Santamarina, J. Carlos

Thumbnail Image
Preferred name
Santamarina, J. Carlos
Official Name
Santamarina, J. Carlos

Research Output

Filters

221
2
2
Reset filters

Settings

Now showing 1 - 2 of 2
  • Publication
    Desiccation crack formation beneath the surface
    (ICE Publishing, 2020-02-01)
    Zhao, Budi 
    ;
    Santamarina, J. Carlos 
    Desiccation cracks affect all mechanical and conduction properties. Previous studies have investigated the formation of surface desiccation cracks in fine-grained sediments in relation to their compressibility and suction potential. This study explores the formation of internal desiccation cracks in saturated kaolinite specimens consolidated inside self-reactive oedometer cells to reproduce the initial effective stress in buried sediments. X-ray tomography is used to monitor internal processes during consolidation and drying. Images capture the evolution of a perimetric fracture, transverse contraction, volumetric changes in entrained gas bubbles and the development of internal desiccation cracks. Entrained gas bubbles act as nucleation sites. They shrink during loading and early stages of desiccation. Eventually, the gas-water interface penetrates the soil at the bubble surface, pushes particles away, enlarges local pores and facilitates further growth of the internal desiccation crack. While air entry is grain-displacive in soft, fine-grained sediments, it becomes pore-invasive in stiff, coarse-grained sediments and internal desiccation cracks are not expected in silts or sands.
      273Scopus© Citations 20
  • Publication
    Particle Migration and Clogging in Porous Media: A Convergent Flow Microfluidics Study
    (Wiley, 2019-09)
    Liu, Q 
    ;
    Zhao, Budi 
    ;
    Santamarina, J. Carlos 
    The migration and retention of fine particles in porous media are important phenomena in natural processes and engineering applications. Migrating particles experience physicochemical interactions with carrier fluids, pore walls, and other migrating particles. The governing dimensionless ratios capture particle-level forces, flow conditions, and geometric characteristics. This study explores micron-size particle migration and retention in microfluidic chips during convergent radial flow, which is the prevalent flow condition in water extraction and oil production. Pore-scale observations reveal the role of electrostatic interactions on clogging mechanisms: Glass particles experience retardation-accumulation bridging, while quasi-buoyant latex particles involve capture and clogging. Consequently, flow rates exert opposite effects on the clogging behavior of inertial glass particles versus electrostatically affected latex particles. Migrating particles experience a varying fluid velocity field in convergent radial flow, and clogging reflects the evolving local conditions (Nad, Ar, Stk, and Re). In particular, clogged pores alter local flow and promote further clogging nearby. Pore network model simulations suggest that such “dependent clogging” lowers the permeability of the porous medium more effectively than independent clogging at random locations.
      123Scopus© Citations 50