摘要
预应力孔道内压浆料浆液及自由水冻胀致使混凝土沿纵向开裂,是高寒地区后张预应力混凝土(PC)梁特有的病害,严重影响结构的安全性、适用性、耐久性.为了明确病害特征,对冻胀受损梁体进行钻孔和解剖检测,进一步精细定量地研究冻胀效应,采用有限元软件ABAQUS建立孔道冻胀非线性模型,开展压浆料浆液冻胀行为分析和自由水冻胀参数分析,研究孔道内压浆液冻胀率和自由水体积的控制指标.研究结果表明:高寒地区后张PC结构孔道压浆后,受冻并先后发生压浆料浆液冻胀和自由水冻胀,致使孔道周围混凝土反复受拉而沿纵向开裂;压浆料浆液的体积膨胀率宜控制在0.80%以内,最高不得超过1.73%;泌水体积比宜控制在0.04%以内,最高不得超过0.52%,由此可有效降低孔道内压浆液及自由水冻胀的风险.
Longitudinal cracks of concrete caused by frost heaving of grouting slurry and free water in ducts is a special damage of post-tensioned PC girders in alpine regions,which affects the safety,serviceability,and durability of the structures significantly.In order to study damage characteristics,borehole and anatomical detections were conducted on damaged girders.The finite element software ABAQUS was used to establish the nonlinear models of frost heaving.Frost heave analysis of grouting slurry and parametric analysis of free water were carried out to study frost heave effects quantitatively.Control indexes of the frost heave ratio of grouting slurry and the volume of free water were obtained.The results show that the frost heaving of grouting slurry and free water occurs successively after grouting the ducts of the post-tensioned PC structures in alpine region,causing concrete to be tensioned repeatedly and cracked along the longitudinal direction.The volume expansion ratio of grouting slurry needs to be controlled within 0.80%,and the maximum should not exceed 1.73%.The volume ratio of bleeding water should be controlled within 0.04%,and the maximum should not exceed 0.52%.Thus,the frost heaving risk of grouting slurry and free water in ducts can be reduced effectively.
作者
孙宝林
杨永清
黄胜前
高玉峰
余小华
李凯
杨成龙
SUN Baolin;YANG Yongqing;HUANG Shengqian;GAO Yufeng;YU Xiaohua;LI Kai;YANG Chenglong(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Jiaoda Engineering Detection&Consulting Co.,Ltd.,Chengdu 610031,China)
出处
《西南交通大学学报》
EI
CSCD
北大核心
2023年第2期406-413,共8页
Journal of Southwest Jiaotong University
基金
中国国家铁路集团有限公司科技研究开发计划(P2019T001)。
关键词
高寒地区
后张PC梁
纵向裂缝
检测
孔道
压浆料浆液冻胀
自由水冻胀
非线性分析
alpine region
post-tensioned PC girder
longitudinal crack
detection
duct
frost heaving of grouting slurry
frost heaving of free water
nonlinear analysis
作者简介
第一作者:孙宝林(1992-),男,博士研究生,研究方向为预应力混凝土桥梁结构行为,E-mail:sunbaolinx@163.com;通信作者:杨永清(1965-),男,教授,博士,研究方向为大跨度桥梁结构行为、新建桥梁及既有桥梁结构评估,E-mail:yangyongqingx@163.com。
