3.3.3 Pilot Work and Practical Execution
Pilot work was carried out at Kumamoto Port at the end of 1990 in order to confirm the field applicability of the air-compressed transport process. Results are as shown in Table 3. The amount of spoil transported per hour was on average 88 to 96% of the nominal capacity.
Water content increased a maximum of only 20% over the level before transportation, measuring 90% or so at the outlet. This high content is considered to have been caused by water addition as sealing water, mechanically needed, and water in the hopper barge mixed with earth when unloaded by the backhoe.
Records of work execution at Kumamoto Port are (as of October, 1991) presented in Table 4. Condition of work is as shown in Photo 2. With regard to sandy silt with in-situ water content of 65% or so (approximately 20% of sand, 60% of silt and 20% of clay), the water content at the outlet was 80 to 90%. Thus, the work effect was averagely 90% of the nominal capacity (600 m3/h), which indicates that the initial target is achieved. 10)
4. Conclusions and Acknowledgements
Work of phase I for Kumamoto Port will be completed in 1992, allowing long-awaited
