Assessment of liquefaction susceptibility of fine grained soils

Download

index.pdf

Date

2009

Author

Pehlivan, Menzer

Metadata

Show full item record

Item Usage Stats

561
views

328
downloads

Recent ground failure case histories after 1994 Northridge, 1999 Kocaeli and 1999 Chi-Chi earthquakes revealed that low-plasticity silt-clay mixtures generate significant cyclic pore pressures and can exhibit a strain-softening response, which may cause significant damage to overlying structural systems. These observations accelerated research studies on liquefaction susceptibility of fine-grained soils. Alternative approaches to Chinese Criteria were proposed by several researchers (Seed et al. 2003, Bray and Sancio 2006, Boulanger and Idriss 2006) most of which assess liquefaction triggering potential based on cyclic test results compared on the basis of index properties of soils (such as LL, PI, LI, wc/LL). Although these new methodologies are judged to be major improvements over Chinese Criteria, still there exist unclear issues regarding if and how reliably these methods can be used for the assessment of liquefaction triggering potential of fine grained soils. In this study, results of cyclic tests performed on undisturbed specimens (ML, CL, MH and CH) were used to study cyclic shear strain and excess pore water pressure generation response of fine-grained soils. Based on comparisons with the cyclic response of saturated clean sands, a shift in pore pressure ratio (ru) vs. shear strain response is observed, which is identified to be a function of PI, LL and (wc/LL). Within the confines of this study, i) probabilistically based boundary curves identifying liquefaction triggering potential in the ru vs. shear strain domain were proposed as a function of PI, LL and (wc/LL), ii) these boundaries were then mapped on to the normalized net tip resistance (qt,1,net) vs. friction ratio (FR) domain, consistent with the work of Cetin and Ozan (2009). The proposed framework enabled both Atterberg limits and CPT based assessment of liquefaction triggering potential of fine grained low plasticity soils, differentiating clearly both cyclic mobility and liquefaction responses.

Subject Keywords

Civil engineering.

URI

http://etd.lib.metu.edu.tr/upload/12610744/index.pdf
https://hdl.handle.net/11511/18566

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Energy based seismic performance assessment of reinforced concrete columns Acun, Bora; Sucuoğlu, Haluk; Department of Civil Engineering (2010) Severe seismic events in urban regions during the last two decades revealed that the structures constructed before the development of modern seismic codes are the most vulnerable to earthquakes. Sub-standard reinforced concrete buildings constitute an important part of this highly vulnerable urban building stock. There is urgent need for the development and improvement of methods for seismic performance assessment of existing reinforced concrete structures. As an alternative to current conventional force-ba...
An integrated seismic hazard framework for liquefaction triggering assessment of earthfill dams' foundation soils Ünsal Oral, Sevinç; Çetin, Kemal Önder; Department of Civil Engineering (2009) Within the confines of this study, seismic soil liquefaction triggering potential of a dam foundation is assessed within an integrated probabilistic seismic hazard assessment framework. More specifically, the scheme presented hereby directly integrates effective stress-based seismic soil liquefaction triggering assessment with seismic hazard analysis framework, supported by an illustrative case. The proposed methodology successively, i) processes the discrete stages of probabilistic seismic hazard workflow ...
Analysis of mechanical behavior of high performance cement based composite slabs under impact loading Satıoğlu, Azize Ceren; Gülkan, Polat; Department of Civil Engineering (2009) Studies on the behavior of steel fiber reinforced concrete (SFRC) and slurry infiltrated fibrous concrete (SIFCON) to impact loading have started in recent years. Using these relatively new materials, higher values of tensile and compressive strength can be obtained with greater fracture toughness and energy absorption capacity, and therefore they carry a considerable importance in the design of protective structures. In this thesis, computational analyses concerning impact loading effect on concrete, steel...
Improving ductility and shear capacity of reinforced concrete columns with carbon fiber reinforced polymer Özcan, Okan; Özcebe, Güney; Department of Civil Engineering (2009) The performance of reinforced concrete (RC) columns during recent earthquakes has clearly demonstrated the possible failures associated with inadequate confining reinforcement. The confinement reinforcement requirements of older codes were less stringent than present standards. Many studies were conducted by applying different retrofitting techniques for RC columns that have inadequate confinement reinforcement. A new retrofitting technique by means of Carbon Fiber Reinforced Polymer (CFRP) was developed an...
Re-examination of damage distribution in Adapazari: Geotechnical considerations Bakır, Bahadır Sadık; Yakut, Ahmet (Elsevier BV, 2005-06-01) The role of ground conditions in damage distribution patterns of buildings in the city of Adapazari during the 17 August 1999 Izmit (Kocaeli) earthquake (M-w 7.4) is investigated. Damage was concentrated in the central districts of the city over the alluvial basin where four to seven-story reinforced concrete buildings were most adversely affected. Two distinct and mutually exclusive modes of building damage were observed on the alluvium: structural system failures due to strong ground shaking, and foundati...

Citation Formats

M. Pehlivan, “Assessment of liquefaction susceptibility of fine grained soils,” M.S. - Master of Science, Middle East Technical University, 2009.