摘要
为构建长期荷载及酸雨侵蚀耦合作用下悬臂抗滑桩耐久性极限寿命准则及服役寿命预测模型,通过开展酸雨单独侵蚀、弯拉荷载及酸雨耦合侵蚀作用下的混凝土中性化试验,构建了混凝土中性化深度多因素时程演化模型;其次通过修正混凝土中性化残量计算模型建立了抗滑桩桩身钢筋初锈时间模型;进一步结合现有钢筋锈蚀速率模型提出了抗滑桩耐久性极限寿命准则及服役寿命预测模型;最后基于控制变量法对桩体材料、桩体施工、外部环境及外部荷载等因素进行了参数研究。结果表明:弯拉荷载及酸雨侵蚀耦合作用下混凝土中性化深度与侵蚀时间、应力水平、模拟酸液酸度均呈正相关,混凝土中性化深度时变演化过程符合三阶段模式;利用所建悬臂抗滑桩耐久性极限寿命预测模型获得的预测值比易丽云建立的模型及黄新朋建立的模型预测值分别长17.52 a及12.47 a,所建模型具有较好的适用性,预测结果更为经济合理且符合工程实际;悬臂抗滑桩服役寿命与桩身混凝土保护层厚度、桩身混凝土强度、施工质量及外部侵蚀溶液pH值成正比,与桩身混凝土水灰比、桩身滑面处应力水平成反比。该研究结果对酸雨侵蚀作用下悬臂抗滑桩服役寿命评估具有重要的科学指导意义及实用价值。
In order to construct the durability limit life criterion and service life prediction model of cantilever anti-slide piles under the coupling action of long-term load and acid rain erosion,a multi-factor time history evolution model of concrete neutralization depth was constructed by carrying out concrete neutralization test under acid rain alone erosion,the coupling action of bending load and acid rain erosion.Secondly,the initial rust time model of cantilever anti-slide pile reinforcement was established by modifying the calculation model of neutralization residue of concrete.Combined with the existing corrosion rate model of reinforcement,the durability limit life criterion and service life prediction model of cantilever anti-slide pile were constructed.Finally,based on the control variable method,the parametric study of cantilever anti-slide pile was carried out,including the pile material,pile construction,external environment and external load.Results indicated that the neutralization depth of concrete under the coupling action of bending load and acid rain erosion is positively correlated with erosion time,stress level and the acidity of simulated acid solution.The time-varying evolution of neutralization depth of concrete conforms to the three-stage model.The predicted values obtained by the durability limit life prediction model of the cantilever anti-slide pile in this work are 17.52 a and 12.47 a longer than those obtained by the original model,the established model has good applicability,and the predicted results are more economical and reasonable and conform to the enginee-ring practice.The service life of the cantilever anti-slide pile is directly proportional to the thickness of the concrete protective layer,the concrete strength,the construction quality and the pH value of the external erosion solution of the cantilever anti-slide pile,and inversely proportional to the water-cement ratio of the concrete and the stress level at the sliding surface of the cantilever anti-slide pile.The research resu
作者
靳红华
任青阳
肖宋强
任小坤
JIN Honghua;REN Qingyang;XIAO Songqiang;REN Xiaokun(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第5期191-198,共8页
Materials Reports
基金
国家重点研发计划专题(2023YFC3008304-4)
国家自然科学基金(U20A20314,41472262,52104184)
重庆市自然科学基金重点项目(cstc2020jcyj-zdxmX0012)
重庆市高校创新研究群体(CXQT19021)
重庆市研究生科研创新项目(CYB21210)
重庆市博士后研究项目特别资助项目(2021XM3038)。
关键词
悬臂抗滑桩
弯拉荷载
酸雨侵蚀环境
中性化深度
耐久性极限寿命准则
服役寿命预测
cantilever anti-slide pile
bending load
acid rain erosion environment
neutralization depth
durability ultimate life criterion
service life prediction
