关键词: 预制梁, 裂缝, 温度, 支承

Abstract: Aiming at the problem that pre-cast beam generated cracks in course of laying aside it，the mechanics knowledge Was utilized to deduce the formula，and the tensile stress under different descending value of temperature Was calculated according to the engineering，and the finite element software ANSYS Was used to verify the formula.The conclusion Was put forward that if the bearings of pre-cast beam were incorrectly installed when it Was laid aside，and the sudden descending of temperature may result in cracks ，then the corresponding avoidance measure was suggested .

Key words: pre-cast beam, crack, temperature, bearing