预应力混凝土小箱梁跨中裂缝成因分析与加固方案比选

摘要

Small prestressed concrete small box-girders are widely used in highway due to their simple structure and convenient construction. During a regular inspection of a highway bridge,diagonal web cracks at midspans of the side girders were inspected and regarded as a common disease. In this paper,the cracking causes were analyzed. T hree reinforcement schemes were proposed: reinforcement with steel plates,extra prestress and external prestress. T he reinforcement effect was assessed through experimental tests.%预应力混凝土小箱梁由于其构造简单、施工方便等特点被广泛应用到公路工程中。某高速公路桥梁定期检查时发现，预应力混凝土小箱梁普遍存在边梁跨中腹板斜向开裂现象。本文对病害成因进行分析，并提出粘贴钢板、体内预应力加固和体外预应力加固3种加固方案，通过加固前后荷载试验对各方案的加固效果进行了评估。