An integrated approach for structural behavior characterization of the Gravina Bridge (Matera, Southern Italy)

An integrated geophysical approach using non-invasive, non-destructive, and cost-effective seismic and electromagnetic techniques has been implemented to recognize the static and dynamic properties (i.e. eigenfrequencies, equivalent viscous damping factors, and related modal shapes) of the Gravina Bridge and its interaction with foundation soils. The “Gravina” is a bow-string bridge located on outcropping calcarenites in the city of Matera (Southern Italy) and develops for 144 m along a steel-concrete deck. The foundation soil characteristics have been evaluated by means of three high-resolution geo-electrical tomographies, one Vs velocity profile, and two site amplification functions. The main structural characteristics of the bridge have been estimated through permanent and on-demand monitoring using seismic and electromagnetic sensing. The former consisted of accelerometers and velocimeters installed with different geometrical arrangements for permanent earthquake and on-demand ambient vibration test recordings. The electromagnetic sensing was realized by a microwave radar interferometer placed below the deck to measure the displacements of the whole scenario illuminated by the antenna beam providing a continuous mapping of the static and dynamic displacements of the entire target. Acquired data have been analyzed in both frequency and time-frequency domain with the aim to study the stationary and non-stationary response of the monitored bridge. These experimental campaigns allowed us to assess the robustness of the proposed approach and to set up the zero-time reference point of the bridge dynamic parameters.

Download Full-text

An integrated geophysical approach for structural behavior characterization of the Gravina bridge (Matera, Southern Italy)

10.5194/egusphere-egu2020-10663 ◽

2020 ◽

Author(s):

Vincenzo Serlenga ◽

Maria Rosaria Gallipoli ◽

Nicola Tragni ◽

Rocco Ditommaso ◽

Tony Alfredo Stabile ◽

...

Keyword(s):

Southern Italy ◽

Dynamic Properties ◽

Structural Characteristics ◽

Continuous Mapping ◽

Seismic Array ◽

Equivalent Viscous Damping ◽

Time Frequency ◽

Microwave Radar ◽

Single Station ◽

Electromagnetic Sensing

Civil infrastructures (i.e bridges, galleries ...) are crucial parts of the road asset and their possible degradation, with related consequences, may have great social, economical and safety impacts. On these grounds, the periodic monitoring of such infrastructures, from a static and dynamic point of view, is required for identifying possible changes in the structure properties, in order to prevent serious damages and disasters.In this study we propose an integrated geophysical approach by using non-invasive and non-destructive seismic and electromagnetic techniques with standard and low-cost sensors. It has been implemented to understand the static and dynamic properties of the Gravina bridge and its interaction with foundation soils. Gravina Bridge is a bow-string bridge located few km far from Matera (Southern Italy) and developing for 144 m along a steel-concrete deck. First, the properties of the foundation soils were studied by carrying out three high-resolution geo-electrical tomographies, one bi-dimensional seismic array and two single-station seismic noise measurements. Then, the structural characteristics of the bridge were inferred through seismic and electromagnetic sensing. The former was performed by means of recordings by accelerometers and velocimeters. The accelerometers were installed in a continuous acquisition mode, along the deck and on the top of the arch. In that way, several local and regional earthquakes were recorded and detected. The velocimeters were deployed along different seismic array configurations for on-demand ambient noise recordings, in normal traffic conditions and during vibration tests. The latter were executed by using vehicles as dynamic sources.The electromagnetic sensing was performed by using the Microwave Radar Interferometer: it was placed below the deck to measure the displacements of all the scenario illuminated by the antenna beam providing a continuous mapping of the static and dynamic displacements of the entire target.The acquired dataset was analyzed both in frequency and time-frequency domain in order to characterize the stationary and non-stationary response of the monitored bridge in terms of fundamental frequencies of vibration, equivalent viscous damping factors and modal shapes. The consistency between the results retrieved by different geophysical techniques provides therefore an importan hint about the reliability of the described approach.

Download Full-text

Soil-Structure Interaction in Buildings from Earthquake Records

Earthquake Spectra ◽

10.1193/1.1585590 ◽

1990 ◽

Vol 6 (4) ◽

pp. 641-655 ◽

Cited By ~ 4

Author(s):

Gregory L. Fenves ◽

Giorgio Serino

Keyword(s):

Soil Structure ◽

Dynamic Properties ◽

Strong Motion ◽

Longitudinal Direction ◽

Soil Structure Interaction ◽

Base Shear ◽

Foundation Soil ◽

Soil System ◽

Structure Interaction ◽

Building Foundation

An evaluation of the response of a fourteen story reinforced concrete building to the 1 October 1987 Whittier earthquake and 4 October 1987 aftershock shows significant effects of soil-structure interaction. A mathematical model of the building-foundation-soil system provides response quantities not directly available from the records. The model is calibrated using the dynamic properties of the building as determined from the processed strong motion records. Soil-structure interaction reduces the base shear force in the longitudinal direction of the building compared with the typical assumption in which interaction is neglected. The reduction in base shear for this building and earthquake is approximately represented by proposed building code provisions for soil-structure interaction.

Download Full-text

Regional Seismic Characterization of Shallow Subsoil of Northern Apulia (Southern Italy)

Geosciences ◽

10.3390/geosciences11100416 ◽

2021 ◽

Vol 11 (10) ◽

pp. 416

Author(s):

Enrico Paolucci ◽

Giuseppe Cavuoto ◽

Giuseppe Cosentino ◽

Monia Coltella ◽

Maurizio Simionato ◽

...

Keyword(s):

Southern Italy ◽

Carbonate Platform ◽

Low Cost ◽

Principal Component ◽

Ambient Vibration ◽

Resonance Effects ◽

Resonance Phenomena ◽

Single Station ◽

Seismic Characterization

A first-order seismic characterization of Northern Apulia (Southern Italy) has been provided by considering geological information and outcomes of a low-cost geophysical survey. In particular, 403 single-station ambient vibration measurements (HVSR techniques) distributed within the main settlements of the area have been considered to extract representative patterns deduced by Principal Component Analysis. The joint interpretation of these pieces of information allows the identification of three main domains (Gargano Promontory, Bradanic Through and Southern Apennines Fold and Thrust Belt), each characterized by specific seismic resonance phenomena. In particular, the Bradanic Through is homogeneously characterized by low frequency (<1 Hz) resonance effects associated with relatively deep (>100 m) seismic impedance, which is contrasting corresponding to the buried Apulian carbonate platform and/or sandy horizons located within the Plio-Pleistocene deposits. In the remaining ones, relatively high frequency (>1 Hz) resonance phenomena are ubiquitous due to the presence of shallower impedance contrasts (<100 m), which do not always correspond to the top of the geological bedrock. These general indications may be useful for a preliminary regional characterization of seismic response in the study area, which can be helpful for an effective planning of more detailed studies targeted to engineering purposes.

Download Full-text

Strengthening and Retrofitting of Motín de Oro II Bridge in Mexico

Case Studies on Conservation and Seismic Strengthening/Retrofitting of Existing Structures ◽

10.2749/cs002.193 ◽

2020 ◽

pp. 193-209

Author(s):

Jose M. Jara ◽

Bertha A. Olmos ◽

Guillermo Martínez

Keyword(s):

Material Properties ◽

River Flow ◽

Dynamic Properties ◽

Flow Characteristics ◽

Ambient Vibration ◽

Structural Elements ◽

Box Girder ◽

Prone Area ◽

Scour Protection ◽

Ambient Vibration Measurements

This chapter presents the studies conducted to retrofit an existing bridge in a seismic prone area of Mexico. The Motín de Oro II Bridge was built in the 1970s with a continuous box girder superstructure and wall-type substructure. From the 1970s to nowadays, the design truck loads in Mexico have been substantially incremented and many bridges built in that period have required to be evaluated and, in some cases, rehabilitated and retrofitted. Firstly, the study presents the results of visual inspections of all parts of the bridge and a description of the preliminary studies conducted to determine the material properties, to evaluate the river flow characteristics and to calculate the scour depth. Secondly, the chapter discusses the initial structural analyses of the bridge subjected to the original gravitational and seismic loads and to the current loads before the intervention. These analyses allow to select the structural elements that require to be retrofitted and the best strategy to follow. Finally, the study presents results of the numerical retrofitted model and the experimental assessment of the dynamic properties based on ambient vibration measurements. Additionally, the scour protection and the general construction procedure are also described.

Download Full-text

Structural Behavior of the General Archive of the Nation (AGN) Building, Mexico

Infrastructures ◽

10.3390/infrastructures3030039 ◽

2018 ◽

Vol 3 (3) ◽

pp. 39

Author(s):

Marcos Chávez ◽

Fernando Peña ◽

Claudia Cruz ◽

Gustavo Monroy

Keyword(s):

Dynamic Properties ◽

Ambient Vibration ◽

Structural Behavior ◽

High Plasticity ◽

Fundamental Vibration ◽

Vibration Period ◽

Ambient Vibration Tests ◽

Smeared Crack ◽

The Government ◽

Vibration Tests

This article presents a study on the structural behavior of the Government Building that is part of the old Lecumberri Palace and which currently houses the Mexican General Archive of the Nation. This building was inaugurated in 1900 and closed in 1976, after serving as a prison for 76 years. It was reopened in 1982 after it had undergone several remodeling works. The construction is made of brick masonry with lime mortar. It is supported by a deposit of overly compressible high-plasticity clays. The main problems of this building are the appearance of cracks in both interior and exterior walls, and moisture in the ground floor, caused by differential settlements. The study entailed a geometric and a damage survey as well as ambient vibration tests in order to determine the dynamic properties of the construction. The data obtained was used for the making of a model that, using the finite element method, was analyzed under different load conditions. This study has focused on the overall response with the assumption of smeared crack damage. According to the results, the building’s safety was deemed as acceptable. It has the capability to withstand seismic actions as established by the Mexican Building Code due to the high density of its walls and the resulting stiffness, which infer that the fundamental vibration period of the building would be distant from the predominant vibration period of the soil. This highlights the idea that the building’s critical condition is constituted by the differential settlements, which cause damage in the construction.

Download Full-text

Research on Boom-Type Roadheader Vibration Testing Based on the LabVIEW

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.1988 ◽

2011 ◽

Vol 418-420 ◽

pp. 1988-1991

Author(s):

Li Juan Zhao ◽

Xiu Mei Lv ◽

Wei Tong

Keyword(s):

Real Time ◽

Detection System ◽

Structural Characteristics ◽

Test System ◽

Vibration Characteristics ◽

Acquisition Time ◽

Vibration Source ◽

Time Data ◽

Vibration Signals ◽

Time Frequency

This develops the roadheader vibration characteristics test system according to the structural characteristics and working principle of the cantilevered roadheader. Using the piezoelectric acceleration sensor detects vibration signal, and passing by signal processing and A/D conversion， vibration signals are sent to the PC with wireless transmission mode, vibration signals detected by the LabVIEW is realized real-time data acquisition, time-frequency analysis and digital processing. Based on this system testing results can effectively master roadheader operation state, identify the vibration characteristics, look for vibration source and put forward reasonable damping vibration measure, which provide the basis for roadheader in the best running condition. The development of roadheader vibration detection system uses the method that combines theory and simulation experiment , which realizes the real-time detection of roadheader vibration behavior, rational signal analysis of roadheader vibration and accurate processing of data results, it provides an important method to ensure the reliability of roadheader.

Download Full-text

Analysis of a damaged 12-storey frame-wall concrete building during the 2010 Haiti earthquake — Part II: Nonlinear numerical simulations

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2012-0099 ◽

2013 ◽

Vol 40 (8) ◽

pp. 803-814 ◽

Cited By ~ 5

Author(s):

Benoit Boulanger ◽

Patrick Paultre ◽

Charles-Philippe Lamarche

Keyword(s):

Structural Damage ◽

Numerical Models ◽

Dynamic Properties ◽

Shear Walls ◽

Element Model ◽

Companion Paper ◽

Ambient Vibration ◽

Wall Structure ◽

Haiti Earthquake ◽

Concrete Building

After the 2010 Haiti earthquake, which destroyed a significant part of the seismically vulnerable city of Port-au-Prince, the country’s capital, a 12-storey reinforced concrete building that behaved well was investigated to understand its dynamic response. This paper completes the experimental work presented in a companion paper, in which the dynamic properties of the building were obtained from ambient vibration tests, and from which a finite-element model was updated. This paper’s main objectives are: (i) to understand the causes that led to the observed structural damage; and (ii) to estimate the likely seismic excitation at the site of the building. Several nonlinear analyses involving various ground motion intensities were conducted and the results were compared with the damage reported during the on-site survey. The numerical models reproduced the observed damages well and helped to explain them. The overall response of the mixed stiff frame–wall structure was clearly dominated by the high stiffness of the shear walls, showing that this type of structural system helps in keeping reasonable interstorey drift levels. Overall, the building’s structure seems to have responded linearly to all the ground motions investigated, but deformation demands imposed to the frame by the shear walls lead to local damages.

Download Full-text

Determination of Period of RC Buildings by the Ambient Vibration Method

Advances in Civil Engineering ◽

10.1155/2019/1213078 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Mehmet Inel ◽

Hayri Baytan Ozmen ◽

Bayram Tanik Cayci

Keyword(s):

Natural Vibration ◽

Dynamic Properties ◽

Shear Walls ◽

Vibration Signal ◽

Analytical Models ◽

Ambient Vibration ◽

Seismic Behaviour ◽

Infill Wall ◽

Infill Walls ◽

Vibration Period

Determining the dynamic properties of structures is important for understanding their seismic behaviour. Ambient vibration signal measurement is one of the approaches used to determine the period of structures. Advantages of this method include the possibility of taking real-time records and presenting nondestructive and rapid solutions. In this study, natural vibration periods are calculated by taking ambient vibration signal records from 40 buildings. The height of the building, infill wall effect, presence of seismic retrofit, and presence of damage are taken into consideration, and their effects on natural vibration periods are investigated. Moreover, the results are compared with the analytical methods to reveal the differences. A significant correlation between the period and height of the building is observed. It is seen that the natural vibration periods of the buildings decrease by 7% to 30% (15% on average) due to infill wall contribution. However, the efficiency of infill walls decreases as the building height increases. Another significant result is that adding shear walls substantially decreases the vibration period values by 23% to 33% with respect to the shear wall ratio. When the analytical estimates and measured building period results are compared, it is seen that analytical models have closer period estimates before infill walls are implemented. The limited data in scope of the study suggest that significant differences may present in the analytical and measured periods of the buildings due to infill wall contributions.

Download Full-text