排序方式: 共有55条查询结果,搜索用时 359 毫秒
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针对西藏地区某水电边坡,在瞬态热传导原理基础上,建立了冻结区和融化区岩体瞬态温度场控制方程,模拟了在低温环境下边坡的温度场响应情况;通过在边坡的不同部位提取特征点,分析了岩体温度场随年气温的演化规律,研究了覆盖层和强风化层在冻结期和融化期的温度影响范围。在此基础上,利用直接耦合法分析了热效应和冻融循环情况下,边坡覆盖层和强风化层位移的变化情况。研究结果表明:边坡浅层岩体温度与环境温度有很强对应性,而边坡深层温度则基本保持在3~5 ℃,边坡冻结最大深度为4 m;覆盖层和强风化层位移受环境温度影响较大,其位移均随时间变化呈近似正弦分布;从影响程度上看,冻胀循环引起的位移变化要远大于热效应的影响。 相似文献
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中国金矿深部开挖中的岩爆预报与控制 总被引:1,自引:0,他引:1
The studies of prediction and control ofrockburst are presented during deep excavation in a gold mine in China Firstly, the stress-relief method is used to obtain a vast amount of data about initial geostress. Secondly, 3D FEM analyses of large scale are performed to find out the law of geostress distribution at various excavation levels of the mining area. At the same time, as an equally important measure, six typical kinds of rock blocks are sampled for the experimental study of rockburst tendency. According to th esynthesized results of the theoretical and testing results, the methods of brittleness coefficient, brittle index and stress, and so on, are adopted. Finally, the evaluation on the possibility of rockbursts is given that may take place at the deep mining area and some effective measures are put forward to prevent and control the rockburst. 相似文献
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融合改进场力和判定准则的点云特征规则化 总被引:1,自引:0,他引:1
为了快速有效地获取散乱点云中的边界特征点和边界线,提出了一种融合改进场力和判定准则的点云特征规则化算法。利用改进的k-d(k-dimensional)树搜索k邻域,以采样点及其k邻域为参考点集拟合微切平面并向该平面投影,在微切平面上建立局部坐标系以将三维坐标转化成二维坐标,利用场力和判定准则识别边界特征点;依据矢量偏转角度和距离对边界特征点进行排序连接;通过改进的三次B样条拟合算法对边界线进行平滑拟合。实验结果表明,该算法能够快速有效地提取边界特征点,且拟合后的边界线偏差量级为10-5 m,具有较高的精度。 相似文献