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Spatial variability of soil resistivity and rational sampling for corrosion assessment of carbon steel in Daqing area

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Acta Metallurgica Sinica(English Letters) 2010年第5期23卷 396-400页

作者： Liangshan QU Cuiwei DU Xiaogang LI Jianlong ZHOU Corrosion and Protection Center Institute of Advanced Materials Ministry of Education Key Laboratory for Corrosion and Protection University of Science and Technology Beijing Beijing 100083 China Oilfield Construction Design & Research Institute Daqing Oil Limited Company Daqing 163712 China

soil resistivity is one of the key indicators of the corrosive classification assessment on metal materials in soil environment. This paper presents variance characters of various quantity of soil resistivity samples data based on the semi-variance function methods of Geo-statistical Analysis by analyzing the regional soil resistivity sampling data in Daqing area. Furthermore, the variance of the soil resistivity as well as entire soil circumstance due to different sampling amounts are also analyzed and compared by means of using the characteristic parameters of the semi-variance function. In addition, this work also studied the rational sampling quantities according to various measurement errors required and evaluated the local soil corrosivity on carbon steel based on the actual measuring data in this area.

关键词： soil resistivity Spatial variability Sampling Corrosion of carbon steel

Influence of Precipitation on the Determination of Proper Time for soil resistivity Measurement

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Acta meteorologica Sinica 2010年第2期24卷 259-268页

作者：李良福李航向波覃彬全 College of Resources and Environment Southwestern University Chongqing Meteorological Administration

In order to obtain reliable and effective upland soil resistivity measurements,it is necessary to know how much time after the rain stops is required before making soil resistivity observations so that the influence of precipitation on the measurements can be *** on the soil resistivity monitoring data at different depths obtained from the soil conductance automatic monitoring system using the triple-electrode method,and the precipitation data from the synchronous and automatic observing system in Hechuan County of Chongqing,this paper analyzed the effect of rain on the determination of upland soil resistivity measurement *** results showed that the required interval time between the measurement and the termination of rain should be as follows：if the rainfall was less than 0.1 mm,the interval time was zero;the interval time was 24 h if the precipitation time was less than 1 h or the rainfall was 0.1-2.0 mm;the interval time was 72 h if the precipitation time was 2-10 h or the rainfall was within 2.1-5.0 mm;and the interval time of 72-232 h was observed when the precipitation time was 10-25 h or longer or the rainfall was 5.0-10.1 mm or *** observations showed that the above conclusions were on the whole valid for different soil *** the other hand,the results indicated that the maximum variance ratio for the influence of precipitation on resistivity measurement was about 28.9%,and the average variance was about 3.9%.Moreover,a preliminary analysis also showed that the precipitation process time might play a more crucial role in the resistivity recovery time than the precipitation *** is also found that it is practically better to use the rank correlation method than the numerical correlation analysis method to determine the time break between the stop of rain and the time to carry out the soil resistivity measurement.

关键词： precipitation effect soil resistivity measurement time

Influence of soil resistivity on stray current in power supply system of urban rail transit

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Journal of Measurement Science and Instrumentation 2022年第3期13卷 261-266页

作者： CHEN Wanglong LI Yaning WANG Ye School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China School of Envirommental and Municipal Engineering Lanzhou Jiaotong Universit yLanzhou 730070China

In order to explore the influence of soil resistivity on stray current in power supply system of urban rail transit,we establish an equivalent circuit model of the rail-to-ground structure based on resistance network method *** measuring the soil resistivity of a real subway system,a simulation model is established in Matlab to obtain the stray currents at different soil *** the influence of soil resistivity on stray current is ***,to verify the rationality and reliability of the simulation model,we design a test circuit to measure the stray current and rail-to-ground voltage in a real subway system,and a comparison of the experimentally measured results and simulation results is *** results show that the stray current is the maximum when the soil resistivity is 211.57Ω·m;when the soil resistivity is 768.47Ω·m,the stray current is the minimum,that is,the smaller the soil resistivity,the greater the stray ***,the resistivity should be increased as much as possible when ramming the track foundation in urban rail transit system.

关键词： urban rail transit power supply system stray current soil resistivity four-electrode method

Design and verification of an improved experimental platform for stray current in urban rail transit

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Journal of Measurement Science and Instrumentation 2024年第3期15卷 379-386页

作者： LI Yaning KANG Hong WANG Ye LI Wenfei JIAO Meng ZHANG Wencai School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China School of Environmental and Municipal Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

With the rapid development of urban rail transit,there have been an urgent problem of excessive stray *** the stray current distribution is random and difficult to verify in the field,we designed an improved stray current experimental platform by replacing the simulated aqueous solution with a real soil environment and by calculating the transition resistance by measuring the soil resistivity,which makes up for the defects in the previous ***,the mathematical models of rail-drainage net and rail-drainage netground were established,and the analytical expressions of current and voltage of rail,drainage net and other structures were *** addition,the simulation model was built,and the mathematical analysis results were compared with the simulation ***,the accuracy of the improved stray current experimental platform was verified by comparing the measured and simulation ***,based on the experimental results,the influence factors of stray current were *** relevant conclusions provide experimental data and theoretical reference for the study of stray current in urban rail transit.

关键词： urban rail transit stray current experimental platform transition resistance soil resistivity

Calculation of Earthing System at Bangladesh Storm Water Pumping Station

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建筑电气 2015年第9期34卷 30-37页

作者： ZHAO Xiaolei QIAN Zhongyang LIANG Wei WANG Qin CSCEC AECOM Consultants Co. Ltd China Electric Power Research Institute OTI Far-east (Nanjing) Computer Technology Co. Ltd

A Storm Water Pumping Station funded by the World Bank is under construction and commissioning,of which the earthing system design is a crucial part for the electrical *** on IEEE and BS standards,this article fully introduces the analysis methodology and calculation of the system within the framework of the World Bank supported project.A solution of this practical case satisfied with the requirements of international standards is shown in order to bring experience and convenience for engineers who are dedicated to projects abroad.

关键词： IEEE BS earthing system step voltage touch voltage earth system potential rise earth potential soil resistivity