土木专业外文翻译--对于结构理论与设计的分析.doc

文献翻译对于结构理论与设计的分析近年来,我国正在从桥梁工程建设大国向桥国迈进.与此同时,大规模的桥梁工程建设也带来了不可忽视的环境问题.当前,可持续发展已成为国际结构工程领域的共同理念,环境与经济的协调发展是促进桥梁工程可持续发展的重要问题,在分析桥梁工程建设带来的环境问题的同时,桥梁工程生命周期环析也逐渐成为国内外研究的热点.我国虽然在材料工业、生态产品等领域开展境影响成本分析研究,但对于桥梁工程生命成本的研究尚处于探索阶段,因此,有必要对桥梁工程生命周期环境影响成本分析方法进行系统的研究. 本文依托湖北省自然科学基金项目“桥梁工程生命周期环境影响评价方法研究”(2008CDB367),以武汉市野芷湖大桥为实际工程背景,以保护环境、降低桥梁工程生命周期环境影响成本为出发点,基于生命周生命周期成本分析理论,进行桥梁工程生命周期环境影响成本分析,构建了桥梁工程生命周期环境影响成本分析模型,主要研究成果如下: 1、运用生命周期评价和生命周期成本分析理论,基于桥梁工程生命周期环境影响因素的多样性和复杂性,按照科学性、完整性等原则桥梁工程环境影响成本分为资源消耗成本、水污染成本.桥梁的结构理论中对桥面铺装层的计算分析论述几近于零,现行规范中只给定了厚度的推荐值,工程界一直在各等级的公路中运用了几十年。随着交通量的增大,现行铺装与重型、超重型汽车的增多和车速的增快已不相适应。桥面铺装层直接承受车轮荷载的冲击,桥面铺装部分或全部参与了主梁结构的变形,因此桥面铺装是一个受力复杂的动力体系,各种形式的主梁及铺装本身的构造均影响其应力的分布。现行桥规第3.2.2条规定:如无精确的计算方法,箱形梁也可参照T形梁的规定处理。从众多箱梁的设计来看,大部分设计者对箱梁构件是按T形梁进行处理的。而箱梁的实际受力虽有近于T梁的一面,又有异于T梁的一面,对于连续箱梁差别更大。桥梁施工过程易发生安全事故的主要原因在于以下四个方面：其一，开挖基坑时由于护壁处理不到位，造成基坑坍塌，孔内爆破未采用电引起爆施工，裸露药包且没有打眼放炮，在孔深大于12m时没有检测有毒气体含量等；在清孔排水时未注意保持孔内水头而造成内外压力差过大，从而导致护筒坍塌，井口周围缺少围护设施和安全标示；其二，由于架桥设备或支架承载能力以及安全宽度不够，导致墩柱施工过程中坍塌或坠落现象，构建运输过程速度超过3km/h；其三，在需要放置安全网和防坠网的施工位置，没有按照规定实行梁体制安，导致人员和机械设备坠落事故；最后，由于员工缺乏安全意识，出现未配备安保设备，不文明生产等现象，如10m以上作业时未加设安全网，导致附属设施施工出现一系列安全事故。尤其是近年来箱梁的桥面越来越宽,桥跨与桥宽之比越来越小,箱梁仍按T梁那种长细杆件设计配筋,就越来越不适宜了,导致按梁设计的箱骨架钢筋在实际受力状态下难以像T梁主筋那样发挥应有的作用。所以,设计的假设状态与箱梁的实际受力状态不一致。采用取孔壁支护等措施防止挖孔较深时坍塌现象，配备专人定期检查孔口防护设施是否完好，以及施工现场的作业设备和流程以及警示标志是否规范到位；挖孔前检测二氧化碳等气体是否超标，孔深超过10m时应当强制通风。高处作业之前需进行安全技术教育，检查投入使用的设备是否完好，如未经上级许可不得擅自拆除高处作业防护设施；高处施工人员需按规定着装，穿软底防滑鞋，系上安全带，与架空输电线路保持规定的安全距离，遇恶劣气候不得进行露天攀登或悬空高处作业；高处作业使用物料应堆放平稳，对于存在安全隐患的物件一律先行撤除或固定，存在人身安全时应立即停止作业。随着材料工业的发展,桥梁承重结构的改进,使桥梁主梁能以较柔的结构达到受力的要求,高等级公路大跨桥梁的横向越来越宽。无论是陆地桥梁还是海上桥梁基坑开挖时都需要根据相关规范先编制施工方案，提出设计计算书；采取安全防护如保持与挖掘机和吊斗升降作业安全距离范围内，检查吊斗绳索、挂钩等是否完好；拆除基坑支撑等作业需在负责人指导下进行，海上桥梁施工安全管理与陆地施工相比主要不同在于存在更多的危险性，因此安全管理工作应该从创造施工安全的工作环境，保证设备设施齐全完好，及时准确收集发布气象水文信息和开展海上施工安全教育四个方面入手。具体说来，应尽量减少海上作业人员流动的频率，保证海上工作平台和通道等安防设施齐全完好；掌握及时可靠的气象水文信息，尽量避免恶劣气象和水文条件下作业；印发安全施工资料，组织开展安全系列教育工作，并进行现场安全技术交底检验；各个作业面加强日常现场安全检查，严抓高处作业、大型构件装载等危险系数大的关键工。由于山区地形复杂给桥梁施工带来了很多不便，因此将安全人机工程技术融入施工安全管理中，有利于减少桥梁施工事故的发生几率并保障施工安全顺利进行。山区桥梁施工安全管理主要从合理利用桥梁施工人员心理特征和防止过度疲劳入手，因为在山区桥梁施工工程中，人为不安全心理与环境条件限制产生的复合作用是主要不良因素，充分保证安全防护系统柔性防护系统的实施到位，加强不安全心理的综合管理，以划分若干个小群体针对性的培养安全骨干，通过群体心理引导养成安全生产习惯，使得每位作业人员具备良好的心理状态；合理安排作息时间，减轻施工劳动强度，提高施工技术熟练程度的同时开展有益身心健康的文体活动。公路桥梁施工受环境的限制和人为因素的复合影响，应充分利用群体心理，通过培养安全骨干提高整体安全意识，养成安全生产的习惯；通过提高机械自动化水平和员工技能，合理安排劳动强度，杜绝过劳现象，对工作人员进行定期部署有针对性的技能考核；采用不同的色彩标志预防事故发生，坚决淘汰高耗能，污染严重，技术改造不经济的设备，定期正确保养机械设备，特种设备需经过安全检测后才能投入使用。出现坑塌或洪水时应当及时采用加固措施并及时撤离现场。 特别在设计计算中侧重于主梁纵向的计算分析,对桥梁横向刚度重视不足,横向构造措施不利使桥面铺装分担了过多的次内力。钢筋加工的质量问题存在于多个方面，在材料选择方面，如果钢筋品种的规格、形状、尺寸不符合要求，或者钢筋有严重的腐蚀问题，都会影响到工程质量。在钢筋加工方面，钢筋的下料和成型尺寸的准确度差、钢筋骨架变形或者钢盘网变形都会造成结构构件的性能下降；在钢筋安装方面，安装位置偏差过大、钢筋少放或漏放、垫块位置固定方法不当、钢筋绑扎接头不正确等都会引起钢筋的严重错位；在钢筋焊接方面，钢筋焊接头的机械性能达不到施工规范的要求、焊条品种存在质量问题，性能不符合要求等都会存在问题。焊接过程中如果焊缝尺寸偏差过大、咬边焊缝与钢筋交接处有缺口、咬边焊缝与钢筋交接处有缺口、电弧烧伤钢筋表面等都会造成钢筋断面局部削弱，或对钢筋产生脆化作用，都会对钢筋的使用性能造成影响。要对有可能出现断桩情况的桩进行重点监测，对于进行过故障处理的桩也要重点监测，对于所有桩都要进行无破坏检测，使所有桩最终都要达到无断层、无夹层，并且强度要符合设计要求。桩头混凝土要凿出密实的层面，并进行大面平整，要求达到无残留混凝土以及其他杂物，另外标高必须符合施工设计要求。需嵌入承台或系梁内的桩头及锚固钢筋长度要符合设计要求，在验收钢筋时，要注意重点验收钢筋骨架以及桩柱钢筋的焊接质量，桩顶锚固筋要与设计角度保持一致，并采用螺旋筋进行缠绕固定。砂浆垫层在平整度方面以及标高方面要符合要求，其尺寸必须满足支立承台、系梁模板的要求，模板板面之间要求不漏浆、接缝严密、支撑牢靠，其各项指标比如位置、几何尺寸、保护层厚度等数据都要符合设计要求。在浇筑混凝土之前，应该为模板涂刷脱模剂，外露面混凝土模板的脱模剂应采用同一品种，在涂刷过程中不能污染钢筋及混凝土的施工缝，这样才能够保证外露面美观，线条流畅。对于连续梁桥、拱桥及悬臂梁桥等桥型结构,由于荷载的作用而产生负弯矩或拉力,使桥面铺装层受到拉力的作用而产生负弯矩区裂缝,从而造成桥面铺装的损坏。桥梁工程建设周期长、投资规模大,施工过程为露天和高空作业,是一项复杂的系统工作.桥梁建设从施工准备到工程竣工时时刻刻存在着危险.工程建设中的不安全因素及危险源众多,涉及面广,各因素交叉,层监管不力容易导致安全事故的发生,则带来重大的经济损失和负面的社会影响.在桥梁建设施工过程中,对不安全因素和危险源进行有效地分析和监测,认清关键要素,构建安全监测指标体础上,开发出危险源无线采集系统和安全监测应急救援系统,有利于提高对危险源的监管能力,以达到减少或降低施的目的. 本文以桥梁重大工程为依托,根据桥梁施工危险源清单,通过层次分析法进行归一化处理后确定危险源的等级,并利用综合变权原理实现桥梁整体的安全性评价,为后续安全监测和应急救援方案做准备、GRPS无线传输、GIS数据处理的基础上,编程研发出无线采集与智能应急救援系统,为应急决策的制定提供数据支持与支持.为了及时准确地掌握事故信息以及快速处理和决策,利用通信技术和计算机软件技术,开发出针对施工事故的实时GSM短信发布移动告警信息发布平台,可以实现更快、更广泛以及更有效的应对安全事故所能够达到的救援.在对高速公路进行交通组织管理中,由于车道功能的不同,人为强制地使桥梁结构运营始终处于偏载状态,使主车道的铺装承担了比超车道高得多（量值可达三至四倍）的运营应力水平,因此加快了主车道铺装层的疲劳。桥梁施工的安全控制要兼顾人员和物两个方面，秉承墩柱的质量控制重点要做好以下工作：首先要检查柱中心位置施工放样，验收墩柱钢筋笼，使其符合设计标准；然后对支模前接触面的松散混凝土进行凿除处理，如果有其他杂物则一并冲洗干净；接下来对立柱模板进行质量检查，要求接缝处必须圆滑平整，拼接严密，模板的定位精度、竖直度以及钢筋保护层厚度必须符合质量要求指标。脱模剂的涂刷一定要均匀，并且定位钢丝绳要求拉紧，以达到受力一致的要求；对混凝土施工的基本要求与承台或系梁施工要求相同，要求用串筒下料，串筒底部距浇筑的混凝土面不超过2米，浇筑完毕将柱顶混凝土面拉毛。台帽的质量控制重点有两个方面，分别是立模工序质量控制和混凝土浇筑工序质量控制，在检验模板时，要对模板的平整性、刚度、尺寸和角度进行重点检测，同时要看模板的支撑是否符合要求，另外还要观察模板接头处的处理情况。混凝土浇筑要求控制好混凝土的制作质量，主要包括原材料质量、混凝土配合比等，另外还要控制好振捣施工工艺，如果振捣时间太长则有可能出现混凝土分层与走模，而振捣时间不足则会出现混凝土的气泡不能完全排出，从而导致形成蜂窝、麻面等病害。盖梁要检查柱顶中心及盖梁轴线，以及钢筋骨架放样，盖梁钢筋骨架在成型后要进行验收，验收时要特别注意检查焊缝质量及弯起筋位置，在安装盖梁钢筋后要对骨架定位进行检查，按设计角度调整柱顶锚固筋，好箍筋。另外还要检查查钢筋保护层厚度，预埋件、预埋筋位置是否正确，模板是否采取措施已加固牢靠，箱梁要检查底板是否清洗干净，接缝处是否用腻子打平，采用塑料板时，要求粘贴紧密、无破洞、无鼓包以及无皱折，伸缩缝梁端要注意设置楔形块，预埋支座钢板，腹板、底板钢筋重点检查正弯矩波纹管定位，确保混凝土浇筑过程中不移位，钢绞线须事先进行编束，整束穿过波纹管，并保证在管内不缠绕。不仅要提高安全管理的理论水平，更应当将理论措施付诸实践，结合法律、经济、文化和科技手段进行安全管理，有利于真正在工程实践中取得实效，为企业创造出更好的经济和社会效益。特别是随着私营运输业的发展,货运业主为追求短期经济利益,通过改变车厢结构如加长车厢和加高车轴弹簧等使汽车的载重、轴重及轮载成倍增加。这些车辆对铺装层具有严重的毁坏作用,并使桥梁结构局部超载,加快了主车道铺装层的病害发展。因此,在设计中应根据运营中车辆荷载的实际分布情况,在明确了桥梁结构受力的基础上,对桥面铺装层进行受力计算。文献原文 on bridge Structure theory and design In recent years, our country from the major briering cn to theion of the powerful country move forward. The sustainable development hase international field of structureing, environmental and economic development is the important question to promote the bridge engineering construction for sustainable development, meanwhile,depend on the analysis of environmental problems from the bridge engineering construction, the bridge engineering life cycle cost of the .bridge structure holds tier of calculation with in theory to bridge floor shop , gives the recommendation value having fixed thickness ,The project boundary has applied several tens years to every grade highway always middle. Already be out of keeping with the fact that the volume of traffic enhancing, active shop hold increasing with the heavy type, increasing by and speed of a vehicle surpassing the heavy type automobile with quickly. The bridge floor lays the impingement pretending to bear carriage wheel load tier directly , the bridge floor lays the deformation having loaded the part or all participation betokening girder construction , bridge floor shop pretends to be a main beam accepting the strenuously complicated driving force system , various form and the distribution laying the structure pretending to be self affect whose strain equally therefore. Bridges currently in effect: The regulation also may consult the T shape beam if there being no accurate reckoning; the box shape beam handles. Judging from a lot of box beams design, the most designer is to handle to box beam component be in progress according to shape beam. Box beam reality accepts but a force though having one aspect bordering on the T beam, one aspect having being different from the T beam, the with regard to continuous box beam difference are bigger.much influenced by his teacher and the Taoism, saw the political corruption in his country and put forward much useful advice to carry out reform. Unfortunately the emperor of Han would not like to adopt his ideas and let his country wither away. However the emperor of admired the talent wanted to give him a position in state. Although finally killed owing to listening to the unfaithful advice of , he ruled his country on the principles advocated by . Until that time did the situation come to an end and the united central right come out. Especially box beam bridge floor is in recent years more and more broad, ratio of bay and bridge width is more and more small , does that long thin member still design the box beam according to T beam matching tendon , push down with regard to more and more no proper , leading to? The box beam framework reinforced bar that the beam designs is difficult to bring the due effect into play like T beam host tendon under actual strenuously circumstances. Therefore, the hypothesis states designing that and box beam reality accept force state disaccords. With material, development of industry, architectural bearing bridge improvement, make bridge host Liang more and more broad reaching the request accepting a force, big advanced level highway transverse direction across bridge with softer structure. Stiffness attaches importance to bridge transverse direction deficiency , disadvantageous messenger of transverse direction structure measure bridge floor shop pretends to have shared more than the correct or required number time of internal forces especially in the analysis designing that the middle secretly scheming against puts particular emphasis on the calculation in main beam direction.When the Medici family regained power in 1512 with the help of Spanish troops, Machiavelli was tortured and removed from public life. For the next 10 years he devoted himself to writing history, political philosophy, and even plays. He ultimately gained favor with the Medici family and was called back to public duty for the last two years of his life. Machiavellis greatest work is The Prince, written in 1513 and published after his death in 1532. The work immediately provoked controversy and was soon condemned by Pope Clement VIII. Its main theme is that princes should retain absolute control of their territories, and they should use any means of expediency to accomplish this end, including deceit. Scholars struggle over interpreting Machiavellis precise point. In several section Machiavelli praises Caesar Borgia, a Spanish aristocrat who became a notorious and much despised tyrant of the Romagna region of northern Italy. During Machiavellis early years as a diplomat, he was in contact with Borgia and witnessed rule first hand. Does Machiavelli hold up Borgia as the model prince? Some readers initially saw The Prince as a satire on absolute rulers such as Borgia, which showed the repugnance of arbitrary power (thereby implying the importance of liberty). However, this theory fell apart when, in 1810, a letter by Machiavelli was discovered in which he reveals that he wrote The Prince to endear himself to the ruling Medici family in Florence. To liberate Italy from the influence of foreign governments, Machiavelli explains that strong indigenous governments are important, even if they are absolutist.To bridge type structure such as continuous beam bridge , arch bridge and cantilever beam bridge, effect because of load but produce negative curved regulation or pulling force , make the bridge floor lay the effect pretending to accept pulling force tier but produce the breakdown shouldering the curved regulation area rift , bringing about bridge floor shop dress thereby.experience Machiavelli learned that weak countries had no diplomatic relationship with other counties. In his work he put forward that the weakest thing in the world was the power that was exaggerated. He tried to persuade the emperor to make a strong army, which would become the solid foundation of any course. While held the same opinion with Machiavelli, he said that the most important task for an emperor was to develop his country in many ways such as increasing the production of agriculture, establish clear encouragement and punishment laws, have a forceful army under his control.Under the influence of his teacher,adhered to the principle that human nature was bad. And his developed his ideas to the enumerated kingdom which he thought was the heaven of the earth. He believed that human beings were driven by the greed for profit. We can see some trace in his famous saying: strict mother has kind children, while kind mother has brute children.Both of them believed that the relationship among human beings was a kind of naked interest_oriented relationship. They make use of each other, not believe in others, and would try every means to reach ones aims. Bridge project is a complicated（omitted） its construction has characteristics of long cycle and huge investmet. Bridge construction process is an open（omitted） working, accompanied by dangers from construction preparing to project completion. The unsafe factors and（omitted）uring project construction involve a wide range of issuses and also w（omitted）ate relationships with each other. Slack regulation（omitted）e hazards can cause accidents, which can bring in major economic loss and negative sociali. manages middle in the organization who carries out traffic on the express highway , different since the lane is functional, person has been to compel a field to make bridge structure be in motion and do business all the time in insisting