Study of the Backfill Confined Consolidation Law and Creep Constitutive Model under High Stress

Abstract

To better understand the mechanical behavior of the compression deformation of backfill under high stresses corresponding to large depths, consolidation compression tests were performed for cemented tailings backfill with a cement-sand ratio of 1:10 and a concentration of 70 % under confined conditions. After applying different loading stress functions from 0.5 to 32 MPa, the final axial deformation of the test specimen of backfill was obtained, and the micromorphology of backfill was studied before and after consolidation by scanning electron microscopy. Additionally, fitting analysis was performed for backfill confined compression deformation data and device model constitutive equations by the minimum square law, and the constitutive model was revised according to the analysis results. The research results indicate that as the load increases, the void ratio e obeys the functional relationship e=algt + b with compression time t. Under the high-stress conditions of confinement, the constitutive model of backfill consolidation and creep can be used to describe the creep behavior of the backfill. Under high-stress conditions, after the consolidation of the confined backfill, the space between the tailing particles diminishes, the particles become more compact, and particle slippage occurs.

On the fracture and energy characteristics of rock–backfill composite structure specimens exposed to fatigue–creep interaction loading

“…The above studies on RBCS mechanical behaviors are mainly focused on static loading paths; damage and fracture evolution characteristics of RBCS material exposed to stress disturbance conditions have not been well understood. In addition, in deep backfill mining, the RBCS material in the underground stope is always subjected to frequent stress disturbance and strong rheology conditions [17][18][19][20] ; the disturbed stress and creep actions influence the long-term stability of deep stope. However, investigations that consider the fatigue and creep effect on RBCS failure evolution are rarely performed.…”

An analytical model for the triaxial compressive Stress-strain relationships of Cemented Pasted Backfill (CPB) with different curing time

“…For backfilling materials under uniaxial compression, existing constitutive models consider various factors, such as: solid content [6][7][8], cement-tailing ratios [7,9,10], layered structure of tested sample [10][11][12], porosity and pore size [14], etc. In addition, different loading methods were also added to some of the existing constitutive models to describe the tested stress-strain curves, such as: creep behaviors [15][16][17], thixotropic [18], and cyclic loading [19], etc. There were also constitutive models in which the complex storage environments of the backfilled CPB and the multi-physics coupling were considered [20][21][22].…”

Experimental Study on Consolidation-Creep Behavior of Subgrade Modified Soil in Seasonally Frozen Areas

“…Wong et al [ 19 ] proposed a methodology to decouple the creep-deformation component from the total deformation measured in oedometer tests, which can determine the intrinsic properties of a 1D normally consolidated curve and creep behavior. Wang et al [ 20 ] proved that the constitutive model of backfill consolidation and creep can be used to describe the creep behavior of the backfill under the high stress conditions of confinement. Yin et al [ 21 ] presented a new simplified hypothesis B method for calculation of consolidation settlement of a clayey soil with creep.…”