基于统一强度理论的TBM斜井围岩弹塑性解及试验研究

发布时间：2018-04-22 21:09

本文选题：TBM斜井 + 统一强度理论　；参考：《中国矿业大学(北京)》2017年博士论文

【摘要】：近年来,随着煤矿开采技术的发展,矿井开采深度日益增大,煤矿产能不断提高,开采过程中遇到的各种问题逐渐增多,斜井开拓逐渐成为提高矿井产能的主要提升方式;TBM施工以其高效、优质、安全等优点逐渐成为斜井建设的重要手段。进行长距离、大埋深TBM斜井施工是我国煤炭建设中的一大挑战,施工过程中会遇到多种不可预测的问题,对长距离斜井开挖后围岩稳定性进行研究,对工程安全具有重要意义,但现有相关研究较少,是目前亟待解决的问题。本文针对TBM斜井建设中遇到的大坡度、大埋深、穿越复杂地层等问题,以神华新街能源公司台格庙矿区TBM斜井工程为依托,采用理论、数值模拟和模型试验相结合的方法,对衬砌-围岩相互作用下的TBM斜井围岩和衬砌力学特性的变化规律进行系统研究;穿越富水地层时,需考虑地下水的渗流作用,文中对渗流影响下斜井围岩进行了力学分析和弹塑性理论推导。主要进行了以下工作:(1)基于统一强度理论对TBM斜井围岩进行弹塑性理论求解结合坐标转换原理,建立TBM斜井横断面内弹塑性力学分析模型;基于统一强度理论推导出两向非等压应力场中围岩塑性区半径、围岩应力及位移的解析计算式。参考神华新街能源公司台格庙矿区TBM斜井工程的实际勘察资料,进行计算和参数分析,深入研究中间主应力影响参数、斜井倾角、原岩侧压力系数和衬砌与围岩弹性模量比等因素对斜井横断面内围岩塑性区半径、弹塑性区应力及塑性区径向位移的影响规律。计算结果表明考虑中间主应力作用时,围岩自稳能力增强;围岩侧压力系数、斜井倾角和衬砌与围岩的弹性模量比均会对围岩塑性区范围及围岩应力、位移产生不同程度的影响;衬砌与围岩的弹性模量比越大,衬砌支护力也越大。研究结果为类似条件下的TBM斜井施工及安全性评价提供了理论依据,具有一定的工程参考意义。(2)考虑渗流影响的TBM斜井围岩弹塑性解对TBM斜井围岩的应力场和渗流场进行耦合分析,建立斜井横断面内弹塑性力学分析模型;基于统一强度理论和非关联流动法则推导出考虑渗流和剪胀作用的TBM斜井围岩弹塑性解,深入研究渗流作用和剪胀角对塑性区半径和围岩应力、位移的影响规律。与无渗流影响的计算结果进行对比,结果表明地下水的渗流作用对围岩力学特性的影响不可忽略;剪胀角对围岩塑性区径向位移有显著影响,对塑性区半径的影响相对较小,对围岩应力的影响不明显。(3)TBM斜井围岩应力和位移变化的数值模拟计算采用FLAC3D计算软件对不同埋深下斜井衬砌和围岩进行模拟计算,得到侧压系数、倾角、衬砌-围岩弹模比和埋深对竖直断面内围岩塑性区范围、应力和位移的变化规律。对计算模型进行切片处理,得到斜井横断面的应力、位移分布规律,并将数值计算结果与理论计算结果进行对比分析,结果表明两者所得结论高度一致。(4)斜井围岩位移和衬砌内力变化的模型试验研究以顶部逐级加载的方式来模拟斜井埋深的变化,通过大型室内相似模型试验,对不同荷载条件下衬砌管片内力和围岩径向位移的变化进行研究,得到斜井围岩径向位移、管片结构不同位置处内力随着竖向加载值的变化规律。采用不同材料制作衬砌管片结构进行模型试验,得到不同材料管片结构对围岩位移的影响及其自身内力的变化情况;将试验结果与文中的理论计算结果进行对比分析和验证。结果显示,随着竖向荷载值的增大,围岩径向位移逐渐增大,且竖直方向围岩的位移明显大于水平方向围岩的位移;管片轴力和弯矩同样随着荷载的增大而增大。管片中各处轴力均为压应力,且拱腰处轴力最大,而顶部轴力最小;管片顶部和底部为正弯矩,拱腰处为负弯矩。将数值计算所得衬砌内力值与试验测得结果进行对比,二者所得结论一致。通过分析不同位置处管片内力值,发现管片接头位置对其内力的影响不显著。实际工程中应根据斜井埋深的不断变化,适当调整管片结构的设计强度和刚度,以满足工程需要。
[Abstract]:In recent years, with the development of coal mining technology, the depth of mine mining is increasing, the productivity of the coal mine is increasing, and the problems encountered in the mining process are increasing gradually. The slope opening gradually becomes the main way to raise the productivity of the mine, and the TBM construction has gradually become an important means of the construction of the inclined shaft with its advantages of high efficiency, high quality and safety. The construction of long distance and deep buried TBM inclined shaft is a big challenge in China's coal construction. There will be many unpredictable problems in the construction process. It is of great significance to study the stability of the surrounding rock after the long distance inclined shaft excavation, but the existing related research is less. This paper is a problem to be solved at present. This paper is aimed at TBM oblique. In the construction of well, large slope, large burial depth, cross complex stratum and so on, based on the TBM slope project of the Tai GG Temple mining area, Huaxin energy company, Shen Huaxin energy company, with the method of combining the theory, numerical simulation and model test, the change law of the mechanical characteristics of the perinas and lining of the TBM inclined shaft under the interaction of lining and surrounding rock is systematically studied. When crossing the rich water stratum, the seepage action of groundwater should be considered. In this paper, the mechanical analysis and elastoplastic theory of the surrounding rock of the inclined well under the influence of seepage are carried out. The following work is done mainly: (1) based on the unified strength theory, the elastoplastic theory of the surrounding rock of the TBM inclined well is solved with the principle of coordinate transformation, and the elastic-plastic in the cross section of the TBM inclined shaft is established. Based on the unified strength theory, the analytical formula of the plastic zone radius of the surrounding rock and the stress and displacement of the surrounding rock in the two non isobaric stress field is derived. The actual survey data of the TBM slope engineering of the Shenhua New Street energy company Tai Ge Temple mining area is calculated and analyzed, and the influence parameters of the intermediate principal stress are deeply studied, and the inclined well is studied. The influence of the angle, the pressure coefficient of the original rock side and the ratio of the elastic modulus of the lining and the surrounding rock to the plastic zone radius of the surrounding rock, the stress of the elastic plastic zone and the radial displacement of the plastic zone in the cross section of the inclined shaft. The results show that the stability of the surrounding rock is enhanced when the intermediate principal stress is taken into consideration, the side pressure coefficient of the surrounding rock, the inclination of the inclined shaft and the lining and the surrounding rock The elastic modulus ratio will affect the plastic zone range of surrounding rock and the stress and displacement of surrounding rock, and the greater the modulus of elastic modulus of the lining and the surrounding rock, the greater the lining support force. The research results provide a theoretical basis for the construction and safety evaluation of TBM inclined well under similar conditions, which has certain engineering reference significance. (2) consideration of seepage. The Elastoplastic Solution of the surrounding rock of the TBM inclined well is coupled to the stress field and the seepage field of the surrounding rock of the TBM inclined shaft, and the elastoplastic mechanical analysis model in the cross section of the inclined shaft is established. Based on the unified strength theory and the unrelated flow rule, the Elastoplastic Solution of the perinas in the TBM inclined well considering the seepage and dilatancy effects is derived, and the seepage action and shear are deeply studied. The influence of the expansion angle on the plastic zone radius and the stress and displacement of the surrounding rock is compared with the calculation results without seepage. The results show that the influence of seepage on the mechanical properties of the surrounding rock can not be ignored; the dilatancy angle has a significant influence on the radial displacement of the plastic zone of the surrounding rock, and the effect on the radius of the plastic zone is relatively small, and the stress on the surrounding rock The influence is not obvious. (3) the numerical simulation calculation of the stress and displacement of the surrounding rock of TBM inclined shaft is calculated by FLAC3D software to simulate the lining and surrounding rock of the inclined shaft under different buried depth, and the change law of the lateral pressure coefficient, the dip angle, the elastic modulus ratio of the lining wall rock and the depth to the plastic zone range of the surrounding rock in the vertical section, the stress and displacement of the surrounding rock are calculated. The model is sliced to get the stress and displacement distribution of the cross section of the inclined shaft, and the results of numerical calculation are compared with the theoretical calculation results. The results show that the results are highly consistent. (4) the model test of the change of the displacement of the surrounding rock and the internal force of the lining of the inclined well is used to simulate the buried depth of the inclined shaft by the way of the top step by step. The changes in the internal force of lining tube and the radial displacement of the surrounding rock under different load conditions are studied by a large indoor similar model test. The radial displacement of the surrounding rock of the inclined shaft and the variation law of the internal force with the vertical loading value at different position of the pipe structure are obtained. The influence of the structure of different materials on the displacement of surrounding rock and the change of its internal force, the experimental results are compared with the theoretical calculation results in the paper. The results show that the radial displacement of the surrounding rock increases with the increase of the vertical load value, and the displacement of the vertical surrounding rock is obviously larger than the displacement of the surrounding rock. The axial force and bending moment of the pipe also increase with the increase of the load. The axial force in each section of the pipe is all pressure stress, and the axial force of the arch waist is the largest, and the top axis force is the least; the top and bottom of the tube are positive bending moment, and the arch waist is negative bending moment. The results of the inner force of the lining of the numerical calculation are compared with the test results, the conclusions of the two are in the same conclusion. Through the analysis of the internal force values at different positions at different positions, it is found that the effect of the position of the joint on the internal force is not significant. In practical engineering, the design strength and stiffness should be adjusted according to the constant change of the buried depth of the inclined shaft, so as to meet the needs of the engineering.

【学位授予单位】：中国矿业大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD26

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