注浆技术在矿井巷道支护加固中的应用

在当前的矿下支护加固工作中,注浆加固技术是一种较为常见的技术,能够起到良好的加固作用。本文对注浆技术进行简要的分析,探究其在支护加固工作中的运用情况进行探究,为日后的矿下支护加固工作提供一定的参考借鉴。     

九顶山铜钼矿软岩巷道锚喷网支护研究

针对九顶山铜钼矿矿体松散破碎、自稳能力差及需大量支护等特点,优选锚喷网支护方式对岩体进行加固;确定了树脂锚杆、基于32.5级普通硅酸盐水泥所制混凝土与Q235钢筋网联合支护巷道;设计了锚喷网支护形式并规定了施工工艺技术,并在五中段二盘二穿2P213测点附近进行了工业试验;为检测支护效果,进行了巷道收敛变形监测,前60天,巷道变形由约7mm加速降低至约3mm;60天后巷道变形趋缓,并在100天后逐渐降低至0.1mm并保持基本不变;水平收敛值大于顶板;结果表明:锚喷网支护能够有效控制巷道移动变形,提高岩体整体性及稳定性,增强井下工人安全性。     

钢筋焊接网及其在煤矿系统的应用

介绍了钢筋焊接网的特点及其在煤矿系统锚喷网支护结构中的应用。     

金岭金矿东沟矿区井下支护技术研究及应用

针对久盛公司金岭金矿东沟矿区岩石破碎、掘进巷道困难、制约工程进度的状况,在探矿巷道进行了支护技术试验。介绍了支护类型选择及锚喷参数的确定,表述了锚杆的安装过程和注意事项以及工程应用效果。通过支护技术的试验和应用,积累了井下掘进工程锚网喷支护技术宝贵的经验,对本矿区其他地段不同类型岩石锚网喷支护具有较强的指导意义。     

巷道锚喷支护数值模拟研究

在对大冶铁矿尖林山-60 m水平现场工程地质调查、室内矿岩物理力学特性试验的基础上,运用FLAC 3D有限差分软件对由工程类比法确定并且正在应用的锚喷参数进行数值模拟研究。通过比较分析不同支护方式的数值计算结果表明,喷锚联合支护方式优于单独的锚杆支护和喷射混凝土支护,更适于在矿岩接触带软弱夹层地段支护。     

金属条带在地下采矿巷道锚喷网支护中的应用

金属条带是一种简单而灵活的支护材料，对提高锚喷网支护的结构性能及在采矿巷道中的应用效果，具有极其明显的作用。本文对金属条带的结构、作用原理及应用进行了论述。     

工程建设中基坑支护技术及质量控制研究

工程建设中的基坑支护技术对建筑工程的质量有着至关重要的影响,基坑支护是一种通过应用加固和支撑来获得保护作用的施工技术,建筑工程可以利用深基坑支护结构来使自身结构更加稳固安全,为了保证建筑工程的质量以及更好地推动建筑业的发展,本文对工程建设中的基坑支护技术及质量控制进行研究。     

应用离散单元法分析工程岩体锚固作用

介绍了离散单元法的基本原理及在此基础上编写的二维离散元程序UDEC.采用UDEC对某矿节理岩体巷道锚喷联合支护效果进行数值模拟分析,得出了锚喷联合支护对节理岩体巷道支护,特别是发生楔形块体破坏时作用效果明显,同时也证实了UDEC特别适用于模拟不连续介质的大变形问题研究.     

废弃矿坑坑壁岩质高边坡支护治理

本文通过长沙某矿坑边坡支护治理设计,综合采用切方、锚杆格构梁和锚喷等支护技术治理高陡岩质坑壁,后续结合矿坑自然风光作为旅游开发用地,使废弃的矿坑变废为宝。     

外刊摘登

*钢纤维喷射混凝土试验研究* 本文对钢纤维喷射混凝土的钢纤维材料选型、材料配比、力学性能、喷射工艺和现场工程应用等进行了多项试验研究,证明了钢纤维混凝土试块的抗压强度比素喷混凝土试块提高13.2％,而抗拉强度(纯拉)比素喷混凝土试块提高118.18％。而扭曲形钢纤维比圆直形钢纤维效果更好。梅山铁矿现场应用表明:将它用于采场进路则比锚喷网支护成本降低10.7％;用于主井贮矿仓则比钢轨和整体浇注混凝土加固的费用降低47.9％;用于加固放矿溜槽,加固费用比原来降低52.7％。因此,它是一项新的有广阔前景的先进技术。     

井塔加固与箕斗提升系统改造实践

介绍了一种在混凝土表面粘贴钢板加固提升井塔的新技术。焦家金矿使用该技术加固井塔，即节省了资金，又缩短了施工周期；叙述了焦家金矿竖井提升系统技术改造的方案及其可行性，对方案进行了优选。     

混凝土结构补强技术在冶金企业中的应用

碳纤维复合材料以其高强轻质、抗腐蚀、耐老化等卓越的性能已广泛应用于混凝土结构加固领域。本文通过长铝公司天车梁的维修加固实例，介绍了碳素纤维布修复补强混凝土结构这一新型结构加固技术在冶金企业加固工程中的应用及效果。     

Behavior of Transverse Confining Systems for Steel-Free Deck Slabs

Extensive research conducted over the past eight years in Canada has led to a concrete deck slab of girder bridges that can be entirely free of any tensile reinforcement. This slab, known as the steel-free deck slab, derives its strength from its internal arching action, which is harnessed longitudinally by making the slab composite with the girders, and transversely by restraining the relative transverse movement of the top flanges of adjacent girders. Two steel-free deck slabs have already been built, in which the transverse confinement is provided by welding steel straps to the girders. This paper presents test results on two other kinds of transverse confining systems, which are applicable to both steel and concrete girders. It is shown that the steel-free deck slab, in addition to being more durable than slabs with steel reinforcement, can also prove to be more economical.     

微合金化金基材料的研究进展

微合金化技术作为一种能够开发金属潜能、优化金属性能的新型冶金技术,近年来在金基材料的应用和开发中得到了广泛应用.从组织结构和原子形态2个角度出发,论述了金基材料微合金化技术的机制,详细介绍了黄金微合金化技术的发展历程和研究现状,并对比了金基材料在不同微量元素作用下所表现出的性能差异.结果表明:稀土元素兼具良好的固溶强化...     

The effect of negative verbal cues upon verbal behavior.

Research which investigated the capacity to modify behavior, starting from the framework of Skinner's operant conditioning paradigm and utilizing verbal behavior, was found to have primarily explored the effect of positive secondary reinforcement. The present investigation explored the effect of a negative verbal cue presented under different schedules of reinforcement upon verbal behavior. Ss (male VA psychiatric patients) responded to projective techniques. The E varied the frequency of negative verbal reinforcement defined as "unh unh." The hypothesis that such a negative reinforcement would depress verbal behavior was substantiated, with a periodic schedule of reinforcement being more effective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of acquisition training schedule on extinction and reinstatement of cocaine self-administration in male rats.

Partial reinforcement is known to increase resistance to extinction (Rn) relative to training with continuous reinforcement. This phenomenon, referred to as the partial reinforcement extinction effect, is one of the most robust in learning and conditioning studies. Experiment 1 investigated manipulations known to affect the partial reinforcement extinction effect and determined their possible relevance for drug use patterns. Male rats received intravenous cocaine self-administration training under partial reinforcement (FR-10) training or continuous reinforcement (FR-1) conditions with either a low (0.25 mg/kg infusion) or a high cocaine dose (1.00 mg/kg infusion). Animals were placed on an extinction (recurrent nonreward) schedule for 10 days (1-hr sessions) prior to being tested for cue-induced reinstatement (single 2-hr session). Experiment 2 involved acquisition of cocaine self-administration under FR-1 conditions of short training (15 days) or extended training (30 days) with a low dose (0.25 mg/kg infusion) or a medium dose (0.50 mg/kg infusion) of cocaine reward prior to extinction or reinstatement. Experiment 1 showed that rats trained with FR-10-high dose outcomes exhibited greater Rn than the remaining groups. Additionally, FR-10-high dose and FR-10-low dose rats were more likely to return to active drug seeking during the reinstatement test. In Experiment 2, rats trained under FR-1-medium dose conditions were more persistent during extinction following short acquisition training than comparable rats experiencing extended acquisition training. The reinstatement test was conducted following extinction, in which it was observed that overtraining under FR-1-medium dose reward schedules resulted in a decrease in the tendency to return to active drug seeking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Single-Span Prestressed Girder Bridge: LRFD Design and Comparison

This report summarizes the comparative design of a single-span AASHTO Type III girder bridge under the AASHTO Standard Specification for Highway Bridges, 16th Edition, and the AASHTO LRFD Bridge Design Specification. The writers address the differences in design philosophy, calculation procedures, and the resulting design. Foundation design and related geotechnical considerations are not considered. The LRFD design was similar in most respects to the Standard Specification design. The significant differences were: (1) increased shear reinforcement; (2) increased reinforcement in the deck overhang; and (3) increased reinforcement in the wing wall. The comparisons would likely change if the bridge were designed purely according to LRFD Specifications rather than as a comparative design. Design procedures under the LRFD Specification tend to be more calculation-intensive. However, the added complexity of the LRFD Specification is counterbalanced by the consistency of the design philosophy and its ability to consider a variety of bridges.     

试析岩土工程深基坑支护施工技术

建筑工程地下施工中,其危险性较强,受地质条件影响较大。施工企业应加强深基坑加固和防护处理,合理利用深基坑技术防止塌方事故,保障项目工程地下施工的质量及安全。本文将分析岩土工程深基坑支护施工技术,以供借鉴。     

Allegations of wrongdoing: The effects of reinforcement on children's mundane and fantastic claims.

S. Garven, J. M. Wood, R. S. Malpass, and J. S. Shaw (1998) found that the interviewing techniques used in the McMartin Preschool case can induce preschool children to make false allegations of wrongdoing against a classroom visitor. In this study, 2 specific components of the McMartin interviews, reinforcement and cowitness information, were examined more closely in interviews of 120 children, ages 5 to 7 years. Children who received reinforcement made 35% false allegations against a classroom visitor, compared with 12% made by controls. When questioned about "fantastic" events (e.g., being taken from school in a helicopter), children receiving reinforcement made 52% false allegations, compared with 5% made by controls. In a second interview, children repeated the allegations even when reinforcement had been discontinued. The findings indicate that reinforcement can swiftly induce children to make persistent false allegations of wrongdoing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peripheral blood stem cells in acute myeloid leukemia: biology and clinical applications

Fifteen persons with profound mental retardation were divided into two groups. One group was identified with chronic training needs by habilitative staff and the other group served as a control. In an attempt to identify a reinforcer, each participant received a preference assessment and a simple, low-effort treatment procedure. In Experiment 1, only individuals who approached at least one stimulus on 80% or more of the preference assessment trials ("high preference") showed reinforcement effects in treatment. However, three individuals showing high preference failed to show treatment effects. All persons identified with chronic training needs failed to show reinforcement effects. Experiment 2 analyzed characteristics of the two groups and found significant differences in overall movement and response latency. Limitations of the current reinforcement technology were apparent for identifying reinforcers in the group with chronic training problems. Research is suggested for evaluating training alternatives for people with profound multiple disabilities who move very little or who respond with very long latencies.