Performance‐based seismic assessment method for Taiwanese historic Dieh‐Dou timber structures     

Pin‐Hui Tsai  Dina D'Ayala 《地震工程与结构动力学》2011,40(7):709-729

Lateral force, response spectrum and step‐by‐step pushover analyses are performed and compared with the post‐earthquake survey of two Dieh‐Dou buildings seriously affected in the 1999 Chi‐Chi earthquake in Taiwan. The results show that the proposed FE model with finite translational and rotational stiffness can successfully be employed to assess the vulnerability of the frames. The fundamental period of Dieh‐Dou structures is about 1.0 s higher than that calculated by the simplified approach of the codes for regular frames; a modal analysis is, therefore, essential for this typology of structure. The elastic analysis, either lateral force or response spectrum, is shown to be reliable to assess Dieh‐Dou frames when quick results are desired. However, a non‐linear step‐by‐step pushover analysis has the advantage of greater accuracy, as it allows mapping the failure trend and indicating the critical elements. The lateral drifts are compared with the actual observed damage pattern and when the damage level is related to the peak ground acceleration on a vulnerability curve plot, it is shown that the joint failure combined with the lateral drift gives an indication of the global structural behaviour of this historic construction typology. Owing to the unique construction features of the Dieh‐Dou, the joint failure represents also a critical criterion in terms of maximum retention for conservation. Based on a damage level approach, an assessment methodology is suggested that would allow optimizing a strengthening strategy, for protection of these precious structures from future earthquakes while avoiding unnecessary interventions. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Estimation of the seismic energy demands of two-way asymmetric-plan building systems     

Jui-Liang Lin  Keh-Chyuan Tsai 《Bulletin of Earthquake Engineering》2011,9(2):603-621

This paper proposes a method for the estimation of the seismic energy demands of two-way asymmetric-plan buildings under bi-directional ground excitations. The modal absorbed energies of asymmetric-plan buildings are estimated by using the three-degree-of-freedom (3DOF) modal systems. The 3DOF modal system represents the two roof translations versus the two base shears and the roof rotation versus the base torque relationships of each vibration mode of two-way asymmetric-plan buildings. Not only the total absorbed energy but also the portions of the total absorbed energy contributed from translational and rotational deformations can be respectively estimated. This study verifies the relationship between the signs of modal eccentricities and the trend of uneven distribution of modal absorbed energy on floor-plan edges of asymmetric-plan buildings. The accuracy of the proposed method was verified by analyzing one 3-storey and one 20-storey two-way asymmetric-plan buildings subjected to bi-directional ground motions. The computational efficiency of the proposed method is confirmed by comparing the computation time with that required by using the nonlinear response history analysis.  相似文献   

Improving information access for emergency response in disasters     

Ming-Kuan Tsai  Nie-Jia Yau 《Natural Hazards》2013,66(2):343-354

During disasters, many researchers highlight the efficiency of the various information techniques that are used for emergency response. However, only a few information systems consider on-site and off-site information requirements synchronously. The results achieved by the emergency responders will not be as effective as they should be, since the emergency responders cannot access necessary information. Therefore, this study proposed an approach for dealing with three problems associated with emergency situations, i.e., inadequate escape guidelines for people, incomplete geographical information for relief workers, and insufficient on-site information for disaster managers. In a simulated scenario, when serious debris flows occurred, this study tested the approach. The test results showed that the people rapidly finished self-evacuation, the relief workers effectively completed their on-site relief work, and the disaster managers successfully managed the on-site activities regarding the people and relief workers. Overall, the recommended approach improved information access for emergency response and provided a useful reference for similar applications in disaster management.  相似文献   

Application of a feature-based approach to debris flow detection by numerical simulation     

Chih-Wei Lin  Cheng-Wu Chen  Wen-Ko Hsu  Chia-Yen Chen  Chung-Hung Tsai  Yi-Ping Hung  Wei-Ling Chiang 《Natural Hazards》2013,67(2):783-796

A debris flow is a serious natural disaster which can occur anywhere whether in a valley or on a mountain slope, destroying everything it passes through. Debris flows can occur suddenly and cause residents in the path to suffer casualties and property loss. An early warning system is necessary to reduce the damage in order to protect human life and personal property. However, most debris flow detection systems, like wireless sensors, satellite images and radar, are not suitable for general public use. Vision surveillance systems are generally erected in Taiwan as public devices for security. Therefore, we propose a novel debris early warning system that uses a computer vision technique and build a simulation environment to prove the feasibility.  相似文献   

Indicator geostatistics for reconstructing Baton Rouge aquifer-fault hydrostratigraphy, Louisiana, USA     

Ahmed S. Elshall  Frank T.-C. Tsai  Jeffrey S. Hanor 《Hydrogeology Journal》2013,21(8):1731-1747

The complex siliciclastic aquifer system underneath the Baton Rouge area, Louisiana (USA), is fluvial in origin and is characterized by strongly binary heterogeneity of sand units and mudstones as pervious and impervious hydrofacies. The east–west trending Baton Rouge fault and Denham Springs-Scotlandville fault cut across East Baton Rouge Parish and play an important role in groundwater flow and aquifer salinization. This study reconstructs the Baton Rouge aquifer-fault system architecture for a Miocene-Pliocene depth interval that consists of the 1,200-foot sand to the 2,000-foot sand. The results show the spatial extent of sand units, their interconnections, and flow paths within each sand unit. The regional-scale formation dip, the sand unit offset on the faults, and the volumetric spatial extent of individual sand units are quantified. The study reveals the complexity of the Baton Rouge aquifer-fault system where the sand deposition is non-uniform, different sand units are interconnected, the sand unit displacement on the faults is significant, and the spatial distribution of flow pathways through the faults is sporadic. The identified locations of flow pathways through the Baton Rouge fault provide useful information on possible windows for saltwater intrusion from the south.  相似文献   

Evaluating heavy metal concentration of plants on a serpentine site for phytoremediation applications   总被引：1，自引：0，他引：1  

Cheng-Ping Ho  Zeng-Yei Hseu  Nien-Chu Chen  Chen-Chi Tsai 《Environmental Earth Sciences》2013,70(1):191-199

The chemical analysis of plants and soils is a frequently used approach in understanding a serpentine ecosystem. Studies on vegetation growth in serpentine soils focused on various plant species for remediation purposes of soil contamination with heavy metals, emphasizing their role in the metal extraction or stabilization in the soil. The aims of this study were to measure the concentrations of Cr, Mn, and Ni in the soils and plants and to elucidate the phytoremediation potential of the studied plants. This study was performed at an abandoned site of serpentine mining in eastern Taiwan. Seven plant species were collected for analysis of Cr, Mn, and Ni, including Crotalaria micans, Miscanthus floridulus, Leucaena leucocephala, Bidens pilosa, Pueraria lobata, Melilotus indicus, and Conyza canadensis. The Cr and Ni concentrations in all studied plants were higher than those in general plants. In all species, the mean concentrations of Cr, Mn, and Ni in the shoots were lower than those in the root. None of the collected specimens exhibited hyperaccumulation of Cr, Mn, and Ni. All studied species may be used to remediate contaminated soils through phytostabilization of Cr and Mn, whereas M. floridulus and M. indicus are appropriate plants for phytostabilization of Ni. However, C. micans, L. leucocephala, B. pilosa, P. lobata, and C. canadensis have the potential to remove Ni from contaminated soils for the purpose of phytoextraction.  相似文献   

Situation-dependent intensity skill metric and intensity spread guidance for western North Pacific tropical cyclones     

Russell L. Elsberry  Hsiao-Chung Tsai 《Asia-Pacific Journal of Atmospheric Sciences》2014,50(3):297-306

A situation-dependent intensity prediction (SDIP) technique is developed for western North Pacific tropical cyclones that is based on the average of the intensity changes from the 10 best historical track analogs to the Joint Typhoon Warning Center best-tracks. The selection of the 10 best track analogs is also conditioned on the current intensity, and it is demonstrated that for a subsample of current intensities less than or equal to 35 kt the intensity mean absolute errors (MAEs) and biases are smaller than for the greater than 35 kt intensity subsample. The SDIP is demonstrated to have advantages as an intensity skill measure at forecast intervals beyond 36 h compared to the current climatology and persistence technique that uses only variables available at the initial time. The SDIP has significantly smaller intensity MAEs beyond 36 h with an almost 20% reduction at 120 h, has significantly smaller intensity biases than the present skill metric beyond 12 h, and explains 36% of the intensity variability at 120 h compared to 20% explained variance for the current technique. The probability distributions of intensities at 72 h and 120 h predicted by the SDIP are also a better match of the distribution of the verifying observations. Intensity spread guidance each 12 h to 120 h is developed from the intensity spread among the 10 best historical track analogs. The intensity spread is calibrated to ensure that the SDIP forecasts will have a probability of detection (PoD) of at least 68.26%. While this calibrated intensity spread is specifically for the SDIP technique, it would provide a first-order spread guidance for the PoD for the official intensity forecast, which would be useful intensity uncertainty information for forecasters and decision-makers.  相似文献   

Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study   总被引：1，自引：0，他引：1  

Tzai-Tang Tsai  Jygau Sah  Chih-Ming Kao 《Journal of Hydrology》2010,380(1-2):4-13

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Book Review
Creep and Fracture of Ice: Erland M. Schulson and Paul Duval, Cambridge University Press, 2009; ISBN: 978-0-521-80620-6 (hardback), USD 130.00     

Victor C. Tsai 《Pure and Applied Geophysics》2010,167(11):1455

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Assessment of uncertainty sources in water quality modeling in the Niagara River     

Samuela Franceschini  Christina W. Tsai 《Advances in water resources》2010

This paper presents a framework to quantify the overall variability of the model estimations of Total Polychlorinated Biphenyls (Total PCBs) concentrations in the Niagara River on the basis of the uncertainty of few model parameters and the natural variability embedded in some of the model input variables. The results of the uncertainty analysis are used to understand the importance of stochastic model components and their effect on the overall reliability of the model output and to evaluate multiple sources of uncertainty that might need to be further studied. The uncertainty analysis is performed using a newly developed point estimate method, the Modified Rosenblueth method. The water quality along the Niagara River is simulated by coupling two numerical models the Environmental Fluid Dynamic Code (EFDC) – for the hydrodynamic portion of the study and the Water Quality Analysis and Simulation Program (WASP) – for the fate and transport of contaminants. For the monitoring period from May 1995 to March 1997, the inflow Total PCBs concentration from Lake Erie is the stochastic component that most influences the variability of the modeling results for the simulated concentrations at the exit of the Niagara River. Other significant stochastic components in order are as follows: the suspended sediments concentration, the point source loadings and to a minor degree the atmospheric deposition, the flow and the non-point source loadings. Model results that include estimates of uncertainty provide more comprehensive information about the variability of contaminant concentrations, such as confidence intervals, and, in general offer a better approach to compare model results with measured data.  相似文献