This article evaluates the efficacy of a tool developed in the Monte Carlo simulation and referred to as control chart. This tool is used in order to detect changes in productivity resulting from the occurrence of a g...This article evaluates the efficacy of a tool developed in the Monte Carlo simulation and referred to as control chart. This tool is used in order to detect changes in productivity resulting from the occurrence of a given event during the welding of land pipelines with self shielded flux cored wire (FCAW). The elaboration of this control chart is based on the data from the Cumulative Probability Density Function (CDF) curve, and generated in the Monte Carlo simulation using version 6 of the Palisade Corporation’s @Risk software for Excel, in a sample with productivity data from 29 welded joints, gathered through direct observation which considers the productive and unproductive times. In order to evaluate the control chart efficacy, the performance of welding productivity with a FCAW process with low alloy steels has been assessed during 29 days, summing up to 842 welded joints registered on “Relatórios Diários de Obras” (Construction Works Daily Reports). The results show that the model developed for the control chart elaboration is effective in monitoring the productivity of the observed welding procedure.展开更多
The gas transport infrastructure is frequently localized in areas subjected to anthropogenic movements and strains.The potential impact of the ground movements on the gas pipeline in the aspect of its damage can be pr...The gas transport infrastructure is frequently localized in areas subjected to anthropogenic movements and strains.The potential impact of the ground movements on the gas pipeline in the aspect of its damage can be properly assessed e.g.by predicting strains,taking into account the causes of terrain movement.On the other hand,the hazard is also related to technological factors like design of the pipeline.The presented method is based on artifcial intelligence methods allowing for evaluation of probability of failure risk in gas supply pipeline sections.The Mamdani fuzzy inference was used in this study.Uncertainty of variables characterizing the resistance of the gas pipeline and predicted continuous deformations of ground surface were accounted for in the model by using triangular-shaped membership functions.Based on the surface deformations and gas pipeline resistance and the inference model one can make prediction when the gas pipeline is hazarded.There were estimated two the most hazarded parts for two pipelines.We proved that the proposed model can contribute to the protection,costoptimization of the designed pipelines and to the repairs of the existing gas pipelines.展开更多
Damage caused by the 2011 Tohoku Earthquake （Mw 9.0） to transmission and distribution pipelines in Sendai City is summarized. The locations of the pipeline repairs are discussed relative to earthquake intensity, geo...Damage caused by the 2011 Tohoku Earthquake （Mw 9.0） to transmission and distribution pipelines in Sendai City is summarized. The locations of the pipeline repairs are discussed relative to earthquake intensity, geomorphologic conditions and landform change in the developed areas of hilly land. Repair rate （repairs/km） is summarized according to pipe material and presence or absence of artificial landform change. The following findings were obtained： （1） More than 80% of the repairs took place in pipelines installed in higher lands such as hill and terrace areas consisting of hard soils; （2） Nearly all the pipe repairlocations in hill areas are where landform change was made through land development tor residential purposes over me past several decades; （3） The aforementioned repair rate was more than 3.6 times than that of other lowland areas where no landform change occurred. The heaviest concentrations of pipe repairs of vinyl chloride pipes and ductile iron pipes were observed within the boundary area between cutting and filling, having a thickness between -2.5 m and 2.5 m. Approximately 78% of the all pipe repairs occurred outside of areas where severe ground failures took place. A mechanism of pipe damage in the areas free of severe ground failure was discussed.展开更多
文摘This article evaluates the efficacy of a tool developed in the Monte Carlo simulation and referred to as control chart. This tool is used in order to detect changes in productivity resulting from the occurrence of a given event during the welding of land pipelines with self shielded flux cored wire (FCAW). The elaboration of this control chart is based on the data from the Cumulative Probability Density Function (CDF) curve, and generated in the Monte Carlo simulation using version 6 of the Palisade Corporation’s @Risk software for Excel, in a sample with productivity data from 29 welded joints, gathered through direct observation which considers the productive and unproductive times. In order to evaluate the control chart efficacy, the performance of welding productivity with a FCAW process with low alloy steels has been assessed during 29 days, summing up to 842 welded joints registered on “Relatórios Diários de Obras” (Construction Works Daily Reports). The results show that the model developed for the control chart elaboration is effective in monitoring the productivity of the observed welding procedure.
基金The research reported in this paper has been supported by a grant from the National Science Centre No.2011/01/D/ST10/06958.
文摘The gas transport infrastructure is frequently localized in areas subjected to anthropogenic movements and strains.The potential impact of the ground movements on the gas pipeline in the aspect of its damage can be properly assessed e.g.by predicting strains,taking into account the causes of terrain movement.On the other hand,the hazard is also related to technological factors like design of the pipeline.The presented method is based on artifcial intelligence methods allowing for evaluation of probability of failure risk in gas supply pipeline sections.The Mamdani fuzzy inference was used in this study.Uncertainty of variables characterizing the resistance of the gas pipeline and predicted continuous deformations of ground surface were accounted for in the model by using triangular-shaped membership functions.Based on the surface deformations and gas pipeline resistance and the inference model one can make prediction when the gas pipeline is hazarded.There were estimated two the most hazarded parts for two pipelines.We proved that the proposed model can contribute to the protection,costoptimization of the designed pipelines and to the repairs of the existing gas pipelines.
文摘Damage caused by the 2011 Tohoku Earthquake （Mw 9.0） to transmission and distribution pipelines in Sendai City is summarized. The locations of the pipeline repairs are discussed relative to earthquake intensity, geomorphologic conditions and landform change in the developed areas of hilly land. Repair rate （repairs/km） is summarized according to pipe material and presence or absence of artificial landform change. The following findings were obtained： （1） More than 80% of the repairs took place in pipelines installed in higher lands such as hill and terrace areas consisting of hard soils; （2） Nearly all the pipe repairlocations in hill areas are where landform change was made through land development tor residential purposes over me past several decades; （3） The aforementioned repair rate was more than 3.6 times than that of other lowland areas where no landform change occurred. The heaviest concentrations of pipe repairs of vinyl chloride pipes and ductile iron pipes were observed within the boundary area between cutting and filling, having a thickness between -2.5 m and 2.5 m. Approximately 78% of the all pipe repairs occurred outside of areas where severe ground failures took place. A mechanism of pipe damage in the areas free of severe ground failure was discussed.
