程潮铁矿大断面采准巷道稳定性数值模拟研究

针对武钢程潮铁矿采准巷道净断面尺寸增大，巷道稳定性下降的状况，采用数值计算方法对程潮铁矿巷道支护方案进行优化计算，并给出合理的支护方案。     

Influence of seismic input on response of Baihetan arch dam

The dynamic responses of the arch dam including dam-foundation-storage capacity of water system, using two different earthquake input models, i.e. viscous-spring artificial boundary （AB） condition and massless foundation （MF）, were studied and analyzed for the 269 m high Baihetan arch dam under construction in China. By using different input models, the stress and opening of contraction joints （OCJs） of arch dam under strong shock were taken into consideration. The results show that the earthquake input models have slight influence on the responses including earthquake stresses and openings of contraction joints in different extents.     

开洞高层建筑风压特性数值模拟研究

基于fluent6.3数值模拟软件,系统研究了4种湍流度、4种积分尺度、5个风向角、4种长宽比、8种开洞位置等条件下,洞口设置对于平均风压的影响。分析发现:洞口使迎风面和背风面洞口附近的测点风压有所减小,而远离洞口的左右测点风压却有所增加;较小的湍流度和积分尺度流场中的模型受开洞影响更大;宽长比越大的模型受影响测点越多,且影响幅度略有增加;洞口使建筑物整体静风荷载减小的主要原因是洞口的存在使受风面积减小所致。     

NIOS模型材料及其在地质力学相似模型试验中的应用

NIOS相似材料是一种新型的地质力学模型相似材料。本文对该相似材料的特点、相关参数、配比组合、成型工艺以及物理力学性能进行了简要的介绍。在溪洛渡电站超大规模地下洞室群三维地质力学模型试验中应用该相似材料 ,取得了良好的效果     

Studies of the combined effects of some important factors on the likelihood of flashover

Among those factors that affect the likelihood of flashover in enclosure fires, the thermal inertia of lining materials, ventilation factor of door openings, heat release rate of fuel, and internal dimensions of the enclosure are the most important. The effects of the four factors are related, so it is very necessary to study their combined effects. In the present study, based on analyzing the approximate heat balance on the control volume similar to that in the MQH method, a dimensional relationship was derived that facilitates the estimation of pre‐flashover temperatures, which is used in the popular guidance literature as the key parameters for practical methods of predicting flashover. By correlating a vast amount of data gained in both small‐scale and large‐scale enclosure fire experiments, an important equation was obtained, which can embody explicitly and quantitatively the combined effects of the four important factors on the likelihood of flashover. According to the temperature criteria of 600°C identifying flashover, a new ‘combined method of predicting flashover’ was put forward. The validity of the method was verified in small‐scale experiments, and the results showed that it could be applied to predict well whether flashover occurs in enclosure fires or not. Copyright © 2010 John Wiley & Sons, Ltd.     

Methods to reduce the CO2 concentration of educational buildings utilizing internal ventilation by transferred air

The aim of this study is to develop internal ventilation by transferred air to achieve a good indoor climate with low energy consumption in educational buildings with constant air volume (CAV) ventilation. Both measurements of CO₂ concentration and a multi‐room calculation model are presented. The study analyzes how to use more efficiently the available spaces and the capacity of CAV ventilation systems in existing buildings and the impact this has on the indoor air quality and the energy consumption of the ventilation. The temperature differences can be used to create natural ventilation airflows between neighboring spaces. The behavior of temperature‐driven airflows between rooms was studied and included in the calculation model. The effect of openings between neighboring spaces, such as doors or large apertures in the walls, on the CO₂ concentration was studied in different classrooms. The air temperatures and CO₂ concentrations were measured using a wireless, internet‐based measurement system. The multi‐room calculation model predicted the CO₂ concentration in the rooms, which was then compared with the measured ones. Using transferred air between occupied and unoccupied spaces can noticeably reduce the total mechanical ventilation rates needed to keep a low CO₂ concentration.     

有岩爆倾向的深井巷道岩层支护控制技术

根据冬瓜山铜矿原岩应力测量、岩石物理力学试验、岩体结构调查、数值模拟计算以及工程实际,冬瓜山铜矿深部属高应力(38 MPa)区,存在岩爆倾向性.为此,针对不同的采准巷道提出了支护方法与设计,比如对充填回风道采用"喷-锚-网"支护,对底部结构采用光面爆破和"喷-锚-网 锚索"支护,对出矿口眉线采用超前锚杆预支护等,均取得了较为理想的效果.     

《钢骨混凝土结构设计规程》讲座 第三讲 钢骨混凝土梁、柱构件受剪承载力计算

介绍了钢骨混凝土构件的受剪性能及其影响因素。着重指出了对开孔梁受剪承载力计算和柱受剪承载力计算中轴压力的分配中应注意的问题。     

开洞矩形截面超高层建筑局部风压风洞试验研究

基于一栋立面上有多个开洞的矩形截面超高层建筑的刚性模型表面压力测量风洞试验结果,分析了矩形截面超高层建筑在长边立面上不同开洞工况下建筑各表面平均风压系数和最不利风压系数的变化规律。试验结果表明:当建筑长边迎风时,开洞使得背风面洞口附近的平均风压系数绝对值增大,但迎风面上的平均风压系数变化很小;当建筑短边迎风时,开洞对洞口附近的平均风压系数和最不利正风压系数均只有微弱影响,但对其最不利负风压系数却有很大影响,特别是中部开洞,将使其周围的最不利负风压系数增大一倍以上;开洞对短边立面上的最不利风压系数不产生明显的影响。为有结构开洞的高层建筑洞口附近的围护结构设计提供了参考数据。     

内压作用下双开孔圆柱壳孔间距限定

多开孔接管结构常用于压力容器和管道,文章重点考虑了不同λ值和不同开孔间距,采用有限元分析法对内压作用下轴向和环向双开孔圆柱壳进行了应力分析,基于弹性应力法和极限载荷法对承压结构进行应力强度评价。研究结果表明,基于弹性应力法的应力强度评价,当轴向双开孔圆柱壳开孔间距不大于2.0L0时,结构不能满足弹性应力强度评定要求;基于极限载荷法的强度评价,双开孔圆柱壳均能满足应力强度评定要求。建议对轴向和环向双开孔圆柱壳开孔间距分别作出限定。