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The Vertic Clay Flora Of The San Joaquin Desert: Niche, Competition & Floral Mosaics On A Novel Substrate, Emma R. Fryer

Master's Theses

Plant communities that occur on edaphically heterogeneous landscapes are ideal systems for exploring questions of niche and community assembly. Species with affinity for harsh substrates often have well-defined edaphic niches and are ideal models for testing ecological and evolutionary theory. While plants on substrates such as serpentine and gypsum have received much attention, those on other harsh substrates, including on vertic clay soils, have gone unstudied. Vertic clay soils are both chemically and physically challenging to plant establishment and productivity. Plant communities associated with vertic clay soils of the San Joaquin Desert appear to have a distinctive mosaic pattern of …

Geochemical Modeling And Hydrothermal Experiments Used To Constrain The Conditions Of Illite Diagenesis In Sedimentary Basins, Michael Joseph Murphy

Master's Theses

Two hydrothermal experiments were performed using sandstone core material from

the Norwegian North Sea with synthetic brines reacted at approximately 150˚C and 450

bars, temperature and pressure calculated to simulate a depth of burial of approximately 4 km. The results of the experiments were analyzed with geochemical modeling and with

chemical and petrographic analyses. Geochemical modeling with several computer

programs indicated that the experimental fluid was undersaturated with respect to K-feldspar, kaolinite, and illite, but supersaturated with respect to muscovite. Chemical

analysis with inductively-coupled plasma mass spectrometry indicated that the fluid

reached saturation with respect to K-feldspar. Petrographic analysis with …

Scale Model Shake Table Testing Of Shallow Embedded Foundations In Soft Clay, Steven Kuo

Master's Theses

This research involves shake table testing of 1g scale models that mimic the coupled seismic response of a structure on a shallow mat foundation and foundation soil (known as soil-foundation-structural-interaction or SFSI). In previous research, SFSI effects have been quantified through analytical models, numerical analyses, and limited field data. This research works towards increasing the amount of empirical data through scale model shake table testing. A suite of earthquake time histories is considered in evaluating a nominal 10^th scale soil-structure model using a flexible wall barrel on a 1-D shake table. San Francisco Young Bay Mud (YBM) is used …

Rate-Dependent Behavior Of Clay, Harry F. Martindale Iv

Master's Theses

This thesis presents a strain-rate dependent two-surface plasticity constitutive model for clays based on the critical-state soil mechanics. The model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both drained and undrained behaviors at small and large strains. Model parameter values are determined for Boston Blue Clay, London Clay and Kaolin Clay. The performance of the model in simulating the mechanical response of clays is demonstrated for a variety of strain rates. Sensitivity of each model parameter is checked for ±5, ±10 and ±20% of the deterministic values. Probabilistic analysis using Monte Carlo simulations were done …