Comparison of Pointed vs. Circular Arches

In Gothic cathedrals the use of pointed arches is widespread because of the decreased thrust compared to the circular arch. While this fact is widely acknowledged and accepted, there has been little theory developed to determine exactly the different behavior of the two arches.

This research develops the comparison between the circular and the pointed arches in terms of geometrical dimensions, weight, maximum and minimum thrust, maximum point load at the crown and the haunches and collapse values due to support movements. Using limit analysis, a parametric study of whole and half arches has been performed varying the angle of embrace, the thickness and the eccentricity of the centers of the arches. A theory, using graphical and numerical codes, was tested to predict when and where failure occurs and a series of experiments on these arches, made of small-scale concrete blocks, has been conducted. Analyzing and comparing the experimental results with the proposed theory has shown good agreement.