Research Trends and Results

Development of inspection and monitoring
technology for preventive control of infrastructure
KOHASHI Hidetoshi, Research Coordinator for Construction Management
Research Center for Land and Construction ManagementSUZUKI Atsushi, ResearcherConstruction System Division（Key words）

Preventive control, Inspection and monitoring technology, Aging of the social capital

1. Introduction
Infrastructure has played a primary role as thefoundation for industrial expansion and was intensely
created during a period of high economic growth morethan fifty years ago. Now this aging infrastructure is aconcern due to an increasing threat of accidents and thepotential results of natural disasters upon it that could
affect society as a whole, in addition to increasing
maintenance costs and reconstruction expense.
To adequately confront our aging infrastructure in thefuture, we must change into an investment-mindedsociety that designs and builds extended life constructions.
For that purpose, in place of reactionary measures used toaddress present damage, we must implement strategic
maintenance and control techniques based on preventive
maintenance thinking to attempt to reduce total costs
through long-lived facilities. This includes regularly
inspecting and diagnosing structures to determine the root
cause of failures, and implementing countermeasures
before critical defects occur to prevent accidents anddisasters from impacting a society that faces a rapidly
increasing risk from aging infrastructure.
In this research, we have identified inspection methods
applicable to various types of construction in order tochange from simply “seeing what is visible” to“observing what we need to observe,” as described
below:I.
Inspection and diagnosis technology on
hidden portions of construction
II.
Inspection and diagnosis technology forvariations of constructions that are visuallydifficult to evaluate
2. Outline of research and development
Ⅰ．Development of inspection and diagnosis technology
for visually difficult portions of the construction① Inspection and diagnosis technology for buried andcovered portions through nondestructive inspection
With a goal of developing nondestructive inspection
and diagnosis technology and evaluation standards forvisually difficult portions, such as buried and covered
portions of concrete in civil engineering constructs, wehave developed prototypes for placement inside anauscultation system. Through nondestructive inspection,

structural endoscopes and wall face detectors runningover outer walls are able to determine actual performanceof structures.
② Inspection and diagnosis technology on visuallydifficult portions through images and data
With the goal of developing inspection and diagnosis
technology and evaluation standards for visually difficult
portions, such as the interiors of sewer pipes or subfloorsof constructions that cannot be approached directly
through image and data technology, we have
implemented a performance verification test using a
prototype screening method of TV camera investigation
for road-caving prediction and deterioration diagnosis ofwooden subfloor materials.
Ⅱ． Inspection and diagnosis technology for variationsof constructs that are visually difficult to evaluate① Inspection diagnosis technology for leaking
constructs using infrared
With the goal of developing inspection and diagnosis
technology and evaluation standards to quantitatively
understand wet portions of dikes that are difficult to
detect with current methods that use infrared ray thermo
sensors, we have implemented a performance verification
test using an infrared ray thermo sensor in an actual riverdike.
② Monitoring of structural subjects and variation ofdetection methods through positional measurement
Utilizing position identification technology throughGPS and road management cameras, we have developedand implemented a performance verification test in thefield on actual bridges. The inspection and monitoring
technology and evaluation standards will allow us tocapture accidental and critical variations of structuralsubjects such as bridges, swiftly and simply.
3．Future planning
We are planning to develop inspection and diagnosis
technology and evaluation standards for portions andvariations of structural objects that are difficult to see, up
until now making evaluation visually difficult.
Additionally, we will establish a multi-purpose evaluation
method and evaluation standard for inspection andmonitoring results and implement them as swiftly as
possible.