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我国是采煤大国,大多数煤矿以井工开采为主,煤矿巷道掘进和支护的工程量很大,巷道支护钻孔施工需要消耗大量锚杆钻头,锚杆钻头的设计和制造技术也得到了快速发展。介绍了锚杆钻头的发展和应用现状,对我国煤矿现用的锚杆钻头的技术特点、适用性进行了分析,并结合煤矿巷道支护的实际需求,提出了施工硬岩和复杂地层时锚杆钻头存在的问题,最后从锚杆钻头设计、加工工艺等方面,阐述了锚杆钻头的发展趋势。 相似文献
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深部高地应力岩巷开挖后围岩内出现分区破裂现象,采用传统的原设计方案巷道稳定性差。根据巷道围岩变形破坏的现场监测结果,经过理论分析和支护试验,提出了“提高法向约束、锚杆增韧止裂、协调耦合支护、应力内部转移、分区充填注浆、增强围岩强度”的锚注一体化综合控制方法理念。并提出了相对应的综合支护技术,即首先采用高预紧力超强锚杆及时支护围岩,锚杆的长度和数量分别由监测结果和分区支护能量判据确定;其次采用高强锚索让压梁支护巷道顶板,实现锚杆、锚索的协调耦合支护和围岩应力内部转移;最后采用中空分段螺旋式注浆技术进行滞后加固。最后针对监测巷道采用锚注一体化综合控制方法和技术进行了支护优化设计并进行现场支护试验,监测结果表明,优化支护的巷道稳定性良好。 相似文献
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锚注支护机理及参数优化研究 总被引:2,自引:1,他引:2
对锚注支护机理进行了分析,得出巷道锚注支护可改善锚杆,裂隙面及围岩的力学性能,减小围岩塑性区及巷道位移,提高围岩的稳定性,并运用正交设计方法对锚注支护参数进行优化,确定了主要影响因素,提出了可供参考的支护方案。 相似文献
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随着矿石开采向纵深发展以及巷道服务年限的变长,巷道围岩应力逐渐增加,巷道支护频率与难度不断加大。以深部复杂地质条件下的贵州某非金属矿巷道为背景,利用深部吸能锚杆巷道支护原理,并结合ANSYS数值模拟方法,对巷道支护方案进行了分析和优化研究。利用SWJ—Ⅳ隧道收敛计监测支护优化前后巷道表面位移,工程实际表明优化后的支护方案大大降低了巷道围岩的变形量,提高了深部复杂地质条件下巷道支护的可靠性与安全性。 相似文献
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An empirical method for design of grouted bolts in rock tunnels based on the Geological Strength Index (GSI) 总被引:4,自引:0,他引:4
The procedure presented in this paper has been developed for the design of grouted rock bolts in rock tunnels during preliminary design stage. The proposed approach provides a step-by-step procedure to set up a series of practical guidelines for optimum pattern of rock bolting in a variety of rock mass qualities. For this purpose, a new formula for the estimation of the rock load (support pressure) is recommended. Due to its wide-spread acceptance in the field of rock engineering, the Geological Strength Index (GSI) is adopted in support pressure equation. For poor and very poor rock mass where the GSI < 27, the use of Modified-GSI is, instead, recommended. The supporting action is assumed to be provided by rock bolts carrying a total load defined by the rock load height. The mechanism of bolting is assumed to rely on roof arch forming and suspension principle. Integrated with support pressure function, the bolt density parameter is modified in order to provide an optimized bolt pattern for any shape of tunnel. The modified bolt density can also be used in analysis of a reinforced tunnel in terms of Ground Reaction Curve (GRC) in such a way as to evaluate the reinforced rock mass and the tunnel convergence. By doing so, the effectiveness of the bolting pattern is well evaluated. The proposed approach based on GSI is believed to overcome constrains and limitations of existing empirical bolt design methods based on RMR or Q-system, which are doubtful in poor rock mass usage. The applicability of the proposed method is illustrated by the stability analysis and bolt design of a rail-road tunnel in Turkey. 相似文献
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Roof bolting in underground mining: a state-of-the-art review 总被引:1,自引:1,他引:1
Conclusions With continuing investigations and developments, roof bolting today can in most cases successfully reinforce the mine roof in underground mining. In order to cope with the increasing use of roof bolts, efforts should be made to maximize the safety and minimize the cost. With regard to mechanical bolting, two important parameters need more advanced improvements and study, namely, optimum design of the shape and type of expansion shell and optimum bolt tension for a specific bolt pattern. For the fully grouted resin bolt, the most critical requirement is to develop a fast-setting, low-cost, intoxic, inflammable grouting material that can be used in the high speed mining cycle. It should be noted that geological conditions such as the strata type, rock properties,in situ stress, and planes of weakness play an important role in the successful application of any roof bolting system. These factors should be specified as accurately and quantitatively as possible in the design of any roof bolting system. Finally, proper and careful installation and continuous monitoring are imperative for the success of any roof bolting system. 相似文献
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INTRODUCTIONThe stability of underground structures duringand after excavation is the most i mportant factor fordesigners because any kind of collapse may destroylarge parts of a finished tunnel,thereby causing ma-jor repairs and ti me loss.To avoid this problem,rock bolts are widely used as ani mportant support el-ement.These are economical,have a short installa-tion ti me,and provide reinforcement to maintain theintegrity of the stressed rock.The effect of the bearing capacity of rock b… 相似文献
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锚杆通常被作为表面粗糙的轴力杆单元进行分析,但在节理边坡加固中,由于节理面的错动,同时考虑锚杆的轴向和横向作用显得更加合理。通过理论分析,建立锚杆三弹簧单元的力学特征模型和变形特征模型,对其受力和变形进行全面分析;运用拉格朗日元数值方法(FLAC3D),建立以理想弹塑性本构Mohr-Coulomb准则为基础的节理边坡模型,应用三弹簧锚杆单元,对其锚固前后的动静态位移响应进行模拟。结果表明:节理面锚固处理后,岩体的刚度得到提高;边坡各部位的位移减小,节理两侧位移的突变值变小;锚杆对节理的上下盘岩体起到有效的拉结作用,抑制了两盘之间的较大变形位移,有利于边坡稳定。 相似文献
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基于块体动力学方法,考虑简谐振动地震波作用,根据Pseudo-static分析原理建立动力荷载下的锚杆支护边坡简化模型,采用解析方法对求得谐振作用下沿滑移面滑移的边坡破坏运动解以及锚杆内力解的表达式,在此基础上,提出可适用于抗震设计的锚杆受力解答。通过锚杆支护边坡的参数影响分析表明,地震波的频率对破坏体的滑动位移幅值有较大影响,在锚杆加固边坡设计中应避免免引起共振现象;锚杆间距对位移振动幅值影响也较大,随着间距的增大,位移幅值也增大;当锚杆间距一定时,随着坡高的增大,边坡滑动位移幅值增大幅度相较其他参数影响较小;随着边坡岩石边坡角度的增大,位移幅值也随之增大,下边坡角度从60°增大到90°时,位移幅值由7 cm增大到25 cm;上边坡坡度超过25°时,位移幅度急剧增大,在设计和施工中应当引起重视。 相似文献
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Avinash Paul A. P. Singh John Loui P Ajoy K. Singh Manoj Khandelwal 《Arabian Journal of Geosciences》2012,5(6):1435-1448
In underground coal mines, a lot of major fatalities have occurred due to roof fall in the newly developed faces or galleries of coal mines during the development or production of coal. There are around 500 underground coalmines in India, and continuous production or development or exploitation of coal depends upon the stability of the gateways developed in the form of galleries, which are supported in such a manner so that they can last up to that period, unless it has been finally extracted out with an operation called depillaring. A system of support design with roof bolting, resin bolting, and cable bolting for the aforesaid galleries is presently being decided on the basis of rock mass rating (RMR). The same support design has been attempted with the use of 3D numerical modeling technique—a tool nowadays very extensively used in geotechnical engineering to predict the stability of structures to be built or for the structures which are built against nature, i.e., underground mines. In this study, the support design system on the basis of RMR has also been validated with a numerical modeling technique for three locations of Monnet Ispat underground coalmine. After the study, it has been found that the numerical modeling technique can give better design of support system in underground coal mines in comparison with RMR-based support design system, and it will also play a major role in reducing the total cost incurred in coal exploitation from the underground coal mines. 相似文献
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基于完整锚杆动测技术的围岩质量识别研究 总被引:1,自引:1,他引:0
完整锚杆系统是由完整的锚杆杆体、饱满的锚固介质以及围岩组成的有机体系。在描述锚杆低应变动力响应的数学力学模型中,将锚固介质与围岩对锚杆体的作用简化为沿杆长均匀分布的杆侧弹性系数与阻尼系数,以及均匀分布在杆底的刚度系数与阻尼系数,即锚杆系统的动力参数。它们不仅表征了锚杆锚固质量,而且体现出锚杆所处围岩的物理参数。通过建立围岩物理参数与完整锚杆系统动力参数的映射关系,可以对围岩质量进行识别。为此,建立了完整锚杆三维轴对称有限元计算模型,得到不同的围岩物理力学参数所对应的锚杆杆顶速度响应;根据完整锚杆低应变动力响应理论解和遗传算法建立了完整锚杆动力参数的识别方法;通过对不同围岩下完整锚杆的数值模拟结果的动力参数识别,建立了杆侧弹性系数与围岩变形模量之间的关系式,提出了一种基于完整锚杆动测技术的围岩质量识别方法。 相似文献
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Hossein Jalalifar Naj Aziz Muhammad Hadi 《Geotechnical and Geological Engineering》2006,24(5):1203-1227
Fully encapsulated rock bolting has, in recent years, become a universally accepted system of ground reinforcement in mining
and tunnel construction. The application of bolting systems extends both to rebar as well as cable bolting. The effectiveness
of the bolt application has been studied in shear, both by laboratory tests as well as by numerical modeling. A specially
constructed double shearing apparatus (DSA) was used to examine the shearing behaviour of a bolt installed perpendicularly
across two joints. The experimental study was complemented with three-dimensional numerical analysis. Parameters examined
include, the effect of reinforced material on tension/compression zones along the sheared bolt, shear resistance, shear displacement
and induced strains and stresses during bolt bending process. The study was undertaken at both free load and pretension conditions.
The conclusions drawn from the study were the level of bolt resistance to shear was influenced by bolt profile configuration,
the strength of the rock or medium influenced the level of load generated on the bolt and the increased bolt pretension contributed
to increased shearing load of the bolted medium. The numerical simulation of the bolt/medium interaction and deformational
behaviour were found to be in close agreement with the experimental test results. 相似文献