2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 319-13
Presentation Time: 12:00 PM

DISTINCT ELEMENT MODELLING OF FRACTURE DEVELOPMENT DURING STRIKE-SLIP FAULT INTERACTIONS


YOU, Seungwan1, KWON, Sanghoon1, KWON, Soondal2 and PARK, Youngdo2, (1)Department of Earth System Sciences, Yonsei University, 134 Shinchon-dong, Seodaemoon-ku, Seoul, 120-749, South Korea, (2)Research Division, Heesong Geotek, Woolim Lion’s Valley 2-cha building, 146-8 Sangdaewon 1- dong, Jungwon-ku, Seongnam-si, 462-807, South Korea, seungwan@yonsei.ac.kr

We have used distinct element method (DEM with a code name, PFC2D developed by Itasca CG) to numerically simulate the sandbox for fracture development during strike-slip fault interactions. DEM is a method for solving mechanical problems of discontinuous materials with particulate data structures and boundary-condition elements. Stored energy in elastically compressed particles with Hookean or Hertzian behavior is the driving force for motions of particles.

A numerical sandbox is designed for modelling formation and evolution of fractures during interactions of strike-slip faults. Strike-slip bend consisting of stepover shear fractures are created to model fault interactions. The biggest advantage of a numerical sandbox compared to physical sandbox in mechanical experiments is that stresses are calculated, instead of guessed, in the numerical sandbox. We have focused on two aspects; (1) fracture development patterns propagated from strike-slip bends and (2) verifying interactions between stress conditions at fault tips and orientations of fracture growths.

From the experiments related to fracture developments during strike-slip fault interactions, we found that shear fractures propagating at fault tips are bent by shear disturbance, which is commonly observed in many strike-slip settings. We are currently studying changes in stress orientations and magnitudes during incipient developments and their evolution.

The quantitative results from the numerical models in this study will provide quantitative results that can help to understand the kinematics and mechanics of fracture developments at strike-slip bends.