendulum can be carried in a pocket. The height, number, and weight of the weights can be changed freely, and a magnet sheet that functions as a friction damper is attached to the pendulum. It is also possible to add a base isolation device under the pedestal. This enables vibration experiments with changes in spring constant, mass, and the number of masses; vibration control experiment with changes in damping constant; and base isolation experiments with a base isolation device. It is possible to make a seismic ground motion experiment by shaking the pedestal by hand and to make a free vibration experiment by fixing the pedestal on a desk, pushing the weights, and releasing the hand. In addition, by grasping the inverted pendulum tightly or softly, it is possible to

reproduce hard rock or soft soil. Free vibration experiments clearly demonstrate that the period becomes

Open ground floor structure

Wall-type structure

Rigid frame structure

glT π2=

(e) Change in dynamic characteristics by addition of mass

(d) Seismic retrofitting and isolation

(b) Replacement of two-degree-of-freedom system to one-degree-of-freedom system

(a) Replacement of frame model with particle model

(c) Change in dynamic characteristics by earthquake-resistant wall

Figure 2 Examples of vibration experiment by hand-rotating potable shaking table

Figure 4 Folding pendulum

Figure 3 Outer appearance of electric portable shaking table and magnification of

seismic isolation part

longer and vibrations soon decrease on soft soil, showing the key point of soil-structure interaction. Although this is an extremely simple experiment, the essence of dynamic phenomena lies in a simple experiment. Experimental education material that uses the cart-type shaking table This is a large-scale education material we developed to show the shaking of a building to many children simultaneously in an elementary school gymnasium. A two-story wooden building model or a child is shaken on a shaking table made from a cart. It is possible to lay a carpet of soft soil and to attach and remove the cross bracing to or from the wooden building. In addition, heavy and light roofs are included as attachments. This material is effective for explaining the key points of seismic retrofit to the general public because it makes it possible to carry out experiments by the use of them to confirm the effect of soft soil, the effect of rigidity balance among floors, the effect of rigidity eccentricity, and the effect of roof weight. Because the table is large, it is suitable for demonstration in gymnasiums or outdoors. In addition, it is also possible to reproduce long-period long-stroke vibrations by tying ropes to both ends of the cart and pulling on them like in a tug-of-war. There is also a collapsible model. By shaking two elaborate two-story wooden models on a scale of 1:10 simultaneously, it is possible to show differences in the collapse of buildings according to the balance of the cross bracing, the weight of the roof, the existence of metal joints, the soil stiffness, the existence of anchor bolts driven into the foundation, etc. Although the collapsed model can be reassembled, the reassembly takes a lot of time so we also use a video CD that records how the model collapses. There is also a flip book based on the video. The educational effect is great because this can show that even a small difference in structure causes a great difference in the collapse of a building. The upper right of Figure 6 is a photo of a collapse experiment carried out before ex-Prime Minister Koizumi. Moreover, to promote the seismic retrofit of temples and shrines, we have prepared a temple model on the scale of 1:10 and a reinforced concrete building model made of blocks and wires. Because these education materials are easy to understand, they are frequently used for events and special TV programs that teach the importance of seismic retrofit of buildings.

(a) Two-story building model (b) Experiment for feeling of vibration

(c) Feeling of long-period vibrations through tug-of-war

Figure 5 Shaking table and model of cart-type shaking table

Digitally-controllable shaking table We developed two types (large and small) of digitally controllable shaking tables, applying the concept of the cart-type shaking table. One of them is a long-period long-stroke shaking table developed to reproduce a high-rise building’s response to long-period seismic ground motions. It is called “LonLon BURURU” (Triple-L Shaker: Long-period Long-stroke Linear Shaker). A cart running on a rail is pulled by right and left pulse motors. It can shake with displacement of 3 m, velocity of 5 m/s, and acceleration of 20 m/s2. It enables PC to calculate vibrations of a certain building constructed on a certain ground and reproduce them in quasi-real time. Using this idea, we also developed a desktop digital-control bilateral shaker (DIC BULULU). We attached a servomotor to a cross linear bearing that can move bilaterally, and made it possible to control vibrations digitally by PC. This shaker is suitable for indoor experiment that uses a small model. Paper building model kit The purpose of this kit is to enable people to easily grasp how a building shakes. It is made of perforated cardboard. Because double-sided tape is attached, the building model can be assembled in about ten minutes. It is possible to understand the importance of light roof weight and balance of cross bracing and feel vibrations of a building. Although the model is basically a two-story building, it is possible to make a tall building model by piling up the models. In addition, if two red pencils are put under the building, the building becomes a base isolated one. This kit is greatly effective for events and lessons at elementary or junior high school. Figure 8 includes a photo of ex-Prime Minister Koizumi, Prime Minister Abe and other ministers assembling “Paper BURURU.” Although this kit is on the market, everyone can download and use the original drawing and manuals from “BURURU Homepage” (http://www.sharaku.nuac.nagoya-u.ac.jp/laboFT/ bururu/index.htm).

Figure 7 Digitally-controllable shaking tables (b) Long-period long-stroke shaker (c) Desktop bilateral shaker

Figure 6 Models for experiments on collapse of wooden two-story houses and temples Light roof Heavy roof

SIMULATOR THAT USES WEBGIS Development of public awareness by the use of experimental models has limits in terms of the number of participants, time, and place. To cope with this, we also developed a simulator system that uses the Internet, which has no such limits. This system complements the above-described materials for vibration experiments. This system consists of a map-based simulator that uses WebGIS and a virtual vibration experiment simulator that uses FLASH. Concretely, it includes the following: a three-dimensional bird’s-eye view system that uses prewar, postwar, and present aerial photos to show changes in the ground of a construction site; simulation of seismic ground motion by the use of a high-resolution soil model; simulation of the collapse of a house by simply inputting characteristics of the house; simulation of falling of indoor furniture; simulation of building and soil responses to seismic ground motion caused by the movement of the mouse; various experiment videos; and downloadable education materials. We are considering using the system to complement lectures on dynamics at universities and to develop residents’ awareness of seismic retrofit. For the former purpose, we are considering having each student experience the following via the Internet as education materials supplementary to university lectures: estimation of a soil model; the soil response to seismic ground motion; simulation of collapse of buildings; simulation of falling of furniture; and experiment on building response to seismic ground motion. For the latter purpose, we are considering using a scenario-type simulation. First, residents know the risks of vibration and liquefaction and the relation between risks of disasters and the soil, referring to the results of the administration’s earthquake damage prediction. Next, residents know from prewar, postwar, and present aerial photos how the ground of each resident’s house has been changed and why the risks of seismic intensity and liquefaction are high. Moreover, each resident directly inputs information on his or her house and furniture to predict the falling of furniture and ascertain risks in the house and rooms. This will encourage residents to carry out disaster prevention activities, such as seismic retrofit and prevention of furniture falling. GIS that shows the relation between the risk of earthquake and changes in the ground As shown in Figure 9, this system simultaneously shows two maps. Because each map displays different information, comparative analysis is possible. Display items include information on seismic intensity and the risk of liquefaction, urban information, topographical and geographical information, and aerial photos. Because both maps are connected with each other in terms of movement and magnification/reduction, it is possible to analyze results of damage predictions, comparing with aerial photos and topographical data. (a) is the result of the comparison of the predicted seismic intensity and an aerial photo. (b) is the result of the comparison of the predicted liquefaction and the topographical classification map. (c) is the display of a wider area on a reduced scale. The area is located on a hill where a valley and a ridge cross. Because the soil of the

Figure 8 Paper building model kit

ridge is relatively hard, seismic intensity will be small. On the other hand, because the soil of the valley is relatively soft, the risk of liquefaction is greater.

Moreover, by using three-dimensional bird’s-eye view images, which are made by adding information on sea levels to aerial photos, and data on the distribution of earth cutting and filling (land changes), we developed a bird’s-eye view system that makes it possible to realize topographical changes by MatrixEngine®, which reproduces three-dimensional contents. As shown in Figure 10, it is possible to change the screen by clicking the mouse and make position changes by mouse dragging, including moving, revolving, and zooming the screen and changing the point of view. It is also possible to go back to the past by dragging the time bar.

Simulator for vibrations of premises Selecting the City of Nagoya as the target area, we developed algorithms for estimating the ground velocity structure shallower than the engineering bedrock and estimated seismic ground motion at the position of the engineering bedrock by the statistical Green’s function method. We used these data to estimate the surface soil structure at a certain point and constructed a system for earthquake response prediction. As shown in Figure 11, if a point on GIS is clicked, the system estimates a ground model at the point and, as shown in the right figure, displays an animation of the soil response. This enables

(a) 50 meter-mesh seismic intensity and aerial photo

(b) 50 meter-mesh liquefaction risk for the same area and topographical classification map

(c) Same prediction with reduced scale Figure 9 Comparison of earthquake damage and various data through double-screen GIS

Before war

After war At present

Distribution of earth cutting/filling

Figure 10 Three-dimensional WebGIS that shows topographical changes

students to know the difference in underground structure between points. In addition, this enables designers to easily grasp the soil amplification characteristics of construction sites and appropriately explain them to the owners. Simulators of house collapse and furniture falling To check the earthquake resistance of houses easily, we have prepared simple tools for simulation of the response and collapse of wooden houses. If the user inputs data into the PC, such as the year of construction and the plan of the house using CAD system, an earthquake response analysis model is produced automatically. If the user inputs surface ground motion calculated as shown in Figure 11, the PC makes an earthquake response analysis and displays a real-time animation of the result. In addition, the user can reproduce the predicted response of the ground surface and the building by the use of the vibration reproduction device shown in Figure 7. If the house collapses, the tool guides the user to websites concerning diagnosis and reinforcement of earthquake resistance so as to encourage the user to carry out the processes from diagnosis to reinforcement. On the other hand, if the house does not collapse, the furniture falling simulator starts. The user inputs the floor on which the furniture is placed, the size and weight of the furniture, the type of floor furnishing, etc. The furniture’s response is analyzed based on the response waveform and displayed as an animation. FLASH vibration simulators and other education materials

Figure 13 shows the website of “BURURU,” vibration experiment education materials described in the previous section. The website includes vibration simulators using FLASH ActionScript, videos of various model experiments, and downloadable education materials. For example, the upper central drawing shows a response simulator for the two degrees of freedom system. If the user inputs the mass and rigidity of the first and second floors, the simulator automatically estimates the eigenvalue and the eigenmode. If the user moves the ground right and left by mouse, the building responses. Through this virtual experiment, the user can understand the effect of the rigidity balance of the first and second floors, feeling the resonance and vibration modes. The simulator increases the user’s understanding of earthquake responses more than formulas and graphs because, by moving the mouse, the user can realize at what period buildings are prone to vibrate and how responses are amplified and damp out according to damping constant. We are trying to make results easy to understand by adopting such diagrams as in the upper right illustration.

(a) Screen for CAD input of wooden house data (b) Simulator of collapse of wooden house and falling of furniture

Figure 12 Simulator of collapse of two-story wooden house and simulator of falling of furniture

As shown in the lower left, we demonstrate the effect of seismic retrofit by videos that show comparative experiments on the effect of seismic retrofit by the use of two-story wooden houses. Regarding these results of collapse experiments, we have prepared PDF data for making flip books. Moreover, the paper model kit described above and the user’s manual can be downloaded so that residents who have gained an understanding of the importance of seismic retrofit can explain the importance to neighboring people. In addition, to promote indoor safety measures, we have uploaded videos of comparative experiments on various methods for preventing furniture from falling. These hands-on education materials are effective for supplementing virtual information systems.

CONCLUSION In this paper, to promote university education on dynamics and residents’ awareness of seismic retrofit, I have explained various educational materials. The education materials consist of various model vibration experiment materials that plainly show the importance of seismic retrofit and the online e-learning system that supplements the materials.

(a) Top page of BURURU

(c) Video of model experiment on effect of seismic retrofitting measures for wooden houses

(e) Video on effect of prevention of furniture falling by shaking table experiment

(b) Vibration simulator for two-degree-of-freedom system

(d) Paper kit of a building

Figure 13 Hands-on education materials that supplement simulators

The experiment materials can be used according to purpose or target. Each of them consists of a vibration-producing device and various building models. We have developed a wide range of vibration-producing devices from hand-rotating ones to digitally controlled ones that make use of a PC. On the other hand, because the e-learning system can be used without limit on the number of persons, time, or place, it can provide information on disaster prevention through WebGIS. Residents can learn vibrations in their community, the earthquake resistance of buildings, and indoor safety on the Internet. At the university where I work, the number of students interested in earthquake engineering or earthquake disaster prevention has been steadily increasing through the use of these education materials. In the community where I live, the number of earthquake-resistant houses and buildings has been steadily increasing because of the promotion of public awareness by the use of these education materials. Recently, at home and abroad, these materials have been used for education and public awareness activities for a wide range of people from government leaders to kindergarten children. This all has a great effect. In the future, it is desirable for many persons to develop and share education materials for the growth of earthquake engineering and make efforts to have society understand the importance of seismic retrofit.

ACKNOWLEDGEMENT When developing the education materials described herein, I received cooperation from Dr. Jun Tobita, Mr. Tetsuo Hara, Mr. Kimio Ogura, Mr. Katsuhisa Suzuki, Mr. Eiji Koide, Mr. Kenji Ota, Mr. Hiroyuki Iinuma, Mr. Naoki Satake, Mr. Tsutomu Hanai, Mr. Wataru Ishii, Mr. Ryoya Ikuta, Mr. Yosuke Tsuruta, et al. I hereby would like to express my thanks to all of them.

REFFERENCES 1. Fukuwa N., Hara T., Koide E., Kurata K. and Tsuruta Y. ” Development of Vibration Experiment

Education Materials to Promote Seismic Retrofit,” Institute of Social Safety Science, No.7, pp.23-34、2005.11

2. Fukuwa N., Tobita J. and Suzuki Y. “Hands-on Research for Raising Earthquake Disaster Prevention Potential in Nagoya Metropolitan Area by University Researchers,” Institute of Social Safety Science, No.6, pp.223-232、2004.11