3.2 Wood structure supported by diaphragm arches

Military architecture treatises require the outer walls of the gunpowder magazines to be reinforced with buttresses. Thus, buttresses were used very often as the abutment of diaphragm arches. These types of design emerged later, and structures thus generated may have a single span. This is the case of the gunpowder magazines in Benimàmet (1751) [MPD, 06, 169] (Figure 4), Valencia (1756) [MPD, 07, 028] (where the arch abutment is built outwards), and A Coruña (1774) [MPD, 28, 027] (where the abutment is concealed in the interior space, as Müller set out in his treatise (1769)). Other larger powder magazines feature two parallel vaulted spans, for instance, the one in Barcelona (1761) [MPD, 20, 031], with a central pillar between each pair of arches.
