In the 20th century， bridge construction technology evolved and was fueled by the Industrial R At the turn of the century， steel bridges were riveted together， not bolted; concrete bridges were cast in place， not precast; and large bridge members were built from lacing bars and smaller sections， not rolled in one Plastic had not yet been Construction techniques such as post-tensioning， slurry walls， soil freezing， and reinforced earth walls had not yet been Surveying was performed mechanically since infrared， optical technology was still 75 years Bridge construction is changing as the new millennium New construction techniques and new materials are There are also new issues facing the bridge building industry relative to the research needs associated with these new techniques and LONG-SPAN BRIDGES Suspension Bridges While suspension bridge building was conducted at a modest pace throughout the 20th century， an unprecedented number of spans of remarkable record lengths were built in the Far East and D Both the Akashi Kaikyo Bridge in Japan and the Great Belt Bridge in Denmark were completed in The Akashi Kaikyo Bridge is the largest suspension bridge in the world， with a span of 1991 m， and the Great Belt Bridge is the second largest， with a span of 1624 While spans lengths have increased nearly fivefold during the course of this century， they may have reached their physical limits with today’s Research will be necessary to develop the new， ultra-high-strength steel wire or carbon fiber wire required to build the longer main suspension cables that will make it possible to increase span lengths to beyond 2000 As we enter the new millennium， rehabilitation and ongoing maintenance of the existing suspension bridges must continue as Recent rehabilitation measures for the main cables and suspension systems of these bridges have uncovered degradation through corrosion and hydrogen Research is needed to determine the remaining useful service life of suspension bridge cables and what measures can be taken to slow or halt the degradation Transportation in the New Millennium 2 Other components of long-span bridges， existing and new， are being revolutionized as technology moves Advances in deck technology are producing stronger， lighter Orthotropic and exodermic decks are becoming increasingly popular on long-span structures as a means of reducing dead Bearings， joint systems， and seismic retrofitting components are becoming increasingly efficient as more large-scale testing facilities are 在20世纪，桥梁施工技术，是由进化而来的 工业革命。随着新世纪的到来，钢桥受到铆接在一起，而不是 螺栓、混凝土桥梁被扔在的地方，不是预制、大型桥梁成员 从系酒吧和小的部分，不卷在一块。塑料尚未 发明了。制作等施工工艺、浆墙、土壤冻结， 加筋土墙尚未怀了孕。测量进行机械 自从红外、光学技术仍然是75年。 大桥建设是新千年开始转变。新建筑 技术和新材料正在浮出水面。也有新的解决面临的桥 建筑行业的相关研究的需要，这些新技术 材料。 大跨度桥梁 悬挂的桥梁 虽然悬索桥建设进行了整个20速度不快 世纪，前所未有的跨越了卓越的长度是建在记录 远东和丹麦。双方在日本明石海峡大桥正式通车，伟大的带桥 在丹麦是在一九九八年完成。这个明石海峡大桥正式通车是世界上最大的悬架 在这个世界上，与桥梁的m，1991年是中国的第二大带桥， 用一段1624)。 虽然已经增加了近5倍长度的跨世纪的过程中， 他们已经达到了他们的物理极限与今天的材料。研究将 必须发展新的、ultra-high-strength钢丝、碳纤维丝要求 建立了悬索，将不再主要可能增加到跨度的长度 超出2000米。 当我们进入新千年、康复和持续的维护现有的 悬索桥必须继续。最近的戒毒措施为主要 电缆悬架系统与这些桥梁发现退化 氢脆腐蚀，。研究还剩下的 寿命悬索桥电缆和什么措施可以减缓或 停止退化的过程。 在新千年的运输 其他组件的大跨度桥梁，现有的和新的，正在发生了革命性的变化 技术的进步。提出了在甲板上技术生产强的，更轻的 甲板。正交各向异性和exodermic牌是大跨度越来越受欢迎 作为一种手段，降低结构自重荷载。轴承、联合系统和抗震能力 越来越多的有效成分是更大规模的测试设备 建造。 50分！！~~谢谢 参考资料：我的大脑
土木工程的英文是Civil Engineering ，直译是民用工程，它是建造各种工程的统称。它既指建设的对象，即建造在地上，地下，水中的工程设施，也指应用的材料设备和进行的勘测，设计施工，保养，维修等专业技术。土木工程随着人类社会的进步而发展，至今已经演变成为大型综合性的学科，它已经出许多分支，如：建筑工程，铁路工程，道路工程，桥梁工程，特种工程结构，给水排水工程，港口工程，水利工程，环境工程等学科。土木工程共有六个专业：建筑学，城市规划，土木工程，建筑环境与设备工程，给水排水工程和道路桥梁工程。土木工程作为一个重要的基础学科，有其重要的属性：综合性，社会性，实践性，统一性。土木工程为国民经济的发展和人民生活的改善提供了重要的物质技术基础，对众多产业的振兴发挥了促进作用，工程建设是形成固定资产的基本生产过程，因此，建筑业和房地产成为许多国家和地区的经济支柱之一。古代的土木工程有很长的时间跨度，大致从公元前500年新石器时代出现原始的土木工程活动到16世纪末意大利的文艺复兴，导致土木工程走上迅速发展的道路为止，前后经历了两千多年。在这段时间内，由于科学理论发展及其缓慢，土木工程也没有突破习惯的发展。从17世纪中页开始到20 世纪40年代第二次世界大战结束为止的300年间，国外的建筑取得了长足的进步。土木工程进入了定量分析阶段。一些理论的发展，新材料的出现，新工具的发明，都使土木工程科学日渐完善和成熟。到了近代，二战结束之后，许多国家经济起飞，现代科学日益进步，从而为进一步发展提供了强大的动力和物质基础。人们生活水平的不断提高，必然要求越来越舒适的居住环境，在这种情况下，建筑的发展直接推动了土木工程的发展。总的来说土木工程是一门古老的学科，它已经取得了巨大的成就，未来的土木工程将在人们的生活中占据更重要的地位。地球环境的日益恶化，人口的不断增加，人们为了争取生存，为了争取更舒适的生存环境，必将更加重视土木工程。在不久的将来，一些重大项目将会陆续兴建，插入云霄的摩天大楼，横跨大样的桥梁，更加方便的交通将不是梦想。科技的发展，以及地球不断恶化的环境必将促使土木工程向太空和海洋发展，为人类提供更广阔的生存空间。近年来，工程材料主要是钢筋，混凝土，木材和砖材，在未来，传统材料将得到改观，一些全新的更加适合建筑的材料将问世，尤其是化学合成材料将推动建筑走向更高点。同时，设计方法的精确化，设计工作的自动化，信息和智能话技术的全面引入，将会是人们有一个更加舒适的居住环境。一句话，理论的发展，新材料的出现，计算机的应用，高新技术的引入等都将使土木工程有一个新的飞跃English is the Civil Engineering Civil Engineering， civil engineering is literally， it is the construction of the project It means building objects that the construction on the ground， underground， water works facilities， equipment and materials to use in surveying， design construction， maintenance， repair and other professional Civil Engineering with the progress of the human society， has been transformed into large integrated disciplines， it has a number of branches， such as : construction， rail projects， road projects， bridge projects， special project structure， water drainage works， the port project， water， environmental engineering A total of six professional Civil Engineering : architecture， urban planning， civil engineering， construction and environmental engineering equipment， water drainage works and road bridge Civil Engineering as an important foundation subjects， its important attribute : an integrated， social， practicality， Civil Engineering for the development of the national economy and improve the living standards of the people provided important material and technological foundation for the revitalization of many industries played a catalytic role in the construction of fixed assets is a basic production process， the construction and real estate in many countries and regions become a pillar of the economyAncient Civil Engineering has a long time span， roughly 500 years before Christ from the original date in civil engineering activities to the 16 century Italian Renaissance， resulting in the rapid development of the Civil Engineering on the road today， and has experienced more than 2，000 During this period， due to the development of scientific theories and slow， there is no breakthrough in civil engineering Century from 17 pages to 40 years in the 20th century end of the Second World War 300 years， foreign construction made great Civil Engineering has entered a phase of quantitative Some theoretical development， the emergence of new materials， new tools of invention， the Civil Engineering Science is perfection and In modern times， after the end of World War II， many countries economic takeoff， the increasing advances of modern science， so as to provide a powerful impetus to further development and material People's living conditions continue to improve， more and more comfortable living environment for the inevitable in the circumstances， the construction of development directly to the Civil Engineering
