淺談橋梁工程發(fā)展史-資料下載頁
2024-11-14 18:39本頁面
【導讀】構(gòu)類型的記載和評述。后來古希臘人創(chuàng)立了靜力學的基本原理，LeonardodaVinci、Cardeno和Galileo等人在工作和應用中也證實了這些原理的正確性。建造橋梁和渡槽。到了17世紀末，隨著Leibnitz、Newton和Bernoulli的數(shù)學理。論的創(chuàng)立，橋梁建筑技術得到了快速發(fā)展。的關于結(jié)構(gòu)理論分析的著作為材料力學領域奠定了基礎。Kuzmanovic指出，石材和木材是橋梁建筑最早采用的材料。到鋼材的轉(zhuǎn)變過程中，鐵作為一種過渡材料被用于橋梁建筑中。石拱橋，而文藝復興時期則是坦拱逐漸占主導地位。的改進，并發(fā)現(xiàn)其在結(jié)構(gòu)上能適應后來的鐵路荷載。通過模型試驗，有關拱結(jié)構(gòu)的主要失。效形式的理論得到了證實。彈性中心的方法，顯示了可用三個協(xié)調(diào)方程求解三個多余參數(shù)。19世紀期間，美國和俄羅斯由于其跨越主。俄兩國有可能取得更為顯著的成績。木制橋梁具有良好的經(jīng)濟性，因為其初期投資較。低，施工速度較快。美國于1840年建成了第一座全鐵桁架橋，勾踐設計準則”中包括了強度和正常使用的極限狀態(tài)設計法。
【正文】 sms are monly integrated into the landuse regulations and design standards . In addition to concern for aesthetics at the state level , federal concern focuses also on the effects of manconstructed environment on human life , with guidelines and criteria directed toward improving quality and appearance in the design process . Good potential for the upgrading of aesthetic quality in bridge superstructures and substructures can be seen in the evaluation structure types aimed at improving overall appearance . LOADS AND LOADING GROUPS The loads to be considered in the design of substructures and bridge foundations include loads and forces transmitted from the superstructure, and those acting directly on the substructure and foundation . AASHTO loads . Section 3 of AASHTO specifications summarizes the loads and forces to be considered in the design of bridges (superstructure and substructure ) . Briefly , these are dead load ,live load , iMPact or dynamic effect of live load , wind load , and other forces such as longitudinal forces , centrifugal force ,thermal forces , earth pressure , buoyancy , shrinkage and long term creep , rib shortening , erection stresses , ice and current pressure , collision force , and earthquake stresses .Besides these conventional loads that are generally quantified , AASHTO also recognizes indirect load effects such as friction at expansion bearings and stresses associated with differential settlement of bridge ponents .The LRFD specifications divide loads into two distinct categories : permanent and transient . Permanent loads Dead Load : this includes the weight DC of all bridge ponents , appurtenances and utilities, wearing surface DW and future overlays , and earth fill EV. Both AASHTO and LRFD specifications give tables summarizing the unit weights of materials monly used in bridge work . Transient Loads Vehicular Live Load (LL) Vehicle loading for shortspan bridges :considerable effort has been made in the United States and Canada to develop a live load model that can represent the highway loading more realistically than the H or the HS AASHTO models . The current AASHTO model is still the applicable loading. 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 本賬號 發(fā)布文檔來源于互聯(lián)網(wǎng)和個人收集，僅用于技術分享交流 ，版權(quán)為原作者所有。 如果侵犯了您的知識版權(quán)，請?zhí)岢鲋刚?，我們將立即刪除相關資料。免費格式轉(zhuǎn)換請發(fā)站內(nèi)信。 網(wǎng)易博客 騰訊微博 新浪微博 直接聯(lián)系 2218108823
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