The dynamic testing of a collision tolerant pile structure

The Collision Tolerant Pile Structure has been under development by the University of New Hampshire and U.S. Coast Guard for ten years. The structure is designed to take the place of standard wooden piles used by the U.S. Coast Guard to mark navigational hazards in narrow ship channels. The CTPS consists of a steel pile that is connected to an omnidirectional hinge at the mudline. This design allows the structure to survive collisions with ships or barges where wooden piles would otherwise fail. Two prototypes deployed in the Houston Ship Channel have survived numerous collisions to date. A third prototype installed at Portsmouth, NH is presently being monitored to determine the fatigue design life. The CTPS is outfitted with an ENDECO/YSI data acquisition field station. This system handles inputs from several meteorological sensors and a pressure sensor in order to obtain continual real time data. Data acquired includes wind speed and direction, air temperature, wave height, and two angles of tilt. This data is acquired and temporarily archived on site. Two way, packet radio communication between the field station and a base station PC located on shore enables adjustment of study patterns and sensor selection. Software running on the base station's PC calls for the field station's data routinely alloying it to be transmitted to the base station packet receiver and archived on the PC. Data is subsequently transferred to UNH or any other location using remote control communications software and a phone line. This software enables the user to remotely control the base station's PC and also allows one to download the data archived there. Sample rates and sensor selection can also be accomplished by this link. Data comes in raw form and, is subsequently processed into engineering units. Initial results are being used to correlate CTPS dynamic response to environmental forcing. Subsequent results will yield data adequate for analytical model verification and stress analysis.