地下洞室位移反分析的测点优化布置研究

发布时间：2018-12-23 12:46

【摘要】：基于现场量测信息的反分析方法为确定岩体力学参数提供了一条新的途径,而准确的现场监测资料是位移反分析取得成功的前提和依据。理论上,位移观测点布设越多,对反分析结果越有利。但测点布设越多,经济成本就越大。如果能够选取合理的测点布设位置,制定合理的布设方案,不仅能够获得精度较高的待求参数,而且可以降低工程经济成本。因此,本文基于最小方差准则和最大灵敏度准则,针对横观各向同性岩体中位移反分析的测点优化布置问题进行了研究,以此来确定最适宜布设测点的位置。根据最大灵敏度准则对横观各向同性岩体中位移反分析的测点优化布置进行了初步研究,推导了位移对角度和半径的灵敏度准则,得到了对应的灵敏度关系式。灵敏度越大,越有利于参数的反演。研究结果表明,在两主应力的角平分线的区域是最适合测点布置的区域,而布置在洞壁处还是极值处,需要根据推导的关系式做进一步的判定。通过数值分析软件FLAC3D进行建模计算,分析了基于最大灵敏度准则的横观各向同性岩体中测点的优化布置问题。对于圆形巷道,在两主应力的角平分线的区域是最适合测点布置的区域,且布置在洞壁或在极值处。对于直墙圆拱形巷道,最适合布置测线的方向在边墙中部,其次为拱肩部位。根据最小方差准则对横观各向同性岩体中位移反分析的测点优化布置进行了初步研究,推导了含有三个变量参数的准则函数,并求出了三个参数估计值。参数的估计值精度越高,越有利于参数的反演。研究结果表明,在较大主应力方向靠近洞壁的区域是最适合测点布置的区域。
[Abstract]:The method of back analysis based on field measurement information provides a new way to determine the mechanical parameters of rock mass, and accurate field monitoring data is the prerequisite and basis for the success of displacement back analysis. In theory, the more the displacement observation points are arranged, the more favorable to the result of back analysis. But the more measuring points are laid, the greater the economic cost. If we can select a reasonable location of measuring points and make a reasonable layout scheme, we can not only obtain the parameters to be sought with high precision, but also reduce the economic cost of the project. Therefore, based on the minimum variance criterion and the maximum sensitivity criterion, this paper studies the optimal layout of measuring points in the inverse analysis of displacement in transversely isotropic rock mass, so as to determine the most suitable location of the measuring points. Based on the maximum sensitivity criterion, the optimal layout of measuring points for the inverse analysis of displacement in transversely isotropic rock mass is studied. The sensitivity criterion of displacement to angle and radius is derived, and the corresponding sensitivity relation is obtained. The greater the sensitivity, the more favorable the parameter inversion. The results show that the area of the angular bisection of two principal stresses is the most suitable for the location of the measuring points, and the location at the wall or the extremum of the tunnel needs to be further determined according to the derived relationship. The optimal layout of measuring points in transversely isotropic rock mass based on maximum sensitivity criterion is analyzed by numerical analysis software FLAC3D. For circular roadway, the area of angular bisection of two principal stresses is the most suitable area for layout of measuring points, and it is arranged at the wall of the tunnel or at the extreme value. For the straight wall circular arch roadway, the direction of the survey line is in the middle of the sidewall, followed by the arched shoulder. Based on the minimum variance criterion, the optimal layout of measuring points for inverse analysis of displacement in transversely isotropic rock mass is studied, and the criterion function with three variable parameters is derived, and the estimated values of three parameters are obtained. The higher the precision of parameter estimation is, the more favorable the parameter inversion is. The results show that the area near the wall of the tunnel in the direction of the larger principal stress is the most suitable area for the layout of the measuring points.
【学位授予单位】：中原工学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU457

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