谈岩石隧道突水涌泥后处治措施

介绍了宝塔山隧道3号斜井XK0+283~XK0+291段大规模突水涌泥的过程,并分析了该坍塌段突水涌泥后的治理方案及施工技术要点,以期为今后处治同类工程问题提供参考借鉴。     

输煤管道工程中浅埋长距离小断面隧道施工工艺

以输煤管道项目洛河隧道工程为基础,结合地质条件及工程施工难点,介绍了浅埋长距离小断面隧道施工工艺,对隧道开挖、排渣、支护、通风、排水等系统进行了论述,分析了各工序施工难点和要点,总结了采用浅埋长距离小断面隧道施工工艺特点及效果,取得了良好的经济和社会效益。     

Effects of openings on the punching shear strength of RC flat‐plate slabs without shear reinforcement

Openings in RC flat‐plate slabs are one of the critical factors that influence the punching shear strength of the slab and determine its thickness in the vicinity of the slab‐column joint. This study experimentally investigates the effects of openings on the punching shear strength of flat‐plate slabs without shear reinforcement. Tests were performed on eight flat‐plate slab specimens considering the layout and number of openings as test variables. The failure characteristics of each specimen are examined, and the effects of the test variables on the punching shear strengths of the test specimens are investigated. The measured punching shear strengths of the test specimens are compared with the predictions of several concrete design codes, including the American Concrete Institute (ACI), Comité Euro‐International du Béton and Fédération Internationale de la Précontrainte (CEB‐FIP) model and fédération internationale du béton (fib) model codes. This indicates that the reductions in punching shear strength due to the existence of openings are generally proportional to the loss of effective critical sections, and an L‐shaped opening layout around the corner of the column may further reduce the punching shear strength and may contribute to the loss of effective critical sections due to the existence of openings. Copyright © 2015 John Wiley & Sons, Ltd.     

Experimental study on seismic performance of mega steel‐reinforced concrete columns subjected to cyclic loads

In recent years, mega steel‐reinforced concrete (SRC) columns have been applied in super tall buildings. The previous research on SRC columns mainly focuses on the components with simple arrangement of shaped steel, such as H‐shaped steel and cross‐shaped steel, with little attention paid to mega SRC columns, which always have complicated encased steel and large steel ratio. The cyclic loading tests were carried out on scaled mega SRC column models with different cross‐section type of encased steel and steel ratio. The principal damage states were investigated throughout the entire testing process. Based on the test results, the effects of steel ratio and the cross‐section type of encased steel on the damage characteristics, hysteretic behavior, ductility, secant stiffness degradation, energy dissipation capacity and maximum crack width were analyzed. The test results indicate that the steel ratio has significant effect on the seismic performance of mega SRC columns while the effect of cross‐section type of encased steel is not significant. Copyright © 2015 John Wiley & Sons, Ltd.     

深井软岩大断面硐室合理支护时机分析

针对淮南朱集煤矿千米深部主井箕斗装载硐室支护设计,引入Burger流变黏塑性模型进行数值计算分析,根据不同支护时间下围岩变形及二次衬砌受力计算结果对比,给出了硐室支护合理时间。结合衬砌结构现场监测结果反映出:以硐室顶板围岩变形特性作为支护施作的基准条件,在硐室开挖完成后及时初期支护,在围岩等速流变期施加二次衬砌能有效控制围岩变形,降低二次衬砌受力。     

瓦斯爆炸事故处理原则和技术要点探讨

为提高瓦斯爆炸事故处理的有效性,减少瓦斯爆炸带来的损失,通过对多起瓦斯爆炸事故案例的分析,结合瓦斯爆炸事故特征,对事故的处理进行了积极有效的探索,提出了"统一指挥、逐级负责、有序进行"、"探明灾情、科学分析、果断决策"、"以人为本、安全抢救、执行到位"的瓦斯爆炸事故处理基本原则,并对瓦斯爆炸事故处理时"是否立即切断电源"、"建立通风条件,排除有害气体"、"恢复通风、建立救援通道"的3大技术要点进行了探讨。在此基础上,通过事故救援案例验证了瓦斯爆炸事故处理原则和技术要点对于瓦斯爆炸事故处理的切实有效性。     

复杂岩层大断面硐室群围岩破坏机理及控制

针对复杂岩层巷道交叉点高应力集中区四周硐室群开挖围岩稳定性控制和支护技术等难题,通过对现场取样测试硐室群围岩物理力学参数、黏土矿物成分和松动圈大小,分析了赵庄煤矿三盘区带式输送机头硐室群及周边巷道围岩变形破坏特征和机理,表明硐室帮部煤柱和底板围岩是加固支护重点。利用FLAC3D数值模拟软件分析了硐室群开挖对硐室群及周边巷道围岩应力分布和塑性区分布范围的影响。基于理论分析和数值模拟提出了硐室及周边20 m范围内巷道围岩"强柱固底"的加固支护方案。现场工业试验表明,加固支护后,硐室群及周边巷道围岩变形得到了有效控制,围岩内部裂隙基本被浆液填充,60 d内围岩顶底板和两帮最大移近量分别为30 mm和50 mm,达到了理想的加固支护效果。     

大断面硐室支护技术研究

阳煤一矿S3采区下山胶带机头硐室巷道高3.5 m、宽6.5 m,由于巷道受地应力影响严重,部分区域高冒,巷道最高处达到7 m。针对该处巷道的地质采矿条件,采用锚网支护技术对该处巷道进行支护,支护效果良好。     

基于贝叶斯网络的某金属矿山风险分析

为了使金属矿山安全管理人员能更有效地对矿山进行风险管理。通过对采矿区间事故数据的统计,依据事故后果严重程度确定其权重值,建立矿山事故灾害事故树模型,并将其转换为贝叶斯网络,对各类生产事故条件概率进行计算。将计算结果与矿山其后几年生产事故数据进行比较,该风险分析模型能有效对矿山事故进行分析。     

平邑石膏矿坍塌事故5号救生孔施工工艺及钻具配置

阐述了2015年12月25日山东省临沂市平邑县保太镇玉荣商贸有限公司石膏矿坍塌事故救援中成功救出4名被困矿工的5号救生孔的施工过程。详细介绍了在抢险救援中国家矿山应急救援淮南队采用德国宝峨公司RB-T90型钻机配套河北省地矿局国土资源勘查中心石家庄探矿机械厂(河北石探机械制造有限责任公司)SG219/152型双壁钻具空气反循环钻进施工5号大直径救生孔的整个过程,包括地层情况、钻孔设计、施工工艺、钻具配置、施工过程和施工中遇到的问题以及最终的解决方法。