混凝土桥墩非结构裂纹成因及受力特性分析_某桥墩为混凝土实体墩

　　摘 要:桥梁墩身开裂普遍存在,其开裂程度对结构承载力及耐久性的影响对保证桥梁的使用寿命和运营的安全非常重要。控制大体积混凝土桥墩早-中期裂纹尤其重要。通过研究桥梁混凝土墩身早-中期非结构性裂缝的成因及其对受力的影响分析,提出了在目前施工技术水平下,桥墩非结构性裂纹主要是由温度变化,混凝土收缩及后期的养护不利引起的,设计对构造约束认识不足导致的设计缺陷也是混凝土开裂的原因之一。对存在典型竖向裂纹的高大桥墩受力特性进行了分析,揭示了裂纹的存在会导致混凝土局部拉应力集中,使得裂纹继续扩展。对桥墩中-早期出现的裂纹,应及时分析原因进行修补,以保证结构的正常及安全使用。
　　关键词:混凝土桥墩 非结构裂纹 裂纹成因 受力特性
　　中图分类号:TU755 文献标识码:A 文章编号:1672-3791(2012)06(a)-0064-04
　　The analysis on the reason of non-structural cracks in concrete piers and its mechanical performance under loading
　　Abstracts:The bridge pier cracking exists generally in most projects.It is very important that the influence of cracks scale to the structural capacity and durability to ensure the service life of the bridge and the traffic running safety.To Control the cracks that emerges during early-middle period is especial important.On the current level of construction technology,the non-structural cracks of bridge concrete piers are mainly caused by the atmosphere temperature,shrinkage of concrete and later maintenance of the piers according to the research of the reason of non-structural cracks emerged in the early-middle period and the analysis of bridge concrete piers on the mechanical performance under loading.At the same time,it is also one of the reasons caused concrete piers cracking that the understanding insufficiency of tectonic constraints of piers leads to design flaws.The mechanical characteristic of tall bridge pier under loading which existing typical vertical cracks is analyzed.The results reveals that the existence of cracks can lead to concrete local stress concentration,make cracks continue to expand.In order to ensure the normal and safety using function of the bridge pier,the early-to-middle emerging cracks in bridge piers must be repaired timely.
　　Key words:Concrete pier;Non-structural cracks;Cause of cracks;Mechanical performance under loading