^pState;
Key;
Laboratory;
of;
Nonlinear;
Mechanics,;
Institute;
of;
Mechanics,;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100190,;
China;
^pof;
Resources;
and;
Safety;
Engineering,;
China;
University;
of;
Mining;
&;
Technology,;
Beijing;
100083,;
China;