内置钢构架钢骨混凝土转换梁力学性能参数分析

Parameter Analysis for Mechanical Properties of Steel-Reinforced Concrete Transfer Girders with Inner Steel Truss

利用有限元方法研究钢构架斜压杆角度、底部纵筋配筋率、腰筋配筋率等参数对内置钢构架钢骨混凝土转换梁力学性能的影响及相应的传力机理.结果表明:钢构架斜压杆角度越大,钢骨混凝土转换梁的刚度和极限承载力越大;钢构架斜压杆的作用越大,水平拉杆所起的作用越小;底部纵筋可以起到水平拉杆的作用,底部配筋率小于1.18%时,增大底部纵筋配筋率可以显著提高内置钢构架钢骨混凝土转换梁的刚度、极限承载力和延性;增大腰筋配筋率可以较显著地提高钢骨混凝土转换梁的延性;内置钢构架钢骨混凝土转换梁呈拉力拱传力模式,混凝土斜压柱截面中部大两端小,呈鱼腹式构件.

In this paper, the mechanical properties of steel-reinforced concrete transfer girders with inner steel truss which are affected by the angle of steel diagonal members, the ratio of bottom longitudinal reinforcements and the ratio of web reinforcements, etc. , are analyzed by means of the finite element method, and the corresponding force transfer mechanism is investigated. The results show that （ 1 ） the rigidity and limited bearing capacity of the transfer girders increase with the angle of steel diagonal members; （2） as compared with horizontal steel ties, steel diagonal members play a more important role in the force transfer; （3） as horizontal tension members greatly enhance the rigidity, ultimate the bottom longitudinal reinforcements working bearing capacity and ductility of transfer girders at a reinforcement ratio of less than 1.18% ; （4） the increase of web reinforcement ratio results in a significant enhancement of the ductility of transfer girders; （5） the transfer girders exhibit a strut-and-tie force transfer mode; and （6） the cross section of the concrete diagonal strut, a kind of fish-bellied member, is big in the middle while small at the two ends.