PHYSICAL EXPERIMENTS AND SIMULATION OF SEA ICE FORCE ON PILE STRUCTURES IN PORTS

A series of physical simulation experiments of ice forces on different kind of piles in ports were performed in order to resolve the ice forces on the vertical piles of large diameters and inclined multi-piles of small diameters in ice-infested port engineering. For expressing the ice forces on lager piles and caissons, Afanasev equation, suitable for small piles with D/h≤6, is extended to larger cylinders with D/h≤50 on the basis of a series of physical simulation experiment results. Because the thickness of Bohai sea ice is less than 20 cm in most time of a winter, the new statistical formula can be used to calculate ice forces on piles or columnar caissons with 25m diameter in Bohai. For obtaining the ice force distribution on each pile in inclined piles and pile arrays, the whole structure is divided into several smaller elements which are tested individually and are compared with the ice forces on the vertical pile with the same diameter while the structure is lager and can not follow the requirement of designed model scale and flume dimensions. Therefore, the relations between ice forces on each pile and each element and their effective factors are set up by the ratio of measured ice forces on them and the vertical pile. The full scale ice force on the vertical pile can be calculated by Afanasev equation and full scale ice compressive strength, the thickness and pile diameter, and the full scale ice forces on inclined pile and pile arrays can be recovered by the full scale ice force on the vertical pile and the effective factors. This way slides over the difficulties of ice forces on complex structures from model scale to full scale by simple similarity theory. Following this principle, the physical simulation experiments obtain the ice force distribution on each pile of three types of pile arrays, their shielding factors between fore and after piles and effective factors to the vertical pile. These results are universality in Bohai ice engineering.