高寒地区预制小箱梁腹板纵向裂缝成因分析及处置  

Analysis and Treatment of Longitudinal Deck Cracks in Prefabricated Small Box Girder in Cold Regions

作　　者：张玉强 魏尊祥 ZHANG Yu-qiang;WEI Zun-xiang

机构地区：[1]呼伦贝尔交通运输局综合保障中心,内蒙古呼伦贝尔021008 [2]中交一公局土木工程建筑研究院有限公司,北京100020

出　　处：《内蒙古公路与运输》2024年第5期34-37,共4页Highways & Transportation in Inner Mongolia

摘　　要：小箱梁因其良好的受力性能和行车舒适性,在工程中被广泛应用,但其缺陷是易产生裂缝。为了解高寒地区预制小箱梁腹板沿波纹管出现纵向裂缝的成因,文章以某工程20 m小箱梁为例,通过现场调查和单梁试验,对其纵向裂缝成因进行了分析。结果表明:该箱梁裂缝为温缩裂缝,对箱梁耐久性有影响。裂缝产生的原因主要有构造因素、环境因素、现场养生等。通过采用压力注胶进行灌缝、环氧树脂胶泥封缝的方法处理后,裂缝未继续发展,也未出现水渍,封闭性能良好;针对预制小箱梁腹板,可通过改善级配、波纹管准确定位、适度振捣、加强养生、控制预制时间、及时封闭预应力管道等措施进行预防。研究成果可为控制箱梁腹板裂缝提供技术参考。Small box girders are widely used in engineering due to their excellent load-bearing performance and driving comfort,but their drawback is that they are prone to cracking.In order to understand the causes of longitudinal deck cracks prefabricated small box girders along corrugated pipes in high-altitude regions,this article takes a 20 m small box girder in a certain project as an example,and analyzes the causes of longitudinal cracks through on-site investigation and single girder test.The results indicate that the cracks in the box girder are thermal shrinkage cracks,which have an impact on the durability of the box girder.The causes of the cracks include construction factors,environmental factors,and on-site curing.After the small box girders were treated with pressure injection and injection of epoxy resin mortar,they were observed for several years,and no further crack or water stains were observed,indicating that it is well disposed.The author proposes the following preventive measures:improving grading,accurately positioning corrugated pipes,moderate vibration,enhanced curing,controlling precasting time,and timely sealing of pre-stressed pipes.The research findings provide technical reference for avoiding deck cracking in small box girders.

关 键 词：桥梁工程 小箱梁 腹板裂缝 裂缝处置 注胶灌缝 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]