预应力矩形钢箱混凝土梁的试验研究

Experimental Research of Prestressed Concrete-filled Rectangular Steel Box Beam

以东平大桥为工程背景,进行8片预应力矩形钢箱混凝土梁的试验研究。试验参数包括混凝土强度、钢板厚度、预应力度及加载模式,获得试验梁的特征点荷载和跨中截面的全过程荷载-挠度曲线,对试验结果进行比较分析。结果表明,预应力矩形钢箱混凝土梁具有较高的承载能力和较好的延性,混凝土强度、钢板厚度和预应力度对构件的受力性能有较大影响,而加载模式的影响不明显。相对于普通矩形钢箱混凝土梁,受压区混凝土的约束效应得到明显增强,使得预应力矩形钢箱混凝土梁具有更为优越的受力性能,并且不增加构件的高度。

Based on the Dongping Bridge, an experiment was made on 8 prestressed concrete-filled rectangular steel box beams. The test parameters included the concrete strength, thickness of steel plate, prestressing degree and loading patterns. The sustaining loads at characteristic points and load-deflection curves at the midspan section were obtained, and the test results were analyzed. The results show that the prestressed concretefilled rectangular steel box beam has higher loading capacity and ductility, and the strength of concrete, thickness of steel plate and prestressing degree significantly affect the mechanical behaviors of the members whereas the loading patterns have little effect. Compared with the normal concrete-filled rectangular steel box beam, the confinement effect of core concrete in the longitudinal compression zone is enhanced due to prestressing and the steel box. So the prestressed concrete-filled rectangular steel box beam has better stressing performance without changing the height of beam members.