In breakwaters covered with wave-dissipating blocks, outer RC walls of the caisson may show local failure due to the repeated collision of the blocks. The failure mode is attributable mainly to punching shear failure. Such local failure induces a large hole on the wall, resulting in flow-out of the filling in the caisson. One of the strengthening methods for outer RC walls may be solidification of filling materials in the caisson, which will contribute to the enhanced resistance of outer walls against repeated impact loads as well as anti-flowing-out of filling even in a case that the walls are failed. Execution of such solidification, however, remains unclear, especially in the field.
This paper reports the field experimental result of solidification of fillings in caisson with various solidification methods. Then, the field performance of these solidification methods was investigated through core boring test. The results showed that the performance of solidification strongly depends on the execution methods. The pre-investigation before the execution was also found to be quite important for leading the solidification to more certainty.

Key Words: caisson, damage, solidification of filling, field test