Safety Management Based on Detection of Possible Rock Bursts by AE Monitoring during Tunnel Excavation

Summary. As underground development continues at great depths, the danger of rock bursts will inevitably increase. It is important to consider countermeasures for avoiding rock bursts in underground work. In Japan, rock bursts have actually been experienced during construction of several tunnels, including the Kan-etsu tunnel construction project, during which many rock bursts were observed. Stress analysis of tunnels is performed based on initial stress measurements in the base rock. In addition, AE measurement has been adopted in construction management, allowing safer excavation. Collective analysis of the data obtained has been shown to be effective for safety control during excavation of hard base rock. In this research, initial stress measurements in base rock, secondary stress analysis around a tunnel, and AE measurements are examined. Based on the results of this analysis, it is clear that the generation of rock bursts is related to the presence of geological discontinuities.     

核电站扩建工程基坑开挖爆破振动安全控制

结合秦山核电二期扩建工程,在已运行核电站附近新扩建核电站的大型基坑开挖过程中进行爆破振动的监测与爆破振动的控制。通过理论分析与监测等多种手段对爆破振动进行有效的控制,确保了正在运行核电站的安全。所总结的减震措施经验对其他核电站的爆破振动控制具有借鉴作用。     

岩体结构面对巷道工程稳定性影响的初步研究

基于对淮北芦岭煤矿主要岩石巷道围岩结构面及巷道变形破坏的调查和分析，认为结构面是影响巷道工程稳定性的重要因素之一。巷道的变形破坏常受结构面直接控制。结构面的发育程度、组合特征决定了巷道变形破坏的方式。     

Influence of Rock Mass Parameters on the Performance of a TBM in a Gneissic Formation (Varzo Tunnel)

Summary The paper analyses the influence of rock mass quality on the performance of a double shield TBM in the excavation of a tunnel in a gneiss formation which is characterized by high strength and low fracture intensity.As full observation of the rock conditions was prevented by the use of segmental lining, a geomechanical survey of the face was performed during maintenance downtime and the observed conditions were correlated with the machine performance parameters for that same day. A statistical analysis of the data shows that penetration rate correlates well with a slightly modified RMR index (in which the influence of the water conditions and joint orientation were discounted), but the most important factor is by far the partial rating of the RMR classification related to joint spacing only. However in tunnels characterized by greater variability in rock strength and joint conditions, it could be worthwhile using the complete RMR index.Given the toughness of the rock, failure of the cutter bearings and supports were a frequent occurrence during excavation. Owing to this factor the influence of rock quality on the rate of advance was found to be weak and the correlation more scattered.The results obtained for the Varzo tunnel were compared with those relative to other tunnels in granitic rocks and found to be in good agreement. However the relationships obtained should be considered valid only for this type of rock; machine behaviour could be found to be markedly different in other rock types, even where rock material strength and joint frequency are the same.     

矿床储量(质量)稳定性趋势分析和可靠程度判定——对陕西旬阳姚沟铜矿勘查成果分析的思考

在陕西旬阳姚沟铜矿详查工作中,发现勘查区构造发育,地层产状复杂;矿化类型、矿石结构、构造、围岩蚀变呈多样化;矿石质量、矿体形态变异性显著,离散度高,对矿床储量（质量）的估算评价其可信度较低。同时,结合我国现行固体矿产勘查规范对储量估算中存在的对其稳定性和可靠程度无量化分析、评价的问题,提出了采用概率统计原理对矿床储量（质量）进行趋势分析和可靠性（可信度）判断的方法。储量稳定性分析采用储量因子积计算储量稳定性指标β,通过β-n曲线分析矿床储量稳定性,提出储量稳定分析准则;质量稳定性采用矿石品位频数分布p-n曲线分析品位变化趋势,提出质量稳定分析准则;储量（质量）可靠程度判定采用储量因子稳定性指标趋势和矿石品位样本频数分布的交集判定法,用可靠度综合值表示。此外,结合姚沟北矿带实例介绍储量稳定性分析、分组方法,采用归纳法,从特殊到一般,以铜矿为例,寻求判定各类矿种储量（质量）可信度的通用方法。此矿床储量（质量）稳定性趋势分析和可靠度判定方法对各类矿种矿床的评价具有普遍意义,特别适用于金属内生矿床和热液交代矿床。     

Effect of Ecological Factors on the Distribution of Microorganisms in Regosols (Steppe of Priol’khonie, Siberia)

正1 Introduction Regosol in Eastern Siberia is intrazonal soil.In Priolkhonie region it occurs among chestnut soils,salt marshes and solonetzes.There are small information about Tagotskij hydrolaccolith in the research articles of geologists,archaeologists,and paleolimnologists when