One of the most common retaining systems for deep excavations is by supporting a wall with multiple levels of anchors. In densely built urban areas, preventing soil movement with such a system can be very costly. Additionally, anchored walls are assumed and forced to act independently during design calculations, thus fail to take the advantage of the rigidity of the whole system at the corners of the excavation area. An alternative support system that uses the entire system is bracing of the walls with struts. But such a system greatly hinders construction space. In this research, a new type of supporting system has been investigated by performing a parametric study in finite element analyses program. New system is a single ring at each support level, supporting the system at several locations. A comparative study has been undertaken between the conventional systems and the new system in both 2D and 3D. PLAXIS finite element analysis software was used for the analyses. The primary aim was to investigate the structural and geotechnical performance of the arch supported system. The study revealed that the new system provides improvement for specific cases and can be considered as an alternatve support system for such cases.

<p>In the current recessionary cycle in which individuals finds themselves, it is interesting to see whether organisations and individuals have changed their strategies or whether they pursued their tried and tested inherent mechanisms of recruitment/work selection. In recessionary times, organisations would usually have a bigger pool to select from whilst employees, in turn, would try to position themselves in a stable work environment. From an organisational perspective, organisations have also undergone major transitions such as downsizing, merges and acquisitions, right sizing, restructuring, and reengineering. These changes have a direct impact on employees&rsquo / level of motivation and job satisfaction (Ellison &amp / Schreuder, 2000). The concept of a traditional career that an employee occupies for a lifetime performing one type of work in an organisation no longer exists. Instead, employees now work for more than one organisation in their lifetime. These changes entail that employees need to be flexible and adaptive in making career decisions (Schreuder &amp / Coetzee, 2006). Career anchors can be operationalized as a representation of self- perceived talents, motives, values and abilities that guide employees to make career decisions. Schreuder and Coetzee (2006), are of the opinion that if employees are not familiar with their&nbsp / career anchors, they could find themselves trapped in work environments that are not satisfactory and would continually be questioning themselves. Suutari and Taka (2004) emphasize the fact that there needs to be a fit between the careers of employees and the work environment. If there is no fit between the career anchors of employees and the work environment then employees are likely to become dissatisfied which may result in a high turnover of staff with a corresponding low productivity rate. This study investigates and explores the phenomenon of career anchors based&nbsp / on Schein&rsquo / s 1978 career anchor theory and how these career anchors affect employees level of job satisfaction. The Career Anchor Inventory and the Job Descriptive Index were administered to a sample of 154 employees at a leading retail organisation who completed the questionnaires. The results of this research study indicate that there are significant relationships between biographical factors and career anchors as well as between biographical factors and job satisfaction and similarly between typology of career anchors and dimensions of job satisfaction.</p>

This thesis describes an experimental study on the long-term creep behaviour of adhesive anchors under sustained tensile loads in combination with different environmental exposures. A comprehensive background and literature review is presented, focusing on various bond stress models for adhesive anchors, factors affecting their bond behavior, and an overview of available testing standards and evaluation criteria. The experimental program comprises of 82 test specimens. The specimens consist of a cylindrical shaped concrete block of 300 mm (12 inch) in diameter and 200mm (8 inch) in depth, with 15M (No. 5) deformed steel bar post-installed to an embedment depth of six times the bar diameter or 125mm (5 inch). Three types of adhesives were used for anchor installation: Type-A a fast setting two component methyl methacrylate adhesive, Type-B a fast setting two part epoxy adhesive, and Type-C a standard set two part epoxy adhesive. The study is divided into four phases. Phase I consists of 27 static pullout tests to determine the yield strength (fy) and the maximum tensile capacity of each anchor system under three exposure conditions. Phase II and Phase III consist of 36 specimens tested under sustained load levels of 40%fy (32kN) and 60%fy (48kN)under normal laboratory conditions (room temperature) and moisture exposure, respectively. Phase IV consists of 9 specimens tested under sustained load with a load level of 40%fy (32kN) with exposure to freeze/thaw cycling. All sustained load tests lasted for a period of at least 90 days. The results of the static pullout testing showed that specimens with epoxy based adhesive exhibited stronger bond strength, forcing the anchor to fail by rupture prior to bond failure. Under sustained load testing, specimens with standard set epoxy based adhesive showed insignificant creep displacement under room conditions, however, when exposed to moisture noticeable creep displacements were recorded. Specimens with both fast setting epoxy and methyl methacrylate based adhesives showed higher creep displacements under environmental exposure (moisture, freeze/thaw) versus those kept at room temperature. Displacement data from creep testing were analysed and projected over a service life span of 50 years for room temperature exposure, and for 10 years for moisture and freeze/thaw exposures. Based on the analysis results, the service life of different anchor systems was estimated. An integrated qualification and testing protocol is proposed for the creep behavior of adhesive anchors under various environmental exposures.

Extreme hurricane events of the past decade are responsible for several drag embedment anchor (DEA) mooring failures of mobile offshore drilling platforms stationed within the Gulf of Mexico. A proposed failure mechanism is caused by out-of-plane loading. The current status of DEA holding capacity is based on empirical design charts and does not include the effects of out-of-plane loading. Experimental modeling using a 1:10 scale generic DEA was performed at the Haynes Coastal Engineering Laboratory at Texas A & M University to examine the effects of out-of-plane load conditions. Instrumentation and specialized devices were constructed to measure the anchor's trajectory through a representative sample of Gulf of Mexico clay with average un-drained shear strength of 0.764 kPa (16 psf). The sediment basin allowed for drag distances of 4.87 m (16 ft) and an embedment depth of 1.37 m (4.5 ft). The measurements included pitch and roll of the anchor and line tension measured at the shank pad-eye. The variables modeled were fluke angle settings of 22°, 36° and 50°. The initial towline angle was varied from a minimum of 5° to upwards of 20°. Surface out-of-plane angles of 45° and 90° and embedment loading of 15°, 30° and 45° were examined. Curves of the ultimate holding capacity with respect to the out-of-plane towline angle and ultimate embedment depth were developed as functions of out-of-plane loading angles. Analysis of the rate effect indicates that a 46 percent increase in towing velocity causes an average 3 percent increase of holding capacity. The 50° fluke angle embeds an average of 0.7 fluke lengths deeper and has a holding capacity of 0.73 units greater than the 36° setting. The surface out-of-plane tests have a 5.1 percent reduction in holding capacity as the out-of-plane load angle increases from 45° to 90°. For all one fluke length initial towing distance tests, the ultimate holding capacity increases and the ultimate embedment depth decreases as the out-of-plane towing angle increases from 15° to 45°. The three fluke length initial towing distance tests indicate a contrasting trend, in that as the out-of-plane tow angle increases, both the ultimate holding capacity and ultimate embedment depth decrease.

The problem of passive earth pressure is one of the important topics in Geotechnical engineering. At attempt is made in this thesis to generate passive earth pressure coefficients for general c-Φ soils using logarithmic spiral failure surface by limit equilibrium approach. Method of slices for the determination of passive force in c-Φsoils is presented and the method is extended to a typical problem of two layered soil system. The application of passive earth pressure coefficients has been demonstrated for pullout capacity of inclined strip anchors in sloping ground. A semi-empirical approach for the determination of displacement-related passive earth pressure is presented. The thesis is organized in seven chapters. In Ch.2, a brief summary of relevant literature is presented along with the scope of the thesis. In Ch. 3, limit equilibrium approach for the determination of the passive earth pressure in soils is presented. The passive earth pressure coefficients are developed for δ/Φ= - 1, - ¾ , -2/3, - ½, 0, ½, ¾ 1; ψ = -60º, -45º, -30º, -20º, -10º, 0º,10º,20º,30º and 45º; i= -30º, -20º, -10º,0º,10º,20º and 30º where δ is the wall friction angle, Φ is the angle of internal friction, Ψ is the inclination of the wall with the vertical and i is the ground inclination with the horizontal. Ch.4 deals with the method of slices. Satisfying all the three equilibrium conditions and using interstice friction as a variable, passive earth pressure coefficients are obtained for soils. Extension of the method to a two layered soil system is demonstrated by an illustrative example. A generalised approach for the determination of uplift capacity of inclined strip anchors in sloping ground subjected to surcharge is presented in Ch. 5. Expressions are provided for the determination of pullout capacity of deep anchors. Displacement-related passive earth pressure is discussed in Ch. 6. Using the earlier experimental observations on the passive earth pressure measurements with displacements, expressions have been fitted for the determination of displacement-related passive earth pressure for the three modes of rigid body movements viz., translation, rotation about the top and rotation about the bottom. The conclusions drawn from the present investigations are listed in Ch 7. (Pl see the original document for abstract)

Using innovative materials or devices in techniques for strengthening or repair of RC concrete members may provide interesting alternatives for structural engineers. Laboratory tests were conducted on full scale reinforced concrete columns and a masonry wall that suffered severe damage. Carbon Fiber Reinforced Polymer - CFRP sheets and anchors were used to improve shear capacity or ductility elements. CFRP jacket were installed on column hinge regions while diagonal ties (tension braces) were used on the masonry wall. Mechanical splices were used in columns where concrete crushed and bars buckled by replacing the buckled bars and providing continuity to the longitudinal reinforcement. It was found that performance of the retrofitted members was comparable to that using conventional techniques and the performance was generally better than certain “fast” retrofit procedures reported in the literature. The choice of technique depends on the degree of damage, the cost of replacement, and performance required. Having the results of cyclic load tests of rehabilitated concrete members, envelope or backbone curves were obtained following the ASCE41-07 and proposed ASCE41-13 procedures. The backbone curves were used to develop behavioral models that can be used in the analysis and design of those types of concrete members and retrofit procedures. The inclusion of the behavioral models into current Performance Based Seismic Design procedures for strengthening of existing or repaired damaged buildings is proposed. / text

This thesis describes an experimental study on the long-term creep behaviour of adhesive anchors under sustained tensile loads in combination with different environmental exposures. A comprehensive background and literature review is presented, focusing on various bond stress models for adhesive anchors, factors affecting their bond behavior, and an overview of available testing standards and evaluation criteria. The experimental program comprises of 82 test specimens. The specimens consist of a cylindrical shaped concrete block of 300 mm (12 inch) in diameter and 200mm (8 inch) in depth, with 15M (No. 5) deformed steel bar post-installed to an embedment depth of six times the bar diameter or 125mm (5 inch). Three types of adhesives were used for anchor installation: Type-A a fast setting two component methyl methacrylate adhesive, Type-B a fast setting two part epoxy adhesive, and Type-C a standard set two part epoxy adhesive. The study is divided into four phases. Phase I consists of 27 static pullout tests to determine the yield strength (fy) and the maximum tensile capacity of each anchor system under three exposure conditions. Phase II and Phase III consist of 36 specimens tested under sustained load levels of 40%fy (32kN) and 60%fy (48kN)under normal laboratory conditions (room temperature) and moisture exposure, respectively. Phase IV consists of 9 specimens tested under sustained load with a load level of 40%fy (32kN) with exposure to freeze/thaw cycling. All sustained load tests lasted for a period of at least 90 days. The results of the static pullout testing showed that specimens with epoxy based adhesive exhibited stronger bond strength, forcing the anchor to fail by rupture prior to bond failure. Under sustained load testing, specimens with standard set epoxy based adhesive showed insignificant creep displacement under room conditions, however, when exposed to moisture noticeable creep displacements were recorded. Specimens with both fast setting epoxy and methyl methacrylate based adhesives showed higher creep displacements under environmental exposure (moisture, freeze/thaw) versus those kept at room temperature. Displacement data from creep testing were analysed and projected over a service life span of 50 years for room temperature exposure, and for 10 years for moisture and freeze/thaw exposures. Based on the analysis results, the service life of different anchor systems was estimated. An integrated qualification and testing protocol is proposed for the creep behavior of adhesive anchors under various environmental exposures.

<p>In the current recessionary cycle in which individuals finds themselves, it is interesting to see whether organisations and individuals have changed their strategies or whether they pursued their tried and tested inherent mechanisms of recruitment/work selection. In recessionary times, organisations would usually have a bigger pool to select from whilst employees, in turn, would try to position themselves in a stable work environment. From an organisational perspective, organisations have also undergone major transitions such as downsizing, merges and acquisitions, right sizing, restructuring, and reengineering. These changes have a direct impact on employees&rsquo / level of motivation and job satisfaction (Ellison &amp / Schreuder, 2000). The concept of a traditional career that an employee occupies for a lifetime performing one type of work in an organisation no longer exists. Instead, employees now work for more than one organisation in their lifetime. These changes entail that employees need to be flexible and adaptive in making career decisions (Schreuder &amp / Coetzee, 2006). Career anchors can be operationalized as a representation of self- perceived talents, motives, values and abilities that guide employees to make career decisions. Schreuder and Coetzee (2006), are of the opinion that if employees are not familiar with their&nbsp / career anchors, they could find themselves trapped in work environments that are not satisfactory and would continually be questioning themselves. Suutari and Taka (2004) emphasize the fact that there needs to be a fit between the careers of employees and the work environment. If there is no fit between the career anchors of employees and the work environment then employees are likely to become dissatisfied which may result in a high turnover of staff with a corresponding low productivity rate. This study investigates and explores the phenomenon of career anchors based&nbsp / on Schein&rsquo / s 1978 career anchor theory and how these career anchors affect employees level of job satisfaction. The Career Anchor Inventory and the Job Descriptive Index were administered to a sample of 154 employees at a leading retail organisation who completed the questionnaires. The results of this research study indicate that there are significant relationships between biographical factors and career anchors as well as between biographical factors and job satisfaction and similarly between typology of career anchors and dimensions of job satisfaction.</p>

近年，投資人對資訊反應不足與反應過度，是行為財務學側重的一塊。許多文獻與實證研究皆探討投資人的投資決策與其對資訊反應不足與反應過度之間的關連性，以及究竟投資人是否有設定投資定錨的傾向。而本研究為了實證台灣股市存在之反應不足或過度反應的現象，且投資人具有限注意力並有設定投資定錨的傾向，在博覽眾多相關文獻與研究後，決定依循Li and Yu（2012）的理論基礎，使用週價比與歷價作為反應不足與過度反應的代理變數，並將模型改建成適用於台灣股市的迴歸模型。 本研究以台灣股價加權指數作為主要迴歸樣本，將模型分為週資料迴歸模型與月資料迴歸模型，檢視兩個代理變數在控制景氣循環以及沒有台灣經濟泡沫樣本下可否用於台灣股市反映投資行為，並作為預測未來市場報酬的指標。最後，為實證投資人有限注意力與心理定錨設置之理論成立，本研究將台灣50指數與摩根台股指數作為樣本分別進行迴歸，以探討是否有比台灣加權股價指數更具顯著預測能力的指數存在。 研究結果顯示，假說一「週/歷價比與未來市場報酬成正/負相關」與假說二「選用能見度高的指數作為樣本應使週價比與歷價比更具顯著的預測能力」皆成立。即台灣股市確實存在反應不足或過度反應的現象，且投資人具有限注意力並有設定投資定錨的傾向，而台灣市場中最具顯著預測能力的指數為摩根台股指數。此外，週資料迴歸模型比月資料迴歸模型更適用於台灣股票市場。 / Currently, much academic research is concerned about investor underreaction & overreaction in behavioral finance. It mainly discusses the relationship between investment strategies and underreaction & overreaction and whether investors have tendency to utilize investment anchor. This study determined to follow basis of Li and Yu（2012） in order to examine the existence of underreaction & overreaction, investor limited attention and the tendency to set anchor in Taiwan stock market. We use nearness to the 52-week high and nearness to the historical high as proxies capturing the degree of investor underreaction and overreaction to news. In this study, we adopt TAIEX as main data and run two different types of regression model based on weekly and monthly data. Except under normal condition, we further examine these two proxies with controlling business cycle and without Taiwan economic bubble. Finally, we compare the predictive ability to forecast future aggregate market returns among TAIEX, TW 50 and MSCI Taiwan index. Our empirical results support the hypothesis 1, “nearness to the 52-week high positively predicts future market returns and nearness to the historical high negatively predicts future market returns” and hypothesis 2, “using index with higher visibility results in significantly predictive ability for nearness to the 52-week high and nearness to the historical high,” while MSCI Taiwan Index is the most significant. Besides, weekly regression is more suited to Taiwan stock market than monthly regression. These findings are consistent with the limited investor attention and anchoring research.

Made available in DSpace on 2014-12-17T14:48:18Z (GMT). No. of bitstreams: 1 FabianaAS_DISSERT.pdf: 5525244 bytes, checksum: b567af14ad5856197ebf8368098dd7fb (MD5) Previous issue date: 2013-12-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / It is presented the analysis of a retaining wall designed for the basement of a residential building, located in Natal/RN, which consists in a spaced pile wall, anchored by tiebacks, in sand. This structure was instrumented in order to measure the wall s horizontal movements and the load distribution throughout the anchor fixed length. The horizontal movements were measured with an inclinometer, and the loads in the anchors were measured with strain gages, installed in three places throughout the anchor fixed length. Measurements for displacement were done right after the implementation of each stage of the building and right after the conclusion of the building, and the measurements for loads in the anchors were done during the performance test, at the moment of the locking off and, also, right after the conclusion of the building. From the data of displacement were obtained velocity and acceleration data of wall. It was found that the time elapsed on braced installation was decisive in the magnitude of the displacements. The maximum horizontal displacement of wall ranged between 0,18 and 0,66% of the final depth of excavation. The loads in the anchors strongly reduced to approximately half the anchor fixed length, followed an exponential distribution. Furthermore, it was found that there was a loss of load in the anchors over time, reaching 50% loss in one of them / O presente trabalho apresenta um estudo sobre uma estrutura de conten??o projetada para constru??o do subsolo de um edif?cio residencial multifamiliar, localizado na cidade de Natal/RN, que consiste em uma cortina de estacas escavadas ancorada por tirantes, em areia. Essa estrutura foi instrumentada a fim de se medirem os deslocamentos horizontais da cortina e a distribui??o de cargas ao longo do trecho ancorado dos tirantes. Os deslocamentos horizontais foram medidos atrav?s de inclin?metro, e as cargas nos tirantes foram obtidas com uso de extens?metros el?tricos de resist?ncia instalados em tr?s pontos ao longo do trecho ancorado. As medi??es de deslocamento foram feitas ap?s cada etapa de execu??o da cortina e ap?s a conclus?o da obra, enquanto as medi??es de carga nos tirantes foram feitas durante os ensaios de recebimento, no momento da incorpora??o e tamb?m ap?s a conclus?o da obra. A partir dos dados de deslocamento foram obtidos dados de velocidade e acelera??o da cortina. Constatou-se que o tempo gasto na instala??o do escoramento foi decisivo na magnitude dos deslocamentos. O deslocamento horizontal m?ximo final da cortina variou entre 0,18 e 0,66% da profundidade final de escava??o. As cargas nos tirantes sofrem uma redu??o muito acentuada at? aproximadamente a metade do trecho ancorado, seguindo uma distribui??o exponencial. Al?m disso, constatou-se que houve perda de carga nos tirantes ao longo do tempo, chegando a 50% de perda em um deles