Up & Coming Vol. 97
User Introduction Vol. 97
Feature Article on Okinawa User (2)

Okinawa Structural Design, Inc.
Abundant Results in Design, Repair, and Reinforcement of Bridges etc.:
Making Full Use of Diverse F8 Products with FEM and VR in Mind

User Information
Okinawa Structural Design, Inc.
URL: http://www.oki-kozo.co.jp/
Location: Uruma city, Okinawa
Services: Construction consultant / survey / geological survey
"Since Okinawa is a very small region, we sometimes treat CG (computer graphics) or perform experiments (about technologies or products developed in-house) depending on the case in addition to designing structures".

Okinawa Structural Design, Inc. is the next one for this special cover on our users in Okinawa. When the Company was founded more than 20 years ago, they were engaged in designing structures including those related with bridges as a subcontractor, then gradually shifting its status as a general contractor. At the same time, the Company also put a great deal of efforts into repair and reinforcement of the structures in response to prevention of salt damage from an early period.

In addition, the Company started studying and developing PC (prestressed concrete) bridges to which they had paid attention ahead of other firms in Okinawa. They also study on developing a fish reef block as part of environmental business. Furthermore, their enterprising way of thinking is reflected in the use of ICT as well, e.g. in adopting CG technology early on in creating photo-montage for public hearing.

Mr. Reiji Iha, Chief Executive Officer of the Company, explains that the Company's stance of dealing with such diversified areas takes root in the local characteristics of Okinawa.

In such processes, the Company has adopted FORUM8 products one by one since about 20 years ago. Out of the plentiful lineup, they mainly use the bridge-related products as follows:
(1) "Bridge pier design": a program for earthquake-resistant design, reinforcement design and drawing of piers by seismic intensity method /ductility design method.
(2) "Seismic coefficient calculation (support design)": a calculation program of Seismic intensity of the bridge having plural vibration systems with the static frame method
(3) "Abutment design": a program for design calculation and drawing of the reversed-T-type abutment and gravity-type abutment.
(4) "Foundation design calculation": an earthquake-resistant design program corresponding to pile foundation, steel pipe sheet pile foundation, caisson foundation, consecutive underground wall foundation, spread foundation and the liquefaction.

Mr. Reiji Iha, Chief Executive Officer,
Okinawa Structural Design, Inc.
With Mr. Iha (left) and Mr. Sueo Okajima,
Director of the Designing Division (right)

Paying Quick Attention to the Salt Damage Problem in the Prefecture,
Promotes Study of Repair / Reinforcement Measures and New Technologies

"Uruma city" lies along the south rim of the Kin Bay that faces the east from the narrowest area of the central part of main island of Okinawa. The city describes an arc ranging from Katsuren Peninsula to several islands connected by Mid-Sea Road that runs through the sea and plural bridges. The city was founded in 2005 by merging the former Gushikawa city, Ishikawa city, Katsuren town, and Yonashiro town.

The headquarters of Okinawa Structural Design, Inc. is located in Nakagusuku Bay Port Development Industrial Complex, established within the coastal area of Nakagusuku Bay at the Southeastern tip of the city.

The Company was founded at Nakama, Urasoe city in 1988 as "Okinawa Structural Design, Ltd." It started as a subcontractor of bridge design to be built in Okinawa.

After getting through gradual increase of capital, its head office was moved to Isa, Ginowan city in 1994. Paying attention to the salt damage problem since that time, they have been coping with repair and reinforcement of structures including bridges.

Indeed, an aim is put into the company name "Okinawa Structural Design" that in some time repair and reinforcement would be needed, as he says. However, the Company was engaged in design in relation to bridges under subcontracts for the first three years or so. Then, as chances increased to design diverse structures under general contracts, more and more weight has been put on repair and reinforcement work.

In particular, as they had to make a judgment on how to deal with the salt damage problem, they established a section in the Company in charge of ion concentration measurement and salinity analysis etc. This section was later separated from the Company as "Environmental Research Ltd." in response to expansion of the range of objects of research and analysis. Currently, both companies are trying to contribute to extend lives of structures by cooperating each other.

On the other hand, though the RC (reinforced concrete) bridges that used to be the core gave way to PC (prestressed concrete) bridges, it was difficult for the enterprises in Okinawa to manufacture PC girders, having limited effect on regional economy. Consequently, the Company developed the RC precast girder bridge that uses epoxy coated reinforcing bars resistant to salt damage, which were not spread so much in those times. In 1997, the Company performed an experiment about its bearing capacity jointly with a concrete manufacturer in the Prefecture.

"This RC precast girder bridge we developed did not particularly go on the market partly because a PC (girder) factory was established in Okinawa". However, since it is still important to take countermeasure for salt damage, Mr. Reiji Iha says that they keep on examining their original approach to realize highly-endurable structures using epoxy coated reinforcing bar and so forth.

In 1998, the Company was reorganized into current "Okinawa Structural Design, Inc." Later in 2002, the head office was moved to the current location (former Gushikawa city).

Office building of Okinawa Structural Design, Inc. Mr. Iha and FORUM8 President Yuji Ito.

Wide Range of Services Reflecting Locality

The Company consists of Designing Division and General Affairs Division that includes the marketing function. Currently they have 15 employees. Collaboration is made with the above-mentioned group company, Environmental Research (located within the head office building of Okinawa Structural Design Inc. with 7 employees), having personnel exchange etc.

Since its foundation, its core service has been to design structures such as bridges in the Prefecture. Especially in Okinawa, countermeasures are needed for salt damage and corrosion of bridges. Besides, it is important to take consideration of environment and landscape in various public work projects, based on the influence on its insular characteristics abundant in nature and on tourism.

So the Company provides a service related with public involvement in linking to structure design. They produce photo-montage based on bird's eye photos shot from a radio control helicopter. Since 1995, the Company started to work out landscape simulation using CG there. Staff members who majored in fine art even tried animation. However, according to Mr. Reiji Iha, its huge amount of work forced them to give it up.

Further, they also have been working on degradation research and diagnosis on concrete and steel structures, as well as the subsequent repair and reinforcement design, as a pioneer in Okinawa. They perform nondestructive inspection, loading tests, stress frequency measurement, and chloride content test etc with apparatus for exclusive use they adopted early.

In relation to environment, in addition, the Company has been conducting water quality research and soil survey with their own equipment such as an ultraviolet and visible spectrophotometer and an atomic absorption photometer, a gas chromatograph mass spectrometer, and a high precision liquid chromatography.

Currently, there are great needs for analysis of salt content that leads to degradation of a structure. Having the US military base in the Prefecture, they also put emphasis on research and countermeasure for soil / water pollution and the tuff loam run-off peculiar to the Okinawa region, where Ryukyu limestone strata are widely distributed.

What's more, the Company took part in the regional regeneration consortium RD project (Ministry of Economy, Trade and Industry) and studied the effect of the concrete fish reef mixed with fly ash. As an extension of this, they also keep on developing the fish-reef block with strained draff of the sugar cane (bagasse).

Staff members of Okinawa Structural Design, Inc.

From Early Introduction to Full Use of F8 Products

It was about 20 years before Mr. Sueo Okajima, Director of Designing Division joined the Company, who had been experiencing stepwise computerizing process in a construction consultant company in the mainland Japan, when the Company introduced a F8 product for the first time. It was about the period for the Company to switch manual calculation to computer-based calculation.

At the beginning, they introduced "Plant foundation design calculation" when they accepted the order of construction project of a power plant. Next, at the times when construction of new bridges were ordered in a large number, they introduced "Caisson type pile foundation frame analysis" to perform design calculation of the caisson type pile foundation, " RC substructure design calculation" to perform design calculation of bridge substructure and RC structures and so on, to promote work efficiency. Mr. Okajima says that they have been using FORUM8 products so far because of their easy input and excellent output.

Regarding bridges, while in recent years the weight of work has shifted from new construction to repair / reinforcement, the Company has been mainly using "Bridge pier design", "Seismic coefficient calculation (support design)", "Abutment design", and " Foundation design calculation". On the other side, although they owned some programs such as "Outline automated design of the continuous composite girder bridge", since they had not used the programs for the steel beam bridge to the fullest so far, they plan to use them and add other lineups according to the orders they receive. At the same time, while taking in the program about repair / reinforcement including "Bridge check support system", they expect to improve efficiency more.

Recently, as the needs for verification of earthquake resistance for water environment mainly in the prefecture and Naha city increase, the Company adopted "Earthquake-resistant design calculation of the distributing reservoir" to perform earthquake-resistant design calculation of a distributing reservoir in conformity to the guideline on water supply facility earthquake-resistant construction method. He says that they are making efforts in this area as well ahead of other firms within the prefecture.

In the mean time, regarding "National Tax Administration Agency West Route of the City Road" to prepare a 2km-long two-lane highway in Okinawa city (project period: 1995 - 2013 fiscal year), when it was demanded to reduce cost from the original project plan, the Company introduced "UC-win/FRAME (3D)", frame analysis for 3-D models, in 2009. It is used in the final verification to review the width and structural type of the bridge.

However, it was only used in that project and actually, UC-win/FRAME (3D) has not been actively used since then. Therefore, Mr. Reiji Iha utilizes this effectively. For example, the Company designs the bridge substructure with it, in accordance with the actual situation of Okinawa, where most of the rivers are set with embankment rather than "excavated" river channel and problems about the earthquake motion prescribed in Government Ordinance for Structural Standard for River Administration Facilities are different from those found in the mainland Japan. He expects this will help meeting the cost reduction needs.

Furthermore, as mentioned above, they paid attention to landscape simulation early. Partly because they once aimed to create animation from CG, Mr. Reiji Iha also notes "UC-win/Road", 3-D real-time VR software.

"Landscape design in combination with environment will become very important from now". All the more, he advocates the potentiality of new services in Okinawa not only with conventional photomontage but also with the communication tool that allows traffic simulation.

Analysis using "Pier Design". Not a few FORUM8 products are used including those on bridges.

(Interviewed and written by Takashi Ikeno)