左宏亮 宋鑫 郭楠 王子元

(东北林业大学，哈尔滨，150040)



张弦及加载方式对预应力胶合木梁受弯性能的影响1)

左宏亮 宋鑫 郭楠 王子元

(东北林业大学，哈尔滨，150040)

采用一点张弦一点加载、一点张弦两点加载、两点张弦一点加载、两点张弦两点加载等4种不同的张弦加载方式，对4组12根预应力胶合木梁进行受弯试验，分析4种不同张弦和加载方式对预应力胶合木梁受弯性能的影响。结果表明：在预加力数值一定的前提下，加载点相同时，改变张弦方式对胶合木梁的极限承载力影响不大；张弦点相同时，两点加载比一点加载胶合木梁的极限承载力提高28.8%～38.9%；只有两点张弦两点加载时，梁顶受压区出现褶皱、梁底发生延性受拉破坏，其余破坏形态均为梁底脆性受拉破坏；加载过程中，两点加载较一点加载梁刚度略有提高、可使木材的抗压强度发挥更为充分，提高木材与钢丝的利用率。

张弦加载；胶合木梁；弯曲性能

Using one point jacking and one point loading, one point jacking and two points loading, two points jacking and one point loading, two points jacking and two points loading with four different jacking and loading methods in bend test of four groups twelve prestressed glue-lumber beams, we measured the effects of the four different jacking and loading methods on the bending performance of prestressed glue-lumber beams. In the same pre-energizer preconditions with the same loading point, changing the way of jacking has little effect on ultimate bearing capacity of glue-lumber beams. The same jacking point, two loading points than one loading point the glue-lumber beams ultimate bearing capacity increased by about 28.8%-38.9%. Only when two points jacking and two points loading the top of the beam compression zone wrinkles and beam bottom occurs ductility tensile failure, the remaining failure modes are brittle beam bottom tensile failure. In the loading process, the two points loading than one point loading beam stiffness increased slightly, it also can make the timber compressive strength play more fully and improve the utilization rate of wood and steel wire.

由于胶合木结构能做到小材大用、劣材优用，并较钢筋混凝土结构更为绿色环保，适用于绿色建筑及绿色施工，符合可持续发展的战略，所以在世界各地得到广泛的应用[1-3]。普通的胶合木梁，存在抗压强度无法得到充分发挥，胶合木梁在破坏时多发生脆性破坏且变形较大等缺点[4]。对普通的胶合木梁施加预应力，可以减小胶合木梁的短期变形，并使胶合木梁由纯弯状态转化为压弯状态，以达到充分利用木材抗压强度的目的[5]。

目前，国内……