Experimental Study on Rock Failure Characteristics of Ejective Rock Burst Based on Energy Compensation

Geotechnical and Geological Engineering - Rock burst is a typical type of dynamic geological disaster in the process of underground engineering excavation under high in-situ stress. Based on the...     

四川锦屏山隧道岩爆综合防治施工技术

锦屏山隧道工程是锦屏水电枢纽工程的关键性控制施工项目,隧道地处我国西南高地应力区,全长约17.5km,隧道最大埋深约为2375 m,埋深大于1500 m的地段长度约12875 m。通过对锦屏山隧道现场岩爆特征的分析总结和研究,介绍了锦屏山隧道岩爆独特的工程特点和综合防治施工技术。     

基于GIS的区域岩爆危险性评价研究

岩爆是一种普遍的地质灾害现象,如何应用现代化的技术手段实现岩爆危险性评价是一个重要的研究课题.以南水北调西线工程达曲-上杜柯线为例,以GIS为技术手段,研究了基于GIS的岩爆危险性评价,得到了区域岩爆危险性评价结果图,并分析了其精确性及工程影响.初步形成了一套较为完整的基于GIS的岩爆危险性评价的研究思路和操作流程,对今后同类研究提供了有益的借鉴.     

A Multidisciplinary Methodology for Hazard and Risk Assessment of Rock Avalanches

Summary A quantitative procedure for hazard and risk assessment of large landslides that can develop as rock avalanches is discussed in this paper. Reference is made to the IMIRILAND project, where a multidisciplinary methodology has been developed paying particular attention to the landslide modeling process that leads to the quantification of the hazard, i.e. the prediction of the occurrence probability, the involved area and the run-out velocity. The risk assessment methodology is exemplified in the paper with reference to two cases: the Ceppo Morelli and Rosone landslides, both of which are located in the Italian Western Alps. The results of these applications show that, despite the development of sophisticated 3D numerical methods, many uncertainties still remain in the process of modeling large and complex landslides, related in particular to the definition of the probability of failure and the rheological parameters to be used for the prediction of rock mass behavior. However geo-mechanical models are found to be very valuable tools to verify, from a mechanical point of view, the assumptions introduced through the geo-structural and geo-morphological analyses concerning the volume and the kinematics of the unstable mass, and their role is fundamental for the determination of the involved area when mechanical parameters can be assumed with sufficient reliability. Author’s address: Marta Castelli, Politecnico di Torino – Dipartimento di Ingegneria Strutturale e Geotecnica, Corso Duca degli Abruzzi 24, 10129 Torino, Italy     

四川达竹金刚煤矿综合防治水技术研究

为解决东翼+120m水平的运输、排水及其通风问题,金刚煤矿决定在该矿西翼+120m水平作石门至东翼,其施工顺利与否影响着矿井延深及深部生产开拓布署。通过分析矿区水文地质条件、构造及水害的形成方式,提出了物探先导、探放水跟进,增加排水能力,优化巷道布置的综合防治水技术,从而解决了须家河二段(T3xj2)砂岩水和雷口坡(T2l)灰岩水对石门安全工作的影响,石门于2013年3月12日安全穿过了5号和6号陷落柱间须家河二段(T3xj2)砂岩裂隙发育区,进入须家河三段(T3xj3)隔水层,为矿井安全生产奠定了基础。     

Enhancing Machine Learning Algorithms to Assess Rock Burst Phenomena

One of the main challenges that deep mining faces is the occurrence of rockburst phenomena. Rockburst prediction with the use of machine learning (ML) is currently gaining attention, as its prognosis capability in many cases outperforms widely used empirical approaches. However, the required data for conducting any analysis are limited, while also having imbalances in their recorded instances associated with rockburst intensities. These, combined with the multiparametric nature of the phenomenon, can deteriorate the performance of the ML algorithms. This study focuses on the enhancement of the prediction performance of ML algorithms by utilizing the oversampling technique Synthetic Minority Oversampling TEchnique (SMOTE). Five ML algorithms, namely Decision Trees, Naïve Bayes, K-Nearest Neighbor, Random Forest and Logistic Regression, were used in a series of parametric analyses considering different combinations of input parameters, such as the maximum tangential stress, the uniaxial compressive and tensile strength, the stress coefficient, two brittleness coefficients and the elastic energy index. All models kept their hyperparameters fixed, and were trained with the initial dataset, in which synthetic instances were added gradually aiming in the attenuation of a balanced dataset and its further expansion, until the number of synthetic instances reached the number of real data. The assessment of the SMOTE technique is given and its performance is evaluated though the different strategies adopted. The results indicate that SMOTE has a considerable positive effect in the accuracy of the overall classification and especially in the improvement of the within-class classification accuracy, even after the balancing of the dataset.

     

瞬变电磁技术在邢台矿区防探水中的应用

邢台矿区属典型的华北岩溶型石炭一二叠系煤田,下组煤普遍受巨厚奥陶系灰岩强岩溶含水层的威胁。根据目前物探方法的特点,决定使用方向性好,对水敏感的瞬变电磁技术探测该矿区水患。针对井下巷道工作条件复杂．干扰因素多的特点,选用两个不同的工作频率25Hz、6．25Hz进行测量。并以显德汪矿1612工作面风巷瞬变电磁侧向探测为例,圈定出其低阻异常区。     

灾后恢复重建中如何做好地质灾害防治工作

5．12汶川地震给灾区造成了巨大的人员伤亡及财产损失,也诱发了大量的崩塌、滑坡、泥石流等次生地质灾害隐患,严重危及灾区广大人民群众的生命财产安全。切实做好地质灾害防治工作是保障灾后恢复重建工作得以顺利进行的一个十分重要的前提条件,文章结合当前实际,从组织管理、队伍建设、防灾减灾等多个方面提出了有针对性及建设性的意见,对指导灾区开展防灾避险工作有一定的借鉴意义。     

工程岩爆灾害判别的RBF-AR耦合模型

岩爆是深部高地应力区地下岩体工程中的主要工程地质灾害之一,其发生及烈度预测是一个复杂的不确定系统问题。为了有效预测和判别深部工程岩爆灾害,在总体考虑岩爆各影响因素的基础上,选取地下工程中岩体完整性指数、岩石单轴抗压强度、岩石单轴抗拉强度、围岩最大切向应力、围岩抗压强度与其抗拉强度的比值、围岩切向应力与围岩抗压强度比值、弹性能量指数、岩爆倾向性指数作为岩爆预测的评判指标,提出了一种基于非线性参数优化的RBF-AR岩爆预测模型。在终南山隧道竖井岩爆判别中,利用RBF-AR法进行计算,计算结果与实际情况完全一致,表明该模型在岩爆预测中的可行性和有效性。     

新建向莆铁路高盖山隧道岩爆预测研究

高盖山隧道岩爆预测采用工程岩体分级标准判别法、Russenes岩爆判别法、Turchaninov岩爆判别法和Hoek岩爆判别法等4种综合评定判别。当硬质脆性岩类隧道埋深小于240 m时,不会产生岩爆;埋深240~368 m时,可能产生轻微岩爆;埋深368~650 m时,会发生中等规模岩爆;埋深大于650 m时会发生较强岩爆。     

地应力测量在矿床突水防治中的应用——以河南夹沟铝土矿床突水防治工程为例

针对铝土矿床突水,开展地应力测量研究,是分析查明突水成因、优化确定防治方案及合理进行矿床底板管理的一项重要手段。夹沟矿床测量分析结果表明:①矿床地区存在较高的水平构造应力,其量值明显高于垂向应力。矿床水平高构造应力对矿床底板及其边坡稳定性具有不良影响,矿床开采掘面轴线走向应沿N70°E方向布设趋佳;②由于持续开采作用,矿床附近地应力状态产生不良扰动,水平高构造应力同开采形成的局部地应力场不良改变的叠加影响对矿床底板岩石场各类裂隙、结构面水起到极为重要的“催化”作用,是造成矿床底板突水的重要因素之一;③防治工作应重视加强矿床底板管理,科学预留安全隔水层屏障。并建议对矿床底板及其下伏一定范围内的灰岩实施预注浆处理,使得裂隙得以加固、溶洞得到堵塞,以抵抗不良应力的作用,消除或减弱对矿床突水的影响。     

岩体稳定分析的广义条分法初步探讨

针对传统竖直条分法和萨尔玛法应用于岩体边坡稳定分析的缺点,提出了适用范围更为广泛的广义条分法,阐明了广义条分法的基本原理,并采用优化搜索的方法给出了相对最危险的潜在滑面及其稳定系数,编制了相应程序,最后结合实例论证了广义条分法的合理性和优越性。     

A Hazard Assessment Method for Potential Earthquake-Induced Landslides – A Case Study in Huaxian County, Shaanxi Province

The hazard assessment of potential earthquake-induced landslides is an important aspect of the study of earthquake-induced landslides. In this study, we assessed the hazard of potential earthquake-induced landslides in Huaxian County with a new hazard assessment method. This method is based on probabilistic seismic hazard analysis and the Newmark cumulative displacement assessment model. The model considers a comprehensive suite of information, including the seismic activities and engineering geological conditions in the study area, and simulates the uncertainty of the intensity parameters of the engineering geological rock groups using the Monte Carlo method. Unlike previous assessment studies on ground motions with a given exceedance probability level, the hazard of earthquake-induced landslides obtained by the method presented in this study allows for the possibility of earthquake-induced landslides in different parts of the study area in the future. The assessment of the hazard of earthquake-induced landslides in this study showed good agreement with the historical distribution of earthquake-induced landslides. This indicates that the assessment properly reflects the macroscopic rules for the development of earthquake-induced landslides in the study area, and can provide a reference framework for the management of the risk of earthquake-induced landslides and land planning.     

拱形洞室围岩内岩爆的计算机模拟与控制方法

借用GDA软件来模拟开挖周边的应力重分布，在此基础上，重点分析了拱形洞室的拱顶、拱肩、两侧及底角的应力分布与岩爆的关系。并提出如何依据dσ3/（σ1-σ3）大小与正负来分析和估计岩爆位置，因为应力差σ1-σ3可表征岩石的变形与静态破坏，而最小主应力增量dσ3的大不可表征抵抗这种变形与破坏的能力。结果是拱肩与底角会出现岩爆。分析结果得到了加拿大某矿山的岩爆发生位置实际资料所验证。最后，提出了如何利用预裂爆破方法使岩爆从拱肩迁移到洞室底角。