An improved analytical solution to estimate the stress state in subvertical backfilled stopes

The increasing use of backfill in underground mines requires a better understanding of the interaction between the relatively soft fill material and the surrounding rock mass. In recent years, it has been shown that stresses in backfilled stopes can be estimated using an approach based on Marston’s arching formulation developed initially for buried conduits in trenches. However, despite its advantages, this approach has some shortcomings. For instance, it postulates that both the vertical and horizontal normal stresses are uniformly distributed across the opening width. Numerical investigations conducted by the authors have shown that this assumption is not always valid. This paper presents a modification to the Marston-based solution, which leads to a nonuniform vertical stress distribution across the opening. This modification of the analytical solution involves parameters that have been calibrated against some numerical modelling results. The same equations and parameters are then shown to provide a go...

[1]  Kousick Biswas,et al.  REVIEW OF CURRENT HIGH DENSITY PASTE FILL AND ITS TECHNOLOGY , 2002 .

[2]  A Marston,et al.  THE THEORY OF EXTERNAL LOADS ON CLOSED CONDUITS IN THE LIGHT OF THE LATEST EXPERIMENTS , 1930 .

[3]  David F. McCarthy,et al.  Essentials of Soil Mechanics and Foundations: Basic Geotechnics , 1982 .

[4]  Michel Aubertin,et al.  Formulation and application of a general inelastic locus for geomaterials with variable porosity , 2005 .

[5]  Jin Y. Ooi,et al.  Wall pressures in squat steel silos from simple finite element analysis , 1990 .

[6]  D. M. Walker.  An approximate theory for pressures and arching in hoppers , 1966 .

[7]  G. E. Blight,et al.  Pressures exerted by materials stored in silos: part I, coarse materials , 1986 .

[8]  Michel Aubertin,et al.  A Three-Dimensional Analysis of the Total and Effective Stresses in Submerged Backfilled Stopes , 2009 .

[9]  Nagaratnam Sivakugan,et al.  Arching within hydraulic fill stopes , 2007 .

[10]  R J Mitchell.  Earth Structures Engineering , 1983 .

[11]  Van Horn.  A STUDY OF LOADS ON UNDERGROUND STRUCTURES , 1964 .

[12]  Joseph E. Bowles,et al.  Foundation analysis and design , 1968 .

[13]  Andy Fourie,et al.  Some aspects of the mechanics of arching in backfilled stopes , 2009 .

[14]  Herbert H. Einstein,et al.  Determination of Vertical Loading on Underground Structures Based on an Arching Evolution Concept , 1999 .

[15]  A. J. Valsangkar,et al.  Earth pressures on unyielding retaining walls of narrow backfill width , 2001 .

[16]  Andrew Drescher,et al.  Analytical methods in bin-load analysis , 1991 .

[17]  Michel Aubertin,et al.  Influence of Water Pressure on the Stress State in Stopes with Cohesionless Backfill , 2009 .

[18]  Tikou Belem,et al.  Effects of settlement and drainage on strength development within mine paste backfill , 2002 .

[19]  R. P. Krushelnitzky,et al.  Response of a landfill drainage pipe buried in a trench , 2005 .

[20]  Li Li,et al.  Formulation of a three dimensional analytical solution to evaluate stresses in backfilled vertical narrow openings , 2005 .

[21]  Michel Aubertin,et al.  Horizontal pressure on barricades for backfilled stopes. Part I: Fully drained conditions , 2009 .

[22]  K. Terzaghi.  Theoretical Soil Mechanics , 1943 .

[23]  R. Handy.  The Arch in Soil Arching , 1985 .

[24]  Dan Kump.  Backfill -- Whatever it takes , 2001 .

[25]  Sven Knutsson.  Stresses in the hydraulic backfill from analytical calculations and in-situ measurements , 1981 .

[26]  B. Ladanyi,et al.  A STUDY OF THE TRAP-DOOR PROBLEM IN A GRANULAR MASS , 1969 .