由图 12 和图 13 可知，无铰拱模型所计算出的拱轴截面弯矩有内部受

由图 12 和图 13 可知，无铰拱模型所计算出的拱轴截面弯矩有内部受拉和外部受拉两种， 11<br><br>拱轴上有反弯点，外部受拉最大弯矩达到 2.87kN·m，出现在距拱脚大致三分之一位置处;而 内部受拉最大弯矩出现在拱脚处，达到 6.68kN·m;三铰拱模型所计算出的截面弯矩只是外部 受拉，最大弯矩为 7.41kN·m，也出现在距拱脚大致三分之一位置处;但是两种力学模型所计 算出的截面最大弯矩绝对值大小基本相同，差值仅为(7.41-6.68)/7.41=9%

It can be seen from Fig. 12 and FIG. 13 that the arch axis section bending moment calculated by the hinged arch model can be divided into internal tension and external tension, 11<br>There is a reverse bending point on the arch axis, and the maximum external tensile bending moment reaches 2.87kn · m, which occurs at about one-third of the arch foot; The maximum internal tensile moment appears at the arch foot, reaching 6.68kn · m; The section bending moment calculated by the three hinged arch model is only external tension, and the maximum bending moment is 7.41kn · m, which also appears at about one-third of the arch foot; However, the absolute value of the maximum bending moment of the section calculated by the two mechanical models is basically the same, and the difference is only (7.41-6.68) / 7.41 = 9%

As can be seen from Figure 12 and Figure 13, the bending moment of the arch shaft section calculated by the hingeless arch model can be divided into internal tension and external tension, 11 There is a reverse bending point on the arch shaft, and the maximum external tensile bending moment reaches 2.87kN·m, which appears at about one-third of the distance from the arch foot. The maximum bending moment of internal tension occurs at the arch foot, reaching 6.68kN·m; The section bending moment calculated by the three-hinged arch model is only external tension, and the maximum bending moment is 7.41kN·m, which also appears at about one-third of the position from the arch foot. However, the absolute value of the maximum bending moment calculated by the two mechanical models is basically the same, and the difference is only (7.41-6.68)/7.41=9%.