全风化花岗岩突水通道扩展的颗粒起动流速研究

发布时间：2018-05-11 05:00

本文选题：全风化花岗岩 + 突水通道　；参考：《岩土力学》2017年04期

【摘要】：突水突泥是富水全强风化花岗岩隧道施工常见的地质灾害,地层颗粒的流失是导致突水通道扩展的关键因素,其中颗粒达到起动流速是其流失的临界条件。考虑水流冲刷和土体黏结作用,对突水通道断面颗粒进行三维受力分析,导出颗粒的临界起动条件,建立了考虑颗粒粒径、颗粒坡面位置、相对暴露度三因素的颗粒起动流速函数,并利用数值方法分析了上述三因素对起动流速的影响规律。计算分析表明:起动流速随粒径增大先减小后增大,通道断面不同坡面位置颗粒起动流速呈明显的对称性,总体上起动流速随相对暴露度的增大呈增大趋势。采用正交试验法研究了三因素对颗粒起动流速的敏感性,发现粒径对起动流速影响最为显著。同时根据断面颗粒起动最小流速标准及相对暴露度的随机性,简化颗粒坡面位置和相对暴露度两因素,导出颗粒起动流速的简化公式,最后利用室内试验和工程实例验证了该公式的合理性。
[Abstract]:Water inrush and mud outburst is a common geological hazard in the construction of water-rich, fully weathered granite tunnel. The loss of formation particles is the key factor leading to the expansion of water inrush channel, and the critical condition for the loss is that the particle reaches the starting velocity. Considering the effect of water scour and soil adhesion, the critical starting conditions of the particles are derived by analyzing the three-dimensional force on the cross section of the water inrush passage, and the particle size and the slope position of the particles are established. The particle starting velocity function of relative exposure three factors is analyzed and the effect of the above three factors on the starting velocity is analyzed by numerical method. The calculation and analysis show that the starting velocity decreases first and then increases with the increase of particle size, and the starting velocity of particles at different slope positions of channel section shows obvious symmetry, and the starting velocity increases with the increase of relative exposure degree as a whole. The sensitivity of three factors to the starting velocity of particles was studied by orthogonal test. It was found that the particle size had the most significant effect on the starting velocity. At the same time, according to the minimum velocity standard and the randomness of relative exposure, the simplified formula of particle starting velocity is derived by simplifying the two factors of particle slope position and relative exposure. Finally, the rationality of the formula is verified by laboratory tests and engineering examples.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中国科学院大学;山东大学岩土与结构工程研究中心;
【基金】：国家重点基础研究发展计划973项目研究课题(No.2013CB036006) 国家自然科学基金(No.51379200,No.51225902)~~
【分类号】：U456.33

【参考文献】