Because the traditional methods for the crack detection of concrete hollow slab bridges do not work quite effectively and safely,a method for the crack detection of the bridges,using the acoustic emission technology,was proposed.The Lianjiang River Bridge in Zhumadian was selected as an example and the static load tests were carried out on the south side span of the bridge.The crack propagation at the bottom and hinge joints of the slabs of the bridge in the load tests was detected,using the acoustic emission technique and the corresponding relationship between the acoustic emission signals and the crack propagation was studied.The results yield that the concrete hollow slabs are in good state of loading in the tests and no macro cracks and structural damage occur in the slabs.At the hinge joints of slabs,the severe damage appears.The low amplitude signals generate from the propagation of the micro cracks and the friction between the fracture surfaces of the existing cracks while the high amplitude signals generate from the further propagation of the macro cracks.The analysis findings of the acoustic emission signals are accordant with the real deteriorations of the bridge and the acoustic emission technique is well feasible when applied to the crack detection of the concrete hollow slab bridges.%由于传统的裂缝检测方法效果差且不安全,提出采用声发射技术进行桥梁裂缝检测的方法.以驻马店练江河桥为背景,对其南边跨进行静载试验,利用声发射技术检测试验过程中混凝土空心板桥板底和铰缝处的裂缝扩展情况,研究声发射信号与裂缝扩展的对应关系.结果表明:试验过程中,混凝土空心板受力良好,没有出现宏观裂缝和结构性损伤,铰缝产生了较为严重的损伤;低幅值信号由微裂纹的扩展和旧裂缝断裂面的相互摩擦产生,高幅值信号由宏观裂缝的进一步扩展产生;声发射信号分析结果与桥梁实际病害一致,声发射技术应用于混凝土桥梁的裂缝检测具有较好的可行性.
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