“…Similarly, in flat, single-and double-curved space structures built since the 1950 with pyramidallateral assembly systems, e.g. Space-Deck (1954) [4,5] Pyramitec (1960) [4,5,6,7], Zachód (1970) [5,8,9,10,11] or Mostostal (1979) [5], twin members of the compressed upper chord were obtained as a result of back-to-back joining of adjacent pyramids and/or flat frames. There is an extensive literature on load bearing capacity and stability of the multiple-chord members, including CSBUMs.…”