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Department of Civil and Environmental Engineering
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- Creator:
- Mozaffarpour Noori, Mohammad
- Description:
- The aim of this thesis is to provide a tool for contractors to select optimal equipment for projects, which will increase cost efficiency and reduce environmental impacts. The target geographic area for this research is the state of California, and the considered type of machinery is heavy construction equipment. In part, this research presents a modified mathematical model, as a decision-making tool, to minimize cost and emission of construction equipment, while meeting project requirements. The optimization model facilitates construction companies in selecting more efficient and sustainable equipment, while also avoiding penalties associated with non-compliance with the state’s environmental regulations. Such approach may lead to more profit by increasing the number of projects due to growing public sentiment towards environmentally friendly businesses. This model uses particular types of fleet data and project data. Construction equipment related data includes fleet size, equipment type, number, model, and year. Project related data includes project’s volumes, schedule, resources, and technical issues described by the contractors. Once this information was collected from equipment rental agencies throughout different geographic locations in California, a spreadsheet incorporated this information, along with mathematical calculations for estimated emissions, as well as the capacity for each type of equipment.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Salamanca, Jenny
- Description:
- This study focuses on the analysis of rainwater runoff from an extensive green roof system. Over time, space that was formally available for rainwater to properly infiltrate to the ground is being taken up by impervious built surfaces. Green roof technologies could be very beneficial in urban development, therefore the evaluation of the runoff quality is necessary to know if green roof systems act as a source of pollutants to receiving water bodies, or if they help mitigate contaminants that are washed off from the atmosphere and transfer to water bodies during rain events. The performance of green roof systems is highly dependent upon the season, temperature, wind condition, humidity, duration, and intensity of rainfall. The design of the green roof also plays an important part in the performance of the green roof, for which, material type, soil thickness, and maintenance influence the runoff quality. The green roof was analyzed for nutrients concentrations, pH, and conductivity of rainwater runoff. It was found that the green roof’s runoff had concentrations of nitrate, phosphate, and chloride ions. To investigate the amount of nutrients found in rainwater collected from different types of roofs, the green roof’s runoff nutrient concentrations were compared to those of a shingled roof. The pH and electrical conductivity of the rainwater runoff of the green roof were compared to those measured on a shingled roof as well.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Ul Quraish, Shahzan
- Description:
- Performance Based Design (PBD) using nonlinear analysis techniques is a well– established method to evaluate the seismic performance of RC coupled wall structural systems and their associated components like coupling beams. In principle, it is crucial to precisely define component behavior (Force–Deformation relation) for an exact evaluation of the global performance of the system. However, it is noticed that at present extensive information is not available for this purpose. ASCE 41 provides nonlinear modeling parameters and numerical acceptance criteria for components but this information is inadequate specifically for Diagonally Reinforced Coupling (DRC) beams. Moreover, vital effects of many key factors are not taken into account in ASCE 41 recommendations for Force–Deformation behavior of the DRC beam. In view of above, this study was intended to evaluate the impact of various key factors on nonlinear behavior of DRC beam at first and eventually to estimate nonlinear modeling parameters with practical considerations of the vital effects of these key factors. Specifically, these key factors were aspect ratio, shear stress levels, confinement, and compressive strength of concrete. The definitive goal of the study was to advocate a reasonable framework for ASCE 41 to incorporate the key factors in the recommendations for DRC beam. However, this study does not warrant the accuracy, content, completeness or suitability of the information provided in the proposed framework.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Kadhim, Ahmed Kamil
- Description:
- Lightweight concrete has been used in construction because of its properties, such as thermal, and fire resistances although it is more expensive and less available than normal weight concrete. One way to save time, cost, and to provide an alternative to lightweight concrete in construction projects is to reduce the number of installed insulations on precast wall panels and to improve the properties of normal weight concrete panels, respectively. These goals can be achieved by improving the four properties of precast panels, such as thermal resistance, fire resistance, heat capacity, and sound insulation by using perlite as insulation. The main goals of this research are getting buildings constructed or modified in less time and cost by producing superior wall panels and improving the properties of normal weight panels. Superior wall panels are new panels that provide the four properties listed above. Precast panels with different cross sections, concrete type, and different amounts of perlite will be investigated to observe the impact of each factor on the mentioned properties. The cost of each panel will be studied, and analytical methods will be used to find the optimum panel that provides the four mentioned properties with least cost. Moreover, theoretical methods will be applied to calculate the four properties for each panel.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Al Quraishi, Murtdha Hashim Hassoon
- Description:
- Improving the engineering properties of soil through soil modification has been implemented in practice for a number of years. However, construction over soft soil sites has remained a major challenge for projects all over the world because the ground shaking amplifies as it travels through soft soils and will result in an increase in the pseudospectral acceleration. Design of infrastructure depends on the seismic shaking levels from an earthquake. If the amplification of the ground motions can be reduced, the design of the infrastructure can be more economical. For this research, a laminar box was constructed, fitted with a drainage system and filled with a soft clay soil. The laminar box can freely deform during shaking tests and is more representative of free-field conditions. However, previous studies were performed using a rigid box. After the soft clay was consolidated to a pressure of the effective vertical pressure of 10 kPa, accelerometers were installed into the soft clay and a series of unidirectional 1-G shake table tests were conducted with different seismic shaking levels on both models with unimproved and improved soil profiles using deep soil mixed soil–cement panels. The improved deep soil mixed soil–cement panels were constructed at 10% and 20% replacement ratios (RR), which is defined as the ratio of the plan area of the soil-cement to the plan area of the soft clay profile. The present research shows that the deep soil mixed soil–cement panels effectively reduced the pseudospectral accelerations of ground shaking with the installation of panels having both the 10 % RR and 20% RR. On average, a reduction in pseudospectral acceleration was observed to be about 63% for 10 % RR and 59% for 20% RR.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Sakban, Haider Kadhem
- Description:
- Reinforced concrete (RC) walls are the most commonly used structural elements in buildings for resisting lateral forces induced by earthquakes. Therefore, reliable and robust analytical models that can predict their behavior under earthquake actions are essential for the design of new buildings and evaluation of existing buildings. Performance-Base Seismic Design (PBSD) and evaluation currently of RC structural walls typically relies on analytical models that do not capture the interaction between shear and flexural responses. Previous experimental and analytical studies showed that this interaction could be important for walls with shear span ratio ranges between 1.5 and 3.0 and that models which do not capture this interaction can overestimate wall strength and stiffness by 30 to 50%. A novel modeling approach that captures shear-flexure interaction (SFI) has been recently developed and implemented in computational platform OpenSees. The model has been previously validated against five RC wall specimens with aspect ratios of 1.5 and 2.0 that experienced significant SFI, and it showed to be capable of reproducing successfully experimentally measured global and local wall responses. However, the model has not been validated extensively over a wide range of wall characteristics, aspect ratio, axial load, reinforcement configuration and shape of the cross-section.The objective of this study is to calibrate and validate the SFI modeling approach recently implemented in computational platform OpenSees against a great number of specimens to assess its capability of successfully reproducing experimentally measured wall responses over a range of wall characteristics. The model was validated against 12 RC wall specimens tested under cyclic loading conditions. Comparison of experimental and analytical wall behavior focused on the overall load versus total top wall displacement and load versus shear displacement (global response) over the plastic hinge region (local response). Based on the results presented, it can be concluded that the model is capable of reproducing successfully experimentally measured wall behavior over a range of considered wall characteristics, including lateral load, stiffness, stiffness degradation and shear displacement within plastic hinge. It has also been observed that the model tends to overestimate the area of the hysteretic loops (i.e., underestimate pinching) for specimens with zero axial load, due to currently implemented models that represent shear transfer mechanisms along concrete cracks. Based on the results presented, future model improvements are suggested. The objective of this study is to calibrate and validate the SFI modeling approach recently implemented in computational platform OpenSees against a great number of specimens to assess its capability of successfully reproducing experimentally measured wall responses over a range of wall characteristics. The model was validated against 12 RC wall specimens tested under cyclic loading conditions. Comparison of experimental and analytical wall behavior focused on the overall load versus total top wall displacement and load versus shear displacement (global response) over the plastic hinge region (local response). Based on results presented, it can be concluded that the model is capable of reproducing successfully experimentally measured wall behavior over a range of considered wall characteristics, including lateral load, stiffness, stiffness degradation and shear displacement within plastic hinge. It has also been observed that the model tends to overestimate area of the hysteretic loops (i.e., underestimate pinching) for specimens with zero axial load, due to currently implemented models that represent shear transfer mechanisms along concrete cracks. Based on results presented, future model improvements are suggested.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Shin, Jean
- Description:
- Reinforced concrete (RC) structural walls are the most commonly used structural elements in buildings to resist earthquake loading. Concrete crushing in wall boundaries followed by buckling of longitudinal reinforcement is one of the most common failure mode of flexure-dominated RC walls. Deformation capacity of a RC wall is influenced by detailing of the wall boundary reinforcement, particularly requirements related to buckling of reinforcing bars. Thus, it is important to understand the buckling behavior of wall reinforcement and to be able to predict the behavior with robust analytical models. The main objective of the research is to conduct systematic calibration and validation studies on existing modeling approach to assess current modeling capabilities and propose future improvements. Analytical studies are performed using a computational platform, and the models are validated against experimental results obtained from tests on single reinforcing bars, RC wall boundary elements and RC wall that experienced buckling failure. Based on the results presented, it has been concluded that current models are capable of capturing buckling of reinforcing bars and RC boundary elements at a local (strain-stress behavior) level. However, for the RC wall considered in this study, although the model predicts stress drop in the wall boundary reinforcement, the model had not predicted reduction of overall deformation capacity of the wall. Based on these observations, model improvements and future research directions are proposed.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Ostorva, Florentino
- Description:
- According to a research conducted by Durham University, UK, landslides kill approximately ten times more people around the world than was formerly believed. Landslides are recurrently perceived in coastal areas where the water has high salinity. It is vital for researchers to appraise the influence of sodium chloride (NaCl) on fully softened shear strength (FSSS) of clays to understand the causes of landslides in coastal areas. for this study, seven clay mineral mixtures were prepared in the laboratory and tested using a fully automated direct simple shear (DSS) device to adjudicate the FSSS when saline water is the pore fluid under drained and undrained conditions. the results were used to examine the influence of the presence of NaCl in the pore fluid on the shear strength parameters. in addition, the curvature in the shear envelope for these samples was quantified and correlated with the corresponding plasticity indices. in general, the shear strength of samples when saline water was the pore fluid is greater than the shear strength of samples when distilled water was the pore fluid. a reduction of NaCl concentration in the pore fluid results in a reduction of FSSS. the variation in the FSSS due to pore fluid salinity in kaolinite-quartz samples is less than that observed in the samples prepared as montmorillonite-quartz mixtures. It is clear from this study that the influence of the pore fluid chemistry on the FSSS is directly correlated to the influence of the pore fluid chemistry on the plasticity characteristics of the clayey soil mixtures.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Yamashiro, Brian
- Description:
- Liquefaction and cyclic mobility are two major modes of ground failure that occur due to earthquake loads. Cyclic mobility is initiated due to a reduction in shear strength of the soil. to evaluate the likelihood of occurrence of such failures, it is important to understand the shear strengths of soil before and after earthquake loading. for this study, samples were collected from the Kathmandu Valley in Nepal after the 2015 Mw 7.8 Gorkha earthquake from an area that experienced failure. Three additional soil samples from the Portuguese Bend area, California, a known area for landslides, were also evaluated during this study. Testing included static shear testing and cyclic loading followed by post-cyclic shear testing to determine the strength degradation that occurs post-cyclically and other cyclic properties of the samples. Results from this study show indications of increased cyclic resistance corresponding to increased plasticity index and lower consolidation stresses, power function representation of cyclic strength curves as identified in previous studies, a reduction in post-cyclic shear strength degradation with an increase in plasticity index, and greater retention of relative stiffness in montmorillonite dominated soil compared to kaolinite dominated soil during cyclic loading. Slight deviations from the predicted trends were observed for a few natural samples, which could potentially be due to their marine environment during formation process or the variable clay minerology found in these natural soils.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Mann, Michael Ford
- Description:
- One of the many problems that engineers face is protecting structures from the disastrous effects of earthquakes, especially at soft soil sites. Soft soils are known to amplify the shaking during an earthquake resulting in higher accelerations at the ground surface, which can be more damaging for the overlaying buildings. in previous studies and in case histories, the use of ground reinforcement has shown positive results in mitigation against liquefaction and ground deformation during earthquakes, but little research was done to experimentally investigate the effectiveness of ground reinforcement in reducing ground motions. in this study, a method of reducing seismic shaking has been studied, which used ground improvement with soil reinforcement panels in the form of deep-soil mixed and soil-cement panels to strengthen a soft soil profile in both a rigid and laminar container. After filtering and comparing the data, comparisons were made in order to analyze the reduction in acceleration during the tests using differing sizes of soil reinforcement panels and the performance of the laminar and rigid containers. in summary, the deep-soil mixed, DSM, panels were more effective at 10% replacement ratios than at 20% replacement ratios at the surface of the clay, reducing the amplification in the clay by as much as 54% at 10% replacement ratio. in addition, the results from using a laminar container were not substantially different than the tests using a rigid container, showing a minimal boundary effect in the middle of the soil sample’s surface.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
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