본 논문에서는 대수-선형 파손율 모형(log-linear ROCOF)과 와이블 파솔율 모형(Weibull ROCOF)을 이용하여 상수도 주철 배수관로의 파손율을 모형화하고, '수정된 시간 척도'를 이용하여 최적교체시기를 산정할 수 있는 방법이 개발되었다. 두 ROCOF의 모형화를 위하여 개별 관로의 파손시간을 기록한 '파손 시간자료(failure-time data)'와 일정 시간간격 사이에서 발생하는 파손횟수를 기록한 '파손 횟수자료(failure-nu

Four cast iron pipe sections containing 3 styrene butadiene rubber (SBR) gaskets (1 joint and 2 end caps) were filled with water and maintained at approximately 40 psi internal pressure. The pipe sections were placed inside 16 gallon drums filled with initially clean sand. Three of the tanks were subsequently contaminated with gasoline, gasoline spiked with pyrene and naphthalene, and toluene. The forth tank served as a control. The water inside each pipe was monitored over time for organic chemical contamination. Permeation of organic chemicals into the water inside the pipe systems was found to occur in all 3 contaminated pipe systems after approximately 100 days as measured organic chemicals concentrations were significantly above those in the uncontaminated cell. Flushing experiments in which the water inside the contaminated pipes was replaced with initially clean water showed that organic chemical concentrations inside the pipe rapidly (12 days) reached their preflushing levels.