7SOROKIN S V, NIELSEN J B, OLHOFF N. Analysis and Opti- mization of Energy Flows in Structures Composed of Beam Ele- ments[ J]. Struet Multidise OPtim, 2001 (22) : 12 - 23.
8KHUBERYAN K M, TSINTSADZE G S. Analysis of Arches of Underground Powerhouses with Crane Supporting Beams [ J ]. Power Technology and Engineering, 1972, 6 ( 4 ) :376 - 382.
