外文翻譯---橋梁工程和橋梁美學(xué)(編輯修改稿)
2024-09-20 11:31 本頁面
【文章內(nèi)容簡介】 dy demonstrated by Manderla (1880) and Bendixen (1914), who developed relationships between joint moments and angular rotations from which the unknown moments can be obtained ,the so called slopedeflection method. More simplifications in frame analysis were made possible by the work of Calisev (1923), who used successive approximations to reduce the system of equations to one simple expression for each iteration step. This approach was further refined and integrated by Cross (1930) in what is known as the method of moment distribution.One of the most import important recent developments in the area of analytical procedures is the extension of design to cover the elasticplastic range, also known as load factor or ultimate design. Plastic analysis was introduced with some practical observations by Tresca (1846)。 and was formulated by SaintVenant (1870), The concept of plasticity attracted researchers and engineers after World War I, mainly in Germany, with the center of activity shifting to England and the United States after World War Ⅱ. The probabilistic approach is a new design concept that is expected to replace the classical deterministic methodology.A main step forward was the 1969 addition of the Federal Highway Adiministration (FHWA)”Criteria for Reinforced Concrete Bridge Members” that covers strength and serviceability at ultimate design. This was prepared for use in conjunction with the 1969 American Association of State Highway Offficials (AASHO) Standard Specification, and was presented in a format that is readily adaptable to the development of ultimate design specifications. According to this document, the proportioning of reinforced concrete members ( including columns ) may be limited by various stages of behavior: elastic, cracked and ultimate. Design axial loads or design shears. Structural capacity is the reaction phase, and all calculated modified strength values derived from theoretical strengths are the capacity values, such as moment capacity, axial load capacity ,or shear capacity. At serviceability states, investigations may also be necessary for deflections, maximum crack width, and fatigue .Bridge Types A notable bridge type is the suspension bridge, with the first example built in the United States in 1796. Problems of dynamic stability were investigated after the Taa bridge collapse, and this work led to significant theoretical contributions Steinman ( 1929 ) summarizes about 250 suspension bridges built throughout the world between 1741 and 1928 .With the introduction of the interstate system and the need to provide structures at grade separations, certain bridge types have taken a strong place in bridge practice. These include concrete superstructures (slab,Tbeams,concrete box gird
環(huán)評公示相關(guān)推薦
鄂ICP備17016276號-1