不同围岩级别下隧道回填材料合理工程参数分析

发布时间：2019-06-25 18:20

【摘要】：改革开放以来,随着我国国力日益强盛,经济繁荣昌盛,我国的交通事业已步入高速发展的时代。作为交通工程的重点之一,隧道的建设更是得到了快速的发展。隧道开挖过程中,由于地质、水文情况的特殊性和施工工艺的局限性,围岩超欠挖现象十分常见。现如今,对围岩的超挖问题的处理缺乏理论支撑,在实际的工程中,大都根据工程经验施作回填层,回填层的不规范施工给隧道工程埋下了很大隐患,影响隧道的安全。因此,对围岩超挖回填层材料工程参数的研究就显得十分迫切。本文将区间分析引入隧道工程用来研究隧道回填层材料的工程参数,研究内容包括以下几个方面:(1)综述了隧道超欠挖、隧道回填层材料及回填层工程参数和隧道围岩、衬砌、回填层相互关系研究现状,分析其存在的问题,并提出了用区间理论研究回填层的工程参数。(2)介绍了区间数学的基本理论;对不同围岩级别下隧道超挖进行统计,得出隧道超挖统计值;结合规范分析了不同围岩级别下,隧道衬砌、回填层的几何参数和围岩、衬砌的物理参数,并提出了衬砌结构内力检验标准。(3)建立圆形隧道围岩、衬砌、回填层力学模型,运用弹性力学理论、区间分析,结合边界条件和接触条件推导出隧道回填层变形模量和泊松比的计算模型。结合具体工程案例,分析回填层变形模量和泊松比与隧道应力传递的关系,提出回填层变形模量和泊松比是隧道应力传递重要的影响因素。(4)结合前面分析的隧道围岩、衬砌、回填的各参数,利用有限元软件Ansys模拟各级围岩下标准二车道公路隧道的受力和变形,分析隧道回填层工程参数和隧道衬砌内力和位移的相互关系,引入衬砌安全轴向力作为衬砌破坏标准,运用区间分析和回归分析理论求出Ⅳ、Ⅴ围岩下,标准二车道公路隧道回填层变形模量、泊松比的区间值,所得到的计算结果为今后隧道工程中回填层的设计和施工提供了指导作用。(5)将有限元标准两车道公路隧道用大小半径之和修正的等代圆半径法简化为圆形隧道,结合回填层工程参数计算模型,计算出Ⅳ、Ⅴ级围岩级别下,隧道回填层变形模量区间值。将回填层工程参数理论计算结果和有限元法结果对比,发现理论计算结果和有限元数值法计算结果整体很吻合,从而验证了理论计算模型的正确性,为今后隧道工程回填材料工程参数的选取提供了理论依据。
[Abstract]:Since the reform and opening up, with the increasing strength of our country and the prosperity of economy, the transportation industry of our country has entered the era of rapid development. As one of the key points of traffic engineering, tunnel construction has been developed rapidly. In the process of tunnel excavation, due to the particularity of geological and hydrological conditions and the limitations of construction technology, the phenomenon of overexcavation of surrounding rock is very common. Nowadays, the treatment of overexcavation of surrounding rock is lack of theoretical support. In practical projects, most of them are used as backfill layer according to engineering experience. The irregular construction of backfill layer places great hidden dangers on tunnel engineering and affects the safety of tunnel. Therefore, it is very urgent to study the engineering parameters of overexcavated backfill layer in surrounding rock. In this paper, interval analysis is introduced into tunnel engineering to study the engineering parameters of tunnel backfill material. The research contents include the following aspects: (1) the research status of the relationship between tunnel underexcavation, tunnel backfill material and backfill layer engineering parameters and tunnel surrounding rock, lining and backfill layer is summarized, and the existing problems are analyzed. The engineering parameters of backfill layer are studied by interval theory. (2) the basic theory of interval mathematics is introduced. The statistics of tunnel overexcavation under different surrounding rock grades are carried out, and the statistical values of tunnel overexcavation are obtained. Combined with the code, the geometric parameters of tunnel lining, backfill layer and the physical parameters of surrounding rock and lining are analyzed, and the internal force inspection standard of lining structure is put forward. (3) the mechanical model of surrounding rock, lining and backfill layer of circular tunnel is established, and the calculation model of deformation modulus and Poisson's ratio of tunnel backfill layer is deduced by using elastic mechanics theory, interval analysis, combined with boundary conditions and contact conditions. Combined with the concrete engineering case, the relationship between the deformation modulus and Poisson's ratio of the backfill layer and the stress transfer of the tunnel is analyzed, and it is pointed out that the deformation modulus and Poisson's ratio of the backfill layer are the important influencing factors of the stress transfer of the tunnel. (4) combined with the parameters of the surrounding rock, lining and backfilling, the finite element software Ansys is used to simulate the stress and deformation of the standard second-lane highway tunnel under all levels of surrounding rock. The relationship between the engineering parameters of tunnel backfill layer and the internal force and displacement of tunnel lining is analyzed. The safety axial force of lining is introduced as the failure standard of lining. The interval values of deformation modulus and Poisson's ratio of standard two-lane highway tunnel backfill layer under IV and V surrounding rock are calculated by using interval analysis and regression analysis theory. The calculated results provide guidance for the design and construction of backfill layer in tunnel engineering in the future. (5) the equivalent circular radius method modified by the sum of radius of finite element standard two-lane highway tunnel is simplified into circular tunnel. Combined with the calculation model of backfill engineering parameters, the interval value of deformation modulus of tunnel backfill layer under grade IV and V surrounding rock grade is calculated. By comparing the theoretical calculation results with the finite element method results, it is found that the theoretical calculation results are in good agreement with those calculated by the finite element numerical method, which verifies the correctness of the theoretical calculation model and provides a theoretical basis for the selection of backfill material engineering parameters in tunnel engineering in the future.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U455.4

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