scholarly journals Rock Strength Anisotropy in High Stress Conditions: A Case Study for Application to Shaft Stability Assessments

2015 ◽  
Vol 37 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Julian Matthew Watson ◽  
Abouzar Vakili ◽  
Mateusz Jakubowski
Keyword(s):  
Rock Strength ◽  
Underground Mining ◽  
Failure Mechanisms ◽  
High Stress ◽  
Strength Anisotropy ◽  
Anisotropic Rock ◽  
Geotechnical Design ◽  
Anisotropic Rocks ◽  
Stress Environment

Abstract Although rock strength anisotropy is a well-known phenomenon in rock mechanics, its impact on geotechnical design is often ignored or underestimated. This paper explores the concept of anisotropy in a high stress environment using an improved unified constitutive model (IUCM), which can account for more complex failure mechanisms. The IUCM is used to better understand the typical responses of anisotropic rocks to underground mining. This study applies the IUCM to a proposed rock shaft located in high stress/anisotropic conditions. Results suggest that the effect of rock strength anisotropy must be taken into consideration when assessing the rock mass response to mining in high stress and anisotropic rock conditions.

scholarly journals GEOLOGICAL CONTROLS ON INTACT ROCK STRENGTH. THE EFFECT OF ANISOTROPY

2004 ◽  
Vol 36 (4) ◽  
pp. 1826
Author(s):  
χ. Σαρόγλου ◽  
Π. Μαρίνος ◽  
Γ. Τσιαμπάος
Keyword(s):  
Mechanical Properties ◽  
Rock Strength ◽  
Dynamic Properties ◽  
Intact Rock ◽  
Metamorphic Rocks ◽  
Deformation Characteristics ◽  
Strength Anisotropy ◽  
Ongoing Research ◽  
Strength And Deformation ◽  
Anisotropic Rocks

The factors that influence the strength and deformation of the intact rock are the mineral composition, the fabric, the grain size and the degree of alteration and weathering. Anisotropy is a characteristic of intact foliated metamorphic rocks (slates, gneisses, phyllites, schists). The current paper deals with the pronounced effect of the fabric of anisotropic rocks on the strength and deformation characteristics of intact rocks. It is part of ongoing research in the Department of Geotechnical Engineering, National Technical University of Athens. Testing was used to establish the anisotropic behaviour of selected metamorphic rocks. The effect of anisotropy on various mechanical properties (strength, deformation) and dynamic properties (wave velocity) was examined. The degree of strength anisotropy of these rocks can be indirectly estimated, by wave propagation through the rock, and thus they can be classified by means of geological and geotechnical indexes.

Advanced IR-OBIRCH Analysis Technique for High Isb Failure Analysis

2010 ◽  
Author(s):  
Kuo Hsiung Chen ◽  
Wen Sheng Wu ◽  
Yu Hsiang Shu ◽  
Jian Chan Lin
Keyword(s):  
Failure Analysis ◽  
Failure Mechanisms ◽  
Fault Localization ◽  
Resistance Change ◽  
The Real ◽  
Analysis Techniques ◽  
Analysis Technique ◽  
Leakage Failure ◽  
Failure Site

Abstract IR-OBIRCH (Infrared Ray – Optical Beam Induced Resistance Change) is one of the main failure analysis techniques [1] [2] [3] [4]. It is a useful tool to do fault localization on leakage failure cases such as poor Via or contact connection, FEoL or BEoL pattern bridge, and etc. But the real failure sites associated with the above failure mechanisms are not always found at the OBIRCH spot locations. Sometimes the real failure site is far away from the OBIRCH spot and it will result in inconclusive PFA Analysis. Finding the real failure site is what matters the most for fault localization detection. In this paper, we will introduce one case using deep sub-micron process generation which suffers serious high Isb current at wafer donut region. In this case study a BEoL Via poor connection is found far away from the OBIRCH spots. This implies that layout tracing skill and relation investigation among OBIRCH spots are needed for successful failure analysis.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

Suction anchor geotechnical design practice: A case study

2015 ◽  
pp. 283-288 ◽  
Author(s):  
J Kennedy ◽  
J Oliphant ◽  
A Maconochie ◽  
B Stuyts ◽  
D Cathie
Keyword(s):  
Design Practice ◽  
Geotechnical Design

scholarly journals Patriarchy in the Digital Conjuncture: An Analysis of Google’s James Damore

2020 ◽  
Author(s):  
Ben Little ◽  
Alison Winch
Keyword(s):  
Scientific Method ◽  
Software Engineer ◽  
High Stress ◽  
Silicon Valley ◽  
High Status ◽  
The Core ◽  
Core Belief ◽  
The World ◽  
New Form

Our case study looks at the events surrounding the sacking ofGoogle engineer James Damore who was fired for authoring a memo which stated that women are biologically less suited to high-stress, high-status technical employment than men. Damore, asserting that his document ‘was absolutely consistent with what he’d seen online’, instantly became an ambivalent hero of the alt-right. Like the men who own and run the companies of Silicon Valley, the software engineer subscribes to the idea that the world can be understood and altered through the rigorous application of the scientific method. And as he draws on bodies of knowledge from evolutionary psychology and mathematical biology, we see how the core belief structures of Silicon Valley, when transferred from the technical to the cultural and social domain, can reproduce the sort of misogynistic ‘rationalism’ that fuels the alt-right. We argue that Damore’s memo is in line with Google’s ideology of ‘dataism’: that is the belief that the world can be reduced to decontextualised information and subject to quantifiable logics.Through its use of dataism, the memo reveals much about the similarities and continuities between Damore, the ideas laid out n his memo, and Google itself. Rather than being in opposition, these two entities are jostling for a place in the patriarchal structures of a new form of capitalism.

Sign in / Sign up

Export Citation Format

Share Document