一、簡介Introduction
桿軸線為曲線在豎向荷載作用下不產(chǎn)生水平反力。
拱--桿軸線為曲線，在豎向荷載作用下會產(chǎn)生水平推力的結(jié)構(gòu)。
三鉸拱的反力只與荷載及三個鉸的位置有關(guān)，與拱軸線形狀無關(guān)
The reactions are related to the locations of the hinges and loads, but have no relationship with the form of the axial line of arch.
荷載與跨度一定時，水平推力與 矢高成反比
Given loads and span, thrust is inversely proportional to rise 1/f
三鉸拱的內(nèi)力不但與荷載及三個鉸的位置有關(guān)，而且與拱軸線的形狀有關(guān)。The internal forces are not only dependent of loads and the positions of hinges, but also of the form of centroidal axis .
由于推力的存在，拱的彎矩比相應(yīng)簡支梁的彎矩要小。Because of the horizontal thrust, the moment of arch is less than that of the corresponding simple beam.
三鉸拱在豎向荷載作用下軸向受壓.Under the action of vertical loads, the arch is axially compressed.
