scholarly journals The CANLEX project: summary and conclusions

2000 ◽  
Vol 37 (3) ◽  
pp. 563-591 ◽  
Author(s):  
P K Robertson ◽  
C E (Fear) Wride ◽  
B R List ◽  
U Atukorala ◽  
K W Biggar ◽  
...  
Keyword(s):  
Laboratory Data ◽  
Sandy Soils ◽  
Cyclic Softening ◽  
Soil Liquefaction ◽  
Western Canada ◽  
Research Project ◽  
Large Loss ◽  
Sand Flow ◽  
Loss Of Strength ◽  
Flow Liquefaction

The Canadian geotechnical engineering community has completed a major collaborative 5 year research project entitled the Canadian Liquefaction Experiment (CANLEX). The main objective of the project was to study the phenomenon of soil liquefaction, which can occur in saturated sandy soils and is characterized by a large loss of strength or stiffness resulting in substantial deformations. The intent of this paper is to compare, interpret, and summarize the large amount of field and laboratory data obtained for six sites in Western Canada as part of the CANLEX project. The sites are compared in terms of both flow-liquefaction and cyclic-softening considerations. The paper presents a number of conclusions drawn from the project as a whole, in terms of both fundamental and practical significance.Key words: sand, flow liquefaction, cyclic softening, CANLEX.

The Canadian Liquefaction Experiment: an overview

2000 ◽  
Vol 37 (3) ◽  
pp. 499-504 ◽  
Author(s):  
P K Robertson ◽  
C E (Fear) Wride ◽  
B R List ◽  
U Atukorala ◽  
K W Biggar ◽  
...  
Keyword(s):  
Mining Industry ◽  
Sandy Soils ◽  
Soil Liquefaction ◽  
Financial Impact ◽  
Engineering Structures ◽  
Collaborative Project ◽  
Large Structures ◽  
Tailings Impoundments ◽  
Project Objectives ◽  
Loss Of Strength

The Canadian geotechnical engineering community has completed a major collaborative 5 year research project entitled the Canadian Liquefaction Experiment (CANLEX). The main objective of the project was to study the phenomenon of soil liquefaction, which can occur in saturated sandy soils and is characterized by a large loss of strength or stiffness resulting in substantial deformations. In many areas of Canada, large structures are constructed on or comprise sandy soils, e.g., some major hydroelectricity earth dams and many tailings impoundments in the mining industry. The behaviour of loose sandy soils can be difficult to predict, but can have a significant financial impact on these types of engineering structures. Consequently, the intent of the CANLEX project was to improve the overall understanding of soil liquefaction. This paper provides an overview of the CANLEX project, outlining the project objectives, major achievements, and conclusions. Four companion papers describe different aspects of the project; thus, together, the five papers provide a summary of the CANLEX project.Key words: geotechnical, liquefaction, CANLEX, collaborative project.

Evaluating cyclic liquefaction potential using the cone penetration test

1998 ◽  
Vol 35 (3) ◽  
pp. 442-459 ◽  
Author(s):  
P K Robertson ◽  
CE (Fear) Wride
Keyword(s):  
Earthquake Engineering ◽  
Sandy Soils ◽  
Cone Penetration Test ◽  
Soil Liquefaction ◽  
Penetration Test ◽  
Cone Penetration ◽  
Liquefaction Resistance ◽  
Liquefaction Potential ◽  
Engineering Research ◽  
Research Workshop

Soil liquefaction is a major concern for structures constructed with or on sandy soils. This paper describes the phenomena of soil liquefaction, reviews suitable definitions, and provides an update on methods to evaluate cyclic liquefaction using the cone penetration test (CPT). A method is described to estimate grain characteristics directly from the CPT and to incorporate this into one of the methods for evaluating resistance to cyclic loading. A worked example is also provided, illustrating how the continuous nature of the CPT can provide a good evaluation of cyclic liquefaction potential, on an overall profile basis. This paper forms part of the final submission by the authors to the proceedings of the 1996 National Center for Earthquake Engineering Research workshop on evaluation of liquefaction resistance of soils.Key words: cyclic liquefaction, sandy soils, cone penetration test

scholarly journals Influence of Soil Liquefaction on the Structural Performance of Bridges During Earthquakes: Showa Bridge as A Case Study

2018 ◽  
Vol 7 (4.20) ◽  
pp. 146
Author(s):  
Mohammed K. Dhahir ◽  
Wissam Nadir ◽  
Mohammed H. Rasool
Keyword(s):  
Lateral Displacement ◽  
Bending Moment ◽  
Sandy Soils ◽  
Soil Liquefaction ◽  
Shallow Foundations ◽  
Structural Performance ◽  
Excess Pore Pressure ◽  
Regular Structures ◽  
Loss Of Contact

Liquefaction is generally defined as the loss of contact between soil particles during shaking (earthquakes), and it usually occurs in saturated loose sandy soils where the timescale is insufficient for the water to drain from the pores, thus increasing the excess pore pressure, and thereby floating the sand particles. For regular structures with shallow foundations, liquefaction normally leads to loss of soil strength, which leads to settlement of foundations. On the other hand, bridges are usually supported with piles foundation, which introduces additional effects during liquefaction. Therefore, this paper examines the possible effects of liquefaction on the structural performance of bridges during earthquakes. Furthermore, the failure of Showa Bridge during the 1964 Nagata earthquake was also discussed and analyzed as an example of the catastrophic effects of liquefaction. The analysis shows that the most influential effect during liquefaction is the increase in the unsupported length of piles, which leads to several adverse effects such as increasing the lateral displacement, reduce the buckling capacity, increase the bending moment, and reduce the shaft capacity of the pile. Finally, recommendations regarding the design of pile supported bridges in seismic areas with liquefiable soils have also been suggested. 

Soil Liquefaction Assessment by Anisotropic Cyclic Triaxial Test

2018 ◽  
pp. 631-664
Author(s):  
Koray Ulamis
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Axial Strain ◽  
Water Pressure ◽  
Sandy Soils ◽  
Soil Liquefaction ◽  
Cyclic Triaxial ◽  
Loading Case ◽  
Anisotropic Consolidation ◽  
Assessment Standard

Liquefaction of saturated sandy soils is one of the most significant aspects of earthquake triggered natural hazards. The main mechanism deals with the loss of effective stress due to rapid pore water pressure generation during earthquake shaking. This chapter involves with the fundamental mechanism and impacts of liquefaction. Liquefaction susceptibility of geological environments are briefly represented for preliminary assessment. Standard procedures of liquefaction are summarized. The dynamic response of sands are also reviewed. A case of anisotropic loading is considered, using three different particle sized sands below a shallow footing. Such sandy soils are subjected to anisotropic consolidation before performing undrained cyclic triaxial testing along limited cycles. Variation of axial strain, pore water pressure and related parameters are investigated. Main outcome of this study is to review the initial liquefaction state of sands by anisotropic loading case.

Reconsideration of case histories for estimating undrained shear strength in sandy soils

1999 ◽  
Vol 36 (5) ◽  
pp. 907-933 ◽  
Author(s):  
C E (Fear) Wride ◽  
E C McRoberts ◽  
P K Robertson
Keyword(s):  
Shear Strength ◽  
Sandy Soils ◽  
Standard Penetration Test ◽  
Undrained Shear Strength ◽  
Soil Liquefaction ◽  
Penetration Test ◽  
Case Histories ◽  
Original Case ◽  
Undrained Strength ◽  
Undrained Shear

When sandy soils respond in a strain-softening manner to undrained loading, an estimation of the resulting undrained shear strength (Su) is required to determine the potential for flow liquefaction at a given site. One of the most commonly used methods for estimating the undrained strength of liquefied sand is an empirical standard penetration test (SPT) based chart (originally proposed by H.B. Seed), which was developed using a number of case histories. The original interpretations of these case histories are viewed by many workers and regulatory agencies as the most authoritative measure of the liquefied strength of sand. Consequently, in comparison, other less conservative methods are generally held in an unfavourable light. This paper reexamines the original database of case histories in view of some more recent concepts regarding soil liquefaction. The objectives of this paper are to explore and reassess the issues involved in the original assessment and to offer alternative views of the case records. The conclusions presented here indicate that alternative explanations of the liquefied strength of sand are not inconsistent with the original case histories. Key words: sandy soils, soil liquefaction, undrained strength, standard penetration test (SPT).

scholarly journals THE EMPIRICAL ANALYSIS OF SOIL LIQUEFACTION IN IMOGIRI SITE, YOGYAKARTA, INDONESIA

2019 ◽  
Vol 21 (1) ◽  
pp. 37
Author(s):  
Lindung Zalbuin Mase
Keyword(s):  
Empirical Analysis ◽  
Strong Earthquake ◽  
Sandy Soils ◽  
Soil Liquefaction ◽  
Public Facilities ◽  
The People ◽  
Peak Ground Accelerations ◽  
High Level ◽  
A Site ◽  
The Empirical Analysis

A strong earthquake with magnitude of 6.3 Mw, which was later known as the JogjaEarthquake, occurred in the southern part of Yogyakarta Special Province. The earthquakehad resulted in the huge damage to the buildings, public facilities as well as triggering theground failure phenomenon, which was known as liquefaction. An empirical analysis usingthe conventional method was performed to investigate the liquefaction severity for the siteinvestigation data in Imogiri, a site with the high-level of the liquefaction damage duringthe earthquake. The peak ground accelerations varied to 0.3 to 0.4g are also implemented inthe analysis. The results show that the investigated site is dominated by sandy soils. Thesandy soil in Imogiri site is categorised as the liquefiable layer during the Jogja Earthquakeand potentially to liquefy on shallow depth. In general, this study could warn the people forthe impact of soil liquefaction if the stronger earthquake happens in the future.

Sand flow liquefaction instability under shear–volume coupled strain paths

Géotechnique ◽  
2018 ◽  
Vol 68 (11) ◽  
pp. 1002-1024 ◽  
Author(s):  
A. Lashkari ◽  
M. S. Yaghtin
Keyword(s):  
Strain Paths ◽  
Sand Flow ◽  
Flow Liquefaction

The Effects of Vertical Stress on the Liquefaction Potential Originated from Buildings in The Urban Areas

2020 ◽  
pp. 351-372
Author(s):  
Mehmet Ozcelik
Keyword(s):  
Urban Areas ◽  
Sandy Soils ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Vertical Stress ◽  
Limited Information ◽  
Liquefaction Potential ◽  
Empirical Procedure ◽  
Seismic Forces

Main purpose of this paper is to study the influence of vertical stress on soil liquefaction in urban areas. The literature provides limited information on vertical stress analysis of multiple footings, and, as a result, there is no accurate way to account for the effect of the foundation depth on liquefaction. Additionally, practical methods do not exist for considering the interaction between the neighboring foundations vertical stress and seismic forces in the urban area. Vertical stress distribution was calculated in examining the soil liquefaction potential exhibited by building foundations as a case study. The vertical stresses were chosen randomly for some buildings with foundation depths of 3.00 m; 4.50 and 6.00 m at the Burkent site (Burdur-Turkey). The influence of 5-storey buildings on the liquefaction potential of sandy soils was evaluated in terms of the safety factor (FS) against liquefaction along soil profile depths for different earthquakes. Standard Penetration Test (SPT) results were used based on simplified empirical procedure.

Improving Creep-Fatigue Design Methodology for Advanced Ferritic-Martensitic Steels

2014 ◽  
Author(s):  
Meimei Li ◽  
William K. Soppet ◽  
Saurin Majumdar ◽  
Ken Natesan
Keyword(s):  
Design Methodology ◽  
Laboratory Data ◽  
Constitutive Models ◽  
Fatigue Loading ◽  
Cyclic Softening ◽  
Advanced Materials ◽  
Critical Element ◽  
Martensitic Steels ◽  
Fast Reactors ◽  
Creep Fatigue

Advanced materials are a critical element in the development of advanced sodium-cooled fast reactors. High temperature design methodology of advanced materials is an enabling reactor technology. Removal of unnecessary conservatism in design rules could lead to more flexibility in construction and operation of advanced sodium-cooled fast reactors. Developing mechanistic understanding and predictive models for long-term degradation phenomena such as creep-fatigue are essential to the extrapolation of accelerated laboratory data to reactor environments with high confidence, and to improve the American Society of Mechanical Engineers (ASME) code rules. This paper examines the cyclic softening and stress relaxation responses and associated plastic damage accumulation for Grade 91 ferritic-martensitic steel. Creep-fatigue experiments were conducted at 550°C in strain-controlled mode under various types of creep-fatigue loading conditions. Constitutive models were developed to describe the creep-fatigue interaction in G91.

scholarly journals Understanding Student Anti-racism Activism to Foster Social Justice in Schools

2008 ◽  
Vol 10 (1) ◽  
Author(s):  
Darren E. Lund ◽  
Maryam Nabavi
Keyword(s):  
Social Justice ◽  
Collaborative Research ◽  
Social Acceptance ◽  
Student Activism ◽  
Western Canada ◽  
Years Of Experience ◽  
Sources Of Resistance ◽  
Research Project ◽  
School Settings ◽  
The Social

The purpose of this study was to understand the experiences of students and teachers who form voluntary coalitions or school projects to address issues of racism and discrimination. The authors draw on several years of experience of facilitating student activism and findings from a recent collaborative research project. This research documents and analyzes experiences from a number of school settings across western Canada but has implications for student social justice activism everywhere. The study examines how students get involved with voluntary coalitions to undertake anti-racism initiatives to enhance the social acceptance of marginalized students and how they can overcome sources of resistance to promote inclusion.

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