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- Creator:
- Koirala, Janak Das
- Description:
- Every year, millions of scrap tires are either discarded in huge piles across the landscape or dumped in landfills in large volumes all over the world. These tire piles cause environmental pollution while posing fire and health hazards. Being volumetric goods in comparison to other wastes, they occupy large volumes in landfills. Rainwater tends to accumulate in the stockpiled tires, which, then become a breeding ground for mosquitoes that carry dangerous diseases, such as encephalitis. Several states in the United States have, therefore, banned the disposal of used tires in the land. Shredded rubber has been used in a variety of applications in geotechnical engineering including in highway pavements and backfills of retaining walls, but mostly as individual material. In this study, kaolinite and montmorillonite were modified using different sizes and quantities of shredded rubber tires and used to evaluate the improvement in geotechnical properties. Five different sizes and five different proportions of shredded rubber tires were mixed with the clay minerals. Laboratory experiments were carried out to evaluate the changes in density, permeability and unconfined compressive strength of such modified soil with shredded tires. The results showed that for kaolinite, the maximum dry density decreased as the percentage of shredded rubber tire in the mixture was greater than 4% by dry weight. In Montmorillonite, the maximum dry density of the modified soil increased till 2 to 4% of shredded rubber tire was added to the soil. The highest strength was observed at 4% shredded rubber tire content in kaolinite and at 5% shredded rubber tire content in montmorillonite. Permeability increased when smaller sized shredded rubber tire was added to kaolinite. In montmorillonite, permeability values sharply increased up to 2% shredded rubber tire content and thereafter, showed a linear increase in permeability for all sizes of shredded rubber tire used. From this study, it is concluded that shredded rubber can be effectively used to improve the compaction and strength characteristics of weak soils.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Ali, Bezait Gashachew
- Description:
- An analysis of green roof water quality was done to answer this question: does the use of green roofs reduce or contribute to storm water pollution? Green Roofs can increase the overall water retention of an urban area and lower the volume of expected stormwater runoff. a Green Roof (GR) prototype was used to compare the runoff contamination level with a Non- Green Roof (NGR) system. Two tests were performed: The first one using rainwater samples collected over a span of three months and the second from a synthetic rainwater sample created in a laboratory. the sample set using rainwater source had a significant increase of Phosphate and a small decrease in Nitrate concentration within the GR system compared to the NGR system. the sample set of synthetic rainwater source had a larger reduction of Nitrate compared to the accumulation of Phosphate. the experiment also includes a peak flow calculation of GR and NGR systems within a study area in the City of Fullerton. GR and NGR systems were simulated using a hydrologic modeling software, Storm Water Management Model (SWMM). a 25%GR, 50%GR, and 60%GR runoff was compared to the NGR. All three GR systems helped reduced the runoff flow and depth. Furthermore, the proposed conditions were significantly effective in decreasing max flow, max full flow, and max full depth. Both rain water samples and synthetic rain samples show that GR system can improve water quality by decreasing nitrate concentration compared to the NGR system.
- Resource Type:
- Masters Thesis
- Identifier:
- 9780438055926
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Al-behadili, Mohammed
- Description:
- Undrained shear strength is important in the evaluation of the stability of both natural and man-made slopes. Some researchers have proposed methods such as SHANSEP to evaluate the undrained shear strength of fine grained soils. However, the impact of plasticity characteristics and mineralogical composition on the undrained shear strength has not been widely studied. to do so, the SHANSEP technique was extended to include the interpretation of the normalized undrained strength ratio in this study. to determine the normalized undrained strength ratio, the undrained strength ratio for a sample at any over-consolidation ratio (OCR) is normalized by the value of undrained strength ratio for a normally consolidated sample of the same soil. This study will also focus on calculating the true friction angle and the true cohesion of various mixtures. in this study, five mixtures of montmorillonite with quartz and three mixtures of kaolinite with quartz were used. Unique relationships dependent on the mineralogical composition were developed between the normalized undrained strength ratio with the OCR. the results also showed that the true friction angle decreases with an increase in plasticity index for soils with plasticity indices less than 60% and liquid limit in soils with liquid limits less than 125%, beyond which there are negligible changes in the true friction angle. the base friction angle increases with an increase in plasticity index and liquid limit in soils with kaolinite as the clay mineral, but does not change significantly in soils with montmorillonite as the clay mineral.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Sompura, Shiven Jiten
- Description:
- In this research, a study was conducted on the feasibility of replacement of concrete pavements with precast concrete pavements which will result in faster construction, thinner slabs and more durable life of the pavement. It was observed that precast concrete pavement provides longer construction season throughout the year and less congestion in traffic while carrying out maintenance of roads or reconstruction of roads. Furthermore, the main goal of this research is to analyze the Life cycle cost of precast concrete pavements over traditional method; by comparing various aspects such as initial cost comparison of precast concrete pavements over onsite casting, the methodology of construction, the material used, recurring cost, maintenance cost, life assessment and life expectancy. the cost of each parameter will be analyzed, and net present worth method will be utilized to find the current dollar value of both the pavement alternative. Also, a series of range analysis will be carried out with different discount rate, uncertainty cost and initial construction cost which will help us in deciding the range of different parameters in analyzing life cycle cost. Moreover, the results obtained after analyzing all the parameters are that precast concrete pavement is 20% more economical than onsite casting and can be implemented places where congestion is a major concern while carrying any construction activities.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Dhital, Smriti
- Description:
- The Mw 7.8 Gorkha earthquake struck central Nepal on April 25, 2015 and brought about a huge loss of life and property. The quake was also responsible for the generation of a large number of landslides. They blocked highways, devastated villages, and temporarily dammed some rivers. About 14,670 landslips were triggered off by the main shock and its numerous large aftershocks. Among the detected failures, about 23% had an area greater than 100 m2. Since such failures can directly affect people’s life and property, they are considered for further investigation in this study. A comparison of these coseismic landslides with the 29 historical failures reveals that these landslides slightly exceed in number from those expected for the peak ground acceleration observed due to these earthquakes. The landslides seem to be concentrated within the area of the fault rupture surface. About 90% of the detected landslips could be classified as earth falls. The areas having relatively soft rocks, such as slates, shales, schists and phyllites of the Lesser Himalaya, suffered from a greater number of failures. The landslides had a strong correlation with the peak ground acceleration and they also showed a positive correlation with some landslide-susceptible geological formations composing the study area.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Phonsiri, Vanh
- Description:
- The emergence of different pharmaceuticals and personal care products (PPCPs) in the environment is a concern due to their potential adverse effect on human health and the environment. Among various sources, wastewater discharged from treatment plants often serve as a source of pharmaceutical compounds that pollute soil, surface water and groundwater. in this study, the occurrence of 30 selected PPCPs including analgesics, hormones, anti-epileptics, antilipidemics, anti-hypertensives, antiseptics, and stimulants were monitored in two municipal wastewater treatment plants. between April and October of 2017, total 77 samples were collected over 7 sampling events and analyzed for the presence of various human and animal pharmaceuticals. an optimized EPA Method 1694 utilizing solid phase extraction and liquid chromatographic separation with MS-MS quantitation was used for analyzing raw and secondary treated wastewater samples collected during 7 sampling events. the results show that 28 of the 30 target chemicals were detected throughout various stages of the wastewater treatment process. the concentrations of hormones and other PPCPs ranged from 0.007 to 7.7 µg/L and 0.05 to 126.3 µg/L, respectively. the removal rates of these constituents by trickling filter were varied: 3 analytes were not removed, six had < 50% removals, five had removal between 50 to 70%, and fourteen has removal > 70%. for activated sludge secondary treatment, two compounds were not removed, four had removal < 50%, four had removal 50 to 83%, and nineteen had removal > 90%.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Ousley, Maria Nassiry
- Description:
- Neonicotinoid insecticides such as Imidacloprid (IMD), Thiamethoxam (THM), and Dinotefuran (DNT) are extensively used in agricultural operations. their occurrence in the environment can have significant adverse ecological consequences to non-target species. in this research, hydrolysis kinetics of these insecticides were investigated at various pHs (acidic, neutral, and basic) and temperature (room temperature [~25°C], 45°C, and 60°C) conditions. Results indicate that of the three neonicotinoids, THM exhibits higher hydrolysis rate across all temperature and pH conditions, followed by IMD and DNT. Both temperature and pH have pronounced effect on the hydrolysis rate. All three neonicotinoids are unstable at pH 11, 60°C, with their hydrolysis rate constants: kTHM = 10.03 hr-1, kIMD = 0.58 hr-1, and kDNT 0.08 hr-1. Slower hydrolysis rate was observed at room temperature with hydrolysis rate constants: kTHM = 0.09 hr-1, kIMD = 0.01 hr-1 and kDNT 5E-04 hr-1. Reduction in temperature and a change in pH induces the largest effect on the hydrolysis rate of the THM. Across all experimental temperature conditions, the hydrolysis rate is fastest at pH 11, followed by pH 7, and stable at pH 4. the difference in the hydrolysis rates for the neonicotinoids tend to shrink as pH changes from alkaline to neutral, with the most unstable compound experiencing the largest effect. the hydrolysis rates clearly demonstrate that these neonicotinoids are stable towards hydrolysis and may pose serious adverse risk to non-target species.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Ibrahim, Suliman
- Description:
- Increased military and industrial activities involving the use of nitroaromatic explosives has led to a renewed focus on their environmental impact on soil, groundwater and surface water. Remediation of wastewater containing 2,4 DNT is critical to prevent its occurrence in environmental matrices and subsequent adverse ecological impacts. in this research, aqueous photodegradation of 2,4 DNT was investigated using a 254 nm UV lamp radiation source, encased in a quartz sleeve and embedded in a continuously stirred reactor. Studies were conducted with and without catalyst and in differing environmental matrices. Cadmium Sulfide in a dispersed form was used and its effect on net degradation of 2,4 DNT in nanopure, filtered and unfiltered natural water studied. Results indicate that, 2,4 DNT in nanopure water has a first-order degradation rate constant of 1.14 hr-1. Filtered and un-filtered river water showed a more rapid degradation rate (approximately two hr-) under similar conditions indicating a catalytic effect of humic and fulvic substances present in natural waters. At higher concentrations (10 mg/l), 95% degradation of 2,4-DNT was achieved in six hours, while similar degradation was achieved in 90 minutes at a concentration of one mg/L (k10 = 0.298 hr-1, k1 = 1.14 hr-1). At lower volumes, similar degradation was achieved in 40 minutes, clearly demonstrating the role of concentration and volume on degradation kinetics (k80 = 5.07 hr-1 >k200 = 4.17 hr-1 >k 800 = 1.14 hr-1).
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Khader, Syed Adnan
- Description:
- Bridges designed to resist earthquake ground-motions are expected to control the vibrations acting through them. These vibrations are to be dissipated during major seismic excitations. This research is focused on the design of a self-centering friction damping brace (SFDB) for the dissipation of such seismic ground-motions. the dissipation is achieved through friction and the super elastic nickel-titanium shape memory alloy wires which are used to gain the self-centering action. the objective of this research is to experimentally evaluate the performance of a SFDB for future research involving the retrofit of the Vincent Thomas Bridge in San Pedro, CA, which experiences large ambient motion. a small scale SFDB was designed, fabricated, and tested by loading the brace cyclically to failure. the results are compared to those of similarly-scaled linear viscous dampers. the force-deformation and energy dissipation characteristics of the SFDB are to be implemented in a model of the Vincent Thomas Bridge to determine its suitability for implementation as a retrofit strategy.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
- Creator:
- Shah, Vandit
- Description:
- Over the last twenty-five years many infrastructure projects have been successfully pursued through the Public-Private Partnership (PPP) approach across the United States (US). While the PPP project delivery model remains the same in principle, the PPP acceptance rate across the different states in the US has been differed significantly. A literature review shows that researchers have identified factors that influence PPP projects at program and project levels but the factors that influence end users’ point of view towards PPPs are not yet identified. This knowledge gap leaves federal agencies with minimal information to adequately plan for PPP success. The main objective of this research is to identify factors that influence public acceptance. Through logical reasoning we selected several demographic and road use factors that could influence end users’ PPP acceptance. The data for all such factors was obtained from several government sources for California, Florida, and Texas. Using SPSS, we conducted Principal Component Analysis (PCA) to identify the most influential factors. Results show that Regional Development, Employment Potential, Congestion, and Vehicle Miles Travelled were the most influential factors affecting PPP acceptance.
- Resource Type:
- Masters Thesis
- Campus Tesim:
- Fullerton
- Department:
- Department of Civil and Environmental Engineering
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