Applied Mechanics and Materials Vols. 284-287

Abstract: This study shows that the traditional engineering method of mountain road construction has not only caused local ecological disturbance directly, but also through each of the stages of the preparation, such as material gathering, construction, continual maintenance, and the diminishing of recycling potential, whereas ecological engineering method, with safety as its main priority, could offer a better ecological condition for construction projects. Through studying the local environmental features and using the proper construction method, the most suitable, corresponding engineering method ought to be adopted. This research uses Analytic Hierarchy Process (AHP) with surveys completed by field experts. This research contains three dimensions: Road Characteristics, Roadside Characteristics, Biological Characteristics. Additionally, actual samples of practical application of ecological engineering would also be discussed to further prove the result and the accuracy of the AHP. Research shows that in the overall planning of a mountain road construction project, ecological engineering method serves to be the better approach.

Abstract: Offshore jacket platforms have been widely used in offshore oil and gas exploitation under hostile ocean environments. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, which leads to more computing power when performing the analysis and what’s more, the incompatibility in the number of degrees of freedom to the experimental models. Therefore, there is a need to simplify the analytical model by reducing the DOFs and in the process, making the essential eigen-properties agree with those of the experimental model is desired. In this paper, a scaled physical experimental model of an offshore jacket platform is simplified using the recently developed model refinement scheme. Mathematically, the procedure to implement the model refinement technique is an application of cross-model cross-mode (CMCM) method for model updating. The master degrees of freedom are chosen according to the placement of accelerometers in the experiment. Upon the completion of the refinement, the improved reduced jacket platform model matches the dynamic characteristics of the experimental model quite well.

Abstract: This paper presents the live load distribution in straight prestressed concrete (PSC) girder bridges with curved deck slab utilizing finite element analyses. Numerical modeling methodology was established and calibrated based on field testing results. A parametric study of 73 cases with varying 6 critical parameters was used to determine a trend over each parameter. Through live load girder distribution factor (GDF) comparisons between the AASHTO LRFD, AASHTO Standard factors and finite element analyses results, both AASHTO live load distribution predicted conservatively in most bridges considered in the parametric study. However, in the bridges with curved slab, GDF was underestimated due to curvature influences. This study proposes a new live load distribution formula to predict rational and conservative live load distribution in PSC girder bridges with curved slab for a preliminary design purpose. The proposed live load distribution provides better live load analysis for the PSC girder bridge with curved slab and ensures the GDF is not underestimated.

Abstract: The object of this study is to propose, develop and apply a risk-based approach to determine the optimal service life for steel framed buildings in seismically active zones. The proposed framework uses models for seismic hazards, structural fragility and loss functions to estimate the system-wide costs owing to earthquake retrofitting and recovery. With the seismic risk curves (i.e. the expected seismic loss and probability of exceeding the loss), the optimal service life can be determined according to the probable maximum loss (PML) defined by the building’s owner. The risk-based approach is further illustrated by examples of 6- and 20-story steel framed buildings. The buildings have three kinds of different lateral load resisting systems, including moment resisting frames, eccentrically braced frames and buckling restrained braced frames. The results show that for the considered PML (i.e. 40% initial construction cost) and risk acceptance (e.g. 90% reliability), steel braced frames can effectively improve seismic fragility and lengthen service life for a low-rise building. However, the same effects cannot be expected in a high-rise building.

Abstract: The goal of school campus renovations in Taiwan is sustainability. In addition to providing an atmosphere of high-performance and learning, these renovations can support school environmental education by being like a ‘living textbook’. In light of Yilan’s climate, a water recycling facility has become the focus of sustainable campus renovation. Considering the 10 elementary and junior high schools in Yilan that have already built water recycling facilities, this research studied the application status of a facility for environmental education, employing such research methods as document reviews, field surveys, lesson plans analysis, user interviews, and questionnaire surveys. According to the results of this research, a water recycling facility can serve as a good textbook for environmental education in elementary, junior high, and high schools in Yilan. Environmental education using water recycling facilities has achieved great success. However, teachers have encountered the following problems while teaching their lessons: anxiety over the depth of the pond and poor water quality, limited instruction facilities and explanations regarding animals and plants, lack of proper operation space for instruction, and teachers’ inadequate understanding of the operation of water recycling facilities.

Abstract: Water quality monitoring is of great importance in managing drinking water lakes or reservoirs. However, developing such an effective monitoring system used in evaluating water quality is difficult, due to spatial and temporal variation in water quality that are usually hard to interpret. Principle component analysis (PCA) and canonical correlation analysis (CCA) techniques were used in this study to determine the principle water parameters, and explore the relationship between the physical and chemical water parameters, respectively in Macau Main Storage Reservoir (MSR) that is experiencing algal bloom in recent years. Twenty-eight water parameters including physical and chemical parameters were monitored each month from Jan 2001 to Dec 2010. The results showed that using PCA, six of the water quality parameters were found less important in explaining the monthly variation of the water quality and thus excluded from the further CCA, while applying CCA, the first six canonical correlations were 0.998, 0.988, 0.937, 0.778, 0.606 and 0.453, indicating that electro-conductivity and chloride compounds were the dominant (highly scored) variables of the physical parameters and chemical parameters, respectively. These results are helpful in understanding the main physical and chemical parameters involved in MSR, thus improving the water quality monitoring system in drinking water reservoirs.

Abstract: The core goal of space management in the Yilan Area is the sustainable development of the eco-environment. To form an ecological corridor network in Yilan, we need to improve the quality of river ecosystems. Our research evaluates the river conditions in the Lanyang Plain using the river ecological corridor evaluation system. The results of this research, as well as a review of the future planning and design of river constructions, show that the quality of most river eco-environments in the Lanyang Plain are either in fair or in poor condition as evaluated by the river ecological corridor evaluation system. The causes of poor quality river ecological corridors include non-ecological hydraulic engineering constructions, the over use of the floodplain area and the establishment of non-ecological bike paths parallel to the river. We suggest that the guidelines of space management for the rivers in the Yilan area should steer towards ecological orientated engineering with no interference in the river area, and that the recreation facilities using the river should be that of point contact rather than a parallel connection.

Abstract: Carbon-Dioxide Capture and Storage (CCS) in deep saline aquifers is one of the most feasible techniques for reducing anthropogenic emission of carbon dioxide (CO2). In this paper, a high-performance parallel computing is used to simulate the large-scale and long-term CO2 geologic storage in the saline aquifer (Sleipner Vest field in the Norwegian) based on the ECO2N module of the flow/transport simulator TOUGH2-MP, which is the parallel version of TOUGH2 implemented by the MPI. We have developed a complex three-dimensional heterogeneous model to study the spatial and temporal distribution and storage of CO2 injection into the sands of the Utsira formation, at the Sleipner Vest field in the Norway. Simulation results demonstrate that the high-speed parallel computing enhanced the capability on handling the large-scale model and the long-term studies. Furthermore, in order to avoid the problems of overpressure in the saline reservoir, the case study employs multi-well (ten-well) injection model, which has been proven to be able to reduce the reservoir pressure effectively when compared to the single-well injection model.

Abstract: The support vector machine (SVM) has been applied to drought prediction and it typically yields good performance on overall accuracy. However, the prediction accuracy of the drought category is much lower than that of the non-drought and severe drought categories. In this study, a two-stage approach was used to improve the SVM to increase the drought prediction accuracy. Four features, (1) reservoir storage, (2) inflows, (3) critical limit of operation rule curves, and (4) the Nth ten-day in a year, were used as input data to predict reservoir drought. We used these features as input data because they are the most commonly kept records in all reservoir offices. Empirical results show that the two-stage SVM outperforms the original SVM and the three other approaches (artificial neural networks, maximum likelihood classifier, Bayes classifier) for drought prediction. Not surprisingly, the longer the prediction time period, the lower the prediction accuracy is. However, the accuracy of predicting conditions within the next 50 days was approximately 85% both in training and testing data set by the two-stage SVM. Drought prediction provides information for reservoir operation and decision making in terms of water allocation and water quality issues. The result shows the benefit of a two-stage approach of SVM for drought prediction, as the accuracy of drought prediction increased quite substantially.

Abstract: The impact of climate change and the pressure of environmental awareness have caused the concepts of energy conservation, carbon reduction, and the sustainable engagement of a production model involving green ecology to become common development goals in power utilities worldwide. This study examines the recycling application framework of microalgal carbon fixation developed by Taipower, which has been used for the past decade, and evaluates the framework using a social survey on the social acceptability of the biotech skincare products that were exploited by microalgal carbon fixation. Research results show that Taipower’s engagement in carbon fixation using microalgae is practicable in reducing carbon, providing an additional production model of circular economy to power business development. The application of microalgal carbon fixation is projected to have numerous benefits, such as tangible profit benefit through future mass production, the intangible benefit from the image of enterprise environmental protection, and the benefit through social promotion. Therefore, focus on the sustainable development of microalgal carbon fixation is worthwhile. This study provides a guideline for future development of the recycling application of microalgal carbon fixation at Taipower and other power utilities.