Study on mechanism of fiber grouted material in pre-stressed anchor rope

The fiber grouted material can reinforce the tension strength, shear strength as well as the index of fracture ductile, and remarkably improve the endurance of pre-stressed anchor rope under long-time loading. As a result, it has the better application foreground. Based on the shear log model and Hashin-Shtrikman upper and lower limited theorem, we have studied the mechanism of fiber grouted material applied in pre-stressed anchor rope and material property, and analyzed the effect of resistance strength of bond, resistance distribution of anchor section and the loading-deformation relationship of anchor body.

Pre-Stressed Rope Reinforced Anti-Sliding Pile

Pre-stressed rope reinforced anti-sliding pile is a composite anti-sliding structure. It is made up of pre-stressed rope and general anti-sliding pile. It can bring traditional anti-sliding pile＇s retaining performance into full play, and to treat with landslide fast and economically. The difference between them is that the pre-stressed rope will transfix the whole anti- sliding pile through a prearranged pipe in this structure. The working mechanics, the design method and economic benefit are studied. The results show that the pre-stressed rope reinforced anti-sliding pile can treat with the small and middle landslides or high slopes well and possess the notable advantage of technology and economic.

Stress Analysis of New Type Pre-Stressed Anchor Bearing Plate Combining Stamping with Welding Forming and Its Anchorage Zone

An anchor bearing plate transfers the anchoring force from anchor plate to the concrete and the pre-stress is formed in the concrete structure. Currently, the main type of anchor bearing plate is cast iron. It is brittle during transportation and tension process. This paper presents a new type of anchor bearing plate combined stamping with welding forming. The structure of the new type anchor bearing plate is introduced. The stress states of the anchor bearing plate and anchorage zone under work are studied. Various specifications of anchor bearing plate are studied by ANSYS finite element analysis software following the AASHTO specification. The analysis results are compared with the results of the same type of OVM round-shaped anchor plate. The study results show that the new pre-stressed anchor plates combined stamping with welding forming are feasible and more sturdy which can meet the engineering demand.

Pre-stressed anchoring beam technique applicable in the reinforcement of high-steep slopes

During the construction of some large-scale rock engineering,high-steep slopes and insufficient slope stability induced by unloading fissures are often encountered.For the reinforcement of these slopes,some techniques(including conventional pre-stressed anchoring cable and unconventional anchoring hole)are usually utilized,however,having several obvious defects.Thus,it is very difficult for a designer to design an efficient reinforcement scheme for the high-steep slopes.For this reason,the authors develop the pre-stressed anchoring beam technique,in which tensile capacity of pre-stressed structures are fully utilized.It is analyzed that the new technique is characterized by multi-functions,including engineering investigation,efficient reinforcement,drainage,monitoring and urgent strength supplement,and hoped to be extensively applicable in the reinforcement of high-steep slopes.

矿用锚索捻距与拉伸力学性能及锚固效果关系研究

矿用锚索主要由多根钢绞线缠绕而成,具有可弯曲、抗破断能力强及成本低廉等优点,在煤矿巷道围岩,特别是巷道顶板稳定性控制中广泛采用。捻距是制作锚索的重要参数之一,当选取煤矿锚索时,因了解尚浅而往往忽略这一参数。为探究捻距参数对锚索拉伸力学性能与锚固效果是否存在影响,论文采用理论分析与室内试验相结合的方法,初步厘清了捻距参数对锚索拉伸时的几何变形特征的影响,明晰了其对锚索锚固力的影响机制。基于试验获得的锚索拉伸及锚固拉拔数据构建数值模拟模型,与井下试验结果进行对比,得到了捻距与其极限拉伸载荷、最大锚固力的关系式,获取了能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距。研究结果表明:当锚索受到拉伸时,在一定范围内捻距与延伸率的关系为负相关,与拉伸极限载荷的关系为正相关;锚索-锚固剂界面存在一定的几何匹配关系,当捻距减小至其13倍公称直径时,最大锚固力随着捻距的减小而增大;综合分析锚索极限拉伸载荷与最大锚固力等因素发现,能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距为13~14倍公称直径。研究成果增加了锚索捻距对拉伸力学性能影响的认识,明晰了对其锚固机制的理解,为锚索制作及选取煤矿锚索提供了参考及理论支撑。

阶段矿房法二步骤采场地压控制研究

在阶段矿房二步骤开采时,为了减小上盘岩移量,常采纳采场中部切槽并向上盘、下盘两侧回采,从而缩短采场暴露时间,以便减小上盘岩移量。当地压达到流变发生的条件后,缩短采场暴露时间并不能有效控制上盘巷道发生岩移破坏。为此,利用三维连续体快速拉格朗日分析数值模拟采场上盘地压,并根据流变理论分析,采纳低松弛预应力大直径钢绞线锚索支护上盘顶板以便减小上盘地压,从而克服发生流变变形的应力条件。结果表明:在上盘岩体上施加支护抗力可减小或消除高地压导致的流变变形;采纳7排7.0 m长的锚索、每排6根支护上盘顶板后大幅度减小了上盘岩移量,但采场第2分层上排锚索及一步骤采场第3分层局部锚索的锚固力超过设计值;采纳8排7.0 m长的锚索、一步骤采场每排7根、二步骤采场每排6根支护上盘顶板后,即使回采底柱,锚索锚固力也不会达到设计值。监测表明,大直径钢绞线锚索支护后上盘岩移量减小到一般不超过6 mm。

Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables

The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway.

不同材质共享缆绳对浮式风电场系泊响应的影响

[目的]旨在合理设计浮式风电场的共享系泊系统,探究不同材质共享缆绳对浮式风电场动力响应的影响。[方法]首先,对浮式风电场设计共享系泊和传统(无共享缆绳)系泊方案,比较两种系泊方案的动力响应和经济成本,验证设计方案的可行性。其次,探究两类共享系泊系统对浮式风电场系泊响应的影响。最后,分析环境载荷的施加方向和缆绳材质对共享缆绳平均张力的影响。[结果]采用不同材质共享系泊系统的浮式风电场,其叶片张力近乎相同;两类共享系泊系统对风机位移和系缆平均张力的影响存在差别。此外,环境载荷施加角度和系缆材质也对风机位移和共享缆绳受力产生影响。[结论]该研究可为系泊系统中共享缆绳选型提供参考。

JGZ97型万米超深井钻机死绳固定器研制与安全性研究

针对死绳固定器绳轮强度、安全裕度不足和结构失稳等安全问题,根据JZG97型万米超深井钻机死绳固定器绳轮受力及结构特点,提出采用增加腹板的方法来解决死绳固定器绳轮存在的问题。采用有限元法数值模拟,分析了不同腹板绳轮的结构力学性能,三腹板绳轮的强度、安全裕度均满足钻井作业时的安全要求,确定采用三腹板绳轮。实物测试试验中,三腹板绳轮仿真结果与试验结果的最大相对误差为12.95%,综合分析仿真结果与实验结果基本吻合;线性屈曲分析表明,最大死绳拉力作用下的三腹板绳轮临界屈曲载荷为绳轮实际受载的48.8倍,满足结构稳定性要求。研究表明,三腹板绳轮可以解决死绳固定器绳轮存在的问题,可以为万米超深井钻机结构设计提供支持。

高速公路边坡支护中预应力锚索施工技术研究

为提高边坡支护中预应力锚索的施工质量,使边坡支护效果达到最佳,开展预应力锚索施工技术的深入研究。基于MATLAB软件模拟高速公路边坡情况,以保证每级边坡支护效果为前提,完成预应力锚固参数设计。以设计参数为基础,结合边坡支护工程锚孔布置图布设锚孔,制作并放置预应力锚索,进入锚索灌浆工序,完成施工。应用分析可知,应用论文所提施工技术,边坡土体沉降量较小,边坡支护的稳固性较高,支护效果优势显著。

双排桩-锚索支护体系在软土地区基坑中的应用

为研究双排桩-锚索结构在软土基坑中的内力变化规律及可行性,本文通过理论计算及数值模拟,以东莞某软土基坑工程为例,对结构水平位移、弯矩等参数的变化规律进行了研究,并将实测值与计算值进行了对比。结果表明,卸荷板可提供一个反弯矩,增加结构稳定性;支护结构水平位移理论及数值计算曲线与实测曲线变化趋势基本相似,变形值均在规范允许范围之内;双排桩-锚索结合卸荷板体系应用于场地受限的软土地区基坑支护效果较好。

煤矿回采巷道快速掘进技术的应用

为探索回采巷道所适用的快速掘进技术,以挖金湾煤业山4^(#)层一盘区2111巷为例,针对其掘进速度和进度缓慢的现状,提出快速掘进技术及支护参数优化思路。结果表明,快速掘进技术和支护技术应用后,回采巷道掘进速度、掘进效率均显著提高,支护作业时间缩短,巷道围岩变形也得到较好控制。

综放回采巷道支护方案设计及工程实践应用

为解决综放回采巷道在断层破碎区域导致其对应地质条件越发复杂,对应支护难度较大导致影响生产效率和安全性的问题,以1193综放工作面为例在分析其基本条件和支护现场的基础上,制定监测方案对当前支护方案的支护效果进行评价;结合监测结果提出支护方案的优化措施,最后对优化后支护效果进行综合评估。

特厚煤层综放开采小煤柱巷道支护技术研究

特厚煤层综放开采时巷道更容易变形,对支护方案提出了更高的要求。在对某特厚煤层进行概述的基础上,结合煤层实际情况设计了小煤柱巷道支护的技术方案。方案主要是使用锚杆、锚索、W型钢带、钢筋网、金属网等进行联合支护,锚杆和锚索的规格型号分别为Φ22 mm×2400 mm和Φ21.8-1×19-6300(或4300)mm。巷道破碎区域可以使用W型短节钢带、矿用工字钢、高强度蝶形托盘等进行强化支护。通过实践观察,发现巷道围岩变形量在可以接受的范围内,锚杆和锚索的预紧力也在理想范围内。支护方案有效保障了小煤柱巷道的稳定性。

采煤工作面过超高空巷支护优化研究

为解决工作面过超高空巷液压支架不能接顶的问题,采用“锚索吊棚+木垛+一梁两柱”支护技术解决超高巷道支架无法接顶和空巷破坏变形的问题。通过空巷支护优化后,工作面矿压观测及支架阻力变化结果表明,该支护技术条件下能够有效阻止空巷变形和解决支架接顶问题,高强度支护较实体煤具有相似的支撑强度,能够满足过空巷要求。

海洋井架钻井钢丝绳导向轮布置的设计与应用

油田钻修井作业现场指重系统测量经验表明,钻机指重系统往往因死绳固定器安装设计不合理而影响其测量精度,为了提高自举式井架指重系统的测量精度并确保指重表的读数能真实反映钻井钢丝绳死绳端的拉力,文章以某海洋自举式井架为例,通过分析钻井钢丝绳的走向、死绳固定器的安装角度,总结了死绳固定器总成布置的基本原则,并运用C语言程序优化了导向轮的安装角度,合理解决了由于导向轮安装角度不合理而引起死绳拉力损失的问题,从而提高了钻机指重系统的测量精度。

接触网中心锚结设计优化研究

针对接触网承力索中锚绳的弛度、张力以及实际长度,系统分析了下锚抬升高度、跨距、坡度、张力、温度等参数对中锚绳最大弛度及其位置的影响,定性分析了接触网系统张力变化对中锚绳的影响,并根据研究结论提出安装优化建议。本研究对承力索中锚绳的设计、施工、运维均有一定的参考意义。

东祁连山3#斜井软弱围岩变形控制技术

为解决过软弱围岩隧道变形大、难以控制的问题,以东祁连山3#斜井为工程背景,通过现场勘测和数值模拟等方法分析了隧道变形破坏特征。根据分析结果,提出了“长短锚杆(索)+钢筋网+喷射混凝土+二次衬砌”的联合支护方案。现场监测结果表明,联合支护方案下隧道拱顶和边墙的最大变形量分别为81 mm和67 mm,围岩压力变化不大,表明隧道结构基本稳定,满足规范要求,有效控制了东祁连山隧道3#斜井围岩变形破坏。研究可为同类地质条件下的隧道支护设计与施工提供参考与借鉴。

锚索与SMW工法桩复合支护在深基坑工程中的应用与性能分析

为了解决水利工程中泵站深基坑的支护问题,研究提出一种结合锚索和SMW工法桩的复合支护技术,并对其应用和性能进行分析。结果表明,广东某拟建的水利泵站深基坑项目应用中,复合支护结构在整体稳定性和抗倾覆稳定性方面的验算结果分别为1.379和2.026,符合设计要求。尽管锚索应力的模拟数据与实际情况存在一定偏差,但整体变化趋势相似。此外,桩身水平位移和周边地表沉降的监测结果与模拟数据基本一致。研究显示,结合锚索和SMW工法桩的支护方案在水利工程泵站建设具有良好的应用效果和性能,可为泵站建设工程的设计和施工提供技术支持。

矿用锚索捻距与拉伸力学性能及锚固效果关系

矿用锚索主要由多根钢绞线缠绕而成,具有可弯曲、抗破断能力强及成本低廉等优点,在煤矿巷道围岩、特别是巷道顶板稳定性控制中广泛采用。捻距是制作锚索的重要参数之一,煤矿在选取锚索时,因了解尚浅而往往忽略这一参数。为探究捻距参数对锚索拉伸力学性能与锚固效果是否存在影响,采用理论分析与室内试验相结合方法,初步厘清了捻距参数对锚索拉伸时的几何变形特征的影响,明晰了其对锚索锚固力的影响机制。基于试验获得的锚索拉伸及锚固拉拔数据,构建数值模拟模型,与井下试验结果进行对比,得到了捻距与其极限拉伸载荷、最大锚固力的关系式,获取了能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距。研究结果表明:在锚索受到拉伸时,在一定范围内捻距与延伸率的关系为负相关,与拉伸极限载荷的关系为正相关;锚索-锚固剂界面存在一定的几何匹配关系,捻距减小至其13倍公称直径时,最大锚固力随着捻距的减小而增大;综合分析锚索极限拉伸载荷与最大锚固力等因素发现,能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距范围为13~14倍公称直径。研究成果增加了锚索捻距对拉伸力学性能影响的认识,明晰了对其锚固机制的理解,为锚索制作及煤矿选取锚索提供了参考及理论支撑。