气候变化和结构工程外文翻译

毕业设计外文资料翻译题 目 气候变化和结构工程 Climate change and structural engineering 51/2 (2007) 4750 Pter LenkeiDepartment of Structural Engineering, University of Pcs, H-7625 Boszorknyu. 2, Pcs, HungaryAbstract Based on last years experiences it is obvious for the majority of professionals and for the general public too, that climate change is a realistic present and future.In the beginning this paper deals with the signs and perspectives of climate change. In the second part the consequences of climate change on building and civil engineering structures are treated. The emphasis is laid on the eect of temperature, windend water circulation of the globe. The research is directed mainly towards getting reliable future data and its evaluation for practical use. Finally some aspects of standardization procedure and the problem of old/existing and new structures are treated. Keywordsclimate change eects on structures meteorological actions AcknowledgementThe author would like to express his sincere gratitude to Professor Judit Bartholy of the Meteorological Chair of L. Etvs University for her help and understanding .Acknowledgements are due to the National Oce for Research and Technology Development (NKTH) and to the Hungarian Scientic Research Fund (OTKA) for accepting this topic for common future nancing. 1 IntroductionThe climate change, the global warming and their consequences are well represented in the media. In addition people experience in everyday life smaller or bigger signs of this process. Nevertheless one can meet skeptic opinions, but the number of such opinions are decreasing due to the obvious evidences. The problem of climate change is very wide and extremely complex, involving every elds of science, and even every side of the life on the globe. It should be pointed out, that this problems in structural engineering are important, but involving only a small part of the general problem. According to the opinion of the author the adaptation and mitigation procedures of the climate change should be applied to the activity of each profession. To draw the consequences, and propose the necessary steps in our profession, in structural engineering is the goal of this paper. 2 The climate changeThe global warming due to the increased emission of greenhouse gases is investigated by many of the meteorological institutions, offices, bureaus and stations. Great many of reports have been published all around the world. One of the most important documents is the series of Assessment Reports of the Intergovernmental Panel on Climate Change(established by the UN). The last one titled Climate Change 2007 Climate Change Impacts, Adaptation and Vulnerability”(IPCC 2007).This Report declares Much more evidence has accumulated over the last ve years to indicate the changes in many physical and biological systems linked to anthropogenic warming.”The Report states for the future Magnitude of impact can now be estimated more systematically for a range of possible increases in global average temperature.” About the future impact due to the altered frequencies, and intensities of extreme weather, climate and see level events. . . ” the Report pointed out Disruption by oods and high wind, withdrawal of risk coverage in vulnerable areas by private insurers. . . ” would be of great importance. Responding to the climate change the Report stressed the necessity of adaptation and mitigation measures.The above described general situation makes necessary the adaptation and mitigation measures in structural engineering too. For specifying our task we should know the perspectives on he long term about global warming in the Carpathian Region. In the following some regional aspects, e.g. average temperature increase (Fig. 1) and average precipitation changes (Fig. 2) are hown in the Carpathian Region elaborated by the Meteorology Chair of the Etvs University, Budapest (Bartholy et al 2).In these diagrams are shown the expected change in the period of 2071-2100 relative to 1961-1990 in case of an adverse scenario. The data was drawn from research results of 18 meteorological institution using regional climate change models.Next years some similar diagrams will be elaborated for average wind speed of the above period by the Meteorology Chairof the L. Etvs University in the frame of a research project sponsored by the National Oce for Research and Technology Development (NKTH) and the Hungarian Scientic Research Fund (OTKA).3 Possible future impacts of climate change on structures There are several possible disadvantageous impacts (the following list is not complete).Impacts of temperature changes Drought areas (long seasons without precipitation) More frequent freezing-thawing cycles (concrete technology) Warming of ocean surfaces (resulting in hurricanes or typhoons) Thawing of ice reserves (resulting in rising of see level) Impacts of precipitation changes Bigger and abrupt oods (higher water levels in lakes and rivers) Changing of ground water level (foundation problems) Heavy abrupt snow falls Heavy hails (precipitation in the form of ice lumps)Impacts of higher wind speed Higher wind impulses Wind intensity increase is time depended Dierent wind proles Impacts of driving rain (combination of heavy rain and largewind speed) Deterioration of structural surfaces Damage to the water tightness of dierent elements Impacts of signicantly more frequent extremes Low cycle fatigue of structural elements Accumulation of damages in structuresThese drawbacks make absolutely necessary the engineering response. But adaptation and mitigation measures are made difcult by the time dependent (mainly increasing) character of these impacts .The other problem is the lack of reliable future data base due to uncertain nature of these impacts.4 Future research tasksOne should understand that all the necessary research tasks cannot be solved in the frame of our actually nanced four years research and the fact that any research in this eld can not made without close cooperation of meteorologists.4.1 This research can not disregard the temperature and precipitation changes in time First of all the temperature changes in time are one of the main bases for every further steps in investigating the eects of climate change The yearly frequency of extremes (min and max) and distribution of extremes are in close connection with temperature changes The number of freezing and melting cycles are depended on temperature and previous precipitation.4.2 The main concerns of this research are the problems connected with future wind actions and the future change of the temperature and change of precipitation.Problems to be solved in the eld of wind actions The rst problem is the traditional wind measuring method.This consists of measuring in each hour or one and half hour the average wind speed in the last ten minutes. Naturally this would not the largest wind speed for the measuring period. In addition we need not the average wind speed, but the wind impulse of 3 sec duration. There should be cleared up the relation between the wind speed and wind impulse. Another open question is the frequency and distribution of maximal wind speeds. The method of interpolation between 1961-1990 and 2071-2100 average wind speeds should be investigated too. Very important question is to determine the relation between the wind prole (the wind speed changes in elevation) and the changing value of the wind speed.Fig. 1. Seasonal temperature change (C) in the Carpathian basin for 2071-2100 based on European regional model simulation ( Bartholy et al.)Dispersion =0,3-1,1oCFig. 2. Seasonal precipitation change (%) in the Carpathian basin for 2071-2100 based on European regional model simulation (Bartholy et al.)Dispersion =12-20%5 Standardization of meteorological actionsThe occurrence probability of meteorological actions in different structural design codes generally equal to 0.02, i.e. 50 years occurrence probability of highest, most dangerous value.It is obvious, that in changing circumstances the 50 years occurrence probability would be dierent in each consecutive year.The other problem is that up to now these values have been determined from relevant past data. In the future these values should be determined from uncertain future data (Lenkei 2006).In addition these uncertain data should be connected function-ally with the measured past data and previous uncertain values.To deal with long term forecast the intervals of revision should be designated. Another solution could be the use of time dependent formulae.6 Different design procedure for old/existing and for new structuresAt rst sight it appears that the problem of new structures is easy: one just should take into account the new design codes suitable to the challenges of the climate change. They will be a little more expensive, that is all. But do not forget, the today new structures in 10-20 years will be old, the change keep on. What to do with old/existing structures? Most probable there should be made more or less signicant and consequently more or less expensive interventions. These interventions could be dierent, e.g. change of some structural element(s), strengthening of some part(s) of the structures, change of structural behavior of the whole structure by increasing static indeterminacy or make the structure more robust. It should be mentioned, that the buildings, the civil engineering and infrastructural objects amounts one of the biggest part of national wealth. Consequently any necessary intervention would be connected with great expenses.7 ConclusionsThe structural engineers should take into account among others the obvious climate change and its impacts on structures .The task is not easy: to work out the answers to the challenges of the climate change, namely the adaptation and mitigation measures for old and new structures of buildings and civil engineering objects. Finding the optimal solution(s) would be even more complicated, but this is our task and our responsibility.References1. IPCC Climate Change 2007, Climate Change Impacts, Adaptation and Vulnerability,: Summary for Policymakers, April 6 2007, available at (http:/www.ipccc/pub/reports.htm).2 .Bartholy J, Pongrcz R, Gelyb Gy, Regional Climate Change Expectedin Hungary for 2071-2100, 2007. Appl.Ecology and Environmental Research 5(1):1-17.3. Lenkei P, Concrete Structures and the Probable Climate Change: 2nd bCongress, Doppieroce, Italy, 2006. Condensed Papers (2) 564-565.Periodica Polytechnica 2007 51/2 (2007) 4750气候变化和结构工程 皮特雷肯 匈牙利佩奇大学摘 要 根据过去几年的经验,显而易见,对大多数的专业人员和广大市民来说气候变化在现在和未来都是一个具有现实意义的问题。本文首先论述了气候变化的迹象和观点。接着分析了气候变化对建筑与土木工程结构的变化带来的后果，重点强调全球范围的温度、风和水循环的影响。这项研究主要是为了获得可靠的未来走向数据及其实际使用的评价。最后，探讨了某些方面的标准化程序,以及现存的和新的结构问题的处理。关键词 气候变化，结构影响，气象行动鸣谢 笔者就Etvs大学气象学主席Judit Bartholy教授对她的帮助和理解表示自己真挚的谢意。由于国家研究和科技开发办公室(NKTH)及匈牙利科研基金(OTKA)接受这个话题,为共同的未来融资。1 引言在媒体上，气候变化、全球变暖及其带来后果是很好的代表。另外，人们在日常生活中的经历较小或更大的彰显着这个过程。由于明显的证据这些意见的数量正在减少。不过，可以满足怀疑论者的意见。气候变化这个问题非常广泛而且非常复杂,涉及每个科学领域、甚至地球上的每一个生命。应该指出,这个问题在结构工程方面是很重要的,但涉及的一小部分的一般问题。据笔者认为，气候变化的适应与减缓程序应运用于各种行业的活动，总之，本文的目的是在给我们专业结构工程提出必要的步骤。2 气候变化许多气象机构、办事处、部门和电台调查发现全球变暖是由于温室气体的排放量的增加。一些大的报道已经将其公布于世界各地，政府间气候变化专门委员会（由联合国设立）已经公布了一系列的评估报告，其中有一个最重要的报告，这份报告题为“气候变化2007 - 气候变化影响，适应性和脆弱性”（IPCC，2007）。该报告宣称“过去五年积累了更多的证据表明在许多物理和生物系统的变化与人为变暖有着密切的联系。”该报告声称对未来的国家的影响程度现在可以更有系统地估计为全球平均气温可能上升的范围。关于未来改变频率和强度的极端天气，气候和级别的事件造成的影响，报告指出 “由洪水和强风的干扰，撤出风险覆盖的脆弱地区的费用由私营保险公司承担。”可能具有十分重要的意义，报告强调气候变化的适应和减缓措施是很必要的。以上所述的一般情况，在结构工程中采取适应和减缓措施是必要的。为了确定我们的任务,我们应该放远目光在全球变暖的喀尔巴阡地区。以下的一些地区,如平均温度升高(图1)和平均降雨量的变化(图2)所示, 在喀尔巴阡地区，Etvs大学的气象学主席阐述了布达佩斯的（Bartholy等2）。在这些图中所示的预期在不利的情况下，1961年至1990年期间在2071年至2100年的相对改变。这些数据来自18个气象机构运用于区域气候变化模型的研究成果。未来几年，由国家研究和技术开发办公室（NKTH）及匈牙利科学委员会（OTKA）资助的在匈牙利Etvs大学开发的研究项目将阐述一些上述时期内的平均风速的类似的图表。 3 可能的未来气候变化对结构的影响有以下几种可能的不利影响（以下罗列是不完整的）。温度变化的影响干旱地区(长期无降水季节)更频繁的冻融周期(混凝土技术)海洋表面变暖(导致飓风或台风)融化的冰储备(能见水平上升导致降水的变化)更大和突发的洪水(湖泊和河流的高水位)改变地下水位（基础问题）重型突然降雪重型冰雹（在冰肿块的形式沉淀）高风速的影响高风冲动时间影响下风强度的增加不同的风廓线的影响雨天行车（大雨和狂风速度的共同影响）表面结构恶化不同元素的水密性损伤明显影响着更频繁的极端情况结构元素的低周疲劳结构中积累的损害赔偿这些弊端使得工程方面进行绝对必要的改变，但适应与减缓措施受时间的影响(主要是增加)而存在困难，另一个问题是由于这些影响的不确定性而缺乏可靠的数据。4 未来的研究任务每个人都应该明白，所有必要的研究工作是不能解决我们实际资助四年的研究，在这个领域中的任何研究都不能没有气象专家的密切合作。4.1本研究不能忽略气温和降水量的变化首先所有随时间变化的温度是进一步进行气候变化影响调查中的一个主要依据每年的极端频率(最小和最大)和极端的分布是随温度变化紧密联系的冻结和融化周期取决于温度和以前的降水4.2本研究的主要问题是未来风行动和未来温度和降水量的变化之间的关系在风行动的领域要解决的问题首先，问题是传统的风的测算方法，这包括测量在每小时或一个半小时，在最后十分钟的平均风速，但这自然不会测量期间的最大风速。此外，我们需要的不是平均风速,而是需要持续3秒的风向的运动，因此应该解决风速和风向运动之间的关系。另一个悬而未决的问题是最大风速的频率和分布。应用插值方法调查1961-1990年和2071年至2100年平均风速。非常重要的问题是确定风廓线（海拔在风速变化）和风速的变化值之间的关系。图1.根据欧洲区域模型模拟在2071-2100年喀尔巴阡盆季节性的温度变化(C) (Bartholy等) 分散=0.3-1.1C图2.根据欧洲区域模型模拟在2071 2100年喀尔巴阡盆地盆地各季降水变化(%)(Bartholy等)分散=12-25 标准化的气象行为气象行为在不同气象结构设计规范的发生概率通常等于0.02,即50年来发生的机率最高，危险性也最强。这是显而易见的，不断变化的环境在50年发生机率会在每一年内连续不同。另一个问题是，到目前为止，这些值已经根据过去的有关数据确定。在未来这些值应该从不确定的未来数据中确定(Lenkei 2006)。此外，这些不确定的数据应在连接功能上与实测的历史数据和以前的不确定值，并指定处理长期预测修订间隔。这些不确定的数据应在另一个解决方案可以利用时变成参数的选取。6 旧/现有的及新的结构的不同设计过程乍一看，似乎新的结构问题很简单：应该考虑到新的设计规范适应于气候变化的挑战。所有的原因在于他们会比较昂贵，但不要忘记, 一切都是变化的，今天的新结构在10-20年内将是旧的。旧/现有结构做什么用？据此应该最有可能的就是或多或少的对其进行干预。这些干预措施可能会有所不同, 例如改变一些结构性因素（S），加强一些部分（S）的结构，由静态的不确定性增加或改变整个结构的结构行为，使结构更稳健。应该提及,建筑，土木工程和基础设施的对象相当于一大部分国家财富。因此，任何必要的干预，将与大的开支有密切联系。7 结论结构工程师应考虑其它明显的气候变化及其对建筑的影响。这项任务并不容易:制定应对气候变化挑战的对策, 即新老结构的适应和减缓措施对建筑和土木工程的挑战。寻找最佳的解决方案（S）将更加复杂,但这是我们的任务和职责。参考文献1. IPCC Climate Change 2007, Climate Change Impacts, Adaptation and Vulnerability: Summary for Policymakers, April 6 2007, available at (http:/www.ipccc/pub/reports.htm).2 .Bartholy J, Pongrcz R, Gelyb Gy, Regional Climate Change Expectedin Hungary for 2071-2100, 2007. Appl.Ecology and Environmental Research5(1):1-17.3. Lenkei P, Concrete Structures and the Probable Climate Change: 2nd bCongress, Doppieroce, Italy, 2006. Condensed Papers (2) 564-565. - 11 -