oCubWTM/ Mobile bridgeTM

Novel scissor-like bridge structure for use during emergencies

Mobile Bridge 2.0 Mobile Bridge 2.0(3) Mobile Bridge 2.0
Mobile Bridge 2.0 (Reference: Original & Credit Hiroshima University) at 25th April 2013.

A test of the Mobile Bridge Version 4.0 (MB4.0) over a real river demonstrated its viability for practical use. During the test, the bridge was set up without any foundation work, and a vehicle could easily travel across it. This was achieved safely with very few people and without any problems. The MB4.0 viability test results were presented at a symposium of the Japan Society of Civil Engineers (JSCE) on June 23, 2015, by Dr. Ichiro Ario, Ass. Professor at the Institute of Engineering, Hiroshima University.

Background of developing MB:
Natural disasters include earthquakes, floods, tsunamis, and landslides. They can occur anywhere in the world. The damage caused by such disasters to infrastructure such as bridges necessitates a rapid response to rescue survivors and deliver medical care to the injured within a new set of localized constraints.

1. New secondary hazards caused by localized damage can impede any rescue operations.
2. This raises the question of what useful activities can be performed in the immediate aftermath of a major natural disaster.
3. In many disasters, urgent medical attention can be delivered to injured survivors only if a new bridge is constructed or deployed rapidly.
4. In certain situations, an emergency bridge may be needed even where no professional structural engineers are available.

We propose a new type of foldable/deployable bridge with a scissor mechanism called Mobile Bridge (MB). MB4 can be deployed and folded quickly, and it therefore provides highly efficient construction and easy transportation.

In the aftermath of a natural disaster, rapid repair of infrastructure is required. A fast response will significantly improve disaster recovery efforts. Dr. Ario of Hiroshima University proposed a new concept in bridge innovation.
1. Rapid response will help provide urgent medical aid to injured survivors.
2. Any rescue technology should have a low level of complexity and high degree of resilience to enable its deployment by any persons in a locality.
3. MB uses a patented technology with a scissor mechanism for deploying an emergency bridge system set within a modular design.
4. MB is a compact transportable bridge system; it is suitable for transportation using a car trailer, and it can be easily deployed and folded using its scissor mechanism.
5. This bridge system has a completely novel design and offers extraordinary performance that cannot be matched by the older block assembly approach for bridges.

MB can be deployed in a wide range of areas and has numerous applications. Many existing bridges are in a poor state of repair owing to poor maintenance and overuse. Smaller bridges can be kept operational using MB. This affords the advantage of keeping bridges fully operational without interrupting traffic and causing further damage to the existing bridge by traffic.

Background of development based on Origami:
MB has a scissor-like structure that is connected to the main structural members to form an gXh shape; this enables expansion and contraction while retaining strength. The idea for this new bridge comes from academic studies on buckling based on Origami (Japanese traditional paper craft), which has attracted the attention of researchers in space development and other fields.

Dr. Ario developed MB4.0 as a type of robotic bridge by improving its mobility and functionality and decreasing its weight. Therefore, MB4.0 has become more transportable and easier to set up at temporary construction places without any foundation construction or crane operations. As a result, it is also less costly.

MB4.0 is the worldfs fastest, largest, strongest, and lightest expanding temporary bridge. In addition, it is the fastest to set up. Because the bridge and its lanes are expanded simultaneously, the bridge is ready for traffic as soon as it is fully expanded. From the arrival of MB4.0 on site to its full expansion only takes around one hour. The actual extension time is only around five minutes. This is especially important for time-sensitive situations during a disaster.

Dr. Ario stated that gFrom this test of a new bridge concept, the next generation of bridge technology starts on a new stage in the field of bridge engineering. It is possible to use a real deployable and smart bridge with a scissor-type bridge system using this structural theory. I will further promote the development and evolution of MB4.0 in the future. Making MB stronger, longer, lighter, more compact, and quicker to set up will promote the development of infrastructure construction technology in general.h


Although this developing story of MB4 may not be perfectly expressed the history of Mobile bridgeTM based on Origami idea with/skills in scientific viewpoints. Will you understand the meaning of the developing story why we develop this type of bridge by scientific and engineering skills?


Topic 0. Kobe earthquake 1995, background my research motivation

When I was 28 age in1995, there was Kobe earthquake, I grew up near Kobe before then. I have just studied the book of ``Instabilities and Catastrophes in Sciences and Engineeringh by J.M.T.Thompson and ``A General theory of Elastic Stability g by J.M.T.Thompson and G.W.Hunt, so I had investigated many damaged infrastructures in Kobe with academic viewpoints.

A singular point(s) in physics is so significant to be recognized ``change of catastrophe in materials and/or structures such as a bridge, a tower, infrastructure etc. However, if we carried out an experiment of the real size structure, it would be very experience. Now, we can use the simulation by computing methods. But, it looks difficult for the forecasting of an earthquake when/where/how size happens. It looks complex even though we can use science tools. Origami is so useful for us, it is taught how to fold/how strong/folding patterns by under nature, in physics of the scientific view.


Topic 1. From MECHANICS of ORIGAMI(܎) in 2003 at Univ. of Bath in UK


The cellular buckling on a cylinder made by Origami (folding paper) and its traditional ideas and/or skills are so useful for the field of current engineering and sciences.


Because this phenomena is worst issue for structural design in general. 

In structural engineering, however, the instability of a structure has an important problem of compression buckling. Under a professor known for buckling theory research, there was an opportunity in the cylindrical shell structure using Origami to study "the compression buckling by which symmetry is broken." If it twists like a dust-cloth iris diaphragm, pressing down the rolled paper fixed at both ends with both hands, periodic wrinkles will appear suddenly in a certain critical point (since a local periodic compression buckling pattern appears, this is a kind of the multiplex bifurcation buckling phenomenon called "cellular buckling"). By the world of Origami, this wrinkles pattern is called a Kresling-pattern", and is introduced by the French origami investigator's Kresling. As an experiment relevant to this, there is a prominent compression buckling experiment of the cylinder shell structure of YAMAKI.

However, the reason revelation and symmetry of actions, such as the number of generating and its angle of the wrinkles, and an angle variation, are torn needs to consider the breakdown (two or more compression buckling modes should appear in a multiplex singular points) of the energy equilibrium of bending moment and in-plane force in the test specimen, and essentially becomes difficult. The author, I did compression buckling research of this origami the analysis comparison model, applied to the post-buckling theory of YAMAKI, and was fighting desperately every day to that solution of a riddle through the geometric observation and reappearance calculation of that way which are folded up.

 An example of the folding cylindrical structure principle using an origami technique and symmetry-breaking phenomena (at the Non-Linear Research Centre, University of Bath in the UK in Dr. Ariofs overseas study, 2003); Academic Paper ``Twist buckling and the foldable cylinder: an exercise in origamih, Giles W. Hunt, Ichiro Ario, Int. Journal of Non-Linear Mechanics, Vol 40, Issue 6, July 2005, Pages 833-843

Topic 2. Discovering/Creation from Structural Instability


One day, the professor Hunt called me, it left the important portion of the Kresling pattern of Origami, the truss was built, and there was a proposal that this would be applied to the lightweight deployment structure. The fault which is regarded as whether does it further clip to unstable phenomenon analysis and to carry out instability to it and in which action and origami carry out compression buckling is turned to its own advantage, the advantage of creating a light trussed structure object foldable like compression buckling by little force is pulled out, and it is said that it will use for the design of space deployment structure. This was conversion of the way of thinking of like scales drop from whose eyes, and when it cultivated the viewpoint for creating and carrying out problem solving of a new innovation and engineering value, it became a turning point of my research.

[Refer to]

Homoclinic bifurcation and chaos attractor in elastic two-bar truss,

International Journal of Non-Linear Mechanics, Volume 39, Issue 4, June 2004, Pages 605-617


Multiple duffing problem in a folding structure with hill-top bifurcation,

Chaos, Solitons & Fractals, Volume 51, June 2013, Pages 52-63


Dynamic folding analysis for multi-folding structures under impact loading,

Journal of Sound and Vibration, Volume 308, Issues 3?5, 4 December 2007, Pages 591-598


Structural stability of multi-folding structures with contact problem,

Journal of Sound and Vibration, Volume 324, Issues 1?2, 10 July 2009, Pages 263-282


Topic 3. Weak point for recovery tools in Japan


At the time, it flowed, the Chuetsu earthquake in the north of Tokyo occurred in October, 2004, and we investigated the damaged structures by its disaster. It had become impossible for the infrastructure to have damaged and used it in guerrilla at the time of a disaster, and it was human-works for the restoration tool of how it was made to restore quickly, and felt very scarce one. Moreover, the restoration technique of the distressed area where in and outside the country is repeated, and the necessity for a temporal bridge as a restoration means and a restoration tool have been realized. The international joint research of the structural instability problem of the buckling theory (including a singular point) of multiplex folding micro-structure theory (MFM) accompanied by the multiplex singular point(s) of the chip box model of a multi-stage pantograph mechanism was tackled with a professor of the Polish science of academy (PAN).


Topic 4. Trigger of MB development & Creation of Deployable Bridge based on Origami and Post-Buckling Theory


It was passed several months after the earthquake. When I saw my kid who played by a childfs toy,

in my brain, it was made up by my knowledge of several hints in fundamental engineering issues that deployable structure of the pantograph, how to recover by a rapid restored way, folding patterns by origami idea, structural optimization, post-buckling with singularity by computing, and related to engineering problem and investigation on disaster zone to might be resolved it by origami ideas. I thought the innovative possibility of the bridge and profitability might be born by the deployable bridge to which "If a bridge could be folded simply whether it couldn not be folded like folding paper, origami?", too. Or the idea that the most suitable structural member is arranged and a bridge is developed by the smallest power with "collapse of catastrophe" more natural than energy minimum principle as an example. A bridge improves in a simple mechanism in precast construction method, and when folding and needing in three dimensions beforehand, it can be extended to choice completion which is not seized with the form of the bridge of existence and is based on a principle of energy-minimum like the buckling pattern of Origami, and after that that maybe it should be made fixing and the structure which can be reinforced, it flashed out.


The bridge combined by scissors structure is possible, but the accordion-like gate across which I often generally come by a construction site and a gate is lack of stiffness and easy for off-plate direction to make more unstable and when not controlling elasticity, it is not possible to keep equilibrium state with design mechanics. After extending during development to prudence, when not enduring a live load in addition to the prudence it is not useful as a bridge. Lightness of the part and the strength are also important, and a dynamics balance, structural stability and the most suitable structural form are needed, and I face choice of the expensive material of the specific tensile strength, a stiff balance and a compound optimization problem realistically.


But a technical skill was requested of the way to make the thing which makes a primary member convergent and the fail safe to secure the part strength and reduce a part score multiple, making them ease stress concentration in the environment bottom where high analysis and design are good at present-day science but I thought it was not impossible by a specification. Or when structure unstableness can be controlled well, it is the enlightenment to which I say "They may be able to fold a bridge efficiently."


But, I had to understand the "Ori (it means FOLDing in Japanese word)" structure which is an unsolved academic problem well for it. For example the way to fold how to fold while keeping the strength as the bridge? The mechanics about the collapse was undeveloped dynamics territory in spite of a specialty of our country for a product of "Ori-Tatami (Multi-FOLDing)". Assistant Prof. Taketoshi Nojima who was retired the department of physical mechanics system in Kyoto University, mechanics researcher claimed "Origami engineering", I got the chance when a study lectured on the solid folding pattern by Origami in JAXA, I had also worked on a buckling analysis study of cylindrical shell of a Kresling-Ori by myself and had developed the mathematical dynamics solution folded like a plane by the smallest energy then at the time exactly. When it will be an efficient collapse in particular, I have found out that I have a multiple singular point (A rip of symmetry and multiple structural instability hide potentially.) mathematically. But for risk to become one in case of heavy construction like the bridge structure highly, that will be sensibly usually evaded, it is compound by use of structural instability of pantograph mechanism and a fixed part of deck slab from underhand idea, the whole system can be developed in multiple structural stability (Multiple fail safe is established structurally.) by combining the most suitable smart structural concept.


The development structure is called ``Deployable Structures" which there is a famous ``Rolling bridgeh in London and often applied to folding mechanism of the space development structure in English, but the development structure on the ground is influence of gravity in fact, and its condition becomes general more severely than zero gravity space. I thought you could not generally understand that I did not give the form to that, and embodiment of an mechanics principle in the bridge was entrusted as a prototype (fold and carry compactly, the specification which can be developed rapidly) and the making was entrusted to a factory in a university for experiments in the limited budget. The forming accuracy has also completed a prototype in an early stage in less than 3 months thanks to a skillful technical staff highly.


Topic 5. Comrade of MB development project

The plan of a temporary bridge which can be folded with this mobility is proposed to the Japan Construction Method and Machinery Research Insititute, and joint research has started to take something used as a restored support structure at a disaster zone. First it started from design model and materials processing test, and these mechanical characteristic of a structure and feature were made clear through a strong experiment at the various condition bottoms using a prototype version with the length 6m for a person walking. I understood that it was unclear gradually and was convinced of a possibility of the development to a bridge of this structure by the folding mechanics such as the validity and the utility of its function actually by making a prototype actually as big research results. What are something useful for the time of an accident and something necessary? What is the function of the bridge of necessity minimum as a true emergency temporary bridge? What is made as a researcher of mechanics and/or dynamics? It was not probable up to now or maybe that the break through might be made a question of the dynamics no one considered as the bridge structure from applied mechanics-like thought. A principle and a general-purpose structure of bridge which is able to be installed development from an idea based on compression buckling can also produce new directionality and uniqueness like technological history and expect the synergistic effect as the construction technology of the construction speed by a few people by such meaning.

Carrying MB0 for a footbridge by a trailer.      The completed construction of MB0 in this campus


I was convinced that I had the effect on the necessity of an organization and construction speed except for budget of development and a point of the scale as a development side of the MB, but these days have kept applying time and again every year you can ask to get the research fund from the solicitation, the academic meeting and the folklore of the research task to which each government office shows a university and the one of the order as competing outside acquisition of funds, and to make this MB development useful for the time of an accident taking the suffering of Chuetsu earthquake as a start. But true meaning of development of a disaster recovery is in the trend which evades the conservative advice and risk a spoil makes the development opposite to which, and we did not prepared the big-scale bridge when it came as the Tohoku earthquake of 3.11.


In 2010, I decided to consult with several engineering staffs of this university and extend a prototype to 9m. On the maintenance this structure unit part composition, and part replacement forms easily, it was made the excellent structure. When it developed by technological application of a collapse, something of 9m even became possible of 1m to fold, and the compactness cut with portability by boat trailer was achieved.

Load testing for design and development was put into effect by the prototype specification of its latter period type, a result was concentrated and the consistency was estimated right from various points of view. Technological development was believed use of this first bridge as history of the bridge world and the development was continued. I got the chance to put an opening to the public construction experiment (walking through this bridge) experience into effect in a river in a prefecture according to the event of a university (Refer Picture-1, 2 ). It was mainly to experiment on opening to the public at this time, but if I failed, there was also resolution which will evacuate development. Happily the first construction experiment has also ended in the successful back as it was lined by load testing.


These study results which I presented our research at JAXA in Japan as the example of the development structure with the expensive and inexpensive efficiency of the structure. When showing the animation developing construction, a clamor and many questions in detail were received. After that the pier special occupation manufacturer which received an approval in bridge company and a pantograph maker take part in joint research, and I have cooperation for an experimental production and practical use of the actual size large at present (Refer Picture-3).


Picture-1 The development landscape of the prototype of the MB0 which is at the time of television station coverage (at this campus of Hiroshima University in 2010)

Picture-2 The store state of the prototype MB0, colleagues and students


Topic 6. Prepare this rescue bridge for the next natural disaster

An earthquake, a Tsunami and a typhoon (heavy rain) experience many natural disasters, and our country will also hold something like fate to have to be coexisting with rage of those accidents from now on. Need will be also indispensable for building of the mobile area disasters prevention system which is analyzing the accident situation of the past for it and is rescuing the human life the intelligence of the modern technology science can help aggressively from now on.


It's repeated though we have learned a lesson to an accident (For example I prepare with a lesson to a tidal wave of fire: Ansei first year (1854) Hiro-village of a rice plant hill (present: Wakayama-prefecture Hirokawa-village).) in the nature from the past and have given many suggestion, various, there is no end to guerrilla-like natural disaster, and much noble life occurs at world all part, and is taken away. Development contribution in detail of country (disaster prevention foundation) making which is strong in necessity of research and development and an accident of this field to defend national assets and human life after accident occurrence so that it may be called "when it's equipped and is here, without fear", even in addition to utilizing a lesson of an accident, it'll be an important thing that the development, the disaster prevention, the restored mood, the industrial reinforcement and the area international contribution which connect with future technology by new structure and concept are being maintained as a system by a set.


It's easy at a site as this match to put together, secure a lifeline at the time of an accident and build a new restoration support system safely quickly and, necessary. I'm thinking MB development for useful infrastructure restoration is also one of important general-purpose quick restored tools technologically socially to prepare for the next accident.


Picture-3 Aiming at practical use of the MB1.0 for first lightweight vehicles, during industry-academia common experimental production development


We realize that we should create a new type of bridge with speedy and automation of construction as a robotic of a bridge in close future. The use of a MB development project is spanned with quickly safely as the next role of "intermediary" is believed. Argument is deepened about a structure of the next generation by volunteers to prepare for the next disasters.


[Refer to]

Development of a prototype deployable bridge based on origami skill, Automation in Construction, Volume 32, July 2013, Pages 104-111


a   c   b 

A test of the Mobile Bridge® Version 4.0 (MB4.0) over a real river demonstrated its viability for practical use. During the test, the bridge was set up without any foundation work, and a vehicle could easily travel across it. This was achieved safely with very few people and without any problems. The MB4.0 viability test results were presented at a symposium of the Japan Society of Civil Engineers (JSCE) on June 23, 2015, by Dr. Ichiro Ario, Assistant Professor at the Institute of Engineering, Hiroshima University.


*Please refer to our original publications for Origami and multi-folding mechanism like pantograph in the following;


Development of a prototype deployable bridge based on origami skill, Automation in Construction, Volume 32, July 2013, Pages 104-111,

Ichiro Ario, Masatoshi Nakazawa, Yoshikazu Tanaka, Izumi Tanikura, Syuichi Ono

< http://www.sciencedirect.com/science/article/pii/S0926580513000228>


Twist buckling and the foldable cylinder: an exercise in origami,

International Journal of Non-Linear Mechanics, Volume 40, Issue 6, July 2005, Pages 833-843, Giles W. Hunt and Ichiro Ario

< http://www.sciencedirect.com/science/article/pii/S0020746204001581>


Non-linear dynamic behaviour of multi-folding microstructure systems based on origami skill, International Journal of Non-Linear Mechanics, Volume 45, Issue 4, May 2010, Pages 337-347, Ichiro Ario and Masatoshi Nakazawa

< http://www.sciencedirect.com/science/article/pii/S0020746209002108>


Structural stability of multi-folding structures with contact problem, Journal of Sound and Vibration, Volume 324, Issues 1–2, 10 July 2009, Pages 263-282, Ichiro Ario and Andrew Watson

< http://www.sciencedirect.com/science/article/pii/S0022460X09001230>