Uma solução computacional geral e expansível de análise da interação estrutura-maciço de solos foi desenvolvida adotando metodologia orientada a objetos. A técnica computacional apresenta um menu de retaguarda que torna a manipulação dos dados de entrada e os processos computacionais mais criteriosos e seguros. Os materiais possuem comportamento perfeitamente elástico-linear, enquanto o mecanismo de transferência de carga estrutura-solo é não linear. O maciço de solos é modelado através de dados de sondagens SPT e mapeamento geotécnico. A fundação é discretizada verticalmente para se obter as matrizes de flexibilidade da estrutura de fundação (MFEF) e do maciço de solos (MFMS). O processo interativo básico consiste em obter o vetor de recalques nos apoios pelo produto do vetor de cargas verticais com as matrizes MFEF e MFMS. Na seqüência, calcula-se o vetor de redistribuição de cargas pelo produto do vetor de recalques com a matriz de rigidez da superestrutura (MRS). Um procedimento iterativo condiciona a convergência de recalques e cargas verticais nos apoios. A solução foi utilizada para analisar o comportamento de edifícios de diferentes geometrias em planta e espacial, variando o perfil geotécnico do maciço suporte e a técnica de execução da estrutura de fundação. / A general and expansible computational code based in the oriented to object programming technique was developed aiming the soil-structure interaction analysis. This computational technique has a special feature that makes the data input operations and the computer processing safer and more criterious. This model considers that all materials behaves as perfectly linear elastic materials, although the soilstructure transfer mechanism is of non-linear nature. The soil mass compressibility and resistance are modelled from soil data obtained from geotechnical mapping techniques and SPT boreholes data. The flexibility matrix (MFEF) of the structural foundation elements and the flexibility matrix (MFMS) of soil mass elements are obtained through a numerical discretization procedure. The basic interative process consists in the calculation of the supports displacement vectors obtained by the multiplication of the vertical load vector by the MFEF and the MFMS matrix. Finally, the load redistribution is obtained by the multiplication of the displacement vector by the structural rigidity matrix (MRS). The uniqueness of the solution is guaranteed by the convergence of the displacements and vertical supports reactions by using an iterative procedure. This computational code was applied to the analysis of the behaviour of spatial framed buildings with varied geometry, taking into account different geotechnical soil conditions and different types of foundations.

The understanding of the spatial distribution of lead (Pb) in soil is important in the assessment of potential risks and development of remediation strategies for Pb contaminated land. In situ heterogeneity of Pb was measured at two heavily contaminated sites in the United Kingdom using the Portable X-ray Fluorescence Spectrometer (P-XRF) over a range of spatial scales (0.02 to 50 m). The pattern of the distribution of Pb was very variable, and when expressed as heterogeneity factor (HF), it ranged from 1.2 to 3.2 (highly heterogeneous). The effect of such Pb heterogeneity on plant uptake was investigated in greenhouse pot trials. Two earlier pot trials, which assessed the effect of Pb in a fixed concentration (1000 mg/kg) and in a range of concentration (100 to 10000 mg/kg) found a significant effect of the Pb added treatments, when compared to a control treatment (0 mg/kg Pb added). Biomass and uptake varied by 20 to 100% within and between 16 species/varieties. Results enhanced the selection of two species (Brassica napus and Brassica juncea) for further pot trials. A third pot experiment with Brassica napus and Brassica juncea in simplistic binary model of heterogeneity found 20 to 60% lower uptake in the binary treatment, than homogeneous the treatment. Biomass was higher by 10 to 50% in Brassica juncea and 20 to 40% lower for B. napus in the bianary treatment, when compared to the homogeneous and control treatments. The effect of a more realistic in situ heterogeneity on plant uptake was investigated in a further pot trial, which simulated low (LH), medium) (MH) and high (HH) heterogeneity treatments, compared to a homogeneous (HO) treatment. It detected a significant (P < 0.05) impact of heterogeneity on biomass and uptake between treatments and species. Four to five fold lower biomass were recorded in HH treatment, when compared to the HO treatment. Shoot and root uptake in (mg/kg) concentration increased with increasing heterogeneity with peak uptake (twice as high as HO treatment) in LH for B. napus and in HH and MH treatments for B. juncea respectively. Shoot and root Pb masses in (μg) were maximum in HO and MH treatments respectively with 50 to 70% lower Pb mass in the HH treatment. Results showed that response to heterogeneity is species specific. A sub-experiment explored the behaviour of plant roots in HH treatment and found 20 to 80% variation in root biomass between concentric patches with same nominal soil Pb concentrations. This provided insights into varied responses of these species to realistic Pb heterogeneity. The research demonstrated that the presence and extent of in situ heterogeneity of Pb in soil plays an important role in Pb uptake by plants. It also showed that the homogeneous and simplistic binary model of heterogeneity do not give reliable estimates of plant growth and Pb uptake in realistic field conditions. This work has implications for improving the efficiency of phytoremediation of Pb contaminated land, phytomining, reliability of risk assessment and models of human exposure to Pb.

Heterogeneity of contaminants in soils can vary spatially over a range of scales, causing uncertainty in environmental measurements of contaminant concentrations. Sampling designs may aim to reduce the impact of on-site heterogeneity, by using composite sampling, increased sample mass and off-site homogenisation, yet they could overlook the small scale heterogeneity that can have significant implications for plant uptake of contaminants. Moreover, composite sampling and homogenisation may not be relevant to target receptor behaviour, e.g. plants, and studies, using simplistic models of heterogeneity have shown that it can significantly impact plant uptake of contaminants. The alternative approach, to accept and quantify heterogeneity, requires further exploration as contaminant heterogeneity is inevitable within soils and its quantification should enable improved reliability in risk assessment and understanding variability in plant contaminant uptake. This thesis reports the development of a new sampling design, to characterise and quantify contaminant heterogeneity at scales, from 0.02m to 20m, using in situ measurement techniques, and 0.005m to 0.0005m, using ex situ techniques. The design was implemented at two contaminated land sites, with contrasting heterogeneity based upon historic anthropogenic activity and showed heterogeneity varying between contaminants and at different spatial scales, for Pb, Cu and Zn. Secondly, this research demonstrates how contaminant heterogeneity measured in situ can be recreated in a pot experiment, at a scale specific to the plant under study. Results, from 4 different plant species, demonstrated that existing simplistic models of heterogeneity are an inadequate proxy for plant performance and contaminant uptake under field conditions, and significant differences were found in plant contaminant concentrations between simplistic models and those based upon actual site measurements of heterogeneity. Implications of heterogeneity on plant roots were explored in the final experiment showing significant differences in root biomass between patches of differing contaminant concentrations.

Underground structures perform an important role in transportation systems in many seismically active regions around the world, but empirical data regarding the seismic behavior of these structures is limited. This research works towards filling that empirical gap through the use of scale model shake table testing. Underground seismic soil-structure interaction (USSSI) effects were investigated for a stiff rectangular tunnel cross-section embedded within soft clay. San Francisco Young Bay Mud was used as a prototype soil for developing a scale model soil mixture consisting of kaolinite, bentonite, class C fly ash, and water. A single cell Bay Area Rapid Transit (BART) cut-and-cover subway tunnel was used as the prototype for the 10th scale model subway cross-section. A flexible walled test container originally developed for a pile study at UC Berkeley was modified for use at Cal Poly, San Luis Obispo. The flexible container allows for close approximation of one-dimensional (1D) free-field site response by significantly limiting the rigidity of the boundary conditions and allowing the soil to deform under simple shear. The study was conducted over two shake table testing phases: Phase I consisted of shaking a model soil column to evaluate the ability of the test container to produce adequate 1D free-field site response, and Phase II tests explored the horizontal racking distortion of a shallow rectangular tunnel cross-section subjected to strong transverse ground shaking. Phase I test results and comparison with SHAKE models indicate that the test container can sufficiently mimic 1D free-field conditions, specifically for the primary shear deformation mode. Similarly, the equivalent linear soil-structure interaction code FLUSH was found to adequately model site response for the Phase II soil-structure system. Comparison of recorded horizontal racking distortions of the model structure with those from numerical modeling suggest that current simplified design methods may overestimate distortions to some degree for cases similar to those examined in this research. Overall, the flexible wall testing container shows promise as a viable means for gaining further insight into USSSI topics, as well as various other geotechnical and soil-structure interaction problems.

No description available.

Abstract not available

Phytoremediation is an innovative technology employing plants for reclamation of soils that have been polluted by industrial contaminants. While it is frequently slower than traditional physicochemical remediation techniques, there are, however, many significant advantages including simplicity, low cost, improvement of soil structure and microbiological fertility. While various hyperaccumulators have been reported from Europe and the USA, there is a need to identify Australian species. This study reports a number of metal accumulators following a soil and vegetation survey of two metal contaminated sites in New South Wales, the spoil (filtercake) heaps of the BHP (Broken Hill Propriety ) steelworks at Port Kembla and the abandoned mine at Sunny Corner. BHP is the largest manufacturer of steel in Australia. The Port Kembla is the largest single steel manufacturing site. Solid by-products from this site totalled 3.1 million tons in 1988. The Sunny Corner mine site was mainly a silver mine which operated over approximately 100 hectares 1184 to 1922 and produced over 100 tonnes of silver during that period. The soil and water in and around the site is heavily contaminated with metals and is distinctly acidic. It was concluded that Ricinus communis, Sonchus oleraceus, baeckea utilis, Poa labillardieri and Pinus radiata are options for heavy metal phytoremediation of contaminated Australian soils. Arbuscular Mycorrhizal infection (particular with Glomus and Gigaspora strains) should be promoted for optimum growth. / Doctor of Philosophy (PhD)

Bibliography: leaves 105-129.

Comprised of the author's previously published works. Includes bibliographical references.

Comprised of the author's previously published works / Includes bibliographical references / 1 v. (various pagings) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D. Sc.)--University of Adelaide, Dept. of Soil Science, Waite Agricultural Research Institute, 1988?