冻结井筒内层钢板高强钢纤维混凝土井壁研究

发布时间：2018-02-01 15:43

本文关键词： 深厚冲积层内层钢板钢纤维混凝土冻结井壁模型实验　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着浅部煤炭资源渐日趋枯竭,为了确保国民经济的可持续发展,必须要开发冲积层更为深厚的深部煤炭资源。当采用冻结法凿井时,井筒支护成为一大技术难题;同时,当采用冻结法修复位于冲积层中的破坏井筒时,为了尽可能保留井筒提升空间,内套井壁厚度应尽可能薄。据此,为解决冻结井筒的支护和修复难题,提出内层钢板高强钢纤维混凝土新型井壁结构,并采用理论分析,模型实验和数值模拟计算对该种新井壁结构的变形、应力及强度特性进行了研究。首先,根据弹塑性力学,对井壁截面的应力变形进行了理论分析,推导了井壁极限承载力计算公式。然后,在模型实验方面,通过高强钢纤维混凝土的配制实验,得到了冻结井筒CF80和CF90的材料及配合比;根据相似理论,推导了井壁模型试验的相似准则、确定了模型参数;通过对这一井壁结构进行模型实验,得到其应力和极限承载力大小;实验结果表明,内钢板和钢纤维分别起到了约束和增韧作用,内钢板高强钢纤维混凝土井壁结构较普通高强混凝土井壁结构脆性特征减少,表现出更加优异的韧性,更加安全可靠。在数值计算方面,采用ANSYS软件对内层钢板高强钢纤维混凝土井壁的极限承载力进行了数值模拟,得到了应力和极限承载力,与实验结果对比,二者数值较为接近。
[Abstract]:With the gradual depletion of shallow coal resources, in order to ensure the sustainable development of the national economy, it is necessary to develop deeper deep coal resources in alluvium. Shaft support has become a major technical problem; At the same time, when repairing damaged wellbore in alluvial layer by freezing method, in order to keep the lifting space of shaft as much as possible, the thickness of inner casing wall should be as thin as possible. Accordingly, in order to solve the problem of supporting and repairing frozen shaft. A new type of high strength steel fiber reinforced concrete shaft lining structure with inner steel plate is proposed. The deformation, stress and strength characteristics of the new shaft wall structure are studied by theoretical analysis, model experiment and numerical simulation. According to elastoplastic mechanics, the stress and deformation of shaft wall section are theoretically analyzed, and the formula for calculating the ultimate bearing capacity of shaft wall is derived. Then, in the aspect of model experiment, the preparation experiment of high strength steel fiber reinforced concrete is carried out. The material and mix ratio of CF80 and CF90 in freezing shaft are obtained. According to the similarity theory, the similarity criterion of wellbore model test is deduced, and the model parameters are determined. The stress and ultimate bearing capacity of the shaft wall structure are obtained by the model experiment. The experimental results show that the inner steel plate and steel fiber play the role of restraint and toughening respectively, and the brittleness of the inner steel plate high strength steel fiber reinforced concrete shaft lining structure is less than that of the common high strength concrete shaft lining structure. In the aspect of numerical calculation, the ultimate bearing capacity of high strength steel fiber reinforced concrete lining of inner steel plate is simulated by ANSYS software. The stress and ultimate bearing capacity are obtained and compared with the experimental results, the two values are close to each other.
【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】：TD265.3

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