Abstract

This paper introduces the test results of dark-gray calcium-shale, discusses the infection of strength characteristic and deformation characteristic due to the angle between structural planes.

Zusammenfassung

Basier auf der Anwendung von Problematik des Felsenbauprojektes und Beschaffenheit Felsen unter Beaugnshme auf den Zustand des Druckes von einzeler Welle legt dieser Text dar, wie der Winkel der Schichtstrukturflaeche des schwarzgrau kalziumhaltigen Schieferblocks θauf die Zerstoerungs-, Intensitaets- und Deformationseigenschaften einwirkt.

Schluesselwoerter

Schwarzgrau kalziumhaltigen Schiefer, Zerstoerungseigenschften, Intensitaetseigenschften, Deformationseigenschaften, Flaeche dar Schichtstruktur.

Resume

En fonction de la configuration du massif rocheux sous l'etat de la contrainte de pression axiale simple et de la pratique de l'ingenierie de roches, le present article fait la description concernant l'influence de l'inclinaison θ de la couche de structure stratifiee du bloc de schiste calcaire gris noir sur ses caracteristiques de destruction, sa specificite de resistance ainsi que sa nature de deformation.

Mot cles

Schiste calcaire gris noir, Caracteristiques de destruction, Specificite de resistance, Nature de deformation, Couche de structure stratifiee

Introduction

During long-term geological-historical process, the structure of rock mass were formed. Rock masses are made of heterogeneous and discontinuous materials. In rock masses, there are full of disfigurements, such as fault, joint, crack, layer, bedding, weathering crack, unloading crack. Generally, disfigurements are anisotropic, Rock mass mechanics is rest with the form of structure. Anisotropy of rock mass is an importance content of rock mechanics. In order to investigate anisotropy of rock mass, uniaxial compression tests of calcium-shale has been performed (see fig 1). The calcium-shale is dark gray, layer.

The influence of strength due to anisotropy
Failure form

Failure of rock has two forms, one is brittleness, another is plastic. Test results show that calcium-shale has two failure forms, tension and tension-shear. With θ changes, mechanism of failure forms can be divided into three types.

(Equation in full paper)

Strength character

Strength character of rock mass was decided by stress state, medium character, structure plains and its correlation. As the correlation changed, ultimate compression strength, destroy form and destroy mechanism will be changed. The experiment result shows that, with _ increases, destroy mechanism and ultimate compression strength of calcium-shale under uniaxial compression stress are also changed.(see table 1 and fig 2).

(Equation in full paper)

Deformation characteristic
Stress-strain relation

The study results showed that stress-strain relation curve of calcium-shale under uniaxial compression stress could be divided into three types.

  1. When θ=0°~15°, compression stress σ vertical to the layers of the rock, deformation of the rock was given priority to the normal deformation of the layers. When σ is lower, layers of the rock were compressed, deformation is larger, the stress-strain relation curve is assumed bend upwards. With the increase of σ, layers closed gradually, normal deformation of the layers is smaller than the former, stress-strain relation curve becomes steeply, near a line. As σ increase continuously, local crack appears in the rock, normal deformation of the layers increases gradually, plastic deformation appears. Stress-strain relation curve is assumed bend downwards.

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