基于随钻参数的隧道围岩地应力智能解析方法

    Intelligent analysis method of tunnel surrounding rock stress based on drilling parameters

    • 摘要: 为突破钻爆法隧道施工过程中地应力实时获取难题,本文研制了冲击回转式随钻参数高精度同步采集装备与三向可控应力加载平台,开展12组不同围岩地应力状态的钻进试验,系统揭示随钻参数与地应力、地应力与波速之间的响应规律。在此基础上,构建6000条多工况五维随钻特征-波速样本库,设计Bagging决策树集成模型,实现三向波速智能预测,并依托声弹性理论反演主应力大小;同时提出基于波速椭球回归的主应力方向解析算法。结果表明:三向波速模型预测准确率84.44%–88.21%,利用预测波速反演的主应力大小与加载值吻合良好;波速椭球法解析的最大主应力方向误差≤0.1°,其余主应力方向误差≤18.2°。研究成果为隧道围岩地应力场的快速、智能化解析提供了新思路,可为高地应力隧道施工安全及支护优化设计提供重要技术支撑。

       

      Abstract: In order to overcome the difficulty of obtaining ground stress in real time during the construction of tunnels using the drilling and blasting method, this paper developed an impact rotary type high-precision synchronous acquisition equipment for drilling parameters and a three-dimensional controllable stress loading platform. 12 sets of drilling tests with different surrounding rock ground stress states were carried out to systematically reveal the response laws between drilling parameters and ground stress, and between ground stress and wave velocity. On this basis, a five-dimensional drilling feature-wave velocity sample library of 6000 multi-conditions was constructed, and a bagging decision tree integration model was designed to realize the intelligent prediction of three-dimensional wave velocity. The principal stress magnitude was inverted based on the acoustic elastic theory. At the same time, a principal stress direction analysis algorithm based on wave velocity ellipsoid regression was proposed. The results show that the prediction accuracy of the three-dimensional wave velocity model is 84.44%-88.21%, and the principal stress magnitude inverted using the predicted wave velocity is in good agreement with the loading value. The maximum principal stress direction error of the wave velocity ellipsoid method is ≤0.1°, and the errors of the other principal stress directions are ≤18.2°. The research results provide new ideas for the rapid and intelligent analysis of the ground stress field of the tunnel surrounding rock, and can provide important technical support for the construction safety and support optimization design of high ground stress tunnels.

       

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