caisson
technology
technology
harbor technology
/green technology
- Mud pressurization (DK) shield method
- Double-O-Tube (DOT) shield method
- Developing Parallel Link Excavation (DPLEX) shield method
- Jack-driven Developing Parallel Link Excavation (J-DPLEX) shield method
- Detaching And Proceeding to dig Piping (DAPPI) construction method
- Mud pressurizing propulsion method
Safety/environment conservation of pneumatic caisson
The pneumatic caisson method is highly safe and has less impacts on surrounding environments.
Countermeasure against
hyperbaric disorder:
Patent No. 3349974
The excavation work using caissons, which are conducted at dozens of meters under the ground, is indoor work under high pressure; therefore, measurement against hyperbaric disorders if decompression sickness are a critical issue.
With the New DREAM construction method, a wide man airlock is used in emergencies; therefore, it allows for depressurization in a lying posture with extended arms and legs, meaning it has less of a burden on the human body.
The New DREAM construction method reduces the physical burden on operators at the time of ascending and descending with an air pressure elevator using double slabs. The conventional pneumatic caisson method uses spiral staircases under high pressure for ascending/descending to the workroom. In the case of high depth, an elevator is used; however, ladders are used under high pressure for 15 to 20 m after the operator gets off the elevator; therefore, there is a large burden on the operator’s body.
The maintenance airlock is a section where inspection/repair of the excavator is conducted under atmospheric pressure by utilizing the double slab structure, and it eliminates work under high pressure.
DHENOX system:
Patent No. 4216157
With the New DREAM construction method, usually no work under high pressure occurs, and only simple helium-containing gas equipment for emergency is needed, which results in reduced costs and superior work environment.
Countermeasure against noise:
Patent No. 3836067
Since this method addresses the issue of impacts on the surrounding environment, such as noise at the time of work, such impacts can be small.
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Silencer lock -
Silencer -
Soundproof house
Measure against humidity
Fill water by setting the air pressure in the caisson a little lower than usual to suppress moisture.
This device recovers moisture leaked outside through the tip of the cutting edge of the caisson from the workroom so that it does not erupt from the ground.This device recovers moisture leaked outside through the tip of the cutting edge of the caisson from the workroom so that it does not erupt from the ground.
By installing holes for passing through moisture around the caisson, it prevents impacts to other locations.
Conservation of surrounding
environment
The working air pressure of pneumatic caisson is set to be the same as the pressure of interstitial water; therefore, since this construction method does not reduce the underground water level of the peripheral ground, there is no need to worry about the subsidence of peripheral ground and depletion of wells. Since structures can be fixed at the required depth, interception of underground water can be minimized.
Utilization of AI Technology
Health Management System
(Daiho Health Management System)
In the field of the pneumatic caisson method, while unmanned work under high pressure is evolving as represented by the generalization of unmanned excavation using a remotely controlled excavator in response to the support for greater depth, manned operation is required in the daily inspection of excavators and other work. In response to this, we developed Daiho Health Management, a health control system that can determine the work state of workers and provide a health check at the same time, by collecting the opinions of on-site/relevant departments and getting advice from medical specialists. Following personal identification through face authentication, the system judges the availability of work and calls for attention by measuring health indicators, such as body temperature and blood pressure, by using Bluetooth-supported measuring instruments. The health management data is saved as a database along with the high-pressure work plan and implementation records and is managed in a uniform manner.
