基于小波变换的时-能密度法优选微差延期时间

在微差爆破工程中,能否顺利实施微差爆破的关键在于确定合理的微差延期时间。首先,利用基于小波分析的时-能密度法,通过从实测爆破震动信号中识别出各段雷管实际的起爆时刻点,得到了爆破中所用雷管的实际延期时间。其次,利用信号时-频转换技术,从实测微差爆破震动信号中分离出各分段震波。最后,通过比较各分段震波在不同延期时间下的叠加效果,可以得到微差爆破的较优延期时间。以某地下工程爆破震动信号进行分析为例,对本方法的有效性作了检验。该方法具有较高的理论和应用价值,为系统开展爆破震动危害控制和预测研究奠定了理论和技术基础。     

东鞍山铁矿爆破工艺及参数优化

为了改善爆破质量,借助有限元软件,对东鞍山铁矿的爆破参数进行了二维数值模拟计算。确定了矿岩爆破的合理微差延期时间为40～60ms,优化的爆破参数为7m×6．5m。试验结果表明,利用推荐的微差延期时间及改进的孔网参数进行爆破,爆堆块度更加均匀,电铲装车的效率提高了9％。     

微差爆破在橡胶坝底板拆除工程中的应用

采用微差爆破技术对青岛大沽河袁家庄橡胶坝底板爆破拆除工程中的混凝土构件进行了爆破拆除。分析了微差爆破技术的施工方法和布孔,并对微差爆破的时间间隔、用药量等参数进行了计算。现场试爆和实爆效果表明,通过微差爆破原理和多循环钻爆工艺的有机结合,成功拆除了混凝土底板的已破坏部分,有效地避免了挤压爆破对保留部位工程质量的影响。     

57型微差爆破仪

1957年鞍山钢铁公司积极研究和推广微差爆破法,由于缺少适合于我国矿山技术条件的微差爆破仪器,只得用中间继电器来代替,但因为它的准确性差,连续发生了拒爆事故,阻碍了这一先进经验的试验和推广。鉴于这种情形鞍山钢铁公司安全技术监察处劳动保护研究室设计并试制出来了57—型微差爆破仪器,它适用于矿山开采,厂房和生产设备附近爆破基础等。     

滚筒式露天采矿机在某露天矿的应用预评价

滚筒式露天采矿机以其卓越的挖掘性能,避免了传统采矿工艺中的穿孔、爆破、粗碎等工作,也可以避免爆破震动对露天边坡造成的次生危害;其超强的选采分采性能,可以实现精细化采矿,极大地降低矿石的损失贫化管理难度。根据实际地质条件、采矿工艺及矿体赋存条件,预评价该设备在某露天矿应有广阔的应用前景。     

降低裂隙性矿体爆破大块率的探讨

通过采取微差挤压爆破技术,选取适合于裂隙性矿体的爆破参数,以及合适的起爆方法和微差间隔时间等控制爆破技术后,使大块率由过去的３０％降至目前的１０％．     

分宜矿白云石采场爆破震动测试研究

使用BlastMateⅢ型测振仪对分宜矿白云石采场爆破震动进行了3次现场测试，运用线形回归推导出最大爆破振速公式，按照国家《爆破安全规程》确定爆破震动对采场周边民房的安全距离．     

爆心距对爆破振动信号频带能量分布的影响

根据爆破振动信号具有短时非平稳的特点,利用小波包分析技术对满足分析要求的多段微差爆破振动信号的能量分布特征进行研究。首先,简略地介绍了小波变换与小波包分析的特点。其次,基于MATLAB对爆破振动信号进行小波包分析,得到了爆破振动信号在不同频带上的能量分布图。最后,总结了爆破振动信号频带能量的分布规律,重点探讨了爆心距对爆破振动信号频带能量分布的影响。结果表明,爆破震动信号在传播过程中,其主振频带有往低频发展的趋势,且宽度增加。     

露天开采台阶逐孔起爆爆破震动数值模拟

为了控制露天台阶爆破中的震动效应,采用ANSYS/LS-DYNA软件模拟逐孔起爆过程中不同起爆延时条件下爆破弹性破坏区质点震动速度的变化规律。结果表明,相邻炮孔起爆形成的应力波阵面相互叠加或削弱可引起质点震动的强弱变化,炮孔孔距9 m时不同延时条件下岩石质点的震动速度变化规律相似;起爆后20~50 ms内质点三向震动速度的合成速度均值最小,因此孔距9 m时台阶微差爆破的最佳起爆延时为20~50 ms。     

测振技术在爆破地震烈度监测中的应用

由于人工爆破和打桩所引起的地振动,往往会给周围的建筑物、仪器设备和人们生活带来影响及危害,因此,在工程施工中,有效监测地震动烈度,评价因地震动而引起的振动影响及灾害程度就显得尤为重要,本文论述了场地受迫振动而产生地震波的岩土动力特性机理,并采用测振技术监测场地在爆破时的各测试点地震烈度,从而来评价爆破震动的安全度,为安全施工和居民的生活提供科学依据.     

Research on the “three shells” cooperative support technology of large-section chambers in deep mines

The "three shells" cooperative support technology was proposed herein according to both the large deformation of the rock surrounding large-section chambers in deep mines and the precarious stability of the support structures therein. The development range of the plastic zone in the surrounding rock was controlled by a stress shell to reduce the difficulty of controlling the surrounding rock. Additionally, the residual strength of the rock mass in the plastic zone and the self-bearing capacity of the surrounding rock were improved by a reinforced load-bearing shell. Furthermore, a passive load-bearing shell could restore the triaxial stress state of the surrounding rock on the free surface, reduce the influence of the external environment on the surrounding rock, and reinforce the surrounding rock with the strength of the shell. Reasonable layouts of large-section chambers were determined by analyzing the control effect of the stress shell on the surrounding rock under three kinds of in situ stress fields. The orthogonal test method was applied to reveal the influences of different support parameters in the reinforced loadbearing shell and passive load-bearing shell on the surrounding rock stability. The surrounding rock control effect of the "three shells" collaborative support technology was analyzed through numerical simulation and field monitoring. The results show that the maximum displacement between the roof and floor of the coal preparation chamber in the Xinjulong coal mine was approximately 48 mm, and the maximum displacement between its two sides was approximately 65 mm, indicating that the technology proposed herein could meet the long-term control requirements of the surrounding rock stability for large-section chambers in deep mines.     

基于DE-BP模型隧道围岩的动态分级

针对隧道施工期间的围岩分级问题,根据地质超前预报获得围岩分级指标,提出了基于DE-BP模型的隧道围岩分级方法,并结合VTK技术、三维地质建模方法及数据库技术编写隧道围岩分级软件,将此方法应用于板石隧道的围岩分级中,进行围岩等级可视化显示与施工方案的调整.结果表明:DE-BP模型的均方差明显小于BP神经网络,分级精度显著提高;DE-BP模型围岩分级结果与勘查设计等级基本相同,验证了该模型的合理性,更加适用于隧道围岩动态分级.     

基于光纤技术的井筒围岩稳定实时监测系统

针对井筒围岩变形监测受采动影响的问题,提出了采用光纤传感技术监测井筒围岩变形的方法.研究了光纤传感器的不同埋入方式、粘结材料以及施工工艺对结构变形监测的影响,结合金川Ⅱ矿区14行风井加固工程,设计并布设了光纤光栅传感监测系统.现场监测结果表明,基于BOTDR的分布式光纤传感技术具有实时性、远程和自动监测围岩变形的优点,可以直观地得到井筒在不同位置的围岩变形分布特征,为井筒围岩变形提供了准确的测试数据.     

三软综放沿空锚网索支护巷道回采期间围岩变形特征

针对三软综放沿空巷道围岩大变形、难支护的特点,提出采用锚网索支护新技术,通过对试验巷道数值模拟以及表面位移、围岩深部位移和围岩应力的现场监测,分析了试验巷道矿压显现活动规律,掌握了试验巷道在锚网索支护下的围岩变形规律,这为锚网索支护在三软煤层巷道的推广应用和支护参数设计提供了科学依据.     

深部巷道围岩控制原理与应用研究

采用理论分析、数值模拟和现场试验的方法，研究深部巷道围岩稳定问题，认为深部巷道围岩控制的基本方法是提高围岩强度、转移围岩高应力以及采用合理的支护技术．提出了深部巷道围岩控制的基本技术和控制过程：1）应力转移降低巷道浅部围岩应力；2）采用高预紧力、大延伸量的高强度锚杆、锚索支护系统，强化锚固区围岩强度，提高巷道围岩自身稳定性；3）加强巷道两帮、底角支护，提高巷道最薄弱部位（两帮、底角）残余强度、提高巷道围岩的整体稳定性；4）应用高水速凝材料注浆加固破碎区，提高破碎围岩的完整性和力学参数．该研究成果已成功应用于工程实践．     

Permeability and pressure distribution characteristics of the roadway surrounding rock in the damaged zone of an excavation

Research on the permeability and pressure distribution characteristics of the roadway surrounding rock in the excavation damaged zone(EDZ) is beneficial for the development of gas control technology. In this study, analytical solutions of stress and strain of the roadway surrounding rock were obtained, in which the creep deformation and strain softening were considered. Using the MTS815 rock mechanics testing system and a gas permeability testing system, permeability tests were conducted in the complete stress-strain process, and the evolution characteristics of permeability and strain were studied over the whole loading process. Based on the analytical solutions of stress and strain and the governing equation of gas seepage flow, this paper proposes a hydro-mechanical(HM) model, which considers three different zones around the roadway. Then the gas flow process in the roadway surrounding rock in three different zones was simulated according to the engineering geological conditions, thus obtaining the permeability and pressure distribution characteristics of the roadway surrounding rock in three different zones. These results show that the surrounding rock around the roadway can be divided into four regions-the full flow zone(FFZ), flow-shielding zone(FSZ), transitive flow zone(TFZ), and in-situ rock flow zone(IRFZ). These results could provide theoretical guidance for the improvement of gas extraction and gas control technology.     

Surrounding rock control of gob-side entry driving with narrow coal pillar and roadway side sealing technology in Yangliu Coal Mine

Gob-side entry driving can increase coal recovery ratio, and it is implied in many coal mines. Based on geological condition of 10416 working face tailentry in Yangliu Coal Mine, the surrounding rock deformation characteristics of gob-side entry driving with narrow coal pillar is analysed, reasonable size of coal pillar and reasonable roadway excavation time after mining are achieved. Surrounding rock control technology and effective roadway side sealing technology are proposed and are taken into field practice. The results showed that a safer and more efficient mining of working face can be achieved. In addition, results of this paper also have important theoretical significance and valuable reference for surrounding rock control technology of gob-side entry driving with narrow coal pillar under special geological condition.     

Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.     

软弱围岩大断面隧道径向注浆变形的控制

研究软弱围岩大断面隧道施工中径向注浆技术,为该类隧道设计施工提供依据．在分析隧道施工中不同注浆方式的基础上,以控制厦门翔安隧道陆域段围岩变形为例,对隧道径向注浆作用机理进行分析。阐述了注浆设计方案及实施情况,用监测结果说明变形的控制效果．在隧道初期支护背后进行径向注浆,能增强与围岩的密贴程度,提高围岩的承载力和自稳力,有效地控制隧道初期支护结构沉降和变形．     

巷道组过断层围岩控制技术研究

以深井巷道组过特大型断层（落差大于100m）破碎带为工程背景,采用数值模拟的办法对比分析了正常地层和断层破碎带中巷道组围岩的力学特征以及相互影响;结合断层破碎带围岩的实际情况,建立了＂早预测、短进尺、弱爆破、强支护、紧封闭、勤量测、防突水＂的断层带施工技术和综合保障体系,形成超前物探、超前加固、微震开挖、分步动态支护等综合配套技术,保证了巷道的施工安全。