摘要：薄煤层N00工法的提出,革新了传统的煤矿开采模式、关键技术与装备系统,并取得了成功应用。而新开采模式下的巷道围岩控制技术尚不完善,为实现薄煤层N00工法巷道顶板结构的安全稳定,考虑其工艺流程和顶板变形特点,将巷道划分为超前硐室、垮落成巷两个阶段。并基于Hoek-Brown非线性岩体强度破坏准则,确定了巷道顶板不同阶段的锚杆/索预紧力的计算公式,提出了巷道顶板锚杆/索预紧力及长度设计方法。此外,结合数值模拟研究了不同阶段巷道顶板锚杆/索支护作用机理及不同锚杆/索支护组合对围岩应力分布的影响,揭示了锚杆/索支护关键参数对顶板稳定性的影响机制。最后,综合理论与数值模拟分析结果,提出了分区补偿支护技术,确定了锚杆/索预紧力、长度及选材的设计原则,该技术在现场取得了良好的应用效果。

摘要：随着采矿进入深部地层,具有长服务年限的各类巷道交岔点围岩发生强烈破坏,需要明晰深部环境下交岔点围岩失效机理,以针对性地指导修复和补强作业。通过对多地矿井交岔点维护情况的调研,全面总结了连接型、交岔型、分岔型和旋岔型(环三角柱)四类16种交岔点类型,提出了三类交岔点的典型应用形式:单一大型交岔点、嵌套式两交岔点组和环三角岩柱式交岔点群。将现场交岔点的破坏情况分为围岩局部破坏、三角岩柱破坏和整体性破坏的三种级别,从灾害的诱因和来源上,提出了外部环境因素、自身结构属性和人为设计隐患的三类13种致灾因素,并详述了各种致灾因素的致灾路径。建立了三类典型应用形式下交岔点的精细化模型,对数值软件进行二次开发,引入了畸变能密度指标进行围岩的能量分析。研究表明,交岔点围岩的畸变能峰值在三角区岩柱内,增高系数在2.5左右。最大断面处围岩畸变能同样发生积聚,增高系数在1.5左右。因此,提出了交岔点的修复需以强化三角岩柱和大断面处围岩为重点,并对深井交岔点的修复提出了以三角岩柱和大断面段补强为主的针对性方案。本研究为深部交岔点的破坏因素分析、数值模拟指标引入和修复支护提供了参考。

摘要：针对大断面隧道初期支护拱架在承载时易发生平面外失稳的问题,本文通过开展单拱架全比尺试验和考虑纵向连接的拱框架结构的数值试验以及现场对比试验,对纵向连接与拱架组成的拱框架结构进行优化研究,使其横向上有足够承载能力、纵向上有较高稳定性。研究结果表明,单个拱架的破坏模式是局部面外失稳导致整体承载力丧失,考虑纵向连接的拱框架结构的平面内承载力和平面外稳定性都得到增强。通过调整纵向连接间距和拱架间距也可以调整初期支护拱框架结构和喷射混凝土的内力分担比,以充分发挥初期支护的承载能力,但纵向连接间距应小于1500 mm,拱架间距也应小于1200 mm。因而,在不改变初期支护现有结构形式的前提下,通过合理地布设纵向连接与拱架形成的具有空间承载效应的拱框架结构,不仅可以保证初期支护的承载能力,而且还提高施工效率和经济效益。研究成果可指导大断面隧道初期支护结构设计。

摘要：渗流特性是影响地下采场胶结充填体稳定性的重要指标。本文以胶结充填体为研究对象,采用室内实验和微观分析相结合的方法,系统分析和讨论了三轴压缩和非压缩条件下,不同水泥掺量(2%、3%、5%)、养护龄期(3d、7d、28 d)和围压(100、200、300、400 kPa)对胶结充填体渗流特性的影响。研究结果表明:胶结充填体的静态渗流系数随着养护龄期和水泥掺量的增加呈非线性下降趋势,围压升高会对充填体的渗流速率产生抑制作用;胶结充填体的动态渗流系数与其变形过程密切相关;充填体在三轴压缩过程中,随着轴向应变的增加,充填体的渗流系数先降低后升高;围压和水泥掺量越大,充填体的动态渗流系数越小;充填体的体积应变表现为先收缩后膨胀,体积应变演化阐释了动态渗透系数时效性。研究结果可为井下充填采场排水以及充填体稳定性分析与设计提供指导。

摘要：充填采煤液压支架是充填采煤技术实现充采一体化的核心设备,其性能的可靠性是实现致密充填的关键。为评价充填采煤液压支架的充填性能,本文提出充填运转特性的概念,并从结构特性、支护特性、夯实特性、力学响应特性及地质适应特性5个方面阐述其内涵,具体通过支护强度、夯实空顶距等14个指标综合体现。选择其中7个独立的评价指标,采用多指标综合评价方法,构建了基于充填运转特性的充填采煤液压支架设计方案评价体系,给出了评价的方法与流程,以及充填运转特性工程控制措施。运用该体系评价了翟镇矿ZC5200/14.5/30型充填采煤液压支架的11个优化方案,评选出的10#最佳方案在夯实离顶距等充填运转特性指标上具有明显优势,验证了评价体系的合理性。基于此构建了"初始方案设计、设计方案优化、评价指标优选、优化方案评价、运转特性控制"的充填采煤液压支架研究框架,为深入研究充填采煤液压支架控顶性能提供借鉴。

摘要：Demand for large vibrating screen is huge in the mineral processing industry. As bending and random vibration are not considered in a traditional design method for beam structures of a large vibrating screen, fatigue damage occurs frequently to affect the screening performance. This work aims to conduct a systematic mechanics analysis of the beam structures and improve the design method. Total motion of a beam structure in screening process can be decomposed into the traditional followed rigid translation(FRT), bending vibration(BV) and axial linear-distributed random rigid translation(ALRRT) excited by the side-plates. When treated as a generalized single-degree-of-freedom(SDOF) elastic system analytically, the BV can be solved by the Rayleigh's method. Stochastic analysis for random process is conducted for the detailed ALRRT calculation. Expressions for the mechanics property, namely, the shearing force and bending-moment with respect to BV and ALRRT, are derived, respectively. Experimental and numerical investigations demonstrate that the largest BV exists at the beam center and can be nearly ignored in comparison with the FRT during a simplified engineering design. With the BV and FRT considered, the mechanics property accords well with the practical situation with the maximum error of 6.33%, which is less than that obtained by traditional method.

摘要：Remodeled clay and sand rock specimens were prepared by designing lateral confinement and water drainage experiments based on the stress exerted on granular materials in a waste *** in situ test was conducted in an internal waste dump;the physical and mechanical parameters of the remodeled rock mass dumped at different time and depths were *** on statistics,regression analysis was performed with regard to the shearing stress parameters acquired from the two *** factors,such as remodeling pressure(burial depth),remodeling time(amount of time since waste was dumped),and the corresponding functional relationship,were *** indicates that the cohesion of the remodeled clay and its remodeling pressure are correlated by a quadratic function but are not correlated with remodeling time *** situ experimental results indicate that the shear strength of reshaped granular materials in the internal dump is positively correlated with burial depth but poorly correlated with time *** Cand burial depth H follow a quadratic function,specifically for a short time since waste has been *** revealed by both in situ and laboratory experiments,the remodeling strength of granular materials varies in a certain *** consistency of such materials verifies the reliability of the remodeling experimental program.

摘要：One of the most important factors influencing on a tunnel blast efficiency is the proper design of blasting pattern. Among blasting parameters, blasthole diameter and tunnel face area are more significant so that any change in these parameters could finally affect on specific charge and specific drilling. There are mainly two groups of methods for tunnel blast design categorized based on the parallel cuts and angular cuts. In this research, a software for tunnel blast design was developed to analyze the effect and sensitiveness of blasthole diameter and the tunnel face area on blasting results in different blast design models. Using the software, it is quickly possible to determine specific charge, specific drilling and number of blastholes for each blast design model. The relations between both of blasthole diameters and the tunnel face area with the above parameters in different blast design models were then investigated to yield a set of equations with the highest correlations to compare the methods. The results showed that angular method requires more blasthole numbers than parallel method in similar condition(blasthole diameter and tunnel face area). Moreover, the specific charge values yielded by the two methods are approximately the same and very close together.

摘要：In recent few years, significant improvement has been made in developing largescale 3 D printer to accommodate the need of industrial-scale 3 D printing. Cementitious materials that are compatible with 3 D printing promote rapid application of this innovative technique in the construction field with advantages of cost effective, high efficiency, design flexibility and environmental friendly. This paper firstly reviews existing 3 D printing techniques that are currently being used in commercial3 D printers. It then summarizes three latest development of largescale 3 D printing systems and identifies their relationships and limiting factors. Thereafter, critical factors that are used to evaluate the workability and printable performance of cementitious materials are specified. Easy-extrusive, easy-flowing, well-buildable, and proper setting time are significant for cementitious material to meet the critical requirements of a freeform construction process. Finally, main advantages, potential applications and the prospects of future research of 3 D printing in construction technology are suggested. The objective of this work is to review current design methodologies and operational constraints of largescale 3 D printing system and provide references for optimizing the performance of cementitious material and promote its responsible use with largescale 3 D printing technology.

摘要：To study the flow characteristics of three-phase foam in gob area,different perfusion experiments in coal mine gob were designed and put forward in the *** the observation of flow range,flow characteristics of three phase foam were analyzed with different flow ***,unsteady seepage process of three-phase foam was simulated with CFD *** on experiment and numerical simulation results,flow characteristics of three-phase foam and its major influence factors are discussed,and the optimal arrangement distribution of mine fire control drills is also *** results show that the flow range and stacking height of three-phase foam in gob are significantly influenced by *** vertical stacking height and horizontal diffusion distance of three-phase foam are also directly related to the flow volume of foam perfusion,the larger flow single hole perfusion volume,the higher stacking height and the longer diffusion distance could be obtained.