Seismic Considerations for Guastavino Ceiling, Vault, and Dome Construction Author(s): Doug Robertson Source: APT Bulletin: The Journal of Preservation Technology, Vol. 30, No. 4, Preserving Historic Guastavino Tile Ceilings, Domes, and Vaults (1999), pp. 51-58 Published by: Association for Preservation Technology International (APT) Stable URL: https://www.jstor.org/stable/1504710 Accessed: 29-08-2018 15:42 UTC JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms Association for Preservation Technology International (APT) is collaborating with JSTOR to digitize, preserve and extend access to APT Bulletin: The Journal of Preservation Technology This content downloaded from 24.4.7.238 on Wed, 29 Aug 2018 15:42:09 UTC All use subject to https://about.jstor.org/terms Seismic Considerations for Guastavino Ceiling, Vault, and Dome Construction DOUG ROBERTSON The seismic and program improve- Guastavino construction is found pre- in past earthquakes has been seldom and ments to the Hearst Memorial dominantly in turn-of-the-century archi- poorly documented. tecture across the eastern United States, The findings presented in this article Mining Building on the University with fewer examples as you travel fur- are based on investigations and evalua- of California, Berkeley campus, ther from New York City, the home of tions related to the seismic behavior of will be the first project in which the Guastavino Company. There are various examples of masonry vaulted Guastavino construction is deliber- very few examples of Guastavino con- and domed construction and, in particu- struction in California, where frequent lar, field investigations and testing of the ately strengthened for improved earthquakes pose a risk to this brittle vaulted ceiling in the Hearst Memorial seismic performance. architectural system. Within the San Mining Building (Fig. 1).1 Francisco Bay region there are three known examples of the Guastavinos' Historical Perspective work: the San Francisco Stock Exchange, Grace Cathedral in San Francisco, and To place the seismic vulnerability of the Hearst Memorial Mining Building Guastavino construction in perspective, on the University of California, Berkeley it is useful to first consider the seismic campus. performance of other forms of unrein- Similar forms of unreinforced ma- forced masonry construction in past sonry vaulted and domed construction earthquakes. Following is an overview are prevalent in older architecture in the of the seismic performance of masonry United States and abroad. Investigation buildings, the behavior of conventional of some of these buildings and literature brick vaulted and domed masonry searches reveal relatively little about the construction, and knowledge of the seismic behavior of this type of con- seismic behavior of Guastavino. struction. Little analysis and testing of vaulted and domed masonry construc- Unreinforced masonry. The majority of tion has been done, and its performance earthquake engineers and researchers consider unreinforced masonry buildings to be the most hazardous form of build- ing construction. Over many years, earthquake after earthquake has reaf- firmed this view. The poor seismic per- formance of this type of building is due to many factors, including the brittle nature of the materials, the non-homo- geneous manner in which the materials jii are used, deficient workmanship, and .... in design and detailing that inadequately consider the effects of earthquakes on I I I . "!I " building construction. The "gluing" together of masonry pieces with mortar and the strong yet ..... .. A:, i?i?.. .. brittle nature of masonry materials make this type of construction subject to potentially sudden and catastrophic Fig. 1. Hearst Memorial Mining Building. Courtesy of Bancroft Library, University of California, failures under dynamic earthquake Berkeley. forces. For this reason, "unreinforced" 51 This content downloaded from 24.4.7.238 on Wed, 29 Aug 2018 15:42:09 UTC All use subject to https://about.jstor.org/terms 52 APT BULLETIN 60 regularly spaced steel wide-flange beams Ductile Concrete Frame, Low Rise (Fig. 3). There are three primary reasons that 50 Wood Frame, Low-Rise this jack vault system is vulnerable to earthquake damage. The most common = URM Bearing Wall, deficiency is that the walls are not posi- tively connected to these relatively rigid vaulted floor, ceiling, and roof systems. In an earthquake, the walls pull away from E a Non-ductile o Low Rise Concrete, Frame, , the vaults, leading to collapse of either 20 Low Rise the walls, the vaults, or both. The walls parallel with the steel I-beams are partic- URM Infill" Frame, . -o.,"- 0000"is 11,00 ularly susceptible to this type of damage 10 --LowRise . -0'0 since, unlike the walls that support the o .......jZ s . - Steel . Frame,- Low Rise steel beams, there are no beams to pro- vide a nominal tie to the walls. These 6 7 8 9 10 vaults also often have a shallow radius, Modified Mercalli Intensity (MMI) which make them prone to earthquake damage when the supporting, unbraced, Fig. 2. Damage projections for various building types. Illustration by author. steel I-beams spread laterally. Lastly, these vaults often support loose, heavy fill materials, such as dirt, ash, or rubble, masonry construction is no longer vaulted which in an earthquake add to theiror domed roof or ceiling con- permitted struction by modernthen becomes U.S. building difficult to iden- inertial forces and their vulnerability. codes tify, in zones In his speechand at the 1893 World's Fair theof moderateinterest in to its high behavior is of seismic risk. little on "cohesive construction,"concern Rafael compared to the general Fig. 2,structural taken Guastavino referred to the Persians as from collapse, ATC-132, concern shows for rescuing the relative potential the "fathers of the cohesiveperformance mode of survivors, andof masonry the urgency to buildings rebuild. compared to other lateral construction."3 Ironically, it is in this building systems. Performance is mea- One regiontype of the world where several exam- of system employed by the sured in terms of damage projections Guastavinos ples of failure of this system have been that is prone to earthquake accessed damage as documented. In 1990,a widespread dam-percentagewas used extensively of building through- replacement out many age occurred in a Richter magnitude cost. 7.3 European Performance cities andwas elsewhere considered in the earthquake in atnorthwest world. Iran that killeddifferent This levelssystem, of ground-sometimes shaking referred intensity an estimated 35,000 to 50,000 people to as using "jack the vault," Modified used bricks Mercalli or clay Intensity and damaged about 100,000 buildings.tile to form(MMI) repetitive scale. vaults These spanning estimates Measured peak ground acceleration between were developed the bottom by flange of polling a substantial number of earth- quake experts with a systematic method- ology. (1tASTxIvIN(O The RIB AND DOME SYSTEVMchart suggests that masonry performs poorly compared to all other , a.. m .-, v R o ~ TT ~_ House r51 btemz -.*&.- materials and systems. ;NGo L,,,,2N GO2D, ,ToI3L, t 5, 8T Masonry vaults and domes. Relatively few records exist of past performance of N1---,--, vaulted and domed masonry construc- tion in earthquakes. There are a number of possible reasons for the limited his- torical record. This type of construction is often found in regions of the world with relatively low seismicity or in third- world countries c Lio CT AB. where earthquake dam- age is poorly documented. Probably the most important reason is that failure of SCALE 1ONE FOOT this type of system -i-Rt M@i C.. is thought, in many instances, to ,,, , ,. *lead ,,z,._ to more significant damage or collapse of the unreinforced Fig. 3. Jack vault. Courtesy of the Guastavino/Collins Archive, Drawings and Archives, Avery Archi- masonry tectural and Fine Arts Library, Columbia University. structure. Damage to the This content downloaded from 24.4.7.238 on Wed, 29 Aug 2018 15:42:09 UTC All use subject to https://about.jstor.org/terms SEISMIC CONSIDERATIONS FOR GUASTAVINO CONSTRUCTION 53 varied from 0.02g to 0.65g in the areas The strength of Guastavino under surrounding the epicenter. Many build- gravity loading is generally undisputed. ings with this type of vaulted masonry/I- ENTRANT CAORNER George Collins pointed out one impor- beam system collapsed. These collapses NAVE tant difference between the timbrel vault were reportedly precipitated in most and the more conventional stone-ma- instances by the walls pulling away from sonry vault. He noted that the vault "is the vaults.4 very thin, consisting of little more than a In March 1997 another earthquake surface, and derives its rigidity not from in northwest Iran, with a magnitude of massiveness or thickness but rather from 5.5, caused widespread damage, killing its particular geometric form." 10 This 965 people and injuring more than statement explains precisely why the Fig. 4. Plan view of the Basilica of St. Francis 2,600. None of the recently engineered of Assisi. (Gray areas indicate collapsed Guastavinos' many works have per- steel or concrete buildings experienced zones.) Illustration by author. formed so well over the past century. any noticeable damage. However, many However, it must be emphasized that of the buildings with this repetitive brick Guastavino construction derives its vaulted roof system collapsed.5 substantial strength not just from its are also often constructed in countries The most widely recognized and vaulted form but also from its geometric where the quality of construction may notable example of earthquake damage orientation relative to the direction of not be well controlled.