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(一)前言本文主要是介紹圓弧无鉸拱在考虑拱內挠矩、軸向力、剪力及曲率等四項因素及現行桥規§268时,拱的弹性中心处贅余未知力的計算方法。 現有的一些参考书关于圓弧无鉸拱的計算公式均只考虑拱內挠矩及軸向力两因素。現行桥規§268,在某些情况下則尚需考虑拱內剪力及曲率的因素。而且由于那些公式的推导都是按照拱的中心綫进行的,計算結果与实际情况也不一致。尤其是对于一些小型拱桥、涵洞及其他拱形結构,这些結构跨径虽小而拱圈較厚,跨度1.0m～2.0m而拱圈厚度为0.5m的拱形結构其計算公式如按拱的中心綫推导,則計算結果与实际情况将会产生較大的誤差。由于这些原因,并为了今后工作中計算小型的拱形結构的方便起見,而編写了本文。文內的公式包括有考虑拱內挠矩、軸向力、剪力及曲率等四項因素的四种近似計算公式,而且这些公式的推导都是按照
(A) Preface This article mainly introduces the arc non-hinged arch arch in the consideration of the four factors of internal bending moment, axial force, shear and curvature, and the existing bridge regulations §268, the elastic center of the arch excess redundant unknown force Calculation method. Some of the existing reference books on the calculation formula of circular arc-free arch consider only two factors of internal bending moment and axial force. Current bridge rules §268, in some cases still need to consider the factors within the arch shear and curvature. And because the derivation of those formulas is carried out according to the center line of the arch, the calculation result is not consistent with the actual situation. Especially for some small arch bridges, culverts and other arched structures, these structures have small span and large arch, span of 1.0m ~ 2.0m and arch thickness of 0.5m arch structure, such as the calculation of the arch Centerline derived, then the calculation results and the actual situation will have a greater error. For these reasons, and for the convenience of calculating small arched structures for future work, we have written this article. The formulas in the text include four approximation formulas that take into account four factors of arch internal torsional moment, axial force, shear force and curvature, etc., and the derivation of these formulas is based on