NAILED- BOARD SPAN Russian patent published in 2001 - IPC

FIELD: construction engineering; erection of bridges with wood spans. SUBSTANCE: span has vertical transverse walls made of two layers of boards, top and bottom ledges, set of trusses pair-wise joined by means of longitudinal horizontal and transversal vertical braces, and roadway with asphalted wood slab. Novelty is that nailed-board span has nailed-board box-shaped blocks joined together by means of field joints and cross wood slab with asphalt- concrete covering stacked on skew foots. Top and bottom ledges of blocks are formed by two layers of blocks crossed at 45 deg. to longitudinal axis; placement of bearing boards in two thin layers at large width of ledges allows for enhancing their bearing capacity, reducing height of walls, increasing their amount, and eliminating necessity of lengthwise joining of ledge boards. EFFECT: reduced constructional depth, cost, material input; enhanced carrying capacity of nailed-board spans; facilitated assembling; improved reliability. 5 dwg