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Applications of OSV Technology (Examples)

Tunnels

Safety Monitoring during Tunnel Construction

After constructing reinforced support structure in unstable ground, LEDs were placed for visually monitoring excessive deformation. This was the first application of LEDs to an actual tunnel construction site.
For details, please refer to News Relase from Konoike Construction Co., Ltd.

Safety Monitoring of a Deformed Tunnel during
Repair Works

For monitoring abnormal deformation, LEDs were installed to the site during repair works in a deformed tunnel.

Monitoring of Strut Removal during Construction of an Open-Cut Tunnel

For monitoring abnormal deformation during removal of struts in an open-cut tunnel after completion of its main body, LEDs were installed around the work site. In this example, deformation of around 0.5mm, an undetectable size of deformation to the naked eyes, was actually detected and visually confirmed by workers immediately.

Model Experiment of a Tunnel

In a destructive experiment of a tunnel model, deformation was monitored and visualized with light colors. In this experiment, progress of deformation of the concrete structure was successfully visualized although the length of LEDs was too long for the reduced scale of the model.

Monitoring of Deformation of Reinforced Earth during Tunnel Construction in an Urban Location

Deformation of partially reinforced ground foundation was monitored during construction of an underground road immediately below an existing above-ground road. In this application, for securing safety, LEDs were installed for display of deformation at two locations i.e. the monitoring site of reinforced earth and a location easy for workers to observe.

Slopes

Monitoring of Tunnel Portal Slopes

Abnormal deformation on a steep slope with free-frame reinforcement was monitored during tunnel construction. LEDs of higher brightness than usual were used in this application, and the same LED display unit as the one with sensor function was prepared and installed at the tunnel portal so that workers can confirm deformation both at the monitoring site on the slope and at another location at the tunnel portal.
For details, please refer to News Relase from Konoike Construction Co., Ltd.

Experiment with Lock Bolts

This was the first example of monitoring deformation of lock bolts by using a simplified light-emitting displacement gauge model. In this experiment, deformation was monitored and visualized not only on the surface, but subsurface deformation of the ground foundation was also monitored and visualized on the surface for the first time. Application of this arrangement to tunnels and mines is expected.

Safety Monitoring in Delhi Metro Construction Project in India

In the 2nd phase construction of Delhi Metro, a JICA project, OSV sensors were used for safety monitoring of workers. This was a large-scale application of the technology as well as the first international project since establishment of OSV Consortium. Thanks to collaborative efforts by our members, our safety monitoring application was highly evaluated by the local people.
A related article on the Internet site of JICA.

Simulated Experiment of Slope Failures

Conventional information communication systems for ground foundational structures have shortcomings in the areas such as emergency response. This was the first experiment with "light-emitting displacement gauges" that had been developed for overcoming such shortcomings and enabling prompt judgment of safety in normal and emergency conditions. It was also the first experiment that provided us with perspectives that we can establish work environment where anyone can easily perceive current status visually and promptly respond to emergency situations by using in-situ on-going display of current status with altering light colors, an unconventional data processing method. This photograph was printed in the newspaper, and we began to receive increasing inquiries from companies in industries concerned.

Safety Monitoring during Landslide Prevention Works around a Dam Lake

Deformation was monitored during reinforcement works in regions with landslide potential around a dam lake. In this application, monitoring using laser pointers was also conducted.

Simulated Experiment of Rock Falls

This experiment was conducted for effective monitoring of amount of fallen rocks accumulated in a rock-fall guard net. LEDs were installed on members of frameworks supporting the guard net whose deformation and stretching were monitored and indicated with lights. The experiment proved that deformation volume can be detected and indicated with LEDs (indication of the amount of fallen rocks) and that people can get to know abnormality occurring to the frame works.

Bridges

Safety Monitoring during Bridge Construction

Stability of temporary structures was monitored during construction of a bridge using cable erection method. Extension of main cables and gradient of towers were visually monitored. This was the first application of light-emitting displacement gauges to bridge construction. Based on the experience in this project, application of the technology to another bridge construction project is planned for May, 2010 or later.

Others

Simulated Experiment of Flow Rate Measurement

In this experiment, the flow rate in a simulated water channel was monitored with altering light colors of LEDs. Through this experiment, it has been demonstrated that visualization of movement with light colors is possible not only with solid objects like ground foundation and structures but also with liquid. The same can be demonstrated with wind velocity.

Simulated Experiment of a Temporary Scaffolds

Strong winds sometimes cause collapse of scaffolds. This experiment has demonstrated that abnormal deformation of scaffolds can be detected at an early stage by application of LEDs. In some countries in Asia and other areas, very unstable temporary scaffolds are often found at construction sites, and stability of scaffolds can be an elemental factor for securing safety of construction workers.

Simulated Experiment of Collapse of Residential Land due to an Earthquake

In this experiment, a retaining wall of postulated developed residential land was artificially deformed to demonstrate conversion of detected slanting of the wall in the process of collapse into altering light colors. There have been many instances of collapsed developed residential land in earthquakes, and for efficient post-earthquake rescue operation, it is considered very effective to visualize degrees of damages with light colors. The light-emitting sensors used in this experiment are tilt-meters manually prepared by students.

Experiment of Visualization of Displacement using Laser Beams

This was an experiment to monitor displacement at multiple locations by using laser pointers. In the experiment, a pointer with green laser light was installed at each of five locations, and displacement of one of the five locations was visualized on a screen to which laser beams were reflected. It has been confirmed that, because the screen can be a building wall or a concrete pillar nearby, effective use of laser beams enables monitoring of extensive areas and visualization of displacement in urban environment at relatively low cost.

Safety Monitoring during Replacement of Obsolete Facilities

LEDs were used for safety monitoring of wooden frameworks of temporary overhead cableway for repair works of utility facilities. To reinforce monitoring capability, the second LED display board was installed in addition to LED sensors themselves in order to eliminate blind spots when workers come to the locations from where they cannot directly see the LED sensors.

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