Salvador Ivorra

Full-Scale Testing of Axially Loaded RC Columns Strengthened by Steel Angles and Strips:

This paper presents the results obtained from full-scale tests on 14 reinforced concrete columns strengthened with steel angles and strips subjected to axial loads. All the columns were subjected to loading before strengthening. The influence of various factors on the behaviour of the strengthened column was studied. The results of laboratory tests show that the system of steel angles and strips is highly effective for increasing ultimate load in a column and also increases column stiffness and its ultimate strain. Furthermore, analysis of the results of the experiments allows the load transfer mechanisms which affect the behaviour of the strengthened element to be determined.

Subsidence damage assessment of a Gothic church using differential interferometry and field data

The Santas Justa and Rufina Gothic church (fourteenth century) has suffered several physical, mechanical, chemical, and biochemical types of pathologies along its history: rock alveolization, efflorescence, biological activity, and capillary ascent of groundwater. However, during the last two decades, a new phenomenon has seriously affected the church: ground subsidence caused by aquifer overexploitation. Subsidence is a process that affects the whole Vega Baja of the Segura River basin and consists of gradual sinking in the ground surface caused by soil consolidation due to a pore pressure decrease. This phenomenon has been studied by differential synthetic aperture radar interferometry techniques, which illustrate settlements up to 100 mm for the 1993–2009 period for the whole Orihuela city. Although no differential synthetic aperture radar interferometry information is available for the church due to the loss of interferometric coherence, the spatial analysis of nearby deformation combined with fieldwork has advanced the current understanding on the mechanisms that affect the Santas Justa and Rufina church. These results show the potential interest and the limitations of using this remote sensing technique as a complementary tool for the forensic analysis of building structures.

Experimental and Numerical Results from the Seismic Study of a Masonry Bell Tower

This paper describes studies carried out to characterize the seismic behaviour of the San Nicolas bell tower in Valencia (Spain), built of masonry between the 17th and 18th centuries. A complete geometric description of the bell tower was carried out and a numerical model developed to obtain the seismic response and its relationship to the seismic Spanish Standard. The model was first calibrated by means of dynamic tests performed directly on the real structure. The calculations were carried out to fit a non-linear behaviour and a failure criterion which included smeared cracking was considered to model cracks on the tower. Five different synthetic accelerograms were introduced at the towers base level to represent the seismic forces. The numerical simulations showed satisfactory performance of the tower as to the basic seismic acceleration proposed by the Spanish Standard. The earthquakes were also scaled until high levels of damage were achieved.

Relationship between static and dynamic elastic modulus of calcarenite heated at different temperatures: the San Julián’s stone

The San Julián’s stone is the main material used to build the most important historical buildings in Alicante city (Spain). This paper describes the analysis developed to obtain the relationship between the static and the dynamic modulus of this sedimentary rock heated at different temperatures. The rock specimens have been subjected to heating processes at different temperatures to produce different levels of weathering on 24 specimens. The static and dynamic modulus has been measured for every specimen by means of the ISRM standard and ultrasonic tests, respectively. Finally, two analytic formulas are proposed for the relationship between the static and the dynamic modulus for this stone. The results have been compared with some relationships proposed by different researchers for other types of rock. The expressions presented in this paper can be useful for the analysis, using non-destructive techniques, of the integrity level of historical constructions built with San Julián’s stone affected by fires.

Optical Scanning for Structural Vibration Measurement

High-speed cameras (HSCs) are often used for monitoring impacts and fast dynamic processes on structures. However, quantitative information about these processes is usually obtained through other means like accelerometers or Doppler vibrometers. In this article, we show that a proper arrangement of the experiment and the camera allows noncontact measurement of the characteristics of the main displacement mode (amplitude, frequency, and attenuation). An application is given for the analysis of structure damages after low-speed car impacts. The method is low cost, fast, and accurate, and it permits direct visualization and measurement of the movement of the vibrating body.

Seismic Behavior of a Masonry Chimney with Severe Cracking Condition: Preliminary Study

This paper presents a structural analysis of a masonry chimney built in the 1940s, which is currently being cataloged as local interest heritage. This structure has not served any industrial purpose for the last thirty years. The chimney is located in the town of Agost (Alicante - Spain) and directly exposed to the prevailing winds from the sea, as it is approximately 12 km away from the waterfront and there are not any significant barriers, which could protect the structure against the wind. There are longitudinal cracks and fissures all along the shaft because of the chimney’s geometrical characteristics, the effect of the masonry creep and especially the lack of maintenance. Moreover, there is also a permanent bending deformation in the upper 1/3 of the height due to the wind pressure. A numerical analysis for the static behavior against gravity and wind loads was performed using the structure’s current conditions after a detailed report of its geometry, its construction system and the cracking pattern. Afterwards, the dynamic behavior was studied, i.e. a seismic analysis using both response spectra and accelerograms in order to examine the structural stability. This work shows the pre-monitoring analysis before any experimental testing. Using the current results the future test conditions will be determined (e.g. number of sensors and monitoring point location, excitation systems, etc) prior to a possible structural reinforcement by applying composite material (fiber reinforced polymers).

On Modeling an Innovative Monitoring Network for Protecting and Managing Cultural Heritage from Risk Events

In this paper the model of an Innovative Monitoring Network involving properly connected nodes to develop an Information and Communication Technology (ICT) solution for preventive maintenance of historical centres from early warnings is proposed. It is well known that the protection of historical centres generally goes from a large-scale monitoring to a local one and it could be supported by a unique ICT solution. More in detail, the models of a virtually organized monitoring system could enable the implementation of automated analyses by presenting various alert levels. An adequate ICT solution tool would allow to define a monitoring network for a shared processing of data and results. Thus, a possible retrofit solution could be planned for pilot cases shared among the nodes of the network on the basis of a suitable procedure utilizing a retrofit catalogue. The final objective would consist in providing a model of an innovative tool to identify hazards, damages and possible retrofit solutions for historical centres, assuring an easy early warning support for stakeholders. The action could proactively target the needs and requirements of users, such as decision makers responsible for damage mitigation and safeguarding of cultural heritage assets.

Checking Gypsum as Structural Material

Gypsum, relegated in contemporaneous architecture to a secondary, auxiliary or decorative role, has been traditionally employed in some parts of Spain for building structural pillars, floors, massive walls, mortars, etc. The authors have studied this gypsum in its several local forms, from its firing in the kiln to the building process in order to unveil the reasons for its excellent structural behaviour. With the first hypothesis, several strength tests with present commercial gypsum have been made at the laboratory. They confirm the extraordinary structural performance of the material, if only some conditions are respected during the building process.

Shaking Table Test Design to Evaluate Earthquake Capacity of a 3-Storey Building Specimen Composed of Cast-In-Situ Concrete Walls

This paper presents the work developed to design a shaking-table test at the EUCENTRE Lab, for the evaluation of the maximum capacity of a 3-storey building subjected to earthquake loading. The structural system of the building is composed of cast-in-situ sandwich squat reinforced concrete walls using polystyrene as a support for the concrete. The purpose of this test is to verify the dynamic behavior of this structural typology under earthquake acceleration. Previous to the shakeing-table tests carried out at the EUCENTRE Lab, extensive analytical and numerical research was developed on a set of models of the building under seismic input. Also, experimental tests were performed on single r.c. panels subjected to pseudo-static cyclic loading. The structural specimen was a structural system composed of cast-in-situ squat sandwich concrete walls characterized by 5.50 × 4.10 m in plan and 8.25 m in height. The input for the simulation was the Montenegro earthquake of April 1979. The construction of this building was developed outside the laboratory; it was lifted and pulled inside using hydraulic jacks and a roller system. A bracing system was developed to assure the integrity of the structure during the transportation process. This chapter presents some preliminary results of the shaking-table tests.

Low-speed vehicle impact against building structures: a review of relevant codes

The new building codes tend to include vehicle impacts as part of the accidental actions to be considered. Most of these codes use equivalent static load to represent the effects of the impact against the structure. In this paper a bibliographical review of the indications is performed as provided by some of the most representative buildings codes in the world relating to impacts caused by vehicles. In particular we will focus on impacts caused by horizontal actions on structures, like car crashes against parking columns. We will show that the indications provided by the different standards studied are widely different each other and that there is not a clearly agreed procedure allowing the assessment of the effects of a vehicle impact through an equivalent static load. Keywords: Building codes & standards, impact, car parks, equivalent static load.