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101.
介绍了嘏基斯坦卡西姆港化学码头钢管桩实施牺牲阳极阴极保护所进行的钢桩保护面积计算和保护电位测量,以及根据涂层状况经设计计算,安装牺牲的阳极的型号、数量和阳极材料的性能检测。 相似文献
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本研究选用一株野生型Pseudomonas sp.为试验菌株,选用X70管线钢作为代表性金属材料,通过细菌生长曲线测定、腐蚀失重测量、扫描电镜(SEM)观察等方法,初步研究在杀菌剂四羟甲基硫酸磷(THPS)耐受条件下Pseudomonas sp.对X70管线钢腐蚀行为的影响。结果表明,75 μL/L的THPS浓度在Pseudomonas sp.的耐受范围内,而且能够轻微促进X70试片表面的腐蚀;不添加THPS的含菌体系中Pseudomonas sp.能抑制X70试片表面的腐蚀;而在添加了75 μL/L THPS的含菌体系中,Pseudomonas sp.显著促进X70试片的腐蚀,并且试片表面附着的细菌数量相比于无杀菌剂的对照体系有所增加。因此,该研究表明在特定浓度范围内,与没有添加杀菌剂的含菌体系相比,杀菌剂THPS使Pseudomonas sp.从抑制腐蚀改变为促进腐蚀。 相似文献
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Jamie E. Padgett 《地震工程与结构动力学》2011,40(15):1743-1761
Deteriorating highway bridges in the United States and worldwide have demonstrated susceptibility to damage in earthquake events, with considerable economic consequences due to repair or replacement. Current seismic loss assessment approaches for these critical elements of the transportation network neglect the effects of aging and degradation on the loss estimate. However, the continued aging and deterioration of bridge infrastructure could not only increase susceptibility to seismic damage, but also have a significant impact on these economic losses. Furthermore, the contribution of individual aging components to system‐level losses, correlations between these components, and uncertainty modeling in the risk assessment and repair modeling are all crucial considerations to enhance the accuracy and confidence in bridge loss estimates. In this paper, a new methodology for seismic loss assessment of aging bridges is introduced based on the non‐homogeneous Poisson process. Statistical moments of seismic losses can be efficiently estimated, such as the expected value and variance. The approach is unique in its account for time‐varying seismic vulnerability, uncertainty in component repair, and the contribution of multiple correlated aging components. A representative case study is presented with two fundamentally distinct highway bridges to demonstrate the effects of corrosion deterioration of different bridge components on the seismic losses. Using the proposed model, a sensitivity study is also conducted to assess the effect of parameter variations on the expected seismic losses. The results reveal that the seismic losses estimated by explicitly considering the effects of deterioration of bridge components is significantly higher than that found by assuming time‐invariant structural reliability. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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硫酸盐热化学还原作用对原油裂解成气和碳酸盐岩储层改造的影响及作用机制 总被引:4,自引:3,他引:1
硫酸盐热化学还原作用(Thermochemical sulfate reduction, TSR)是发生在油气藏中复杂的有机-无机相互作用,它不仅会引起含H2S天然气的富集,其产生的酸性气体对碳酸盐岩储层还具有明显的溶蚀改造作用。本文基于黄金管热模拟实验,研究了TSR反应对原油裂解气的生成的影响,发现这种氧化还原反应的存在能明显降低原油的稳定性,促进具高干燥系数的含H2S天然气的生成。结合原位激光拉曼实验结果,证实了实际油藏中启动TSR反应的最可行的氧化剂应该是硫酸盐接触离子对(CIP)。全面探讨了影响TSR反应的地质和地球化学因素,提出除了初始原油的组分特征、不稳定含硫化合物(LSC)的含量外,地层水的含盐类型及盐度同样是控制TSR反应的关键因素。同时,基于大量地质分析,发现TSR对碳酸盐岩储层具有明显的溶蚀改造作用。结合溶蚀模拟实验,提出了酸性流体对碳酸盐储层溶蚀改造的机制,且深层碳酸盐岩层存在一个由TSR作用形成的次生孔隙发育带。研究认为,烃类与硫酸盐矿物的氧化还原反应与其产物对碳酸盐岩储层的改造是TSR作用的两个不可分割的部分,它们相互依存和制约。 相似文献
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In order to study the durability behavior of marine reinforced concrete structure suffering from chloride attack,the structural service life is assumed to be divided into three critical stages,which can be characterized by steel corrosion and cover cracking.For each stage,a calculated model used to predict the lifetime is developed.Based on the definition of durability limit state,a probabilistic lifetime model and its time-dependent reliability analytical method are proposed considering the random natures of influencing factors.Then,the probabilistic lifetime prediction models are applied to a bridge pier located in the Hangzhou Bay with Monte Carlo simulation.It is found that the time to corrosion initiation t0 follows a lognormal distribution,while that the time from corrosion initiation to cover cracking t1 and the time for crack to develop from hairline crack to a limit crack width t2 can be described by Weibull distributions.With the permitted failure probability of 5.0%,it is also observed that the structural durability lifetime mainly depends on the durability life t0 and that the percentage of participation of the life t0 to the total service life grows from 61.5% to 83.6% when the cover thickness increases from 40 mm to 80 mm.Therefore,for any part of the marine RC bridge,the lifetime predictions and maintenance efforts should also be directed toward controlling the stage of corrosion initiation induced by chloride ion. 相似文献
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WANG Xiuhai TIAN Zhuangcai ZHANG Yanan SU Xiuting LIU Hongjun LIU Tao 《中国海洋大学学报(英文版)》2022,21(1):124-130
Saline soil is widely distributed in the marine sediments along the coast of the world and the arid-semi-arid areas of the Middle East and Iraq,and calcium sulfate erosion has become one of the important factors affecting the durability of concrete in this area.In order to clarify the mechanism of sulfate ion damage to concrete,this paper mainly takes saline soil with high sulfate content in coastal area as well as arid-semi-arid area as the research object,and uses indoor geotechnical test,field test and numerical simulation to study the influence of different dry-wet cycle times on the unconfined compressive strength of concrete test blocks,and puts forward the relationship between the erosion arrival depth and time of sulfate ion in concrete,so as to predict the long-term erosion depth by using the erosion depth of sulfate ion in concrete in short time.The results show that the shorter the erosion time when the erosion reaches a certain depth,and the larger the erosion reaches when the erosion time is the same,the faster the erosion reaches the depth with the increase of erosion time.Compared with rectangular section concrete,circular section concrete penetrates faster.The results of this study can provide a reference for the durability design of concrete in saline soil sites containing sulfate. 相似文献