Papers by Keyword: Earthquake

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Authors: Camilla Colla
Abstract: The 12th C. Modena Cathedral is a masterpiece testimony of early Romanesque architecture, artand civic values of the time. Following the inclusion in the UNESCO list in 1997, studies, surveysand maintenance works have started. The Emilia’s seismic events of May 2012 have happenedwhen the maintenance operations were already in an advanced phase. The quakes caused damageand re-opening of some historical cracks, in particular in the thin vaults of the naves, near thefaçade and at the junction between naves and choir and crypt. Fragments of brick, mortar from thejoints between bricks and even limited portions of a diagonal rib have fallen to the ground. In viewof seismic assessment and strengthening for improvement of the structural behaviour, detailedstudies of the vaults’ mortar became necessary. The investigation approach was minimal andpreservative, combining on-site close-up visual inspections and micro-destructive testing of themortar joints by mortar penetrometer. For this purpose, openings of 0.25x0.25 m2 in the renderlayer of the 23 vaults were created. The outcome has allowed differentiating between repair mortarsof different strength, used in different historic periods. The mortar resistance was very low butdifferent for lime mortar and gypsum. Values, divided in 3 classes of strength, were found tocorrelate well with the location and severity of the crack pattern and damage map in the vaults. Theresults were useful for a correct design (minimal and reversible) of the cathedral strengtheningintervention.
Authors: Da Wei Sun, Kang Ping Wang, Guo Dong Zhang, Hui Qin Yao
Abstract: 3D finite element mesh for a 270m high CFRD was generated with advanced grid discretion technology. Adopting EI-Centro seismic wave with maximum horizontal acceleration 0.277g, dynamic response of this 270m high concrete faced rockfill dam was obtained by equivalent linearization method. Using residual strain model, the permanent deformation of the dam was obtained. Calculation results showed that the maximum acceleration and displacement of dam body, dynamic stress of face slab and deformation of joints are all within normal range. Therefore, the safety of dam would be guaranteed when it is subjected to 7 degree earthquake.
Authors: Mochida Yasuhide, Hanumantharayappa Yashwanth
Abstract: The characteristic methods involved in underpinning construction are studied in this research. The analysis of the structure is performed with respect to the geotechnical risk and possible retrofitting techniques. In the past several decades, a number of studies mainly focused on base isolation techniques to preserve the structure, but the merits of underpinning technique, geotechnical risk involved, temporary support for safety measures and cost ratio induced were unexpressed. The second generation of research evaluates the measure to reduce ground risk with characterization methods and detailed quality check through construction management system. Current research has pointed out the crucial features of underpinning construction process and its scope in restricted locations and geotechnical perils.
Authors: Zhong Tao Wang, Lin Qing Yang, Bo Xu, Mao Tian Luan
Abstract: Miniature pore pressure transducer (PPT) Druck PDCR81 series are used widely and have been proved to have a good performance in the centrifugal tests in the past few decades. However this product has been off production due to unknown reasons from 2010. Therefore, an alternative PPT is urgently needed in the centrifuge research field. A series of comparison between a new PPT and PDCR81 series had been carried out to check its precision and responding rate at 1g and centrifugal condition. The results show that the new PPT has a nearly equivalent performance to PDCR81 series. Also some suggestions are given to modify this new PPT.
Authors: Wei Dong Tian, Hai Qiu Jiang, Hong Juan Zhou, Dan Guo, Wen Bo Li, Yang Lu
Abstract: Different from the other distribution center location methods, there are new characteristics in distribution center location during earthquake disaster responses. In this paper, we investigate the factors impacting the location of distribution center during earthquake responses, and propose a decision-making model based on improved AHP framework for this issue. The improved AHP is extended to automatically calculate large scale judgment matrices by the crosstie model. This decision-making model was successfully applied in the simulation case of Yushu earthquake responses in 2010. The results show that the proposed decision-making model is reasonable.
Authors: Xiao Xi Liu, Ji Hua Fu, Zhi Tao Li
Abstract: In various kinds of natural disasters, earthquake is one of the most serious threats to the lifeline engineering systems. In the earthquake, except of the structure was destroyed, the function of the lifeline engineering systems was often subject to serious damages or totally loss, even caused fire or blood, or gave away poisonous gas and other series of major secondary disasters. To strengthen the function of the lifeline engineering and avoid or reduce the occurrence of secondary disasters, a demonstrated system of earthquake emergency auto-handling applied in water supply was built. The system was composed by the ED-1 type ground motion sensor module unit, the Panasonic FP-X C30R type PLC unit, The Kunlun Tongtai TPC7062K type unified touch screen unit and the multifunction water tower testing unit. The STA/LTA method and spectral intensity method were applied to deal with the distant earthquake and the near earthquake separately. Through theory and experiment analysis, the earthquake emergency auto-handling system could accurately measures the seismic records and performs the earthquake emergency auto-handling rapidly.
Authors: Zhong Jie Fan, Yan Qiu Leng, Yong Long Xu, Zheng Jiang Meng, Ji Wei Xu
Abstract: Based on the analysis of influence factors of saturated sand, this paper expounds the limitations of traditional evaluation of liquefaction, and introduces the criterion of support vector machine (SVM) based on the principle of structural risk minimization. According to the main influence factors of sand liquefaction, a SVM discriminant model of sand liquefaction with different kernel functions is established. Through studying small sample data, this model can establish nonlinear mapping relationship between influence factors and liquefaction type. On the basis of seismic data, a radial based kernel function is selected to predict sand liquefaction type. The research results show that the predicted magnitude is identical with the actual result, to prove that it is effective to apply this SVM model to evaluate the level of sand liquefaction.
Authors: Stefan Jaksch, Alireza Fadai, Wolfgang Winter
Abstract: We present the refurbishment work on a 200-year-old timber structure the principal cupola on top of the main building of the Vienna University of Technology (VUT). Retrofitting plans for this structure included a different use of the space underneath the cupola and leaving the ancient timber construction visible. This called for an examination of the quality of the ancient wood material, the development of modern safety concepts for fire and earthquake incidents within the modified use scenario, additional constructional measures to fulfil the requirements of these new concepts and doing an up-to-date structural analysis following the regulations given by the Eurocodes.
Authors: Caterina F. Carocci, Serena Cattari, Chiara Circo, Davide Indelicato, Cesare Tocci
Abstract: The paper illustrates the preliminary results of a research carried out on a historical centre heavily damaged by 2009 L’Aquila earthquake; in particular it presents shortly the Rubble Removal Plan realized and more in detail, the analysis conducted on a sample block. The detailed knowledge of the block is are essential for identifying probable causes that led to the present damage scenario and for planning consciously the reconstruction and restoration of the historical centre.
Authors: Qing Xu, Fei Kang, Jun Jie Li
Abstract: Evaluation of liquefaction potential of soils is important in geotechnical earthquake engineering. Significant phenomena of gravelly soil liquefaction were reported in 2008 Wenchuan earthquake. Thus, further studies on the liquefaction potential of gravelly soil are needed. This paper investigates the potential of artificial neural networks-based approach to assess the liquefaction potential of gravelly soils form field data of dynamic penetration test. The success rates for occurrence and non-occurrence of liquefaction cases both are 100%. The study suggests that neural networks can successfully model the complex relationship between seismic parameters, soil parameters, and the liquefaction potential of gravelly soils.
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