ブックタイトル「煉瓦造建造物の保存と修復」英語版

概要

「煉瓦造建造物の保存と修復」英語版

4.2. The Spanish FortressThe Spanish Fortress is located in the northeast area ofL'aquila (photo 9). This fortress was constructed duringthe 16th century, when L'Aquila was a powerful city of theKingdom of Naples and is a representative work of historiccastle architecture. It has housed a national museum sincehaving been renovated in the mid 20th century.It was damaged in the L'aquila Earthquake which occurredin 2009. Damage was particularly severe in the upper levels,where the walls collapsed outwards and the vaulted ceilingand floors also partially fell. Numerous shear cracks formedin the exterior and interior walls, while fissures were seen inthe columns of lower levels (photo 10). After the earthquake,emergency treatment was undertaken involving temporarysupports composed of wire or scaffolding pipe frames. Also,visual inspection of the damage as well as surveys on thedegree of damage to wall interiors were made, relying onmeasurements using ultrasonic wave propagation rate orinfrared thermography; flat jacks were employed for on-siteloading tests for verifying material strengths.Oscillation and crack width measurements werecontinuously observed using a wireless data transmissionsystem which sends data at regular intervals as well attimes of aftershocks. This was used to monitor increaseddamage following such movements as aftershocks andalso to verify changes in performance before and afterreinforcement. Also, these measurements were takenalong with the temperature and humidity, so that influencefrom environmental changes such as increase in naturaloscillation frequency can be eliminated in monitoringchanges in structural characteristics.The following restoration and reinforcement were plannedfollowing results obtained from these survey results aswell as numerical analysis based on surveys (figure 6, 7).Firstly, brickwork of the damaged areas was to be rebuiltwith lime mortar injection. Stone masonry walls were to bestrengthened with a three-course layer of bricks reinforcedwith steel bands every 80 centimeters in height, to be toppedwith a reinforced concrete beam. Tie beams will be installedparallel to the short side of the structure at the height offigure 4Macro model of the facadefigure 5Three-dimentional model of the facade by the finite element analysis method42Chapter 4 Earthquake-Proofing Measures for Masonry Structures in Italy