A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Nondestructive evaluation of existing transmission tower foundations
This paper presents a methodology developed by the Author using nondestructive stress wave testing. Impulse Response is the primary method used, and the data acquired is further analyzed by amplified Sonic Echo, Velocity Reflector and Impedance Log methods. Simulation techniques are also valuable, especially when variable concrete deterioration is present in the pile shafts. Case histories including both straight-sided and belled shafts are presented, as well as pile shafts with concrete deterioration such as alkali-silica reaction and freeze-thaw damage. The Impedance Log treatment of the Impulse Response data was of great value in determining pile length as well as the presence and the size of enlarged pile bases (bells) for the Chicago area radio transmission towers, even with the presence of pile caps and damaged concrete in the pile heads. In the case of the California and Texas piles damaged by AAR, the high success rate in matching simulation responses with field test mobility plots from Impulse-Response tests for at least 90 % of the shafts tested allowed the piles along these transmission lines to be rated according to the severity of the concrete AAR attack. Those piles requiring immediate attention were selected in this way, and listed in order of decreasing damage. To the author's knowledge, this is the first documented occasion where small-strain stress wave methods have been successful in quantifying the degree of AAR damage to concrete structural elements buried in the ground.
Nondestructive evaluation of existing transmission tower foundations
This paper presents a methodology developed by the Author using nondestructive stress wave testing. Impulse Response is the primary method used, and the data acquired is further analyzed by amplified Sonic Echo, Velocity Reflector and Impedance Log methods. Simulation techniques are also valuable, especially when variable concrete deterioration is present in the pile shafts. Case histories including both straight-sided and belled shafts are presented, as well as pile shafts with concrete deterioration such as alkali-silica reaction and freeze-thaw damage. The Impedance Log treatment of the Impulse Response data was of great value in determining pile length as well as the presence and the size of enlarged pile bases (bells) for the Chicago area radio transmission towers, even with the presence of pile caps and damaged concrete in the pile heads. In the case of the California and Texas piles damaged by AAR, the high success rate in matching simulation responses with field test mobility plots from Impulse-Response tests for at least 90 % of the shafts tested allowed the piles along these transmission lines to be rated according to the severity of the concrete AAR attack. Those piles requiring immediate attention were selected in this way, and listed in order of decreasing damage. To the author's knowledge, this is the first documented occasion where small-strain stress wave methods have been successful in quantifying the degree of AAR damage to concrete structural elements buried in the ground.
Nondestructive evaluation of existing transmission tower foundations
Zerstörungsfreie Bewertung der Fundamente von vorhandenen Sendetürmen
Davis, A.G. (author)
2001
9 Seiten, 6 Bilder, 9 Quellen
(Nicht paginiert).
Conference paper
English
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