scholarly journals Liquefaction Potential Analysis in Bucharest City as a Result of the Ground Shaking during Strong Vrancea Earthquakes

2021 ◽  
Vol 8 (2) ◽  
pp. 113-138
Author(s):  
ANDREI BALA ◽  
DIETER HANNICH

Bucharest, the capital of Romania with about 2.5 million inhabitants, is frequently struck by intense, damaging earthquakes (2–3 events per century). The Collaborative Research Center 461 (CRC-461) entitled: “Strong Earthquakes - a Challenge of Geosciences and Civil Engineering” was established in July 1996 and ended in December 2007, but some projects continued until 2010. It was funded by the German Research Foundation and involved the University of Karlsruhe which today belongs to Karslruhe Institute of Technology. The CRC aimed strategic research in the field of strong earthquakes with regional focus on the Vrancea seismic events in Romania. Between 1995–2007 several research works were done in Romania, with the support of several Romanian research institutes and the University of Bucharest. One of the research questions was to study the occurring of liquefaction during strong earthquakes within the shallow sandy layers in Bucharest. In suitable conditions, strong earthquakes can cause, under certain geologic conditions, liquefaction and therewith ground failure as sand boils, lateral spreading, or differentiated subsidence. In the present paper we analyze the liquefaction risk for Bucharest. For this purpose, at 10 representative sites in Bucharest, Seismic Cone Penetration Tests (SCPTu) were executed. An area-wide evaluation of the liquefaction probability in Bucharest was established. The factor of safety (FS) against liquefaction and the probability of liquefaction (PL) were computed from the obtained test-data. For the first time, maps of the liquefaction potential index (Li) for Bucharest were outlined. This map shows how severe the liquefaction phenomena might be during strong Vrancea earthquakes in Bucharest, amplifying the site effects. Keywords: hydrogeologic conditions, liquefaction probability, liquefaction hazard, Bucharest city, strong Vrancea earthquakes

2001 ◽  
Vol 7 (4) ◽  
pp. 301-320 ◽  
Author(s):  
Marshall Lew

Abstract Liquefaction is a seismic hazard that must be evaluated for a significant percentage of the developable areas of California. The combination of the presence of active seismic faults, young loose alluvium, and shallow ground water are the ingredients that could result in the occurrence of liquefaction in many areas of California. These ingredients are also found in other seismically active areas of the United States and the world. The state of California, through the Seismic Hazard Mapping Act of 1990, has mandated that liquefaction hazard be determined for new construction. On a parallel track, the Uniform Building Code, since 1994, has provisions requiring the determination of liquefaction potential and mitigation of related hazards, such as settlement, flow slides, lateral spreading, ground oscillation, sand boils, and loss of bearing capacity. Fortunately, the state of knowledge has now evolved to where there are field exploration methods and analytical techniques to estimate the liquefaction potential and the possible consequences arising from the occurrence of liquefaction. There are some areas that still need further research. Mitigation for liquefaction has become more commonplace and confidence in these techniques has been increased based on the relatively successful performance of improved sites in the past several major earthquakes. Unfortunately, not all practicing engineering and geological professionals and building officials are knowledgeable about the current state-of-practice in liquefaction hazard analysis and mitigation. Thus, it was considered necessary to develop a set of guidelines to aid professionals and building officials, based on California's experience with the current practice of liquefaction hazard analysis and mitigation. Although the guidelines reported in this paper were written specifically for practice in California, it is believed that guidelines can benefit practitioners to evaluate liquefaction hazard in all seismic regions.


1974 ◽  
Vol 5 (1) ◽  
pp. 32-49 ◽  
Author(s):  
JOHN TVEIT

This article deals with the problem of insulating measuring weirs to avoid ice disturbances. The development of a simple method for insulating a conventional V-weir is described. This method will serve its purpose in many cases. For more difficult cases a special type of a fully insulated weir is described. The experiments described were carried out by The Division of Hydraulic Engineering, The University of Trondheim, The Norwegian Institute of Technology, at the River and Harbour Laboratory of the University, and at the IHD representative basin Sagelva.


1963 ◽  
Vol 53 (6) ◽  
pp. 1403-1414
Author(s):  
Stanley N. Davis ◽  
Juan Karzulovíc K.

ABSTRACT Strong earthquakes of 22 May 1960 produced three large landslides which blocked the outlet of Lago Riñihue, 65 kilometers east of the city of Valdivia, Chile. The lake level rose 26.5 meters before water began discharging through artificially constructed canals during the last week in June, 1960. The largest landslide involved about 30 million cubic meters of unconsolidated sediments, the intermediate landslide about 6 million cubic meters, and the smallest landslide about 2 million cubic meters. The surface of rupture of the largest landslide is within an 80-meter sequence of Pleistocene lake clays. The clays are underlain by till and overlain by outwash sands and gravels. Movement of the landslide is interpreted as having been principally block gliding and lateral spreading. Secondary landslides within the larger landslide were produced by rotational slumping, debris falls, and earth flows. Several ancient landslides exist in the vicinity of Lago Riñihue, the largest involving more than 100 million cubic meters of unconsolidated sediments. Many of the older landslides also were probably triggered by earthquakes.


2021 ◽  
Author(s):  
Roger Few ◽  
Mythili Madhavan ◽  
Narayanan N.C. ◽  
Kaniska Singh ◽  
Hazel Marsh ◽  
...  

This document is an output from the “Voices After Disaster: narratives and representation following the Kerala floods of August 2018” project supported by the University of East Anglia (UEA)’s GCRF QR funds. The project is carried out by researchers at UEA, the Indian Institute for Human Settlements (IIHS), the Indian Institute of Technology (IIT), Bombay, and Canalpy, Kerala. In this briefing, we provide an overview of some of the emerging narratives of recovery in Kerala and discuss their significance for post-disaster recovery policy and practice. A key part of the work was a review of reported recovery activities by government and NGOs, as well as accounts and reports of the disaster and subsequent activities in the media and other information sources. This was complemented by fieldwork on the ground in two districts, in which the teams conducted a total of 105 interviews and group discussions with a range of community members and other local stakeholders. We worked in Alleppey district, in the low-lying Kuttanad region, where extreme accumulation of floodwaters had been far in excess of the normal seasonal levels, and in Wayanad district, in the Western Ghats, where there had been a concentration of severe flash floods and landslides.


2010 ◽  
Vol 40 ◽  
pp. 69-76 ◽  
Author(s):  
Rama Mohan Pokhrel ◽  
Jiro Kuwano ◽  
Shinya Tachibana

Liquefaction hazard zonation mapping of the Saitama City targeted on the Kanto Plain NW Edge Fault is described in this paper. The study involves the geotechnical properties of the alluvial soil of the city including Standard Penetration Test (SPT), shear wave velocity and other geological data analysis. The city being highly urbanized is situated on the soft soil (alluvial deposits) at the proximity of an active seismic fault that has increased the possibility of liquefaction hazard in the area. Kanto Plain NW Edge Fault is an active fault that lies very near to the Saitama City having the estimated possible earthquake magnitude of 7.4. The possible peak horizontal ground acceleration (amax) from this earthquake is calculated as from 0.15 g to 0.30 g. By considering all possible acceleration values the liquefaction potential maps were prepared and presented in this paper. Additionally, the shear wave velocity is very low and amplification ratio is very high at the marshy deposit but it has comparatively high velocity and low amplification ratio at the marine loam deposit area of the Omiya Plateau. In this paper the liquefaction potential of the area is expressed in terms of liquefaction potential index (PL). The PL value for the clayey silt deposit in the marshy area with shallow water table is very high. In addition, the PL value in the marine loam deposit of the Omiya Plateau is less which indicates that loam deposit has less liquefaction potential than marshy deposit. The map obtained from this study was validated with the field condition of the study area. Hence, it is expected that this study will assist in characterizing the seismic hazards and its mitigation and will provide valuable information for urban planning in the study area in future.


Author(s):  
Jian Zhang ◽  
Dick Beetham ◽  
Grant Dellow ◽  
John X. Zhao ◽  
Graeme H. McVerry

A New empirical model has been developed for predicting liquefaction-induced lateral spreading displacement and is a function of response spectral displacements and geotechnical parameters. Different from the earlier model of Zhang and Zhao (2005), the application of which was limited to Japan and California, the new model can potentially be applied anywhere if ground shaking can be estimated (by using local strong-motion attenuation relations). The new model is applied in New Zealand where the response spectral displacement is estimated using New Zealand strong-motion attenuation relations (McVerry et al. 2006). The accuracy of the new model is evaluated by comparing predicted lateral displacements with those which have been measured from aerial photos or the width of ground cracks at the Landing Road bridge, the James Street loop, the Whakatane Pony Club and the Edgecumbe road and rail bridges sites after the 1987 Edgecumbe earthquake. Results show that most predicted errors (defined as the ratio of the difference between the measured and predicted lateral displacements to the measured one) from the new model are less than 40%. When compared with earlier models (Youd et al. 2002, Zhang and Zhao 2005), the new model provides the lowest mean errors.


1960 ◽  
Vol 33 (5) ◽  
pp. 1323-1374 ◽  
Author(s):  
C. L. Weidner ◽  
G. J. Crocker

Abstract An increasing number of papers in the field of adhesion have been appearing in Rubber Chemistry & Technology. In the period 1941–1950 twenty-two papers appeared in this Journal covering various aspects of adhesion, whereas in the year 1959 alone eleven papers appear. The Rubber Division Library at the University of Akron has compiled bibliographies as follows: Bibliography # 10, “Use of Synthetic Resins in Natural and Synthetic Rubbers”, covering the period 1930–1952; Bibliography # 18, “Rubber to Metal Bonding”, in two parts, one covering the period 1937–1954 and a supplement covering 1955–1958; and Bibliography #20, “Reclaim Rubber Cements”, covering the period 1927–1954. In addition, special bibliographies were prepared covering the period 1949–1958 on the subjects “Rubber to Wood Adhesives”, “Rubber to Fabric Adhesives”, “Bonding of Polyurethanes”, “Metal to Metal Adhesives”, and “Chemistry of Rubber Adhesives”. The most comprehensive text in the field is “Adhesion and Adhesives” edited by N. A. DeBruyne and R. Houwink. More limited in scope are “Adhesive Bonding of Metals” by Epstein, “Adhesives for Wood” by Knight, “Adhesive Bonding of Reinforced Plastics” by Perry. Also “Rubber to Metal Bonding” by Buchan, which stresses the brass plating technic. Skeist has recently edited a “Handbook of Adhesives”. The Encyclopedia of Chemical Technology contains articles on “Adhesives” in Volume I and the First Supplement Volume. Various symposia have been sources of worthwhile papers on adhesion. The Division of Paint, Plastics, and Printing Ink Chemistry, ACS, published such papers in their preprint booklets, volume XV, No. 1 (1955) and volume XX, No. 1 (1960). Papers given at this division's “Recent Advances in Adhesives” symposium in 1957 are also published. Publication of papers at two symposia held in 1952 (Society of The Chemical Industry, London; Case Institute of Technology, Cleveland) form a valuable collection. Papers from The Second International Congress of Surface Activity in London in 1957 are also published. Papers from a Symposium on Adhesion held by the Society of Rheology in 1959 are published in volume IV of the Society's Transactions. General review articles on adhesion with extensive bibliographies were published as follows : Rinker-Kline “Survey of Adhesives and Adhesion; Kline-Reinhart “Fundamentals of Adhesion”; Brantley-Charnell “Investigation of the Nature of Forces of Adhesion”; Reinhart-Callomon “Survey of Adhesion and Adhesives” and Rutzler “Types of Bonds Involved in Adhesion”. The Reinhart-Callomon survey is quite extensive in its bibliography.


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