there are various parameters that affect stability and expansion of failure zones in under pressure tunnels. among the important parameters that affect failure zones around the tunnels are cohesion and internal friction angle of the rock mass. in addition, the cross sectional shape is the considerable point in failure distribution around the tunnels. the stress analysis method is one of the app...

Strength reduction finite element method (SRFEM) has been widely used to analyze the slope stability. Strength Reduction Factor (SRF) is yielded as the slope Factor Of Safety (FOS) when a running-though shear failure zone comes into being, in which the Plastic Element EQuivalent strain (PEEQ) is employed as the judgment of shear failure initiation in this paper. Moreover, the filed variable is ...

this paper aims at investigating the effects of weld nugget size and expulsion on the mechanical properties of low carbon steel resistance spot welds using tensile-shear test. mechanical performance of spot welds are described in terms of failure mode, peak load and failure energy obtained from the tensile-shear test. the effects of voids and porosity as well as electrode indentation associated...

Determination of the borehole and fracture initiation positions is the main aim of a borehole stability analysis. A wellbore trajectory optimization with the help of the mud pressure may be unreasonable since the mud pressure can only reflect the degree of difficulty for the initial damage to occur at the wellbore rather than the extent of the wellbore damage. In this work, we investigate...

BACKGROUND Most quantitative diagnostic tests do not perfectly differentiate between persons with and without a given disease. We present a simple method to construct a 3-zone partition for quantitative tests results, including positive and negative zones and a gray zone between, and we describe its use in the diagnosis of heart failure by brain natriuretic peptide (BNP) measurement in acute dy...

PURPOSE We determine whether biochemical prostate specific antigen (PSA) failure can be accurately predicted from preoperative serum PSA combined with 6 morphological variables from radical retropubic prostatectomy specimens in men with peripheral zone cancers. The unexpected limitation imposed by preoperative serum PSA on biochemical failure led us to compare peripheral zone to transition zone...

The development of yielded or failure zone due to an engineering construction is a subject of study in different disciplines. In Petroleum engineering, depletion from and injection of gas into a porous rock can cause development of a yield zone around the reservoir. Studying this phenomenon requires elasto-plastic analysis of geomaterial, in this case the porous rocks. In this study, which is a...

the development of yielded or failure zone due to an engineering construction is a subject of study in different disciplines. in petroleum engineering, depletion from and injection of gas into a porous rock can cause development of a yield zone around the reservoir. studying this phenomenon requires elasto-plastic analysis of geomaterial, in this case the porous rocks. in this study, which is a...

This paper discusses Coulomb failure criteria for brittle deformation of intact rock and fault gouge. Data are presented from laboratory experiments designed to identify the critical gouge layer thickness required to effect a transition from the standard Coulomb criterion to a modified failure law (referred to as Coulomb plasticity) appropriate for simple shear of a gouge layer. Experiments wer...