盾构隧道钢纤维混凝土管片接头极限承载力试验

发布时间：2018-03-12 13:44

本文选题：盾构隧道　切入点：管片接头　出处：《中国公路学报》2017年08期 　论文类型：期刊论文

【摘要】：针对钢纤维混凝土管片在盾构隧道工程中应用日益频繁的现状,以盾构隧道钢纤维混凝土管片接头为试验对象,采用足尺试验方法对钢纤维混凝土管片接头和传统钢筋混凝土管片接头的极限承载能力进行研究,归纳宏观破坏现象,获得了荷载-挠度曲线和弯矩-转角曲线等整体力学响应特性,得到了荷载-螺栓应变关系和荷载-混凝土表面应变等局部力学响应特性,分析了受压区剪裂缝的扩展规律,探讨了接头的延性指标,并对接头进行了基于性能的极限承载能力评价。研究结果表明:钢纤维混凝土管片接头的开裂荷载比钢筋混凝土管片接头提高12.9%;钢纤维混凝土管片接头的极限荷载与钢筋混凝土管片接头基本一致(略微增加4.4%);钢纤维混凝土管片接头具有优良的抗裂能力,受压区剪裂缝数量为1个,少于钢筋混凝土管片接头的3个,承载能力极限状态时的最大裂缝宽度从3.82mm减少到1.35mm,正常使用状态时的最大允许裂缝宽度(0.2mm)对应的荷载抗力提高了43.75%;钢纤维混凝土管片接头的受力性能优于钢筋混凝土管片接头;研究成果可为钢纤维混凝土管片在盾构隧道工程中的应用提供理论支撑和技术参考。
[Abstract]:In view of the increasingly frequent application of steel fiber reinforced concrete (SFRC) segments in shield tunnel engineering, the steel fiber reinforced concrete segment joint of shield tunnel is taken as the test object. The ultimate bearing capacity of steel fiber reinforced concrete segment joint and traditional reinforced concrete segment joint is studied by means of full-scale test, and the macroscopic failure phenomenon is summarized. The overall mechanical response characteristics such as load-deflection curve and moment-angle curve are obtained. The local mechanical response characteristics such as load-bolt strain relation and load-concrete surface strain are obtained. The propagation law of shear crack in compression zone is analyzed. The ductility index of the joint is discussed. The ultimate load-bearing capacity of steel fiber reinforced concrete segment joint is evaluated based on performance. The results show that the cracking load of steel fiber reinforced concrete segment joint is 12.9 higher than that of reinforced concrete segment joint, and the ultimate load of steel fiber concrete segment joint is higher than that of reinforced concrete segment joint. The load is basically the same as the reinforced concrete segment joint (a slight increase of 4.4%); the steel fiber reinforced concrete segment joint has excellent crack resistance, The number of shear cracks in compression zone is 1, which is less than 3 joints of reinforced concrete segments. The maximum crack width is reduced from 3.82 mm to 1.35 mm in the ultimate state of load-carrying capacity, and the load resistance corresponding to the maximum allowable crack width of 0.2mm in normal condition is increased by 43.75 mm, and the mechanical properties of the steel fiber reinforced concrete segment joint are better than that of the reinforced concrete segment joint. The research results can provide theoretical support and technical reference for the application of steel fiber reinforced concrete segment in shield tunnel engineering.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;
【基金】：国家自然科学基金项目(51378388) 上海市科学技术委员会项目(15XD1522500,15DZ1204003)
【分类号】：U455.43

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