This paper introduces an excel tool created to improve the accuracy of electrical subcontracting prices for solar photovoltaic energy systems while also minimizing the time needed to create these price estimations. The need for improved precision, specifically during the early…
This paper introduces an excel tool created to improve the accuracy of electrical subcontracting prices for solar photovoltaic energy systems while also minimizing the time needed to create these price estimations. The need for improved precision, specifically during the early stages of a project, is examined and the paper also goes into detail about the components and pricing method that are incorporated into the excel tool. Lastly, the results of the price estimation tool are compared to real bids and recommendations are made for improvement to the tool.
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The 8.1 magnitude earthquake that struck Mexico City in 1985 left 10,000 people dead, and over 400 buildings collapsed. The extent of the damage left behind by this powerful quake has been extensively studied to make improvements to engineering and…
The 8.1 magnitude earthquake that struck Mexico City in 1985 left 10,000 people dead, and over 400 buildings collapsed. The extent of the damage left behind by this powerful quake has been extensively studied to make improvements to engineering and architectural practices in earthquake-prone areas of the world. Thirty-two years later, on the exact anniversary of the devastating earthquake, Mexico City was once again jolted by a 7.1 magnitude earthquake. Although still significant, the 2017 earthquake collapsed only about a tenth of the buildings collapsed by the 1985 Earthquake, and in turn resulted in a lower death toll. Even though these earthquakes struck in the same seismic region, their effects were vastly different. This thesis completes a comparison between the two earthquakes focusing on the structural impacts including background on Mexico City's unique geology, basic concepts necessary to understand the response of structures to earthquake excitation, and structural failure modes observed in both earthquakes. The thesis will also discuss the earthquake's fundamental differences that led to the discrepancy in structural damage and ultimately in lower death tolls. Of those discussed, is the types of buildings that were targeted and collapsed. In 1985, buildings with 6 or more floors had the highest damage category. Resonance frequencies of these buildings were similar to the resonance frequencies of the subsoil, leading to amplified oscillations, and ultimately in failure. The 2017 earthquake did not have as much distance from the epicenter for the high frequency seismic waves to be absorbed. In contrast, the shorter, faster waves that reached the capital affected smaller buildings, and spared most tall buildings.
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Arizona's transportation infrastructure is in need of an update. The American Society of Civil Engineers (ASCE) State Infrastructure 2017 Report Card scores Arizona's roads at a D+ and Arizona's bridges at a B. These grades are indicative that the serviceability…
Arizona's transportation infrastructure is in need of an update. The American Society of Civil Engineers (ASCE) State Infrastructure 2017 Report Card scores Arizona's roads at a D+ and Arizona's bridges at a B. These grades are indicative that the serviceability levels of the roads and bridges are less than adequate. These grades may seem tolerable in light of a national bridge C+ grade and a national road D grade, but the real problem lies in Arizona's existing funding gap that is in danger of exponentially increasing in the future. With an influx of vehicles on Arizona's roads and bridges, the cost of building, repairing, and maintaining them will grow and cause a problematic funding shortage. This report explores the current state of Arizona's roads and bridges as well as the policy and funding sources behind them, using statistics from the ASCE infrastructure report card and the Federal Highway Administration. Additionally, it discusses how regular, preventative maintenance for transportation infrastructure is the economically responsible choice for the state because it decreases delays and fuel expenses, prevents possible catastrophes, and increases human safety. To prioritize preventative transportation infrastructure maintenance, the common mentality that allows it to be sidelined for more newsworthy projects needs to be changed. Along with gaining preventative maintenance revenues through increasing vehicular taxes and fees, encouraging transportation policymakers and politicians to make economic decisions in favor of maintenance rather than waiting until failure is a reliable way to encourage regular, preventative maintenance.
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The School of Sustainable Engineering and the Built Environment (SSEBE) used to have a shake table where FSE 100 professors would use students' model structures to demonstrate how failure occurs during an earthquake. The SSEBE has wanted to build a…
The School of Sustainable Engineering and the Built Environment (SSEBE) used to have a shake table where FSE 100 professors would use students' model structures to demonstrate how failure occurs during an earthquake. The SSEBE has wanted to build a shake table ever since the original table was no longer available to them. My creative project is to design and build a shake table for FSE 100 use. This paper will go through the steps I took to design and construct my shake table as well as suggestions to anyone else who would want to build a shake table. The design of the shake table that was constructed was modeled after Quanser's Shake Table II. The pieces from the shake table were purchased from McMaster-Carr and was assembled at the TechShop in Chandler, Arizona. An educational component was added to this project to go along with the shake table. The project will be for the use of a FSE 100 classes. This project is very similar to the American Society of Civil Engineers, Pacific Southwest Conference's seismic competition. The main difference is that FSE 100 students will not be making a thirty story model but only a five story model. This shake table will make Arizona State University's engineering program competitive with other top universities that use and implement shake table analysis in their civil engineering courses.
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In the Spring 2013 and Fall 2013 semesters, a survey was taken of students enrolled in the principal undergraduate civil engineering structures course, CEE 321: Structural Analysis and Design, to assess both the prevalence of technology in the lives of…
In the Spring 2013 and Fall 2013 semesters, a survey was taken of students enrolled in the principal undergraduate civil engineering structures course, CEE 321: Structural Analysis and Design, to assess both the prevalence of technology in the lives of the students and the potential ways this information could be use to improve the educational experience. The results of this survey indicated that there was a considerable demand for additional online resources outside of the formal classroom. The students of CEE 321 requested online lecture videos in particular, and so a project was launched at the start of the Spring 2014 semester to deliver a large body of academic instructional videos. In total, a collection of 30 instructional videos which covered all key topics covered over a semester of CEE 321 was published. The driving interest behind this creative project is to increase the level of understanding, comfort, and performance in students enrolled in the class. Although the quantity of initial student feedback is relatively small, the reactions are distinctly positive and reflect an improvement in understanding amongst the responding students. Over the course of upcoming semesters, qualitative and quantitative assessments of the impact of the videos are expected to provide a better indication of their quality and effectiveness in supporting student comprehension and performance in CEE 321. Above all, the success of these videos is directly tied to their ability to function as living, adaptable resources which are continuously molded and improved by student feedback.
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Teaching methods in the present day are beginning to transition from the traditional lecture style to the flipped learning style. The flipped classroom, also known as an engaged learning classroom, follows the model where students are presented with lecture material…
Teaching methods in the present day are beginning to transition from the traditional lecture style to the flipped learning style. The flipped classroom, also known as an engaged learning classroom, follows the model where students are presented with lecture material prior to attending class. Instead of being lectured in class, they work on applications of the material with the help of their peers and the instructional staff. One component that many engaged learning environments have in common is lecture videos for the students to view prior to attending class. An undergraduate civil engineering course at Arizona State University is modeled using an engaged learning environment; however, it does not provide lecture videos for the students. Many students in this course are seeing an engaged learning environment for the first time and need guidance on how to prepare for the course, how to approach course material, and how to interpret feedback, in addition to getting help in the technical concepts. This project aims to create supplemental lecture videos based on the concepts that students in the class identified as needing more information, as well as topics that will help students make this transition to an engaged learning environment. A series of sixteen videos were created and posted for the students to view prior to attending recitation periods. The feedback from the students regarding the videos was studied and implementation techniques for future semesters were tested.
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America's infrastructure is in dire straits according to the 2013 American Society of Civil Engineers (ASCE) Report Card, giving America a D+ average for all infrastructure categories. "The World Economic Forum's Global Competitiveness Report 2014-2015 ranks the U.S. 16th in…
America's infrastructure is in dire straits according to the 2013 American Society of Civil Engineers (ASCE) Report Card, giving America a D+ average for all infrastructure categories. "The World Economic Forum's Global Competitiveness Report 2014-2015 ranks the U.S. 16th in quality of overall infrastructure" (Peters State). This paper addresses the need for investment in transportation infrastructure starting today, with a focus on bridges. The rates at which infrastructure is being built and maintained is not sustainable. Lack of funding causes states to practice deferred maintenance of infrastructure which ultimately results in higher overall costs. Timely maintenance and investment in current infrastructure is almost always the more economical approach. Despite conditions in Arizona, the rest of America is struggling with crumbling infrastructure. This paper stems from the Tex Wash Bridge failure on the Interstate-10 between California and Arizona in July 2015. A case study of four potential causes of the Tex Wash Bridge's collapse are discussed, along with several solutions that could have lessened the likelihood of failure. The condition of bridges are cataloged in the National Bridge Inventory managed by the Federal Highway Administration. In all reality, cost is not incurred at the instance of a bridge collapse, rather it is incremental throughout the infrastructure's lifetime. The impact of infrastructure failures are economic, social, and political. In the last decade, 33 short term fixes for project funding of roadways have been passed by Congress, none lasting longer than two years. The federal budget's underinvestment in infrastructure limits state departments of transportation ability to address high risk issues. Transportation is funded via the federal gasoline tax and vehicle license tax, along with state gasoline taxes. Unfortunately, the federal gasoline tax has not been increased since 1993. The Highway Trust Fund has subsequently faced insolvency in recent years. In 2011, America only committed 2.4% of its GDP to it's over 4 million miles of roads concluding that there is no interest to make transportation infrastructure a national priority. Currently, each state needs an average of $1 billion to address deficient bridges, and America needs $3.6 trillion to raise infrastructure ratings in the next five years. These needs can only be addressed at the federal level through long-term transportation legislation. It will require gaining investor confidence in tax spending, looking towards alternate funding such county taxes or toll roads, and capitalizing on the immediate interest generated by catastrophes. Mary Peters, former United States Secretary of Transportation, emphasizes the economic impact of underinvestment to foster political will, as opposed to focusing on America's crumbling infrastructure. Public safety and the economy are tied directly to the condition of America's infrastructure. For improvement on the national level, the disconnect between public understanding, engineering judgement, and political action must be remedied. The process starts by making America's infrastructure a national priority.
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Civil infrastructures undergo frequent spatial changes such as deviations between as-designed model and as-is condition, rigid body motions of the structure, and deformations of individual elements of the structure, etc. These spatial changes can occur during the design phase, the…
Civil infrastructures undergo frequent spatial changes such as deviations between as-designed model and as-is condition, rigid body motions of the structure, and deformations of individual elements of the structure, etc. These spatial changes can occur during the design phase, the construction phase, or during the service life of a structure. Inability to accurately detect and analyze the impact of such changes may miss opportunities for early detections of pending structural integrity and stability issues. Commercial Building Information Modeling (BIM) tools could hardly track differences between as-designed and as-built conditions as they mainly focus on design changes and rely on project managers to manually update and analyze the impact of field changes on the project performance. Structural engineers collect detailed onsite data of a civil infrastructure to perform manual updates of the model for structural analysis, but such approach tends to become tedious and complicated while handling large civil infrastructures.
Previous studies started collecting detailed geometric data generated by 3D laser scanners for defect detection and geometric change analysis of structures. However, previous studies have not yet systematically examined methods for exploring the correlation between the detected geometric changes and their relation to the behaviors of the structural system. Manually checking every possible loading combination leading to the observed geometric change is tedious and sometimes error-prone. The work presented in this dissertation develops a spatial change analysis framework that utilizes spatiotemporal data collected using 3D laser scanning technology and the as-designed models of the structures to automatically detect, classify, and correlate the spatial changes of a structure. The change detection part of the developed framework is computationally efficient and can automatically detect spatial changes between as-designed model and as-built data or between two sets of as-built data collected using 3D laser scanning technology. Then a spatial change classification algorithm automatically classifies the detected spatial changes as global (rigid body motion) and local deformations (tension, compression). Finally, a change correlation technique utilizes a qualitative shape-based reasoning approach for identifying correlated deformations of structure elements connected at joints that contradicts the joint equilibrium. Those contradicting deformations can help to eliminate improbable loading combinations therefore guiding the loading path analysis of the structure.
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Most engineers may agree that an optimum design of a particular structure is a proposal that minimizes costs without compromising resistance, serviceability and aesthetics. Additionally to these conditions, the theory and application of the method that produces such an efficient…
Most engineers may agree that an optimum design of a particular structure is a proposal that minimizes costs without compromising resistance, serviceability and aesthetics. Additionally to these conditions, the theory and application of the method that produces such an efficient design must be easy and fast to apply at the structural engineering offices.
A considerable amount of studies have been conducted for the past four decades. Most researchers have used constraints and tried to minimize the cost of the structure by reducing the weight of it [8]. Although this approach may be true for steel structures, it is not accurate for composite structures such as reinforced and prestressed concrete. Maximizing the amount of reinforcing steel to minimize the weight of the overall structure can produce an increase of the cost if the price of steel is too high compared to concrete [8]. A better approach is to reduce the total cost of the structure instead of weight. However, some structures such as Prestressed Concrete AASHTO Girders have been standardized with the purpose of simplifying production, design and construction. Optimizing a bridge girder requires good judgment at an early stage of the design and some studies have provided guides for preliminary design that will generate a final economical solution [17] [18]. Therefore, no calculations or optimization procedure is required to select the appropriate Standard AASHTO Girder. This simplifies the optimization problem of a bridge girder to reducing the amount of prestressing and mild steel only. This study will address the problem of optimizing the prestressing force of a PC AASHTO girder by using linear programming and feasibility domain of working stresses. A computer program will be presented to apply the optimization technique effectively.
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In this thesis, the author described a new genetic algorithm based on the idea: the better design could be found at the neighbor of the current best design. The details of the new genetic algorithm are described, including the rebuilding…
In this thesis, the author described a new genetic algorithm based on the idea: the better design could be found at the neighbor of the current best design. The details of the new genetic algorithm are described, including the rebuilding process from Micro-genetic algorithm and the different crossover and mutation formation.
Some popular examples, including two variable function optimization and simple truss models are used to test this algorithm. In these study, the new genetic algorithm is proved able to find the optimized results like other algorithms.
Besides, the author also tried to build one more complex truss model. After tests, the new genetic algorithm can produce a good and reasonable optimized result. Form the results, the rebuilding, crossover and mutation can the jobs as designed.
At last, the author also discussed two possible points to improve this new genetic algorithm: the population size and the algorithm flexibility. The simple result of 2D finite element optimization showed that the effectiveness could be better, with the improvement of these two points.
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