Background to conducting technical exploration:
When constructing an offshore wind farm, it is necessary to conduct a geophysical ground survey known as boring exploration or CPT (Cone Penetration Test). The CPT can be conducted using a “Vessel-based” solution to drill or analyze the ground from the shipboard or a “Seafloor-based” solution which installs large scale exploration equipment on the sea floor. We are looking for a technology consisting of a Vessel-based solution.
Guidelines/constraints for the desired solution:
- Specifications required for products and technologies
- Solutions using “Vessel-based” CPT. We do not need to deal only with improvement of existing methods, but also with newly developed technologies for investigation.
- The depth of water is from 15m to 60m and the depth of mining (extraction) is up to 100 m
- Mining (extraction) in a water area with a depth of 15 m or less where a large ship cannot enter
- The place of implementation is on the Pacific Ocean
- Geotechnical survey for gravity base offshore wind farm
Currently recognized issues
- CPT is difficult to apply for hard bedrock / ground
- Both ship and equipment are large-scale and costly
- Because we mine or bore directly from the equipment installed on board, we are vulnerable to shake from wave (rolling and/or pitching)
- Existing technologies cannot withstand significant waves higher than 1.5 m and the cycle of 7 seconds or longer.
- A large ship cannot enter depths of 15 m or less and “Vessel-based” solutions cannot be used, while small ships are vulnerable to the above-mentioned disturbances.
- Technology under development and under research are also acceptable.
- Although it is not a target only with ideas/concepts, it is acceptable if the technology under development at universities etc. is at the stage right before demonstration.
Possible solution areas:
- Offshore wind power development, oil field development, resource exploration, bridge construction at the sea (marine civil engineering) etc.
Desired outcome of the solution:
- Ground survey from shipboard using boring / CPT
- If possible, it is possible to conduct ground survey even in environments where the significant wave height is 1.5 m or above and the cycle time is 7 seconds or longer.
- It is possible to conduct ground survey even at depth of water from 15 m to 60 m and/also preferably at depths of water of 15 m or less
- The depth of the mining (extraction) is up to 100 m