基于遗传与序列二次规划算法的复杂巷道断面应力解

发布时间：2018-05-14 02:21

本文选题：隧道工程 + 保角映射　；参考：《岩石力学与工程学报》2017年02期

【摘要】：在求解具有复杂巷道断面形状的应力解时,保角映射函数的精确性最终决定巷道围岩应力解析解的精确性。鉴于此,利用遗传与序列二次规划算法,实现任意复杂巷道断面的高精度映射,解决以往优化算法中所存在的鲁棒性较差及初值敏感性较强的问题,当映射系数个数≥14,可将平均相对误差控制在0.5%以下。以三心拱巷道为例,利用复变函数所推导的任意轴对称巷道断面的应力解,系统性地分析该巷道周边围岩的力学行为。研究结果表明:(1)在单向竖向荷载下,巷道边的切向应力曲线呈现一低一高的双峰形态,其双峰区域分别对应巷道小拱区域及直角区,应力集中系数分别为1.5~3.0,3.5~8.0。在大拱区域,切向压应力与拉应力均有表现,应力集中系数为-1.0~1.5。直墙区域与底板区域的应力集中系数相对稳定,分别维持在2与-1左右。(2)巷道周边围岩的应力分布特征表明巷道边界各点所对应的影响范围呈现不一致性,直角区所对应的影响范围最大,其次是拱形区域,再次是侧墙区域,最后是底板区域。(3)应力集中系数与侧压力系数λ保持着严格的线性关系,其斜率对应于应力集中系数增长速率k′,由k′在巷道边的分布规律,可最终掌握不同λ作用下的应力分布规律。
[Abstract]:In solving the stress solution with complex roadway section shape, the accuracy of the conformal mapping function ultimately determines the accuracy of the analytical solution of the surrounding rock stress of the roadway. In view of this, the genetic and sequential quadratic programming algorithm is used to realize the high-precision mapping of arbitrary complex roadway sections, which solves the problems of poor robustness and strong sensitivity to initial values in the previous optimization algorithms. When the number of mapping coefficients is more than 14, the average relative error can be controlled below 0.5%. Taking the three-core arch tunnel as an example, the mechanical behavior of surrounding rock around the tunnel is systematically analyzed by using the stress solution of any axisymmetric roadway section derived from the complex variable function. The results show that under unidirectional vertical load, the tangential stress curve of roadway edge presents a low and high bimodal shape, and its bimodal region corresponds to the small arch area and the right angle area, respectively, and the stress concentration factor is 1.5 ~ 3.0 ~ 3.58.0. In the large arch region, both the tangential compressive stress and the tensile stress are observed, and the stress concentration factor is -1.0 ~ 1.5. The stress concentration factor of the vertical wall area and the floor area is relatively stable, and the stress distribution characteristics of surrounding rock around the roadway around 2 and 1 respectively indicate that the influence range of each point of the roadway boundary is inconsistent. The right angle region corresponds to the largest influence range, followed by the arched area, the side wall area, and the bottom plate area. Finally, the stress concentration factor maintains a strict linear relationship with the lateral pressure coefficient 位. The slope corresponds to the growth rate of the stress concentration factor, and the stress distribution law under the action of different 位 can be finally grasped by the distribution law of k'on the side of the roadway.
【作者单位】：北京科技大学金属矿山高效开采与安全教育部重点实验室;河北工程大学水利水电学院;江西理工大学工程研究院;
【基金】：“十二五”国家科技与支撑计划项目(2013BAB02B08)~~
【分类号】：U451

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