This project report presents a laboratory investigation of the dynamic behavior of saturated alluvial silty soils from sites in Oregon and Washington. The focus of the study was to document the liquefaction susceptibility, post cyclic strength, and volumetric strain behavior of the silt soils based on cyclic, undrained triaxial compression testing. A cyclic triaxial testing apparatus with computer control and data acquisition was assembled, calibrated, and used to perform undrained cyclic triaxial testing and post cyclic testing on undisturbed and reconstituted specimens. The results of this investigation are compared with the undrained cyclic triaxial testing data on silty soils published by others. The influence, of grain-size distribution, plasticity index, and overconsolidation ratio (OCR) on the dynamic behavior was identified. Several cyclic resistance curves were prepared that show the cyclic resistance for the silts for OCR values of 1 to 2.5. The cyclic resistance curves observed in the laboratory likely overestimate the in-situ cyclic resistance of the material due to sample disturbance during sampling, transport, and testing. It was observed that OCR has a significant influence on the cyclic resistance of silt soils. Cyclic resistance was observed to increase with increasing plasticity and percent passing the U.S. Standard Number 200 Sieve and percent finer than 2 ��m. It was observed that excess pore pressure measurements recorded at the transducer for fine-grained soils subjected to rapid loading may not accurately represent the actual pore pressures of the soil. Therefore, it is proposed that strain criteria be used, rather than excess pore pressure generation, to define initial liquefaction for fine-grained soils. Post cyclic undrained strength test data shows that the silts are dilative under compressive loading in the triaxial apparatus. Peak strengths were not observed due to the dilative nature of the silty soil tested. Therefore, post cyclic undrained strengths were strain based. The strain based strengths were compared with relationships developed by Baziar and Dobry (1995) and Ishihara (1993) and were found to have a higher residual strength than the sandy soils. Unusually high S[subscript u]/p' ratios were also recorded for the silt soils. This observation highlights the need to obtain post-cyclic strength at a consistent strain. The post cyclic volumetric strain data was compared with the findings of Ishihara and Yoshimine (1992). Plots of volumetric strain versus maximum axial strain were created. These plots were then used to establish a relationship between post cyclic volumetric strain and the factor of safety against liquefaction. The volumetric strain behavior of the silt was observed to be very similar to sand at relative densities of 40 to 80 percent. / Graduation date: 2003

This study collected relevant data of construction sites between January 1990 and December 2011 to estimate the emission factors of various construction projects for Kaohsiung City using Jhang¡¦s equations. The emission factors of various construction projects are as follows: about 0.121 kg/m2/month for reinforced concrete construction, about 0.141 kg/m2/month for steel constructed buildings, 0.228 kg/m2/month for road (tunnel) works, 0.126 kg/m2/month for bridge works, 0.101 tons/ha/month for regional construction projects, and 0.223 kg/m2/month for others. Based on these emission factors, the total fugitive dust emissions for 2,011 construction projects is estimated to be about 22,087.98 tons, and the exposure of per unit area to the fugitive dust pollution is approximately 11.98 ton/km2/month. The total fugitive dust emissions of 2,011 construction projects is estimated about 10528.14 tons (based on Kaohsiung City construction information database). According to the Department of Land, Kaohsiung City Government, Kaohsiung city is 27.8 kilometers from south to north, 10.4 kilometers from west to east, and the administrative area is 153.6029 square kilometers. The exposure of per unit area to the fugitive dust pollution is about 5.71 ton/km2/months.

Doctor of Philosophy / Suction caissons have been used in the offshore industry in the last two decades as both temporary mooring anchorages and permanent foundation systems. Although there have been more than 500 suction caissons installed in various locations around the world,understanding of this concept is still limited. This thesis investigates the installation aspect of suction caissons, focusing on the installation in dense sand and layered soils, where sand is inter-bedded by silt and weakly cemented layers. The research was mainly experimental, at both normal gravity and elevated acceleration levels in a geotechnical centrifuge, with some numerical simulations to complement the experimental observations. This study firstly explored the suction caisson installation response in the laboratory at 1g. The influence and effect of different design parameters, which include caisson size and wall thickness, and operational parameters including pumping rate and the use of surcharge were investigated in dense silica sand. The sand heave inside the caisson formed during these installations was also recorded and compared between tests. The 1g study also investigated the possibility of installing suction caissons in layered sand-silt soil, where caissons were installed by both slow and rapid pumping. The heave formation in this case is also discussed. The mechanism of heave formation in dense sand and deformation of the silt layer was further investigated using a half-caisson model and the particle image velocimetry (PIV) technique. The installation response at prototype soil stress conditions was then investigated in a geotechnical centrifuge. The effects of caisson size, wall thickness, as well as surcharge were investigated in various types of sand, including silica sand, calcareous sand dredged from the North Rankin site in the North West Shelf (Australia), and mixed soil where silica sand was mixed with different contents of silica flour. Comparison with the 1g results was also made. The general trend for the suction pressure during installation in homogenous sand was identified. The installation in layered soil was also investigated in the centrifuge. The installation tests were performed in various sand-silt profiles, where the silt layers were on the surface and embedded within the sand. Comparison with the results in homogenous sand was made to explore the influence of the silt layer. Installations in calcareous sand with cemented layers were also conducted. The penetration mechanism through the cemented layer is discussed, and also compared with the penetration mechanism through the silt layer. Finite element modelling was performed to simulate key installation behaviour. In particular, it was applied to simulate the sand deformation observed in the PIV tests. The likely loosening range of the internal sand plug during suction installation in silica sand was estimated. By investigating the development of hydraulic gradient along the inner wall, the principle underlying the suction response for different combinations of selfweight and wall thickness was identified. FE modelling was also performed to explore the influence of the hydraulic blockage by the silt layer. This study found that the caissons could penetrate into all soils by suction installation. Among the key findings are the observations that the suction pressure increases with depth following a distinct pressure slope, corresponding to a critical hydraulic condition along the inner wall; and the installation was possible in both layered sand-silt and uncemented-cemented soils if sufficient pumping was available. While the caisson could penetrate the weakly cemented layers well with no notable adverse effects, problems were observed in the installation in layered sand-silt soil. These include piping failure in slow pumping rate installation at 1g, and the formation of extremely unstable soil heave during installation.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2008. / Includes bibliographical references (p. 67-71).

Thesis (Ph. D.)--Carleton University, 1996. / Also available in electronic format on the Internet.

Thesis (M.S.)--Naval Postgraduate School, Monterey, 1971. / Includes bibliographical references (leaf 78).

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 24, 2007) Vita. Includes bibliographical references.

A consequence of stirring sea bottoms within construction sites is that suspended particles are being released. Pollutants such as heavy metals are often bonded to suspended particles which can spread over long distances. Analyzing the levels of particles in the water can either be made in a laboratory, or by measuring turbidity. Turbidity is a measure of the water’s ability to diffuse light and is used to determine the content of suspended material. This thesis is made in collaboration with AFRY who is preforming water sampling during a construction of a new quay area in Kallholmsfjärden, Skellefteå. The purpose of this study has been to investigate if, and how, suspended substances are being spread during water-based constructions that causes stirring of the sea bottom. The study was carried out by analyzing data sampled from Kallholmsfjärden. In summary, the result indicate that water-based constructions may result in suspended substances being spread into the water. Suspended material is correlating with turbidity, which means that turbidity can be used as an indicator for suspended materials. The kind of operation preformed during construction, affects the turbidity and dredging leads to higher particle scattering than padding. The result underlines the importance of taking preventive measures that reduce particle scattering, and one way of doing that is by using silt curtains. According to the result, silt curtains fulfill its purpose by preventing particle scattering. Finally, there is no difference in suspended material between dissimilar depths. The result of this theses is relevant when planning similar projects.

Topics in geology, which inevitably excite professional discussion and even tempered debate, often present challenging targets for the exploratory jabs of Master's degree candidates. The Portland Hills Silt and the controversy concerning its genesis provides just such an object. Although the physical descriptions of the silt are generally in agreement, they remain somewhat generalized and, at present, no single definition is generally accepted. Moreover, incongruities concerning structural and textural details--notably, the presence of minor stratification and/or scattered pebbles in the silt--have resulted in considerable disagreement regarding its mode of origin.