76 research outputs found
Doctor of Philosophy
dissertationThis paper proposes a probabilistic-based method to produce liquefaction-induced ground failure maps so that hazard levels can be assessed for a large area, such as a county, township, or quadrangle. The method focuses on using probabilistic approaches to map estimates of liquefaction-induced lateral spread displacement, and defining the uncertainty associated with the displacement estimates. The proposed mapping method uses a newly developed empirical model for estimating quantities of lateral spread displacement, current probabilistic liquefaction triggering analyses, probabilistic strong ground motion estimates, surficial geologic maps, digital elevation models, and geotechnical data compiled into a spatial database. The proposed method accounts for variations in soil conditions, age, topography, spatial distribution, and major sources of uncertainty. Such major uncertainties include variability over space, lack of or poor quality data, and limitations of the empirical models to estimate liquefaction phenomena. The proposed mapping method accounts for these uncertainties by Monte Carlo random sampling. Soil type and thickness are important factors in estimating horizontal displacement from lateral spread. Thus, this paper presents a new empirical model for estimating the amount of lateral spread displacement based on these factors, along with other factors such as earthquake magnitude, distance to the seismic source, and topography. In addition, the paper discusses how cone penetration test (CPT) data can be used in conjunction with the proposed empirical model to estimate the amount of lateral spread displacement. To test its suitability and provide an example, the proposed mapping method is implemented to produce probabilistic liquefaction triggering and lateral spread displacement maps for a study area in Weber County, Utah. The new maps indicate substantial risk for liquefaction-induced ground failure in the study area during largemagnitude seismic events. This is because the study area is filled with potentially liquefiable sediments, nearly all subsurface explorations encountered shallow groundwater, and the study area is near the seismically active Wasatch fault zone. Large uncertainties in the mapped estimates leads to producing maps for 16th, 50th, and 84th percentile probabilities-enabling estimation of a distribution of probabilities
Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier flight test configuration to determine separation characteristics utilizing 0.0125-scale models (48-0/AX1318I-1) in the LTV 4 x 4 foot high speed wind tunnel (CA26), volume 5
For abstract, see Vol. 1
Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier vehicle configuration to establish a free-stream data base for ALT separation investigations, utilizing a 0.0125-scale model (48-0/AX1318I-1) in the ARC 14-foot wind tunnel (CA23A)
Force and moment data are presented which were obtained for each vehicle separately at a Mach number of 0.6, and for the mated orbiter/747 configuration at Mach numbers of 0.3, 0.5, 0.6, and 0.7. Orbiter angles of attack from 0 degrees to +12 degrees and 747/Carrier angles of attack from -3 degrees to +7 degrees were investigated at angles of sideslip of 0 degrees and -5 degrees. Model variables include orbiter elevon and rudder deflections, orbiter tail cone-on and off, various orbiter/747 attach structure configurations, 747 stabilizer and rudder deflections, and 747 CAM modification components-on and off. Photographs of test configurations are included
Airloads investigation of an 0.030 scale model of the space shuttle vehicle 140A/B launch configuration (model 47-OTS) in the ARC 11-foot Unitary Plan Wind Tunnel for Mach range 0.6 to 1.4 (IA14A), volume 7
Pressure data are presented in tabular form on the left and right vertical tail surface of the space shuttle launch vehicle configuration model. For Vol. 3, see N75-23657
Airloads investigation of an 0.030 scale model of the space shuttle vehicle 140A/B orbiter configuration (model 47-0) in the 11-foot unitary plan wind tunnel for Mach 0.6 and 0.9 (0A22A)
For abstract, see N75-23647
Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier flight test configuration to determine separation characteristics utilizing 0.0125-scale models (48-0/AX1318I-1) in the LTV 4 x 4 foot high speed wind tunnel (CA26), volume 1
Results of tests conducted on a 0.0125-scale model of the Space Shuttle Orbiter and a 0.0125-scale model of the 747 CAM configuration in a 4 x 4-foot High Speed Wind Tunnel were presented. Force and moment data were obtained for each vehicle separately at a Mach number of 0.6 and for each vehicle in proximity to the other at Mach numbers of 0.3, 0.5, 0.6 and 0.7. The proximity effects of each vehicle on the other at separation distances (from the mated configuration) ranging from 1.5 feet to 75 feet were presented; 747 Carrier angles of attack from 0 deg to 6 deg and angles of sideslip of 0 deg and -5 deg were tested. Model variables included orbiter elevon, aileron and body flap deflections, orbiter tailcone on and off, and 747 stabilizer and rudder deflections
Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier flight test configuration to determine separation characteristics utilizing 0.0125-scale models (48-0/AX1318I-1) in the LTV 4 x 4 foot high speed wind tunnel (CA26), volume 4
For abstract, see Vol. 1
Results of the Low Speed Aeroelastic Buffet Test with a 0.046-scale Model (747-ax1322-d-3/orbiter 8-0) of the 747 Cam/orbiter in the University of Washington Wind Tunnel (CS 3)
A series of wind tunnel studies designed to assess the potential buffet problems resulting from orbiter wake characteristics with its tailcone removed are presented to provide design loads and acceleration environments, and to develop data on buffet sensitivity to various aerodynamic configurations and flight parameters. Data are intended to support subsequent analyses of structural fatigue life, crew efficiency, and equipment vibrations
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