摘要
以某在建跨海大桥为例,通过数值仿真分析预制桥墩在与现浇承台连接施工时的温度应力及其影响因素,结合海上施工条件提出裂缝控制措施并进行现场试验.分析结果表明,填芯混凝土热膨胀是预制桥墩温度应力的主要因素,温度梯度为次要因素.混凝土入模温度从10°C提高到40°C,最大拉应力增加15.4%.作为单项措施,设置隔热缓冲层的控制效果最佳,其次为冷却水管、优化混凝土配合比、分层施工和应力消散孔,外壁保温与内腔通风措施的效果较差.提出的裂纹控制方案是采用优化混凝土配合比,且分3层浇筑混凝土,第1层和第2层分别设置隔热缓冲层和应力消散孔,通过现场试验验证了该方案可以有效地控制裂纹.
A cross-sea bridge under construction was considered as an example.The thermal stress and its influencing factors of the prefabricated bridge pier during connection with the cast-in-place cap were analyzed through numerical simulation.Crack control measures were proposed and field tests were conducted combined with the offshore construction conditions.Results show that the main factor causing thermal stress is the thermal expansion of the core-filled concrete,and the secondary factor is the temperature gradient of the pier.The maximum tensile stress increases by 15.4%when the concrete pouring temperature is increased from 10°C to 40°C.The control effect of setting the thermal insulation buffer layer is the best as a single measure,followed by the cooling water pipes,optimization of concrete proportion,layered construction and stress dissipation hole.The effect of outer insulation and inner cavity ventilation is poor.The recommended strategy includes optimizing concrete proportion and pouring concrete in three layers,in which the first layer and the second layer are respectively provided with a thermal insulation buffer layer and a stress dissipation hole.The results of field tests verify the effectiveness of the recommended strategy for crack suppression.
作者
李中南
朱海波
赵阳
罗雪
徐荣桥
LI Zhong-nan;ZHU Hai-bo;ZHAO Yang;LUO Xue;XU Rong-qiao(Department of Civil Engineering,Zhejiang University,Hangzhou 310058,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2021年第1期46-54,共9页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(51478422).
关键词
装配化施工
预制桥墩
温度应力
裂纹控制
现场试验
assembly construction
prefabricated bridge pier
thermal stress
crack control
field test
