煤矿锚杆机除尘马达改进

针对煤矿进口锚杆机除尘马达频繁出现故障的情况,通过排查除尘装置的安装方式和监测马达工作时的压力状态,查找故障原因,并制定解决方案。通过马达外接单向阀,可满足马达进油口最低安全压力限制的要求,解决了马达频繁损坏的问题,保障了设备工作的稳定性,提高了工作效率。     

Anchor plate bearing capacity in flexible mesh facings

This work addresses the problem of the loading capacity of an anchor plate coupled with a steel wire mesh in soil retaining applications. The interaction mechanism between the flexible mesh facing, the underlying soil layer and the plate is studied starting from the results of several laboratory punch tests involving both the plate and the mesh only, and the whole soil-mesh-plate system. The experimental tests have been reproduced by adopting a 3D discrete element model where also the wire mesh is discretized as an assembly of interconnected nodal particles. The interaction between these particles is ruled by elasto-plastic tensile force–displacement laws in which a distortion is introduced in a stochastic manner to account for the wires’ geometrical irregularities. The mesh model is then validated with reference to a set of punch tests in which the shape and size of the punching element as well as the nominal wire diameter were varied. Subsequently, the model is extended to a punch against soil test configuration permitting an insight into the nontrivial local mechanism between the mesh facing and the underlying granular layer. The good agreement between the numerical predictions and the experimental observations at the laboratory scale allowed us to extend the model towards more realistic field conditions for which the role of the mesh panel boundary conditions, the mesh mechanical properties, the soil mechanical properties and the anchor plate geometry is investigated.     

Experimental study on uplift behavior of shallow anchor plates in geogrid-reinforced soil

Geogrid reinforcement can significantly improve the uplift bearing capacity of anchor plates. However, the failure mechanism of anchor plates in reinforced soil and the contribution of geogrids need further investigation. This paper presents an experimental study on the anchor uplift behavior in geogrid-reinforced soil using particle image velocimetry (PIV) and the high-resolution optical frequency domain reflectometry (OFDR). A series of model tests were performed to identify the relationship between the failure mechanism and various factors, such as anchor embedment ratio, number of geogrid layers, and their location. The test results indicate that soil deformation and the uplift resistance of anchor plates are substantially influenced by anchor embedment ratio and location of geogrids, whereas the number of geogrid layers has limited influence. In reinforced soil, increasing the embedment ratio greatly improves the ultimate bearing capacities of anchor plates and affects the interlock between the soil and geogrids. As the embedment depth increases, the failure surfaces gradually change from a vertical slip surface to a bulb-shaped surface that is limited within the soil. The strain monitoring data shows that the deformations of geogrids are symmetrical, and the peak strains of geogrids can characterize the reinforcing effects.     

薄喷涂层技术在底抽巷围岩防风化中的应用

针对传统喷浆作业喷射水泥浆,效果差、效率低、粉尘治理难度大等问题,采用薄喷涂层技术对底抽巷进行喷浆作业。经过岳城矿实测证明,薄喷涂层有效遏制了底抽巷围岩的变形速度,保持了围岩的整体塑性,防风化效果显著,可通过及时补强加固实现围岩的有效控制,提高底抽巷掘进效率。     

煤矿巷道支护技术的研究

基于煤矿巷道支护技术研究的现状,详细分析了现阶段起主导作用的锚杆支护技术,总结出巷道支护存在的问题及改进方向,对安全可靠有效巷道支护技术的研究提供借鉴经验。     

综放巷内充填原位沿空留巷技术

针对综放沿空留巷的技术难点,在分析综放沿空留巷围岩结构力学模型的基础上,提出了巷内充填原位沿空留巷的新技术。此项技术有两个关键方面:一是大断面全煤巷道顶煤完整性的维护;二是大体积长距离充填体的整体稳定性控制。对巷内基本支护为梯形金属支架的原有巷道,提出了实施此项新技术的具体方案。现场工业性试验表明,该项技术的应用是成功而有效的,可在类似条件的综放工作面推广应用。     

铝合金结构的连接及其设计方法

铝合金结构中构件的连接方式有三种：焊接、机械连接和粘接.文中介绍铝合金的焊接方法、焊接热影响区以及焊接强度的设计方法.铝合金机械连接分为铆接、螺栓连接和螺丝连接,文中详细介绍了国外规范中铝合金结构机械连接的设计方法.粘接在建筑结构中很少应用.铝合金结构连接与钢结构连接存在明显差异;本文通过总结国内外规范和文献中的相关内容,重点介绍了二者的不同之处,为今后的研究提供了一些参考.     

深基坑支护工程失事原因分析（3）

本文结合广西南宁市宫华大酒店、财政厅深基坑支护及抢险工程中的体会以及对泰安、银都、人防办、交易场等二十几个高层建筑深基坑支护工程中存在的问题调查、分析基坑失稳的主要原因，提出避免工程失事的一些有效措施，以供设计、施工时参考。     

锚索的锈蚀、防护及永久锚索的合理结构

随着锚索在岩土工程加固中的普及，近期人们普遍关注的焦点是锚索的永久性问题。锚索的永久性与锚索的结构和锚索材料有关，也与锚索所处环境及人为因素有关。本试图就锚索可能遭到的破坏因素及防护，提出永久锚索的合理结构，供同行参考。     

土层锚杆在抗浮结构中的应用

本文着重介绍了土层锚杆在抗浮结构中的应用 ,提出了土层锚杆在工程实践中的设计及施工方法。并通过基本试验及验收试验等现场实测数据和测试曲线进行分析论证 ,说明土层锚杆在抗浮结构中应用是可行和可靠的 ,并且是经济的。