局部均匀压力作用下斜井井壁的受力与变形规律研究

发布时间：2018-05-04 11:54

本文选题：斜井 + 井壁　；参考：《中国矿业大学》2015年硕士论文

【摘要】：斜井已成为我国西部矿区矿井建设的重要开拓方式。在软弱、富水岩层中,斜井井壁结构易遭受水压或注浆压力等局部荷载的作用,进而威胁其安全。为此,本文采用数值计算、模型试验方法,开展了局部均匀压力作用下的斜井井壁受力与变形规律的研究。首先,基于典型参数模型,将井壁划分为19个局部均匀压力作用区域,开展了典型参数模型论证及单因素循环数值计算,结果表明:井壁和围岩接触面的允许拉应力影响井壁力学响应参数的叠加,而其摩擦系数仅在一定范围内影响井壁力学响应参数的叠加;井壁力学响应参数与混凝土弹性模量成线性关系,与边墙高度、仰拱半径、井壁厚度呈非线性关系。通过井壁典型断面模型的数值分析,研究表明:井壁力学响应参数与荷载呈线性关系。在井壁与围岩间允许拉应力为零、摩擦系数小于等于0.25的条件下,依次对井壁十九个区域分别作用单位荷载,得到了井壁特征点的力学响应参数数据表,并开展了力学响应参数的叠加分析,结果表明:同样宽度的单位荷载作用下,仰拱受力最不利,其中仰拱中部即区域十九的内表面将出现最大环向应力,其次是直墙与顶拱部位。其次,基于典型参数模型,开展了斜井井壁的极限承载力研究。单因素循环试验研究表明:井壁极限承载力与混凝土强度、井壁厚度近乎呈线性关系,与边墙高度、仰拱半径呈非线性关系。基于一定影响因素水平开展了全组合试验,得到了井壁极限承载力与混凝土强度、边墙高度、仰拱半径、井壁厚度关系的数据表,进而对局部荷载分别作用在井壁右直墙、顶拱、仰拱全断面时的井壁极限承载力开展了对比分析,研究表明:荷载作用在井壁仰拱全断面时,井壁最易遭受破坏。最后,开展了局部均匀压力作用下斜井井壁力学特性的相似模型试验研究,结果表明:荷载作用区域,井壁内表面主要处于受拉状态,外表面处于受压状态。以荷载作用在区域十九(仰拱外表面中间部位)为例,当荷载P小于2.95MPa时,井壁处于弹性状态;当荷载达到5.26MPa时,特征点YZ1、YZ2的环向应变分别达到143.02??、-1115.75??,此时,井壁失去承载能力。
[Abstract]:Inclined well has become an important development mode of mine construction in western mining area of our country. In weak, water-rich rock formations, the sidewall structure of inclined wells is vulnerable to local loads, such as water pressure or grouting pressure, which threaten its safety. In this paper, numerical calculation and model test method are used to study the stress and deformation of inclined shaft wall under the action of local uniform pressure. Firstly, based on the typical parameter model, the shaft wall is divided into 19 local uniform pressure regions, and the typical parameter model is demonstrated and the single factor cyclic numerical calculation is carried out. The results show that the allowable tensile stress of the contact surface between the wall and surrounding rock affects the superposition of the shaft wall mechanical response parameters, while the friction coefficient only affects the superposition of the shaft wall mechanical response parameters in a certain range. The mechanical response parameters of shaft lining are linearly related to the elastic modulus of concrete and nonlinear to the height of side wall the radius of inverted arch and the thickness of shaft wall. Through numerical analysis of typical cross-section model of shaft lining, it is shown that the mechanical response parameters of shaft lining are linearly related to load. When the allowable tensile stress between the wall and surrounding rock is zero and the friction coefficient is less than 0.25, the mechanical response parameter data table of the characteristic point of the shaft wall is obtained by applying unit load to the 19 areas of the shaft wall in turn. The superposition analysis of mechanical response parameters is carried out. The results show that under the action of the unit load of the same width, the stress of the invert is the most disadvantageous, in which the maximum circumferential stress will appear on the inner surface of the middle part of the invert, that is, region 19. The second is the straight wall and the top arch. Secondly, based on the typical parameter model, the ultimate bearing capacity of inclined shaft lining is studied. The results of single factor cyclic test show that the ultimate bearing capacity of shaft lining is linearly related to the strength of concrete and thickness of shaft wall and nonlinear to the height of sidewall and radius of inverted arch. Based on the full combination test of certain influencing factors, the data table of the relationship between ultimate bearing capacity of shaft wall and concrete strength, sidewall height, radius of inverted arch, thickness of shaft wall is obtained, and then the local load acts on the right straight wall of shaft wall, respectively. A comparative analysis of the ultimate bearing capacity of the shaft wall under the full section of the top arch and the inverted arch is carried out. The results show that the shaft wall is most vulnerable to damage when the load is acting on the full section of the inverted arch of the shaft wall. At last, a similar model test on the mechanical properties of inclined shaft wall under the action of local uniform pressure is carried out. The results show that the inner surface of the shaft wall is mainly in the tensile state and the external surface is in the state of compression in the loading area. Taking the load action in area 19 (the middle part of the outer surface of the inverted arch) as an example, when the load P is less than 2.95MPa, the borehole lining is in elastic state, and when the load reaches 5.26MPa, the circumferential strain of the characteristic point YZ1 / YZ2 reaches 143.02 ~ 1115.75, respectively. At this time, the bore loses its bearing capacity.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD262

【参考文献】