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Modeling of Post-Failure Behavior of the Rock Mass and its Effect on the Stress-Deformation State in the Vicinity of a Mining Excavation

Marczak Halina

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 2

130--140

EN

The study investigated the impact of post-failure properties of the rock mass on the stress-deformation state in the vicinity of the underground excavation and the pressure exerted on the support. An analytical solution to the problem was presented, including the creation of inelastic zones in the vicinity of the excavation: ideal-plastic zone with residual strength and plastic zone with mild decrease of rock medium strength and taking into account the dilatancy. The analysis of the obtained dependencies was carried out using geotechnical parameters characterizing the Carboniferous rock mass of a hard coal mine. The influence of the plastic zone was determined with a mild decrease in strength to the state of stress, deformation and pressure on the rock mass support. The results of the considerations were compared with the solution, which omitted the softening of the rock mass and the solution based on the model of the elastic-plastic-brittle medium. The results of the analysis broaden the knowledge on the behavior of the rock medium in the vicinity of the excavation. The obtained solution can be further developed in order to enable its practical application, especially under the conditions in which the behavior of the rock medium in the vicinity of the excavation well reflects the elastic-plastic model with a gentle drop in the strength of the rock material.

2

FEM based analysis of wing wall to culvert connection

Voitenko P., Anderson J. B.

Builder

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2017

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R.21, nr 11

78--81

EN

As part of transportation systems, culverts are subjected to complex load conditions such as earth pressure and traffic live load. In addition, culverts may experience differential settlement of underlying soils, hydrostatic load, and aggradation/degradation scour. Combinations of these effects may cause crack formation or even structural failure. The objective of this paper is to study factors that lead to crack formation in the culvert-wing wall connection immediately after construction. Finite element models (FE) with Plaxis 3D software were used to analyze the stress distribution along the wing wall connection under different load scenarios and geometries. Mohr-Coulomb (MC) and Hardening soil (HS) non-linear material models were utilized. Tension stresses were occurred at the top of the wing wall as well as out of plane rotation away from the culvert, contributing to cracks as observed in the field.

3

Warunki stanu granicznego dla ośrodków rozdrobnionych

Dołżyk K.

Budownictwo i Inżynieria Środowiska

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2011

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Vol. 2, no. 2

123-128

PL

W latach 60-tych ubiegłego wieku zaproponowano wiele warunkow stanu granicznego dla ośrodkow rozdrobnionych. Większość warunków uwzględnia wpływ pośredniego naprężenia głównego na wytrzymałość i przyjmuje liniową zależność wytrzymałości od wartości średniego ciśnienia. Przyjmując że wytrzymałość ośrodka rozdrobnionego nie zależy od pośredniego naprężenia głównego, wytrzymałość ośrodka rozdrobnionego może być określona warunkiem Coulomba-Mohra o dwoch parametrach: kohezji c i kącie tarcia wewnętrznego. Ze względu na swoją prostotę warunek Coulomba-Mohra jest najczęściej wykorzystywany w praktyce inżynierskiej.

EN

Many failure criteria were proposed for geomaterials in the sixties of the 20th century. In most of them the influence of middle main stress is neglected and linear influence of hydrostatic pressure on failure is assumed. The most popular and simplest is the Mohr-Coulomb criterion of failure with two material failure parameters: angle of friction and cohesion c. The Mohr-Coulomb criterion is most often used in engineering practice.

4

Ocena stateczności skarp i zboczy z wykorzystaniem kryterium Coulomba-Mohra o zmiennych parametrach

Srokosz P. E.

Inżynieria i Budownictwo

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2009

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R. 65, nr 12

675-678

PL

Przedstawiono możliwości analizy stateczności skarp z wykorzystaniem MES ze sprężysto-plastycznym prawem konstytutywnym z kryterium Coulomba-Mohra opisanym zmiennymi wartościami parametrów. Parametry modelu konstytutywnego są uzależnione od dewiatora skumulowanych odkształceń plastycznych i mogą być wyznaczane z badań trójosiowego ściskania techniką analizy wstecznej.

EN

The paper presents possibilities of slope stability evaluation using FEM with elastic-plastic constitutive law with Mohr-Coulomb criterion defined by a set of variable parameters. The parameters of constitutive law vary with accumulated deviatoric plastic strains and can be determined from triaxial tests results using back analysis technique.