Field sites Index
- RETAINING WALL
- PAVEMENT TEST
- Small FWD
- PILE LOADING TEST
- UNDERGROUND CONSTRUCTIONS
- COMPUTERIZED CONSTRUCTION OF CONCRETE
- LAND SLIDE
- NUCLEAR POWER PLANT
- QUAKE DAMPING AND ABSORBING
Steel beam bridge measurement is divided into four categories: static loading measurement, dynamic loading measurement, frequency measurement and vibration measurement. In the static loading measurement, the status of the generation of static stress using a test car is seized, and in the dynamic loading measurement, that of dynamic stress during a test car or ordinary car passing is observed.
When installing a caisson, the following conditions must be monitored and controlled to gather data on the degree of sinking of the caisson body.
Conditions to be monitored when constructing retaining walls include subsidence, movement and displacement of ground, groundwater conditions, lateral pressure on earth retaining walls, deformation and pressure conditions of earth retaining structures, and so forth. The collapse of retaining walls, effects of collapse on surrounding ground, heaving, boiling, and other dangerous phenomena must be detected and necessary actions must be taken as quickly as possible. Therefore, an online measurement system using computers and data loggers is used.
During pavement construction, driving tests, loading tests, and long-period deterioration tests are conducted using various types of sensors to check the degree of fatigue in relation to the load bearing capacity.
TML small FWD system "FWD-LightŪ"is a testing device applicable for management and rigidity evaluation of soil structures such as a fill, cut, subbase course and subgrade. As it is easy-to-handle and portable and can measure subgrade reaction coefficient "K"and subgrade elastic modulus "E"in a short period of time, real time feedback to construction site is possible.
For filling work on soft ground, the following conditions must be monitored: (1) Conditions of ongoing work and the status of process management by performing measurement control operations (2) Safety factor or margin of a fill, (3) Critical load and deflection, (4) Amount of subsidence and heaving With a computer, a data logger and measuring instruments linked in an online measurement network, conditions of ground subsidence, horizontal displacement, earth pressure in subterranean ground and pore water pressure are monitored so that appropriate action can be taken if any abnormal condition is detected.
On-site pile measurement includes test measurement to determine design specifications, pile work control measurement during pile work execution, post-execution verification measurement, and follow-up measurement after completion of pile work. It is necessary to build a static and dynamic measurement system suitable for each measurement method, the type of measuring instrument used, the purpose of measurement, and site conditions.
The displacement of surrounding ground and tunnel support structures along with stress conditions are measured during tunnel excavation to ensure work safety and economic efficiency.
As the cross section of an underground opening becomes large, ground stability decreases and a large-scale support structure is required. The stability of an opening depends on surrounding ground. Since it is very difficult to clarify the level of ground stability by conducting surveys, data on the behavior of ground gathered during construction is analyzed and analysis results are reflected to design and construction. This is an observational construction control system that our company proposes to customers.
During construction of an earth dam, pore water pressure in the dam body and its foundation ground is measured and data obtained is used to control earth (concrete) filling speeds. Deformation of the dam body and its foundation and the earth pressure on them are also measured during construction. After completion of a dam, the amount of infiltrating water in the dam body and foundation ground and the deformation of the dam body are measured to ensure safe dam operations. In addition, pore water pressure, osmotic pressure on foundation ground, the level of groundwater and so on are measured in order to grasp the state of water infiltration in both the dam body and its foundation ground.
With the spread of an excellent self-filling and high fluid concrete, a method of concrete being placed in the form directly has been frequently used. When concrete is filled in a narrow space or complicated shaped form, it is very difficult to visually observe the filling status of concrete. Here, we suggest a concrete filling management system for observing the condition of concrete placement.
In making a landslide measurement plan, it is necessary to have a thorough knowledge of the three-dimensional profile and the ground-movement direction of landslide area. A measurement system that TML recommends is a centralized, automated measurement control system in which measuring instruments, data loggers, computers, and so on are connected in an online network. The addition of a communication function would turn this system into a wireless communications measurement system.
Stress and strain on a pier under no-load conditions are measured.
Stress and strain on a pier are measured by running a vehicle, such as a forklift loaded with maximum weight assumed to be applied.
The stress and strain of a pier are measured when a ship of 10,000 D.W.T. or heavier comes alongside the pier.
The structural integrity test (SIT) of a reactor containment vessel is carried out using various sensors.
During construction of a dome and gymnasium, data on load and stress is collected using various sensors to verify the load bearing capacity (jacking-up and -down capacity).
A quake-damping structure uses various types of damping materials. For example, laminated rubber having low horizontal rigidity, slide bearings and so on are designed as part of the quake-damping structure in order to damp seismic force. A quake-absorbing structure uses a powerful shock-absorbing device to absorb seismic energy. Static and dynamic conditions of a structure are measured to check its quake-damping and quake-absorbing performance.