せん断時の土の応カ―ひずみ関係について

Abstract

The shearing mechanism of soils has been studied from the microscopic point of view in orderto analyze their macroscopic stress-strain relation. Special shearing tests were carried out usingaluminium rods and similar rods made of a photoelastic material to simulate granular mass in two-dimensional state. The concept of the frequency distribution of the contact angle between parti-cles 0 and its variation during shear was introduced to represent the shearing resistance anddilatancy character. The basic relation of stress ratio (τ/σN) ～ the mean value of θ (θ) and that ofnormal strain caused by dilatancy (εN) ～ θare derived as follows;τ/σN=λ・θ+μ εN=(cosθ-cosθ0)/cosθ0whereλ= 1.4-. 1.5 (coust.), μ; the coefficient of friction between particles, θ0; θ immediately af-ter the beginning of shearing. From these microscopic consideration, the stress-strain relationof soils under shearing which can be applied to sands and clays has been derived as follows;where μ'=-λ・θ0+μ, γ0;γ at the maximum compression point of εN.