基于风险更新理论的高速公路动态风险判别方法

为了进一步丰富高速公路交通安全保障理论体系,提出一种包括风险源、影响场、作用对象、测度空间以及时间尺度等风险要素的高速公路动态风险判别方法。首先,通过美国加州交通管理系统(PeMS)采集了I80-W高速公路上2019年1~6月的交通流数据和事故数据;其次,以时序为刻度将风险研究场景分为过去、现在与未来3类,并以判别分析法为测度空间,建立以5种交通流参数为自变量的风险判别函数,同时以风险更新理论作为时间尺度,利用判别函数计算风险值R,并应用于风险更新算法中的输入场,完成旧风险模型更新;最后,采用统一样本对旧判别函数R1-4、新判别函数R5、新旧混合判别函数R1-5以及利用风险更新得到的判别函数Ru进行精度检验,其判别精度分别为67.5%、61%、66%、74%。结果表明:更新后的风险判别函数应用于高速公路动态风险判别具有更高的预测精度,基于判别分析法和风险更新算法的高速公路动态风险判别方法可以持续对动态风险评价模型进行更新,能够应用于未来各时间段的高速公路动态风险判别。

Risk evaluation of rock burst through theory of static and dynamic stresses superposition

Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.