SEISMIC VULNERABILITY OF SHALLOW UNDERGROUND CAVITIES IN SOFT ROCK

This paper investigates the effects of the nonlinear behaviour of isolation pads on the seismic capacity of bridges to identify the parameters of base isolation systems that can be used to improve seismic performance of bridges. A parametric study was conducted by designing a set of bridges for three different soil types and varying the number of spans, span lengths, and pier heights. The seismic responses (acceleration, displacement and pier seismic forces) were evaluated for two structural models. The first model corresponded to the bridges supported on elastomeric bearings with linear elastic behaviour and the second model simulated a base isolated bridge that accounts for the nonlinear behaviour of the system. The seismic demand was represented with a group of twelve real accelerograms recorded on the subduction zone on the Pacific Coast of Mexico. The nonlinear responses under different damage scenarios for the bridges included in the presented study were estimated. These results allow determining the seismic capacity of the bridges with and without base isolation. Results show clearly the importance of considering the nonlinear behaviour on the seismic performance of bridges and the influence of base isolation on the seismic vulnerability of medium size bridges.

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SEISMIC VULNERABILITY ASSESSMENT FOR SAN FRANCISCO TEMPLE IN MORELIA, MEXICO

NED University Journal of Research ◽

10.35453/nedjr-stmech-2019-0071 ◽

2019 ◽

Vol 3 (Special Issue on First SACEE'19) ◽

pp. 207-2016

Author(s):

Guillermo Martinez ◽

David Castillo ◽

José Jara ◽

Bertha Olmos

Keyword(s):

San Francisco ◽

Seismic Vulnerability ◽

Seismic Analysis ◽

Three Dimensional ◽

Middle Part ◽

Seismic Demands ◽

Modeling And Analysis ◽

Seismic Records ◽

Cracking Pattern ◽

The Temple

This paper presents a first approximation of the seismic vulnerability of a sixteenth century building which is part of the historical center of Morelia, Mexico. The city was declared World Heritage by United Nations Educational, Scientific and Cultural Organization in 1991. The modeling and analysis of the building was carried out using a three-dimensional elastic tetrahedral finite elements model which was subjected to probabilistic seismic demands with recurrences of 500 yrs and 1000 yrs in addition to real seismic records. The model was able to correctly identify cracking pattern in different parts of the temple due to gravitational forces. High seismic vulnerability of the arched window and the walls of the middle part of the bell tower of the temple was indicated by the seismic analysis of the model.

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Integrated economic and environmental building classification and optimal seismic vulnerability/energy efficiency retrofitting

Bulletin of Earthquake Engineering ◽

10.1007/s10518-021-01101-4 ◽

2021 ◽

Author(s):

Martina Caruso ◽

Rui Pinho ◽

Federica Bianchi ◽

Francesco Cavalieri ◽

Maria Teresa Lemmo

Keyword(s):

Energy Efficiency ◽

Life Cycle ◽

Seismic Hazard ◽

Environmental Impacts ◽

Classification System ◽

Seismic Vulnerability ◽

Performance Metrics ◽

Climatic Conditions ◽

Economic Losses ◽

Operational Energy

AbstractA life cycle framework for a new integrated classification system for buildings and the identification of renovation strategies that lead to an optimal balance between reduction of seismic vulnerability and increase of energy efficiency, considering both economic losses and environmental impacts, is discussed through a parametric application to an exemplificative case-study building. Such framework accounts for the economic and environmental contributions of initial construction, operational energy consumption, earthquake-induced damage repair activities, retrofitting interventions, and demolition. One-off and annual monetary expenses and environmental impacts through the building life cycle are suggested as meaningful performance metrics to develop an integrated classification system for buildings and to identify the optimal renovation strategy leading to a combined reduction of economic and environmental impacts, depending on the climatic conditions and the seismic hazard at the site of interest. The illustrative application of the framework to an existing school building is then carried out, investigating alternative retrofitting solutions, including either sole structural retrofitting options or sole energy refurbishments, as well as integrated strategies that target both objectives, with a view to demonstrate its practicality and to explore its ensuing results. The influence of seismic hazard and climatic conditions is quantitatively investigated, by assuming the building to be located into different geographic locations.

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New opportunities and challenges in surveying underground cavities using photogrammetric methods

International Journal of Mining Science and Technology ◽

10.1016/j.ijmst.2020.12.005 ◽

2020 ◽

Author(s):

Malte J.M. Gurgel ◽

Axel Preusse

Keyword(s):

Underground Cavities

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Seismic vulnerability analysis in Poso Distric

Journal of Physics Conference Series ◽

10.1088/1742-6596/1763/1/012015 ◽

2021 ◽

Vol 1763 (1) ◽

pp. 012015

Author(s):

M Rusydi ◽

M B Cyio ◽

Rahmawati ◽

Ramlan

Keyword(s):

Seismic Vulnerability ◽

Vulnerability Analysis ◽

Seismic Vulnerability Analysis

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Research on Supporting Method for High Stressed Soft Rock Roadway in Gentle Dipping Strata of Red Shale

Minerals ◽

10.3390/min11040423 ◽

2021 ◽

Vol 11 (4) ◽

pp. 423

Author(s):

Chunde Ma ◽

Jiaqing Xu ◽

Guanshuang Tan ◽

Weibin Xie ◽

Zhihai Lv

Keyword(s):

Failure Process ◽

High Stress ◽

Soft Rock ◽

In Situ Stress ◽

Mechanical Parameters ◽

Deformation And Failure ◽

Deep Mine ◽

Plastic Energy ◽

Roadway Stability ◽

Phosphate Mine

Red shale is widely distributed among the deep mine areas of Kaiyang Phosphate Mine, which is the biggest underground phosphate mine of China. Because of the effect of various factors, such as high stress, ground water and so on, trackless transport roadways in deep mine areas were difficult to effectively support for a long time by using traditional supporting design methods. To deal with this problem, some innovative works were carried out in this paper. First, mineral composition and microstructure, anisotropic, hydraulic mechanical properties and other mechanical parameters of red shale were tested in a laboratory to reveal its deformation and failure characteristics from the aspect of lithology. Then, some numerical simulation about the failure process of the roadways in layered red shale strata was implemented to investigate the change regulation of stress and strain in the surrounding rock, according to the real rock mechanical parameters and in-situ stress data. Therefore, based on the composite failure law and existing support problems of red shale roadways, some effective methods and techniques were adopted, especially a kind of new wave-type bolt that was used to relieve rock expansion and plastic energy to prevent concentration of stress and excess deformation. The field experiment shows the superiorities in new techniques have been verified and successfully applied to safeguard roadway stability.

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Fragility curves for Italian URM buildings based on a hybrid method

Bulletin of Earthquake Engineering ◽

10.1007/s10518-021-01155-4 ◽

2021 ◽

Author(s):

A. Sandoli ◽

G. P. Lignola ◽

B. Calderoni ◽

A. Prota

Keyword(s):

Seismic Vulnerability ◽

Fragility Curves ◽

Limit State ◽

Ultimate Limit State ◽

Masonry Building ◽

Masonry Buildings ◽

Seismic Behaviour ◽

Building Stock ◽

Ground Acceleration ◽

Damage Scenario

AbstractA hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

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