钢纤维高强混凝土力学性能试验与井壁结构研究

发布时间：2018-05-12 12:20

本文选题：钢纤维混凝土 + 力学性能　；参考：《安徽理工大学》2017年硕士论文

【摘要】：随着煤炭资源的不断开发,新井建设时立井井筒穿过的含水不稳定冲积层将越来越厚,井壁承受的外荷载也将随之增加。为抵抗强大的外荷载作用,必须要采用高强井壁结构。采用高强混凝土是提高井壁承载能力的最有效途径,但随着混凝土强度等级的提高,混凝土的脆性明显增加,结构破坏显突然性。为解决含水不稳定冲积层井筒支护难题,改善高强混凝土的脆性缺陷,提出采用钢纤维高强混凝土作为筑壁材料,对其力学特性和井壁结构进行研究。首先分析了钢纤维对混凝土的增强作用和破坏机理、以及增强效应的主要影响因素,进行了井壁钢纤维高强混凝土配制试验,并在此基础上进行了力学性能试验,得到了钢纤维高强混凝土的单轴抗压、劈裂抗拉、弹性模量、应力-应变关系、三轴抗压等力学指标;然后,开展了钢筋钢纤维高强混凝土井壁结构模型试验,通过模型设计和加载试验,得到了该种井壁结构应力、变形和强度特性;最后,通过ABAQUS软件,建立了井壁结构分析模型,对该种井壁结构进行了数值模拟分析,根据计算结果,回归得到了井壁承载力计算公式。本论文研究结果表明,钢纤维能够有效阻止宏观裂缝的发展,钢纤维高强混凝土的脆性明显改善,具有较好的延性特征。钢筋钢纤维高强混凝土井壁结构在极限承载力和受力特性方面都明显优于钢筋高强混凝土井壁结构,提高了井壁结构的工程可靠性,是一种较为理想的高强井壁结构。
[Abstract]:With the continuous development of coal resources, the unstable alluvium passing through the vertical shaft will be thicker and thicker, and the external load on the shaft wall will also increase during the construction of the new well. In order to resist the strong external load, high-strength shaft lining structure must be adopted. The use of high strength concrete is the most effective way to improve the bearing capacity of shaft lining, but with the increase of strength grade of concrete, the brittleness of concrete increases obviously, and the structural failure is sudden. In order to solve the problem of wellbore support in water-bearing unstable alluvium and to improve the brittle defect of high-strength concrete, steel fiber high-strength concrete is used as wall building material, and its mechanical properties and shaft wall structure are studied. Firstly, the reinforcing effect and failure mechanism of steel fiber on concrete and the main influencing factors of strengthening effect are analyzed, and the preparation test of steel fiber high strength concrete in shaft lining is carried out, and the mechanical properties test is carried out on this basis. The uniaxial compressive resistance, splitting tensile resistance, elastic modulus, stress-strain relation and triaxial compressive strength of steel fiber high strength concrete are obtained. Through model design and loading test, the stress, deformation and strength characteristics of the shaft wall structure are obtained. Finally, through ABAQUS software, the shaft wall structure analysis model is established, and the numerical simulation analysis of the shaft wall structure is carried out, according to the calculated results. The formula of shaft bore bearing capacity is obtained by regression. The results of this paper show that steel fiber can effectively prevent the development of macroscopic cracks and the brittleness of steel fiber high strength concrete is obviously improved and has better ductility. The reinforced steel fiber high strength concrete shaft lining structure is obviously superior to the reinforced high strength concrete shaft lining structure in ultimate bearing capacity and stress characteristics. It improves the engineering reliability of the well wall structure and is an ideal high strength wall structure.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD352;TU528

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