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Evaluation of the application uniformity of subsurface drip distribution systemsWeynand, Vance Leo 30 September 2004 (has links)
The goal of this research was to evaluate the application uniformity of subsurface drip distribution systems and the recovery of emitter flow rates. Emission volume in the field, and laboratory measured flow rates were determined for emitters from three locations. Additionally, the effects of lateral orientation with respect to slope on emitter plugging was evaluated. Two different emitters were tested to evaluate slope effects on emitter plugging (type Y and Z). The emitters were alternately spliced together and installed in an up and down orientation on slopes of 0, 1, 2 and 4% and along the contour on slopes of 1 and 2%. The emitters were covered with soil and underwent a simulated year of dosing cycles, and then flushed with a flushing velocity of 0.6 m/s. Initial flow rates for the two emitter types were 2.38 L/hr with a C.V. of 0.07. There was no significant difference in flow rates among slopes for type Y emitters, but there was a significant difference between the 1% and 2 % contour slopes for type Z emitters. Application uniformity of three different laterals at each site was evaluated. Sections of the lateral from the beginning, middle and end were excavated and emission volumes were recorded for each emitter. Application uniformity of laterals ranged from 48.69 to 9.49%, 83.55 to 72.60%, and 44.41 to 0% for sites A, B, and C, respectively. Mean emitter flow rate was 2.21, 2.24, and 2.56 L/hr for sites A, B, and C, respectively under laboratory conditions. Application uniformity under laboratory conditions ranged from 70.97 to 14.91%, 86.67 to 79.99%, and 85.04 to 0.00% for sites A, B, and C, respectively. A flushing velocity of 0.15 m/s with no chlorination, shock chlorination of 3400 mg/L and flushing velocity of 0.15 m/s, and shock chlorination of 3400 mg/L and flushing velocity of 0.6 m/s treatment regiments were applied to all laterals collected to assess emitter flow rate recovery to the nominal flow rate published by the manufacturer. All laterals showed an increase in the number of emitters within 10% of the published nominal flow rate.
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Evaluation of the application uniformity of subsurface drip distribution systemsWeynand, Vance Leo 30 September 2004 (has links)
The goal of this research was to evaluate the application uniformity of subsurface drip distribution systems and the recovery of emitter flow rates. Emission volume in the field, and laboratory measured flow rates were determined for emitters from three locations. Additionally, the effects of lateral orientation with respect to slope on emitter plugging was evaluated. Two different emitters were tested to evaluate slope effects on emitter plugging (type Y and Z). The emitters were alternately spliced together and installed in an up and down orientation on slopes of 0, 1, 2 and 4% and along the contour on slopes of 1 and 2%. The emitters were covered with soil and underwent a simulated year of dosing cycles, and then flushed with a flushing velocity of 0.6 m/s. Initial flow rates for the two emitter types were 2.38 L/hr with a C.V. of 0.07. There was no significant difference in flow rates among slopes for type Y emitters, but there was a significant difference between the 1% and 2 % contour slopes for type Z emitters. Application uniformity of three different laterals at each site was evaluated. Sections of the lateral from the beginning, middle and end were excavated and emission volumes were recorded for each emitter. Application uniformity of laterals ranged from 48.69 to 9.49%, 83.55 to 72.60%, and 44.41 to 0% for sites A, B, and C, respectively. Mean emitter flow rate was 2.21, 2.24, and 2.56 L/hr for sites A, B, and C, respectively under laboratory conditions. Application uniformity under laboratory conditions ranged from 70.97 to 14.91%, 86.67 to 79.99%, and 85.04 to 0.00% for sites A, B, and C, respectively. A flushing velocity of 0.15 m/s with no chlorination, shock chlorination of 3400 mg/L and flushing velocity of 0.15 m/s, and shock chlorination of 3400 mg/L and flushing velocity of 0.6 m/s treatment regiments were applied to all laterals collected to assess emitter flow rate recovery to the nominal flow rate published by the manufacturer. All laterals showed an increase in the number of emitters within 10% of the published nominal flow rate.
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Experimental and Numerical Investigations on the Hydrodynamic Loading of Tsunami-like Surges on InfrastructuresLiu, Shilong 15 December 2022 (has links)
Tsunamis have caused severe damage to coastal communities and associated infrastructure over the past decades. Thus, researchers deemed necessary to investigate and better understand the mechanisms loading associated with tsunami waves and the inundation caused by them. Over the past few years, researchers have demonstrated that the dam-break waves are hydrodynamically similar to the onshore propagation of tsunami inundation; hence, dam-break waves are now widely used to investigate tsunami impacts. Various studies related to dam-break waves have been conducted to investigate their characteristics: the kinematic behavior, including free surface profiles, wave height, wave front velocity, and dynamics including the impact pressure and associated force. Most dam-break experiments have been conducted on a horizontal bed, in a tank or a flume, while few studies had employed sloped surfaces. However, natural and artificial beaches usually have slopes ranging from 0-degrees to 20-degrees (or more).
In this study, downstream slopes are considered to investigate the influence of slope effects on the kinematic behaviors and associated hydrodynamic loadings due to dam-break waves. The Volume of Fluid method (VOF) code of the OpenFOAM and the Smoothed Particle Hydrodynamics (SPH) code of the DualSPHysics were applied to reproduce the results of physical tests and provide a comparison with the experimental results. First, existing boundary treatment methods in the SPH were studied and compared to a self-developed code in order to select the best performing method by checking the flow behaviors. In the second part of the thesis, experimental investigation of the impact of dam-break induced surges over a horizontal bed against a vertical wall was conducted by analysing the rapidly varying correlation between the wave height and the associated dynamic pressure. In the third part of this study, three different downstream slopes were added in the experimental setup to investigate the beach effects on the kinematics of dam-break flow, including the free surface profiles, wave height, wave front location and its velocity. In the last part, the impact dynamic pressure on the vertical straight wall from the horizontal and sloped cases were captured to investigate the slope effects on the hydrodynamic loading. The impact force integrated from the dynamic pressure was determined with a simplified calculation formula. In addition, the physical experiments were also reproduced by the numerical models of OpenFOAM and DualSPHysics to compare and investigate their accuracy and to analyze the differences between the physical tests and numerical simulations.
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Effects of soil slope on the lateral capacity of piles in cohesionless soilsBarker, Paul D. (Paul David) 12 March 2012 (has links)
Deep foundations, including driven piles, are used to support vertical loads of structures and applied lateral forces. Many pile supported structures, including bridges, are subjected to large lateral loads in the form of wind, wave, seismic, and traffic impact loads. In many practical situations, structures subjected to lateral loading are located near or in excavated and fill slopes or embankments. Full-scale research to examine the effects of soil slope on lateral pile capacity is limited. The purpose of this study is to examine the effects on lateral capacity of piles located in or near cohesionless soil slopes.
A full-scale lateral load testing program was undertaken on pipe piles in a cohesionless soil at Oregon State University. Five piles were tested near a 2H:1V test slope and located between 0D to 8D behind the slope crest, where D is the pile diameter. Two vertical baseline piles and three battered piles were also tested in level ground conditions. The cohesionless backfill soil was a well-graded material with a fines content of less than 10% and a relative compaction of 95%, meeting the Caltrans specification for structural backfill.
Data collected from the instrumented piles was used to back calculate p-y curves, load-displacement curves, reduction factors, and load resistance ratios for each pile. The effects of slope on lateral pile capacity are insignificant at displacements of less than 2.0 inches for piles located 2D and further from the crest. For pile located at 4D or greater from the slope crest, the effect of slope is insignificant on p-y curves. A simplified p-multiplier design procedure derived from back-calculated p-y curves is proposed to account for the effects of soil slope.
Comparisons of the full-scale results were made using proposed recommendations from the available literature. Lateral resistance ratios obtained by computer, centrifuge, and small scale-models tend to be conservative and overestimate the effects of slope on lateral capacities. Standard cohesionless p-y curve methods slightly over predict the soil resistance at very low displacements but significantly under predict the ultimate soil resistance. Available reduction factors from the literature, or p-multipliers, are slightly conservative and compare well with the back-calculated p-y curves from this study. / Graduation date: 2012
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