Fire behaviour of multiple fires in a mine drift with longitudinal ventilation

The fire behaviour involving multiple fires in a mine drift with longitudinal ventilation was analysed. The conditions and fire phenomena occurring were described. The analysis was based upon experimental data from model-scale fire experiments. A fire involving several fuel items may lead to flames tilted horizontally and filling up the entire cross section, leading to earlier ignition, higher fire growth rates, higher fire spread rate and severe fire behaviour. Longer flame lengths will also result due to decreased air entrainment. A correlation for the continuous flame length was proposed. The results of the analysis will help identifying and preventing potentially dangerous fire situations with several large combustible items distributed along a mine drift.     

应力集中区域矿体开采过程的应力与位移监测

七角井铁矿采用分段空场法开采,在采深185m范围内形成了约350万m~3的采空区,导致2016年6月出现了一次大规模的地压活动,并在塌陷区底部的S19、S21和S27采场周围出现了应力集中现象。为了预测应力集中区域的矿体回采过程的地压变化规律,提出采用应力监测和位移监测相结合的地压监测技术。结果表明,经过半年的监测,确定了地压集中区域和相对稳定区域,根据监测结果调整了采矿方法及回采顺序,保障了应力集中区域S19、S21和S27采场的安全回采,矿石综合回收率达到74%,贫化率为18%。     

Aligning stakeholder interests: How ‘appropriate’ technologies have become the accepted water infrastructure solutions for low-income areas

Service differentiation and the use of "appropriate technologies" are often presented as alternative approaches to providing water service to low-income areas. Service differentiation allows water service providers to manage the risks associated with service expansion to these areas. We argue that rather than a choice of the service provider alone, the decision for service differentiation should be seen as a consensus between different actors in the water services sector. A review of secondary data, and semi-structured interviews with diverse stakeholders in three Kenyan cities, show that managers of water utilities also choose these strategies because they appeal to and align with the interest of donors, governments, sector organisations, and alternative providers.     

泰莱盆地地下水蓄水构造特征及勘查定井研究

针对基岩山区勘查定井问题,以旱区找水定井为目标,在地形地貌、地质和水文地质等实测资料的基础上,对泰安市地下水蓄水构造进行了分类,并阐述其特征。针对不同蓄水构造类型,基于构成地下水蓄水构造"三个基本要素"原理,并结合水文地质钻孔、高密度电阻率法、可控源音频大地电磁测深法等方法,对典型蓄水构造区构造特征及勘查定井进行了研究。结果表明:山东泰安市蓄水构造可分为水平岩层蓄水构造、断裂蓄水构造和基岩风化壳蓄水构造3种类型;水平岩层蓄水构造的含水层为古河道沉积砂层,隔水层为下伏古近系的泥岩和页岩,该区定井井位应布设在砂层上,井深宜在200 m左右,且应揭露砂层;断裂蓄水构造的含水层为奥陶系和寒武系白云岩和灰岩,隔水层为下伏的基岩岩层,导水通道为张性断裂带,在该区定井主要寻找奥陶系和寒武系地层,并尽量在断裂处或断裂交汇处定井;基岩风化壳蓄水构造的含水层为基岩风化壳,隔水层为下伏的基岩岩层,导水通道主要为张性断裂带,在该区定井主要是寻找基岩风化壳地层。     

南方地区塔式高层住宅设计有关消防问题探讨

本文回顾和分析了塔式高层住宅公共部位的常见设计类型。针对目前在消防设计方面存在的有关前室和走道布局等方面的矛盾和问题,结合自己对规范的理解,进行了思考和探讨。对在我国南方地区充分利用自然排烟的有利条件,以达到消防的安全性、可靠性与使用的合理性、经济性的统一,表达了自己的见解;并就目前存在问题可能的解决途径,提出初步设想。     

塑料制品防火涂料的制备和应用

介绍了一种塑料制品防火涂料的制备和使用方法，并扼要地阐述了该产品的基本性能和防火机理。     

论我国矿区资源开发中生态经济社会协调发展的问题和对策

本文以长江中下游多金属矿区为例，以生态经济社会协调发展的观点，将矿区作为社区来考虑。着重阐述了矿产资源的合理开发利与保护，以及土地、水、大气、地表、劳动力、人文历史、乡镇、社会等其他资源保护与开发利用方面存在的问题和对策。     

液压挖掘机配重的优化选择

为使挖掘机工作时具有良好的稳定性，保证挖掘机性能充分发挥，论述了对配重进行优化选择的方法。     

单片微机火灾报警区域控制器

本文介绍了单片微机火灾报警区域控制器,它以可靠性和性能价格比高的INTEL8039单片微机为核心,充分发挥软件特点,使系统的硬件配置最小,系统配有实时多功能键盘能对全部96个部位任意设置成双头、单头或不接,延迟时间也可以任意设置。文中介绍了系统的硬、软件设计和工作原理。     

Composite beams with partial fire protection

This paper presents the results of a theoretical investigation into the effectiveness of a novel way to significantly reduce the fire protection cost to a composite beam. In this method, only the steel lower flange and a fraction of the steel web are protected. The effectiveness of a partially protected composite beam is assessed by comparing its plastic moment capacity with that of a fully protected beam subject to both the standard fire exposure and design fires.

The parametric time–temperature curves in Eurocode 1 are used to determine the time–temperature relationships of design fires. A finite element analysis computer program for heat transfer is used to evaluate the temperature field in the composite cross-section. The plastic moment capacity is calculated by dividing the composite cross-section into many small blocks and summing their contributions.

Partial protection is suitable for situations where the protection is applied along the steel profile. Results from this study indicate that the total fire protection cost may be reduced considerably due to more than 50% reduction in the protected surface area, despite similar material costs.