摘要
对地铁施工过程中由于工程施工所导致的结构裂缝问题进行了相关的试验和研究,并从中得到对大面积混凝土梁的裂缝预防和控制方式的研究成果和理论,提出对大体积混凝土梁分段浇筑从而控制裂缝的产生,使用了灰色预测模型进行建模模拟,预测混凝土随着温度的降低从而产生的应变,并通过有限云对混凝土梁的应力分布情况作了分析研究,其结果和实际监测结果相符。随着时间的变化,各测点应变的走势趋向一致性,并且伴随着大体积混凝土混凝土浇筑的前期阶段,水化过程开始释放出大量热量,从而转变成压应变,随着水化进程的进一步进行,在75~100 h后,混凝土温度出现下降趋势,大体积混凝土梁的最大拉应变值为398.5με。在各测点,应变分布不均匀,地铁大体积混凝土会产生裂缝的最主要因素为施工分期阶段进行浇筑时,由于分段进行施工,从而致使混凝土湿度温度不能保持一致性。在本研究中,采用了一定的防护措施,避免大体积混凝土裂缝的产生和抑制裂缝的进一步发展扩散。
Taking a subway as the research object,this paper studies the method of preventing structural cracks by pouring mass concrete in the construction process,puts forward the control method of cracks caused by sectional pouring of mass concrete beams through the study of crack control technology of mass concrete beams,and adopts grey prediction model.The stress distribution of mass concrete beams is analyzed by finite element method.The results are consistent with the actual monitoring results.With the change of time,the strain trend of each measuring point is basically the same.In the early stage of mass concrete pouring,all the hydration exothermic stages are compressive strains.With the further hydration process,concrete temperature shows a downward trend after 75~100 hours,and the maximum tensile strain of mass concrete beams is 398.5με.At each measuring point,the strain distribution is not uniform.The cracks of mass concrete in subway are mainly caused by the asynchronous humidity and temperature shrinkage of concrete caused by sectional pouring.Concrete cracks can be effectively controlled by taking certain measures to prevent cracks.
作者
徐红
XU Hong(Jiangsu College of Engineering And Technologyl,Nantong 226007,China)
出处
《混凝土》
CAS
北大核心
2020年第8期147-150,共4页
Concrete
基金
2018年江苏工程职业技术学院校级课题(虚实结合“三位一体”项目化教学应用研究——以《建筑施工技术》课程为例)(GYJY201824)。
关键词
裂缝
浇筑
混凝土
大体积
有限元
crack
pouring
concrete
large volume
finite element method
