■Mr. Takuyuki Tamura made a presentation at "Structural Faults and Repair-2010".

Mr. Takuyuki Tamura, a senior research engineer of Research Institute of Technology, TOBISHIMA Corporation, made a presentation at "Structural Faults and Repair-2010", a international conference on health monitoring by non-destructive inspection technology of structure, held in Edinburgh, UK on June 15th-17th. A total of 220 papers were submitted by researchers and engineers from all over the world. Two papers were submitted from TOBISHIMA Corporation. The title and abstract of the papers are as follows; One is the paper of Mr. Takuyuki Tamura, co-authors are Koki KUMAGAI and Noboru KAMIAKITO who belong to TOBISHIMA Research Institute of Technology. TITLE: HYBRID STRAIN MONITORING SYSTEM BY MEANS OF TWO DIFFERENT FIBRE OPTIC SENSORS Authors: Takuyuki TAMURA, Koki KUMAGAI, Noboru KAMIAKITO ■ ABSTRACT Recently Fiber Bragg Grating (FBG) based optical fiber sensing systems have been applied widely for many civil structures. Contrary to the Wavelength Division Multiplexing (WDM), in FBG adapting Time Division Multiplexing (TDM), multiple points of more than 100 points on a single line can be monitored, that is suitable for long-term health monitoring of large civil structures. In the present paper, this TDM based FBG sensing system was installed at a deformed tunnel in a cold region. A total of 100 strain and deformation on the surface of lining concrete was measured with the optical interrogator at about 1 km away from the sensors. So far even under such a severe monitoring condition, continuous data acquisition with good accuracy has been successfully conducted. The other paper was presented by Dr. Shiotani, the associate professor of Kyoto university. Shohei MOMOKI, HwaKian CHAI who belong to TOBISHIMA Research Institute of Technology are the co-authors of the paper. TITLE: VISUALIZATION OF FATIGUE DAMAGE FOR CONCRETE BRIDGE DECK WITH STRESS WAVE TECHNIQUES Authors: Tomoki SHIOTANI, Shimpei YOSHIMI, Shohei MOMOKI, Hwa Kian CHAI, Hiroshi ONISHI, Toshiro KAMADA ■ ABSTRACT Different from post failure maintenance, preventive maintenance is a very crucial issue not only for distributing limited budget over existent ageing infra-structures but also extending their service life. Functional failure of road bridges causes serious impact on logistics, which eventually leads to enormous damage on social economy. To maintain a large number of the ageing infrastructures appropriately, a strategic maintenance program, innovating rational and efficient non-destructive testing, is of high demand. In this study to provide useful information on early damage for concrete bridge deck, the fatigue damage process of concrete deck due to repeated traffic loads is visualized by means of active and passive elastic wave techniques, namely elastic wave tomography and acoustic emission. A full-scale concrete deck was subjected to thousands of passages of moving wheel load. At three stages of intact (after initial loading), 10,000 passages and 20,000 passages of 150 kN-wheel loading, the test was momentarily suspended and elastic waves were excited to obtain the internal conditions of the specimen represented by elastic wave velocities. Applying incremental static load, acoustic emission testing was followed to perform at each stage to extract characteristic AE parameters with regard to the damage. The findings through the experimental studies were finally verified with in-situ specimens that were hewed out from actual bridge deck.

Presentation by Mr. Takuyuki Tamura

Takuyuki Tamura Tobishima Corporation