テクニカルリンク List of Products and Services

In the "Ground Investigation Service," we can understand the vibration characteristics and health of the subject of investigation without damaging the measurement target. Our company not only handles measurement tasks but also provides comprehensive support in the field of ground and structure investigation, from formulating overall plans on what and how to measure to proposing data analysis. 【Investigation Achievements】 ■ Static load testing of bridges ■ Static load testing of Fukurai Bridge ■ Shaking table experiments for a three-story building ■ Traffic condition surveys (BWIM) ■ Shear wave velocity measurement for gravity dams, etc. *For more details, please feel free to contact us.

The "static load test of bridges" is conducted to evaluate the integrity of the girder. The testing method involves placing a known test vehicle at the center of the span and measuring the deflection of the girder at that time. From the relationship between the obtained load and deflection, the integrity of the girder can be assessed. Here, we introduce a method using a communicating tube type displacement gauge for measuring the deflection of the girder. 【Features】 ■ The deflection of the girder can be measured with a resolution of 1/20 mm. ■ The communicating tube type displacement gauge can be installed on top of the girder, making it easy to work with. *For more details, please download the PDF or feel free to contact us.

A "static load test" was conducted to understand the bearing capacity of the P3 pier. The Fukurai Bridge is a road bridge spanning Fukuni Street in Joso City, Ibaraki Prefecture, and repair work is planned due to the settlement of the P3 pier caused by the Great East Japan Earthquake. The measurement of the pier's settlement was carried out using a communicating pipe type displacement gauge, and the tilt angle was measured with a stationary two-axis inclinometer. The load was applied by placing a plastic tank on the P3 pier and pumping water from the river to reach up to 60 kN in increments of 10 kN. 【Test Overview】 ■ The measurement of the pier's settlement was conducted using a communicating pipe type displacement gauge, and the tilt angle was measured with a stationary two-axis inclinometer. ■ The load was applied by placing a plastic tank on the P3 pier and pumping water from the river to reach up to 60 kN in increments of 10 kN. ■ The vertical displacement of the P3 pier and the two-axis (X, Y) tilt were measured at this time. ■ To confirm daily fluctuations, automatic measurements were conducted for about one week before and one week after the static load test. *For more details, please download the PDF or feel free to contact us.

To evaluate the performance of the horizontal vibration device "M009" using a linear motor, we conducted an "excitation machine experiment on a three-story building." We carried out practical vibration experiments such as sweep vibration tests and steady-state vibration tests (2.5Hz to 7.5Hz) to confirm the operating conditions and usability. [Summary] ■ Conducted an excitation machine experiment on a three-story building to evaluate the performance of the horizontal vibration device using a linear motor. ■ Carried out practical vibration experiments such as sweep vibration tests and steady-state vibration tests to confirm the operating conditions and usability. *For more details, please download the PDF or feel free to contact us.

We would like to introduce the traffic condition survey "BWIM." Using a system developed by the National Institute for Land and Infrastructure Management's Bridge Research Laboratory, which allows for the simple measurement of vehicle weights and other parameters (Bridge Weigh-in-Motion), we carry out bridge maintenance and management operations. Our company conducts traffic condition surveys and stress frequency measurements using this system, as well as remaining lifespan prediction analysis. [Overview] ■ We implement bridge maintenance and management operations using a system (Bridge Weigh-in-Motion) that allows for the simple measurement of vehicle weights and other parameters. ■ We conduct traffic condition surveys and stress frequency measurements, as well as remaining lifespan prediction analysis using the "BWIM system." *For more details, please download the PDF or feel free to contact us.

We would like to introduce the "Shear Wave Velocity Measurement Work for Gravity Dams." The purpose is to estimate the strength of concrete by calculating the elastic modulus from the shear wave velocity. Accelerometers were placed in the inspection gallery of the gravity concrete dam, and vibrations were applied using a hammer near the reference point, measuring the acceleration during this process. The impact vibrations were separated into cases for P-wave velocity and S-wave velocity, with more than five vibrations conducted for each case. The sampling frequency of the recording device was set to over 10 kHz, and the time history waveforms of the accelerometers were recorded. 【Measurement Overview】 - Accelerometers were placed in the inspection gallery of the gravity concrete dam, and vibrations were applied using a hammer near the reference point, measuring the acceleration during this process. - Impact vibrations were separated into cases for P-wave velocity and S-wave velocity, with more than five vibrations conducted for each case. - The sampling frequency of the recording device was set to over 10 kHz, and the time history waveforms of the accelerometers were recorded. *For more details, please download the PDF or feel free to contact us.*

We would like to introduce the "Vibration Characteristics Survey for the National Treasure Bronze Amida Nyorai Sitting Statue." We conducted continuous micro-vibration measurements of the statue and assisted the Tokyo National Research Institute for Cultural Properties in their investigation. This time, we aimed to understand the natural period and vibration characteristics of the statue, which is equipped with a sliding seismic isolation device made of stainless steel, and we conducted this survey simultaneously. 【Survey Overview】 - Continuous micro-vibration measurements were conducted using a highly sensitive servo-type velocimeter (Tokyo Sokushin), measuring 24 components simultaneously at 8 locations with 3 components each. - We analyzed these velocity waveforms (transfer functions and Fourier spectra) to grasp the natural frequencies and dynamic characteristics. - By using 24 highly sensitive servo-type velocimeters (Tokyo Sokushin) for simultaneous measurements, we were able to obtain highly accurate and reliable valuable data. *For more details, please download the PDF or feel free to contact us.

We will introduce the "Inspection and Investigation of Vibration Control Devices." To evaluate the performance of the vibration control devices installed on the cables of the cable-stayed bridge, a shaker test was conducted. The test involved exciting the cables with the shaker set to the first to fifth natural frequencies, stopping the excitation when the vibrations increased, and recording the subsequent free decay vibration waveforms. 【Business Overview】 ■ Conducted shaker tests to evaluate the performance of the vibration control devices installed on the cables of the cable-stayed bridge. ■ Stopped the excitation when the vibrations increased and recorded the subsequent free decay vibration waveforms. ■ The shaker tests were conducted in two cases: with and without the vibration control device, and the damping performance of the device was evaluated by comparing the logarithmic decay rates of these cases. *For more details, please download the PDF or feel free to contact us.

We would like to introduce the "Maintenance and Management of Cable-Stayed Bridges." A cable-stayed bridge is a type of bridge that supports the main girder with cables that are diagonally stretched from a main tower built on piers. Due to this structure, the cable components are crucial elements that determine the shape of the bridge, and any change in the tension balance of the cables increases the stress on the girder, tower, and bearings, leading to strain in each component. Therefore, for important cable-stayed bridges, we regularly inspect the cable tension and the shape of the bridge (longitudinal profile). [Overview of Services] - A cable-stayed bridge is a structure that supports the main girder with cables that are diagonally stretched from a main tower built on piers. - The cable components are crucial elements that determine the shape of the bridge, and any change in the tension balance of the cables increases the stress on the girder, tower, and bearings, leading to strain in each component. - Important cable-stayed bridges are regularly inspected for cable tension and bridge shape (longitudinal profile). *For more details, please download the PDF or feel free to contact us.

I would like to introduce the "Shaking Table Experiment of Building 3 at Kanagawa University Yokohama Campus." Building 3 of the campus, completed in March 2014, is a steel structure with 2 basement levels (reinforced concrete) and 4 above-ground levels (steel), featuring a damage control structure using buckling-restrained braces. Our company assisted with the shaking table experiment for this building. [Overview] - Building 3 of the campus is a steel structure with 2 basement levels (reinforced concrete) and 4 above-ground levels (steel), utilizing a damage control structure with buckling-restrained braces. - We assisted with the shaking table experiment for this building. *For more details, please download the PDF or feel free to contact us.

We would like to introduce the "Stress Investigation of G Bridge." To create foundational data for maintenance management, we conducted a traffic condition survey and stress frequency measurement (using the rain flow method and peak valley method) using the BWIM system. Additionally, we also calculated the estimated remaining lifespan based on these results. 【Business Overview】 ■ Conducted a traffic condition survey and stress frequency measurement (using the rain flow method and peak valley method) using the BWIM system to create foundational data for maintenance management. ■ Calculated the estimated remaining lifespan based on these results. *For more details, please download the PDF or feel free to contact us.