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Modern building procedures and requirements demand that the selection and stabilisation of soils for the purposes of rammed earth construction be better quantified. This study examines the relationships between soil properties, stabiliser treatments, and stabilised strength and density for 111 soil samples taken from sites in New South Wales (Australia), and develops new quantitative criteria for soil assessment, selection, and stabilisation. Laboratory measurements of soil particle size distribution, plasticity, and shrinkage were made for each soil. Various quantities from 0-6 % of lime, cement, and asphalt were added to the soil samples, and the resulting 230 specimens were compacted, and cured for 28 days. Determinations were made of the optimum moisture content, maximum dry density, and compressive strength of the stabilised material. The samples showed stabilised strengths ranging from 1.0-5.4 MPa, with a mean of 2.62 MPa, and densities from 1.44-2.21 t/m3, with a mean of 1.86 t/m3. The results show that over 90 % of the variation in stabilised strength and density of the samples is due to variation in soil properties, with differences in stabiliser type or stabiliser quantity being relatively minor. The most important soil properties explaining stabilised strength are linear shrinkage and plasticity index. These properties have been used to categorise the soils into three groups on the basis of their suitability for stabilisation as measured against a compressive strength criterion of 2 MPa. Favourable soils have shrinkages of &lt 7.1 % and plasticities of &lt 16 %, and 90 % of these samples passed the 2 MPa criterion. Satisfactory soils have shrinkages of 7.1-13.0 % and plasticities of 16-30 %, and 65 % of these samples had strengths in excess of 2 MPa. Unfavourable soils have shrinkages of &gt 13 % and plasticities of &gt 30 %, and only 10 % of these samples exceeded the 2 MPa value. Soils in the favourable and satisfactory categories can be further discriminated using textural information. On that basis, all soils classified as favourable, and those classified as satisfactory and which also have sand contents &lt 60 %, are recommended as being suitable for stabilisation. Soils not fulfilling these criteria are unlikely to be successfully stabilised and should be rejected. These results stress the importance of selecting a soil favourably predisposed to stabilisation. Field techniques to search for such soils could be refined on the basis of the new soil criteria presented. Use of the criteria should also minimise unnecessary laboratory testing of the density and strength of soils that subsequently prove unsuitable for stabilisation. A flow chart is presented to guide practitioners through the different stages of soil testing, assessment, and rammed earth stabilisation.

A considerable amount of research has focused on load-sharing and system effects in repetitive-member wood floor systems subject to transverse loading. However, relatively few studies have been conducted to investigate load-sharing and system effects in repetitive-member wall systems which may be subject to combined transverse and gravity (vertical) loading, and which may have different boundary conditions from floors. This research investigates load-sharing and system effects in light-frame wood wall systems and seeks to develop repetitive-member system factors for codified design that rationally account for load sharing and other system effects. These factors are intended for use in the design of individual wall members, much as repetitive-member factors are used in the design of parallel-member floor and roof systems. As part of this research, an analytical model was developed to account for partial composite action, two-way action, and openings in the wall system. The model was validated using experimental test results and was shown to be able to predict reasonably well the response of light-frame wall systems. The model was then incorporated into a Monte Carlo simulation to perform reliability analyses of light-frame wall systems. Since the structural model is complex, and including a time-history analysis within the time-dependent simulation was not computationally practical, the load combination issue was considered separately from the reliability analysis. Sensitivity studies were conducted to investigate how different system parameters affect strength and reliability of light-frame wall systems. The reliability of light-frame wall systems was next evaluated using a portfolio of representative light-frame wall systems designed according to current code provisions. This portfolio approach was also used in evaluating system factors for light-frame wall systems. Thus, two different approaches (a reliability-based approach and a strength-ratio approach) were considered for developing system factors for member-design to account for load sharing, partial composite action and other system effects. Using the strength-ratio approach, a new framework for system factors (i.e., partial system factors) is suggested in which the effects of partial composite action, load sharing, load redistribution and system size (number of members) are treated separately. / Graduation date: 2003

"November 2004" / Bibliography: p.167-179. / xi, 333 p. : ill., photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Focuses on behavioural models of masonry walls with a view to improving their accuracy and extending their application. Results include a numerical model and mathematical expressions capable of predicting the key stages of the non-linear load-deflection behaviour of walls subjected to vertical bending and axial loading; new mathematical expressions for horizontal and diagonal bending moment capacities that are dimensionally consistent and account for the beneficial effects of compressive stress; and. Experimental test data for masonry sections subjected to horizontal and diagonal bending, which were used in the development and verification of the new mathematical expressions. / Thesis (Ph.D.)--University of Adelaide, School of Civil and Environmental Engineering, 2004

Performance-based design has gained interest in recent years among structural designers and researchers. Performance-based design includes selection of appropriate building sites, structural systems and configurations, as well as analytical procedures used in the design process, to confirm that the structure has adequate strength, stiffness and energy dissipation capacity to respond to the design loads without exceeding permissible damage states. Although performance-based seismic design has advanced for some materials and structural types, such as steel and reinforced concrete buildings and bridges, its application to light-frame structures remains largely unexplored. The objective of this research was to explore the potential for the application of performance-based engineering concepts to the design and assessment of woodframe structures subject to earthquakes. Nonlinear dynamic time-history analysis was used to predict the performance of shearwalls considering a suite of scaled characteristic ordinary ground motions to represent the seismic hazard. Sensitivity studies were performed to investigate the relative effects of damping, sheathing properties, fastener type and spacing, panel layout, and other properties on the performance of wood shearwalls. In addition, the effects of uncertainty in ground motions and variability in sheathing-to-framing connection hysteretic parameters were investigated. Issues such as the contribution of nonstructural finish materials, different seismic hazard regions, and construction quality also were investigated and modification factors to adjust peak displacement distributions were developed. The peak displacement distributions were then used to construct performance curves and design charts as a function of seismic weights for two baseline walls. Finally, fragility curves were developed for the baseline walls considering different nailing schedules, corresponding allowable seismic weights, and various overstrength (R) factors. / Graduation date: 2004

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"November 2004" / Bibliography: p.167-179. / xi, 333 p. : ill., photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Focuses on behavioural models of masonry walls with a view to improving their accuracy and extending their application. Results include a numerical model and mathematical expressions capable of predicting the key stages of the non-linear load-deflection behaviour of walls subjected to vertical bending and axial loading; new mathematical expressions for horizontal and diagonal bending moment capacities that are dimensionally consistent and account for the beneficial effects of compressive stress; and. Experimental test data for masonry sections subjected to horizontal and diagonal bending, which were used in the development and verification of the new mathematical expressions. / Thesis (Ph.D.)--University of Adelaide, School of Civil and Environmental Engineering, 2004

Thesis (MScEng)--Stellenbosch University, 2013. / Durability and impermeability in a water-retaining structure are of prime importance if the structure is to fulfill its function over its design life. In addition, serviceability cracking tends to govern the design of water retaining structures. This research concentrates on load-induced cracking specifically that due to pure bending and to direct tension in South African reinforced concrete water retaining structures (WRS). As a South African design code for WRS does not exist at present, South African designers tend to use the British codes in the design of reinforced concrete water-retaining structures. However, with the release of the Eurocodes, the British codes have been withdrawn, creating the need for a South African code of practice for water-retaining structures. In updating the South African structural design codes, there is a move towards adopting the Eurocodes so that the South African design codes are compatible with their Eurocode counterparts. The Eurocode crack model to EN1992 (2004) was examined and compared to the corresponding British standard, BS8007 (1989). A reliability study was undertaken as the performance of the EN1992 crack model applied to South African conditions is not known. The issues of the influence of the crack width limit and model uncertainty were identified as being of importance in the reliability crack model.

Soil nail walls are a form of mechanical earth stabilization for cut situations. They consist of the introduction of passive inclusions (nails) into soil cut lifts. These nailed lifts are then tied together with a structural facing (usually shotcrete) . The wall lifts are constructed incrementally from the top of cut down. Soil nail walls are being recognized as having potential for large cost savings over other alternatives. The increasing need to provide high capacity roadways in restricted rights of way under structures such as bridges will require increasing use of techniques such as combined soil nail and piling walls. The Swift Delta Soil Nail wall required installing nails between some of the existing pipe piling on the Oregon Slough Bridge. This raised questions of whether the piling would undergo internal stress changes due to the nail wall construction. Thus, it was considered necessary to understand the soil nail wall structure interaction in relation to the existing pile supported abutment. The purpose of this study was to investigate the Swift Delta Wall using finite element (FE) modeling techniques. Valuable data were available from the instrumentation of the swift Delta Wall. These data were compared with the results of the FE modeling. This study attempts to answer the following two questions: 1. Is there potential for the introduction of new bending stresses to the existing piling? 2. Is the soil nail wall system influenced by the presence of the piling? A general purpose FE code called ABAQUS was used to perform both linear and non-linear analyses. The analyses showed that the piling definitely underwent some stress changes. In addition they also indicated that piling influence resulted in lower nail stresses. Comparison of measured data to predicted behavior showed good agreement in wall face deflection but inconsistent agreement in nail stresses. This demonstrated the difficulty of modeling a soil nail due to the many variables resulting from nail installation.