The conventional continuum-based numerical approaches confront bottleneck in dealing with the problems associated with failure and instability of geomaterials, which are very common in nature and engineering practice. In contrast, the distinct element method (DEM) provides a powerful tool to capture the entire process of failure in geomaterials. Due to necessity of modeling details at the particulate scale, DEM is costly for large-scale boundary problems, in which a rigorous multi-scale approach is desired.

 

Objective: 

（1）To apply DEM analysis to engineering problems such as rock instability, in situ penetration, wheel-soil interaction, tunneling, foundation capacity and failure. 

（2）To develop multi-scale DEM-FEM-analytical coupled method for solving large-scale engineering problems. 

 

Approach: 

DEM were used to directly analyze engineering problems associated with geohazards and failure in geomaterials. Multi-scale methods were developed by coupling analytical solution, the finite element method and DEM. The enhanced methods were then used to investigate large-scale engineering problems such as tunneling in highly fractured and heterogeneous rocks. 

 

Significant Results and Potential Impact: 

DEM has been successfully applied to many boundary-value problems associated with geohazards and failure, which have gained detailed microscopic information during process towards failure. The coupled method will provide a rigorous and efficient tool to investigate large-scale engineering problems from both macroscopic and microscopic standpoint.   

 

Principal Investigator:

Mingjing Jiang, Fang Liu, Huaning Wang.

 

Funding: 

      Marie Curie Actions—International Research Staff Exchange Scheme: Geohazards and Geomechanics (294976)

      973Program: Interaction between TBM and Surrounding Rock in Deep Multiple Stratum and Safety Control (2014CB046901)

      973 Program: The Performance Evolution in Life Cycle and Safety Control of High-steep Slope in Large-scale Water Conservancy and Hydropower Engineering (2011CB013504)

      National Science Foundation of China: Stochastic Model of Regional Liquefaction-Induced Lateral Deformation (41102173)

      International collaborative project: Earth pressure against combined walls (20110603009)

      Program of Shanghai Academic Chief Scientist: Test and DEM Analysis of Mechanism of CPT on Lunar Soil Simulant (11XD1405200)

 

Key Publication: 

      1.Jiang M J, Liu F, Shen Z F, Zheng M. Distinct element simulation of lugged wheel performance under extraterrestrial environmental effects. Acta Astronautica, 2014, 99: 37-51.

      2.Jiang M J, Dai Y S, Cui L, Shen Z F, Wang X X. Investigating mechanism of inclined CPT in granular ground using DEM. Granular Matter, 2014, DOI: 10.1007/s10035-014-0508-2.

      3.Jiang M J, Yin Z Y. Influence of soil conditions on ground deformation during longitudinal tunneling. Comptes Rendus Mecanique, 2014, 342(3): 189-197.

      4.Sima J, Jiang M J, Zhou C B. Numerical simulation of desiccation cracking in a thin clay layer using 3D discrete element modeling, Computers and Geotechnics, 2014, 56C:168-180.

      5.Wang H N, Utili S, Jiang M J. An analytical approach for the sequential excavation of axisymmetric lined tunnels in viscoelastic rock, International Journal of Rock Mechanics and Mining Sciences, 2014, 68: 85-106.

      6.Wang H N, Li Y , Ni Q, Utili S, Jiang M J, Liu F. Analytical solutions for the construction of deeply buried circular tunnels with two liners in rheological rock. Rock Mechanics and Rock Engineering, 2013, 46: 1481-1498.

      7.Jiang M J, Shen Z F, Zhu F Y. Numerical Analyses of Braced Excavation in Granular Grounds: Continuum and Discrete Element Approaches. Granular Matter, 2013,15(2): 195-208.

      8.Jiang M J, Murakami A. Distinct element method analyses of idealized bonded-granulate cut slope, Granular Matter, 2012, 14: 393–410.

      9.Jiang M J, Yin Z Y. Analysis of stress redistribution in soil and earth pressure on tunnel lining using the discrete element method. Tunnelling and Underground Space Technology, 2012, 32: 251-259.

      10.Jiang M J, Sun Y G. Cavity expansion analyses of crushable granular materials with state-dependent dilatancy. International Journal for Numerical and Analytical Methods in Geomechanics, 2012, 36:723-742.