A literature survey on rock anchor design revealed that current rock anchor design methods are empirical and conservative in nature. The stability of a rock anchor depends on the assumed yield surface which has been found to be difficult to predict. A simple conical yield surface is currently adopted in practice. In this approach important rock parameters such as shear stress on the surface of the cone are usually ignored. Although both theoretical and experimental evidence are available to indicate that bond distribution along the fixed anchor length is highly non-linear at the tendon/grout/rock interfaces, current design still assumed the bond to be uniformly distributed along the whole fixed anchor length. Anchor interactions group effects, debonding at the proximal end of the anchor, the effect of tendon spacing and spacers, the effect of lateral pressure on the fixed anchor are not considered in current rock anchor design. To provide a more fundamental understanding of rock anchor behaviour a simple isoparametric finite element program has been written and thoroughly tested. The initial stress method with associated flow rules was used to simulate rock anchor behaviour. The plastic potentials used for simulating the tendon and, the grout and the rock, were respectively the Von-Mises and the octahedral shear stress yield criteria. Double nodes at interfaces provided a method of simulating a perfectly smooth interface without having to resort to special interface elements. The stress strain distribution pattern in the fixed anchor zone has been obtained for a modular ratio of 2.1, The results produced have indicated, that, in addition to physical material parameters, anchor behaviour is also dependent on the applied load, the slenderness ratio and the fixed anchor diameter. The most severe position of shearing has been found to be at the grout/rock interface. Analyses show that partial debonding is not a serious problem. Surcharge tends to reduce the shear stress at the grout/rock interface however the effect is negligible. A design curve is proposed for consideration.

Reinforced concrete deep beams have useful applications in construction. However, their design is not yet covered by the British Standard BS 8110: 1985 which explicitly states that "for the design of deep beams, reference should be made to specialist literature". A selection of literature on deep beams is considered. First, the major works that have led to design recommendations are reviewed. Then, the current major codes and manuals covering deep beams, namely the CIRIA Guide, the European CEB-FIP model code, the American ACI(318-83) (revised 1986) code and the Canadian CAN3-A22.3-MB4 code are outlined; worked examples are given in order to illustrate their practical applications and compare their different approaches to deep beam design. The purpose of this literature review was to define the deep beam problem and identify the major questions still remaining unanswered together with the limitations of the present design documents on the subject. The nature of diagonal cracking in slender deep beams has recently raised a question as to the application of the shear-strength equation in cl.3.4.2 of the CIRIA Deep Beam Guide. The effectiveness of web reinforcement on serviceability and strength of deep beams in general is also an area where strong disagreement exists. A testing programme, consisting of 15 beams of height/thickness ratios ranging from 20 to 50 and grouped in 3 different series, was performed to provide information on these two areas. The main variables were the height/thickness ratio and the quantity and arrangement of web steel. The beams were tested under concentrically applied two point-loads. Based on the test results and observations, modifications are given for the CIRIA equation and other formulae derived from stocky deep beam tests to be used in slender ones for analysis and design purposes. A new formula is also proposed for the prediction of the ultimate shear capacity. The stability of deep beams is another area which has received less attention in the past by researchers and designers who often avoided the problem by opting for stocky sections. To quote from the CIRIA Guide "as a possible criterion of failure, buckling can not be disregarded". However, information on such topic is very scarce in the literature. Currently, the only documents that provide design guidelines for buckling are the CIRIA Guide and the Portland Cement Association Design Aid, both of which are based on theoretical studies and engineering judgement. An experimental testing programme, consisting of 7 large scale beam-panels with height/thickness ratios in the range of 20 to 70 and a constant span/depth ratio of 1.0, provided buckling data against which the reliability of the two design documents was assessed. These tests confirmed that both documents offer a safe buckling design with the CIRIA Guide being too conservative. Although deep beams are frequently continuous over several spans, very little published data exist for such beams. For this purpose, 12 two-span continuous concrete deep beams with span/depth ratios less than 1.0 and having different quantities and arrangements of web reinforcement were tested under two point-loads. The specimens were heavily instrumented to obtain as much information as possible about the behaviour of the beams at each stage of loading. Applied loads and reactions were among the measurements made and enabled the actual bending moment distribution to be determined and compared to that of corresponding continuous shallow beams. Based on the test results and observations and in the light of other published work, recommendations are given for the bearing, shear and flexural design of continuous deep beams.

In recent years the use of masonry as a structural material has increased in advance of the necessary theoretical and corroborative experimental investigations. One aspect of structural masonry where particular problems have been encountered is the design of masonry panels subjected to lateral loadings. Research undertaken, principally in the United Kingdom and Australia, has led to the development of empirical methods of analysis applicable to solid rectangular panels. However, the effects of the presence of openings on the behaviour of a masonry panel has received scant attention. The aim of the research is to rectify this situation. The principal objective of the research is to put the design of this form of panel subjected to lateral load, on a more rational footing. To do this it has been necessary to investigate the behaviour of masonry panels with openings. The research can be divided in four stages. Firstly, an extensive literature survey has raised questions concerning the suitability of the current British Standard Code of Practice ,BS5628, and other design methods such as elastic plate theory, and empirical strip method, for the design of laterally load masonry panels. Secondly, a non-linear finite element analysis has been developed. The analysis is capable of analysing panels under lateral loading up to and beyond the peak load. The results obtained using the computer program were initially validated with the existing results from two previous laboratory investigations [1,2]. Initial analysis of the results from the experimental and theoretical studies highlighted areas where further investigation was required. In conjunction with the development of the computer program, the investigation involved the laboratory testing of 18 full scale panels. One of the major problems encountered was the determination of material parameters. In this work wallettes have been used to obtain flexural strength values, however the strength of the specimen is influenced by the size of specimens and the number of bed and perpend joints [3,4]. In order to clarify the position, a computer based statistics analysis similar to that reported by Lawrence [4], was employed to investigate the format of the specimens. Estimations of the single joint strengths from the wallette results were obtained from the analysis. Single joint strengths obtained from the statistics analysis were then used in the finite element analysis and comparisons with the experimental load-displacement relationships and the failure patterns made. A Monte-Carlo simulation of the finite element analysis was also carried out to investigate the effect of material variability on the failure strength of masonry panels. Good correlation has been obtained. Lastly, parameter studies using the finite element analysis and the experimental results have indicated that yield line method consistently over estimates the failure strength of masonry panels. However, the reduction of strength due to the inclusion of openings predicted by yield line is in a reasonable good agreement with the experimental results obtained. A simple formula for the design of laterally load

Maps in pocket.

M.A. / The purpose of this study is to examine structural unemployment in the post apartheid South Africa and propose possible policy options to reduce structural unemployment in the new South Africa. In coming to some possible solutions, it is necessary to consider the South African labour market before and after the elections in 1994 when the Apartheid struggle was ended in a formal and legitimate manner. It is also necessary to research the dilemma of structural unemployment in South Africa and search for possible solutions to the problem by looking at current government policy and other views from the different stakeholders in the economy. It is only through this process that one can start coming to some kind of conclusion as to possible measures to reduce structural unemployment in the post-Apartheid South Africa. This study should by no means be considered as the answer to the problem of unemployment in South Africa, but only acts as an introductory study into the problem of rising structural unemployment in the country.

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A Dissertation Submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in Fulfilment of the Requirements of the Degree of Doctor of Philosophy. / The Gariep Belt is an arcuate north-south trending tectonic unit extending ;along the western coast of southern Namibia and northwestern South Africa. It forms part of the Pan-African Damara Oragert, which consists of a north-south trending coastal branch (Kaoko and Gariep Belts) and an east-west trending inland branch. The Gariep Belt is subdivided into an eastern parautochthonous passive continental margin on the western edge of the Kalahari Craton, the Port Nolloth Zone, and a western allochthonous ophiolitic terrane, the Marmora Superterrane, thrusted on the Port Nolloth Zone. The sedimentary evolution of the Gariep Belt was initiated with the deposition of sediments of the Rosh Pinah Formation into fluvial, alluvial and lacustrine depositional systems, which are associated with bimodal volcanic activity and related Zn-Pb-Cu-Ag- (+Ba) sulphide mineralization. The overlying mixed continental/shallow marine deposits of the Gumchavib Formation are overlain by the carbonate dominated Pickelhaube Formation, which was deposited in shallow marine to pelagic depositional settings. The Rosh Pinah, Gumchavib and lower Pickelhaube Formations are intruded by basic volcanic sills of the "Gannakouriep dyke swarm", The conformably overlying Obib Peak Formation was deposited into a fluvial/alluvial palaeoenvlronrnent, The Numees Formation unconformably overlies the underlying stratigraphic units and consists predominantly of glaciomarine massive diamictites and occasionally interbedded iron formations, which are occasionally interbedded with interglacial sediments and volcanics. The regional structural pattern is characterized by three phases of deformation. The earliest deformational event, D1, comprises intrafolial small scale recumbent and isoclinal F1 folds, a penetratlve beddlnq-subparatel 81 cleavage and a preferred elongation of boulders, pebbles, grains and minerals (11). Associated with D1 are bedding-subparallel thrust faults. The D2 deformational phase is characterized by small to large scale, north to northwest trending F2 folds with a generally easterly vergence, which can change into a westerly direction due to backfolding. The F2 folds are associated with a penetrative axial planar S2 cleavage. Thrusting continued during the D2 deformational phase. The latest deformational event, D3, is characterized by small to large scale open F3 folds with southerly to south-westerly trending fold axes. The metamorphic evolution of the Gariep Belt during the Damara Orogeny was associated with barrovtan-type metamorphism with a geothermal gradient of about 20oC/km, reaching greenschist to lower amphibolite facies metamorphism. The sedimentological and structural features are explained in a tectono-sedimentery model, which started with rift initiation during the deposition of Rosh Plnah Formation lithologies along old tectonic weakness zones of Middle Proterozoic age at about 780Ma. Supercontinenta! breakup is documented by the initial transgression of Gumchavib Formation sediments and the continuous trensgression of the Pickelhaube Formation, which is related to thermal subsidence after the initiation of oceanic spreading of the Adamastor Ocean. Renewed rifting and/or glacial outwash heralding' the advance of the Numees glaciation and associated seale': :'changes may be responsible for the sudden break in marine sedimentation during the deposition of the Ohio Peak Formation. The Numees glaciation is probably contemporaneous with the 670Ma old Varangian glacial and the Rapitan glacial episodes and provides a minimum age for the deposition of Gariep Group lithologies. Rifting and spreading was followed by the closure of the Adamastor Ocean, associated with. a southeastward directed subduction. of oceanic crust under the Kalahari Craton and was accompanied by intense southeastward and subsequently eastward directed tectonic transport during 01 and D2. During D3, a late Sinistral movement developed along tre defined fault zones in the late stages of the Adamastor Orogeny.Metamorphic ages from the Nama and Vanrhynsdorp Groups indicate that that the tectonic evolution of the Gariep Belt only ceased at about 500Ma. / Andrew Chakane 2018

A Thesis Submitted to the Faculty of Engineering University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy Johannesburg 1981 / This thesis describes the development of an alternative aooroximate technicue for the elasto—plastic analysis c^ unbraced and partially-braced rigid rrames. The proposed technigue, which allows for the treatment o_ simple portal frames as well as for multi-storey and multibay structures, is not confined to steel to which it has been applied in this research but could also be developed for other materials such as reinforced concrete. In essence, the method represents a refinement and extension of the Merchant-Rankine interaction formula. The proposed concept makes use of a multi-curve interaction principle placing the failure load of the actual frame oetween its plastic collapse load on the one hand and a load related to the elastic buckling load on the other hand. The failure curves in the inelastic range are empirical. The plastic collapse load is obtained using the standard first-order approach. The required elastic parameters are evaluated from an elastic buckling analysis and a second-order elastic load analysis, both performed on suitable subassemblages for the general frame. The mathematical derivations are based on the slope-deflection equations including stability functions. For the elastic analyses a purpose-made computer program has been developed. This program makes allowance for transverse column loads, patterned beam loadings and the special case of sway buckling including bending, termed "Symmetry-Buckling". In this thesis the proposed method has been applied to the structure as a whole. In this case the plastic collapse load of the entire frame is determined, whereas the corresponding elastic parameters are evaluated from as many subassemblages as are contained in the structure. The combination of plastic collapse load and elastic parameters which gives the lowest failure load is significant . It is also possible to calculate failure loads for individual sections of a framework. The plastic collapse load and the salient elastic parameters would then both be examined on matching subassemblages. Furthermore, it has been demonstrated that a graphical presentation of the elastic results is possible, thus allowing a "manual" evaluation of the failure load, i.e. without the need of a computer, once the plastic collapse load is known. The derivation of the plastic collapse load is not included in the scope of this thesis. In addition, an approximate analytical procedure, using established computer methods, has been formulated for the calculation of the elastic values. A number of frames have been evaluated by the proposed method and the results have been compared both, to the Merchant-Rankine solutions and to mathematical solutions obtained using an elasto-plastic, computer analysis. The accuracy of the new method has also been tested against published laboratory results of other researchers. In addition, ten small-scale model frames were analysed and tested for this research to confirm the validity ot the empirically evolved interaction curves. It has been concluded that the proposed method is in good agreement with test results anc discrete mathematical solutions, and thus represents a satisfactory substitute for the more complex approaches, without the loss in accuracy and the restriction in usage which applies to the Merchant-Rankine formula. Some other related aspects such as the application of the proposed method to other materials and structures, deflections at the working load level, in-plane member instability, lateral torsional buckling and additional P - A effects have been identified as areas recommended for future research.

Thesis advisor: Zhijie Xiao / This dissertation contains three chapters in theoretical Macroeconometrics and applied Macroeconometrics. This first chapter addresses the issues related to the estimation, testing and computation of ordered structural breaks in multivariate linear regressions. Unlike common breaks, ordered structural breaks are those breaks that are related across equations but not necessarily occurring at the same dates. A likelihood ratio test assuming normal errors is proposed in this chapter in order to detect the ordered structural breaks in multivariate linear regressions. The estimation of ordered structural breaks uses quasi-maximum likelihood and adopts the efficient algorithm of Bai and Perron (2003). I also provide results about the consistency and rate of convergence when searching for ordered structural breaks. Finally, these methods are applied to one empirical example: the mean growth rate of output in three European countries and United States. This second chapter focuses on the parameter stability of dynamic stochastic general equilibrium (DSGE) models. To this end, I solve and estimate a representative New Keynesian model using both linear and nonlinear methods. I first examine how nonlinearities affect the parameter stability of the New Keynesian model. The results show that parameter instabilities still exist even using nonlinear solutions, and also highlight differences between two nonlinear solution methods: perturbation method and projection method. In addition, I propose a sequential procedure for searching for multiple structural breaks in nonlinear models, and apply it to the New Keynesian model. Two common structural breaks among these estimated parameters are identified for all the five solutions considered in this chapter. One structural break is in the early 1970s, while another one locates around the middle 1990s. In the third chapter, we investigate changes in long run productivity growth in the United States. In particular, we approach productivity growth from a sectoral perspective, and decompose the whole economy into two broad sectors: investment goods-producing sector and consumption goods-producing sector. Although the evidence of changes in the aggregate productivity growth is far from obvious at conventional test size, we find evidence of structural breaks in the sectoral productivity growth using both growth accounting and DSGE model based measures. There are two structural breaks in investment goods-producing sector using growth accounting measures, which indicates that the era of investment and productivity boom in the middle 1990s may have ended before the Great Recession. In addition, our results show there is one structural break in consumption goods-producing sector around the 1970s and attribute the aggregate productivity slowdown at that time to consumption goods-producing sector. These results are broadly consistent with Ireland and Schuh (2008). Our results offer up with a modestly pessimistic outlook on future productivity growth and, therefore, potential output. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

The complete analysis of problems of solid mechanics must include the nonlinear effects of large deformations, inelastic material behaviour and changing boundary conditions. The finite element analysis of such problems using continuum finite elements is well established. However, the analysis of such problems using structural finite elements such as beams, plates and shells is still subject to restrictions which do not apply to continuum elements. The removal of these restrictions is important because (i) structural finite elements are widely used in current engineering practice (ii) the reduced number of variables associated with these elements leads to greater computational efficiency. The work carried out and reported in this thesis addresses the following areas of finite element analysis; the geometrically nonlinear analysis of two- and three-dimensional beams subject to arbitrarily large displacements and rotations; the elasto-plastic analysis of two- and three-dimensional beams using both multi-fibre and stress resultant approaches; the nonlinear analysis of two-dimensional reinforced concrete beams; the elasto-plastic analysis of shells using both the multi-layer and stress resultant approaches. A wide range of two- and three-dimensional problems have been analysed and the results reported. These problems cover a large number of two-dimensional beam, frame and arch problems including geometric and material nonlinearity. Results are compared with simple beam theory, other analytical solutions such as elliptic integrals, other finite element results and experimentation. Other problems analysed are three-dimensional beams with geometric and material nonlinearity, imperfect steel plates subject to large deformation elasto-plastic behaviour and two sample shell problems of practical application.