289 research outputs found
Factors contributing to large diameter water pipe failure
No full textPathmanathan Rajeev, Jayantha Kodikara, Dilan Robert, Peter Zeman and Balvant Rajani look at a case study in which failure inspection data from five Australian utilities was analysed to determine the factors contributing to failures in large diameter pipes
Increased accuracy of vector-IM-based seismic risk assessment?
No full textThe vector-valued ground motion intensity measure (IM) consisting of spectral acceleration at two different periods is considered for seismic risk assessment of structures. The first component of the IM is the spectral acceleration at the first-mode structural period T-1. The second period is selected to increase efficiency in the estimation of seismic risk (i.e., minimizing dispersion). A method to assess vector structural fragility using a scalar global measure of structural performance is proposed. With reference to an example RC frame structure, the accuracy of prediction of the seismic risk using the considered vector IM vs. a conventional scalar IM is presented. In both cases, probabilistic seismic hazard analysis (scalar and vector) is carried out by means of a subset simulation approach that employs a stochastic model of ground motion. Results show that an effective choice of the second period T-2 leads to an estimate of the seismic risk close to that obtained employing the scalar IM consisting of S-a(T-1) only, while reducing the associated dispersion in the estimate. For the examined example structure, however, the reduction is negligible in light of the effort required for switching from a scalar to a vector IM
Confidence Factor?
No full textEurocode 8 Part 3 (EC8-3) is devoted to assessment and retrofitting of existing buildings. In order to take into account the uncertainty in the knowledge of structural properties, EC8-3 defines, analogously to the ordinary material partial factors, an adjustment factor, called oconfidence factor (CF),o whose value depends on the level of knowledge (KL) of properties such as geometry, reinforcement layout and detailing, and materials. This solution is plausible from a logical point of view but it cannot yet profit from the experience of its use in practice, hence it needs to be substantiated by a higher level probabilistic analysis accounting for and propagating epistemic uncertainty (i.e., incomplete knowledge of a structure) throughout the seismic assessment procedure. This article investigates the soundness of the format proposed in EC8-3. The approach taken rests on the simulation of the entire assessment procedure and the evaluation of the distribution of the assessment results (distance from the limit state of interest) conditional on the acquired knowledge. Based on this distribution, a criterion is employed to calibrate the CF values. The obtained values are then critically examined and compared with code-specified ones. The results pinpoint a number of deficiencies that appear to somewhat invalidate the approach. The methodological significance of the work extends beyond the assessment procedure in EC8-3, since similar factors appear in other international guidelines (e.g., the knowledge factor of FEMA356)
Effect of soil parameter uncertainty on seismic response of buried segmented pipeline
No full textPipelines are important lifeline facilities spread over a large area and they generally encounter a range of seismic hazards and different soil conditions. The seismic response of a buried segmented pipe depends on various parameters such as the type of buried pipe material and joints, end restraint conditions, soil characteristics, burial depths, and earthquake ground motion, etc.\ud
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This study highlights the effect of the variation of geotechnical properties of the surrounding soil on seismic response of a buried pipeline. The variations of the properties of the surrounding soil along the pipe are described by sampling them from predefined probability distribution. The soil-pipe interaction model is developed in OpenSEES. Nonlinear earthquake time-history analysis is performed to study the effect of soil parameters variability on the response of pipeline. Based on the results, it is found that uncertainty in soil parameters may result in significant response variability of the pipeline
Writing Self, Writing Empire
No full textWriting Self, Writing Empire examines the life, career, and writings of the Mughal state secretary, or munshi, Chandar Bhan Brahman (d. ca. 1670), one of the great Indo-Persian poets and prose stylists of early modern South Asia. Chandar Bhan’s life spanned the reigns of four emperors: Akbar (1556–1605), Jahangir (1605–1627), Shah Jahan (1628–1658), and Aurangzeb ‘Alamgir (1658–1707), the last of the “Great Mughals” whose courts dominated the culture and politics of the subcontinent at the height of the empire’s power, territorial reach, and global influence. Chandar Bhan was a high-caste Hindu who worked for a series of Muslim monarchs and other officials, forming powerful friendships along the way; his experience bears vivid testimony to the pluralistic atmosphere of the Mughal court, particularly during the reign of Shah Jahan, the celebrated builder of the Taj Mahal. But his widely circulated and emulated works also touch on a range of topics central to our understanding of the court’s literary, mystical, administrative, and ethical cultures, while his letters and autobiographical writings provide tantalizing examples of early modern Indo-Persian modes of self-fashioning. Chandar Bhan’s oeuvre is a valuable window onto a crucial, though surprisingly neglected, period of Mughal cultural and political history. “Adds significant depth to our understanding of the intellectual and cultural atmosphere of the Mughal court at its height.” -RICHARD M. EATON, author of A Social History of the Deccan, 1300–1761 “The fullest study so far of the understudied phenomenon of Hindu writers of Persian. Through the prism of Chandar Bhan’s writings, Rajeev Kinra presents a holistic treatment of the cultural concerns of the Mughal empire’s Hindu ‘men of the pen.’” -NILE GREEN, author of Making Space: Sufis and Settlers in Early Modern India RAJEEV KINRA is Assistant Professor in the Department of History at Northwestern University
Writing Self, Writing Empire
No full textWriting Self, Writing Empire examines the life, career, and writings of the Mughal state secretary, or munshi, Chandar Bhan Brahman (d. ca. 1670), one of the great Indo-Persian poets and prose stylists of early modern South Asia. Chandar Bhan’s life spanned the reigns of four emperors: Akbar (1556–1605), Jahangir (1605–1627), Shah Jahan (1628–1658), and Aurangzeb ‘Alamgir (1658–1707), the last of the “Great Mughals” whose courts dominated the culture and politics of the subcontinent at the height of the empire’s power, territorial reach, and global influence. Chandar Bhan was a high-caste Hindu who worked for a series of Muslim monarchs and other officials, forming powerful friendships along the way; his experience bears vivid testimony to the pluralistic atmosphere of the Mughal court, particularly during the reign of Shah Jahan, the celebrated builder of the Taj Mahal. But his widely circulated and emulated works also touch on a range of topics central to our understanding of the court’s literary, mystical, administrative, and ethical cultures, while his letters and autobiographical writings provide tantalizing examples of early modern Indo-Persian modes of self-fashioning. Chandar Bhan’s oeuvre is a valuable window onto a crucial, though surprisingly neglected, period of Mughal cultural and political history. “Adds significant depth to our understanding of the intellectual and cultural atmosphere of the Mughal court at its height.” -RICHARD M. EATON, author of A Social History of the Deccan, 1300–1761 “The fullest study so far of the understudied phenomenon of Hindu writers of Persian. Through the prism of Chandar Bhan’s writings, Rajeev Kinra presents a holistic treatment of the cultural concerns of the Mughal empire’s Hindu ‘men of the pen.’” -NILE GREEN, author of Making Space: Sufis and Settlers in Early Modern India RAJEEV KINRA is Assistant Professor in the Department of History at Northwestern University
Community mental health practices in Kerala: challenges and opportunities for social work practice
No full textThis paper is based on community practice experience and a reflection on the community Mental Health well-being initiatives implemented in Kerala, the southernmost State of India as a collaborative effort of Australian Mental Health Practitioners and Indian Professionals in 2012. With the support of collaborating Australian partners, an International Centre for Wellbeing was started to initiate community mental health practices. Mental Health wellbeing is viewed as experiencing healthy or positive self esteem and contributing positively to the society with a sense of worthwhile. The major elements of mental health wellbeing initiatives encompass mental health promotion activities, which aim at increasing wellbeing, competence and resilience by creating conducive living environment and conditions. Decreasing mental health disorders are also included as the secondary result of mental health promotion activities. Partnerships in mental health practice between the professionals of two different nations, where human development indices are in two extremes, demand a synchronization of many professional attributes. Evidence based practices are inevitable in working with communities to enhance the wellbeing of people in a developing country. In this paper, the authors discuss the very nature of establishing collaboration, the design of community mental health programs and the delivery of services to people in Kerala. Further, based on the field evaluations and evidences gathered from the service by the first author, the presentation will explore the challenges and opportunities for social work practice in Kerala context
Field performance of in-service cast iron water reticulation pipe buried in reactive clay
No full textField monitoring is an important means for understanding soil behaviour and its interaction with buried structures such as pipeline. This paper details the successful instrumentation of a section of an in-service cast iron water main buried in an area of reactive clay where frequent water pipe breakage has been observed. The instrumentation included measurement of pipe strain; pipe water pressure and temperature; soil pressure, temperature, moisture content and matric suction, as well as the meteorological conditions on site. The data generally indicated that changes in soil temperature, suction and moisture content were directly related to the local climatic variations. The suction and moisture content data indicated that the soil profile at the site down to around 700 mm, and probably down to 1000 mm, is affected by changes in surface weather, while soil conditions below this depth appear to be more stable. Analysis of pipe strain indicated that the pipe behaves like a cantilever beam, with the top experiencing predominantly tensile strains during summer. Subsequently, these trends reduce to compressive strains as soil swelling occurs due to increase of moisture content with the onset of winter
Effects of vertical irregularities and construction quality in seismic fragilities for reinforced concrete buildings
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