Analysis of dam response for foundation fault rupture

Author(s):  
Lelio Mejia ◽  
Ethan Dawson

Considerable knowledge and experience has been developed over the past 40 years in the engineering profession regarding the seismic performance and analysis of dams for earthquake shaking. However, comparatively limited experience is available regarding the evaluation of dams for the effects of foundation fault rupture during earthquakes. This paper examines the factors to be considered in the evaluation of embankment dams for foundation faulting, and illustrates the analysis of dam response under foundation faulting by means of a case history, the seismic evaluation of Aviemore Dam.

Author(s):  
Nils Brunsson

This chapter argues that organizational reforms are driven by problems to be addressed, by solutions to be applied, and by forgetfulness. The greater the supply of any of these factors, the more likely it is that reforms will occur. Without problems, reforms are difficult to justify; without solutions they cannot be formulated; and without forgetfulness there is a risk that people will be discouraged by the fact that similar reforms have been tried and have failed in the past. In contemporary large organizations, problems tend to be easily found. Those interested in selling solutions often try to supply problems as well — problems that can be solved by their solutions. Forgetfulness can be promoted by the use of consultants with limited experience of the implementation and long-term effects of reforms. Reforms are also self-referential; they tend to cause new reforms. Thus, reforms can be considered as routines: they are likely to be repeated over and over again.


1893 ◽  
Vol 10 (9) ◽  
pp. 401-412 ◽  
Author(s):  
Karl A. von Zittel

In a spirited treatise on the ‘Origin of our Animal World’ Prof. L. Rütimeyer, in the year 1867, described the geological development and distribution of the mammalia, and the relationship of the different faunas of the past with each other and with that now existing. Although, since the appearance of that masterly sketch the palæontological material has been, at least, doubled through new discoveries in Europe and more especially in North and South America, this unexpected increase has in most instances only served as a confirmation of the views which Rutimeyer advanced on more limited experience. At present, Africa forms the only great gap in our knowledge of the fossil mammalia; all the remaining parts of the world can show materials more or less abundantly, from which the course followed by the mammalia in their geological development can be traced with approximate certainty.


2021 ◽  
pp. 875529302199636
Author(s):  
Mertcan Geyin ◽  
Brett W Maurer ◽  
Brendon A Bradley ◽  
Russell A Green ◽  
Sjoerd van Ballegooy

Earthquakes occurring over the past decade in the Canterbury region of New Zealand have resulted in liquefaction case-history data of unprecedented quantity. This provides the profession with a unique opportunity to advance the prediction of liquefaction occurrence and consequences. Toward that end, this article presents a curated dataset containing ∼15,000 cone-penetration-test-based liquefaction case histories compiled from three earthquakes in Canterbury. The compiled, post-processed data are presented in a dense array structure, allowing researchers to easily access and analyze a wealth of information pertinent to free-field liquefaction response (i.e. triggering and surface manifestation). Research opportunities using these data include, but are not limited to, the training or testing of new and existing liquefaction-prediction models. The many methods used to obtain and process the case-history data are detailed herein, as is the structure of the compiled digital file. Finally, recommendations for analyzing the data are outlined, including nuances and limitations that users should carefully consider.


Author(s):  
K McCormick

British engineers have claimed that their important contributions to economic and social well-being, based on their achievements as practical people, have gone unrecognized or unrewarded. Yet over the past thirty years efforts to boost the social prestige of British engineers appear to have undermined the social arrangements which fostered the strong practical ethos. Increasing reliance on the full-time educational system is tending to raise social prestige through bringing the ‘all graduate profession’ and through trends to recruitment from higher social backgrounds. Yet these trends have been associated with a fall in traditional and recognizable training. This paper examines both the nature of the ‘practical’ tradition and efforts to raise ‘prestige’ and asks whether the engineering profession is caught on the horns of an irresolvable dilemma—to boost either prestige or practicality. The paper concludes that in principle the British pattern of education and training has much to commend it still, with the strong emphasis on training elements in a working environment. But it is argued that its success will depend on engineers and their employers becoming much more active in the field of training.


2020 ◽  
pp. 107754632096693
Author(s):  
Jun Dai ◽  
Zhao-Dong Xu ◽  
Pan-Pan Gai ◽  
Xiao Yan

Experimental results show that mechanical behaviors of viscoelastic dampers are greatly affected by ambient temperature. Neglecting the ambient temperature effect will lead to an inaccurate seismic evaluation on viscoelastically damped structures. This study investigates the ambient temperature effect on the seismic performance of viscoelastically damped structures. An efficient algorithm is proposed to solve the seismic response of viscoelastically damped structures at different ambient temperatures based on the time–temperature correspondence. Numerical simulations of a ten-story viscoelastically damped steel frame under historical earthquakes are presented to illustrate the ambient temperature effect on the seismic performance. The results show that the natural frequency decreases with the increase in ambient temperature, whereas the damping ratio change with ambient temperature greatly depends on the viscoelastic damper properties. The seismic displacement reduction, in general, decreases with the increase in ambient temperature. The seismic acceleration reduction with ambient temperature is affected by the viscoelastic damper properties, structural parameters, and earthquakes together.


2018 ◽  
Vol 188 ◽  
pp. 03010
Author(s):  
Maria Basdeki ◽  
Argyro Drakakaki ◽  
Charis Apostolopoulos

Greece is an earthquake prone area, which is also exposed to coastal environment. Most existing buildings present common characteristics, concerning quality of the materials and environmental conditions [1].The vulnerability of these structures is exteriorized under powerful seismic loads. This is because they were designed, according to older regulations, primarily to bear vertical loads and secondarily to bear horizontal loads, an indicative sign of the absence of anti-seismic design. Designing and evaluation of the seismic performance of existing structures is a really complex issue, because structural degradation phenomenon is related to both corrosion damage of steel reinforcement on RC structures and high vulnerability of masonry. Precisely, the inadequate seismic performance of masonry structures, which is recorded under intense earthquakes, is attributed to the characteristics of masonry and to the ageing phenomena of the materials. For the seismic inspection of masonry structures, both EC2 and OASP can be used [3], although there is often a great misunderstanding concerning the range of the maximum permissible interventions, the financial inability and modern perceptions of redesigning [2]. On the other hand, in the case of RC structures, there is no prediction –concerning the corrosion factor- included in the international regulations and standards. In the current study is presented an experimental procedure, concerning a RC column before and after corrosion. An estimation concerning the drop of its mechanical performance has taken place, indicating the importance of the corrosion factor. Additionally, an existing monumental masonry tower building, was subjected to seismic evaluation [4]. Both OASP and EC2 inspection methods were used. The results pointed out that, for medium–intensity earthquakes, both analytical and approximate methods are respectable and reliable.


2019 ◽  
Vol 28 (3) ◽  
pp. 446-461
Author(s):  
Nadya A. Fouad ◽  
Michael B. Kozlowski ◽  
Romila Singh ◽  
Nina G. Linneman ◽  
Samantha S. Schams ◽  
...  

Women’s departure or nonentrance into science, technology, engineering, and mathematics professions, particularly engineering, has been a lively source of scholarly inquiry for the past three decades. Much of the literature in this area has been with solely female samples of participants, begging the question as to whether or not men and women either choose to leave the profession or not enter for the same or similar reasons. This present study collected a large sample of men ( n = 1,273) who had either left or never entered the engineering profession and compared their responses to a large sample of women ( n = 1,235) on a set of categorical response variables. Using the perspective of the Theory of Work Adjustment, our results suggest that there are gender differences in reasons for departure, raising the possibility that engineering climates differentially reinforce needs for men and women. Implications of this research are discussed.


1914 ◽  
Vol 60 (248) ◽  
pp. 39-56
Author(s):  
H. S. Gettings

Dr. Sidney Coupland, in opening the discussion, said: I need hardly say that I have read Dr. Gettings' paper with great interest, and have found it, as other readers must have done, very instructive as well as entertaining. What gives particular interest to his graphic story is the fact that it is based upon the continuous medical records of an institution for nearly a century, and in this respect it must surely be unique. From a remark in the paper, apparently more zeal in clinical note-taking was exhibited in the earlier than in the later period of the history of Wakefield Asylum, but I feel sure that, if this be so, the lapse can only be temporary. As regards dysentery, it is certainly remarkable that a disease, once fairly common in this country, should have almost entirely disappeared from the community at large, a disappearance which seems to have coincided with that of the last serious visitations of cholera in the middle of last century. Even if we accept the usual explanation that these diseases, like typhus, have been banished in consequence of wide-spread improvement in urban and rural sanitation, especially as regards drainage and water supply, we yet cannot ignore the fact that many an insanitary area still exists which à priori might be expected to favour the spread of such disorders. We know, too, how great a scourge dysentery has been to armies in the field, where conditions of fatigue, exposure, imperfect diet, as well as defective sanitation, favour the development of intestinal disorders. My own limited experience confirms the fact of the rarity of dysentery in the general population. During the past thirty or forty years the average number of cases of dysentery admitted into the wards of the Middlesex Hospital has not exceeded one per annum, and in the seven years (1873–9) that I worked in the post-mortem room I only had to examine two subjects of dysentery, one of whom had contracted the disease in India. I was therefore much surprised to find, on joining the Lunacy Commission, that almost daily notifications were received from asylums of deaths from “colitis,” mostly ulcerative in character, and clinically indistinguishable from dysentery, as had been well shown by Dr. Gemmel just about that time. Dr. Gemmel's monograph, published in 1898, was founded on his personal observations at Lancaster Asylum, where for some years “idiopathic ulcerative colitis” had prevailed. It would, therefore, seem as if dysentery, whilst dying out from the population at large, had found a habitat in asylums, whose inmates, owing to their careful segregation, were less liable to most of the zymotic diseases. Regarded as an infective disease, which Dr. Gettings holds to be a sufficient explanation of its persistence in asylums, one can well understand the difficulty in getting rid of it once it has gained a footing, owing to the conditions of asylum life, and the faulty habits of many of the inmates. But it is only of late that it has been so regarded, for it has been customary to ascribe its occurrence to bad sanitation, of which, indeed, colitis was almost considered to be an index. Such a view seemed to be supported by instances like those mentioned by Dr. Gettings in the Wakefield Asylum, of outbreaks of dysentery coinciding with grave sanitary defects, the removal of which was followed by the subsidence of the disease. A classical instance is that of the outbreak at the Cumberland and Westmorland Asylum in 1864, reported on by Dr. (now Sir) Thomas Clouston, then its medical superintendent. The outbreak, which was a severe one, and accompanied with a high mortality, was connected with the irrigation of fields adjoining the asylum with untreated sewage. Col. Kenneth Macleod referred to this epidemic in a discussion at the Epidemiological Society in 1901, and said that when he himself was assistant medical officer at the Durham Asylum in 1864 there was a similar outbreak of dysentery also, and, as at Garlands, it was associated with sewage irrigation. These and similar instances all lent support to the opinion that dysentery resembled enteric fever in being a “filth disease,” meriting as much as the latter the appellation of “pythogenic,” which Murchison applied to typhoid.


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