Computer-aided modeling of the protective effect of explosion relief vents in tunnel structures

This paper aims at contributing to the efficient design of explosion protection systems against confined explosions. The issue addressed concerns the quantitative estimation of the protective effect of explosion relief vents in the case of confined explosions inside tunnels. A series of virtual experiments performed by computer simulation, revealed how the number of vents, their diameter, as well as the angle between the vents and the tunnel, influences the blast wave attenuation. The computational study was performed considering a complicated large-scale tunnel configuration with branches on its half portion. The purpose was the calculation of the attenuation effect due to the presence of vents by comparing the total explosion-specific impulse developing at antidiametric positions inside the tunnel. Simulations were carried out via a three-dimensional numerical model built in the computational fluid dynamics code CFX 5.7.1, which has been validated in previous papers against experimental overpressure histories data demonstrating reasonable performance. Computer results showed that the use of branch vents provides an effective method for shock wave attenuation following an explosion, whereas their statistical elaboration revealed that the attenuation is mainly affected by the number of vents and their diameter. In contrast, the angle between the side vents and the main tunnel appeared to slightly affect the pressure wave weakening. Eventually, the quantitative influence of the above parameters was effectively illustrated in functional diagrams, so that the total attenuation effect may be promptly estimated, if the design variables are known. In addition, two statistical models with reasonable fitting to the calculated data are proposed, which express the attenuation effect as a dependent variable of the design variables including their interactions.     

数字化记录地震分析中的一个技巧

本文通过远震S波到时减P波到时(或极远震PP到时减PKP到时)之差与地震最大面波到时的关系,来推测一个地震发生后,只要震相S、P(或PP、PKP)已确定,就能推测最大面波的到时。反过来,最大面波到时一定,就能基本确定S(或PP)波到时的大致位置,再根据其它震相在S(或PP)波前后出现的规律,从而可靠的分析地震,在地震速报和震相分析当中很有实用价值。     

浅谈烟气调质系统在电厂中降低烟尘排放量的应用

通过烟气调质,来降低烟气温度,同时降低飞灰比电阻,使除尘效率得到提高,电厂周围环境得到保护。该系统的使用在其它电厂也得到应用。     

地震科技档案管理初探

地震科技档案是科技档案的一部分。本文在系统介绍地震科技档案定义和特点的基础之上,深入剖析了我国地震科技档案的管理在档案意识增强,档案人员专业化,行业档案分类标准统一的大背景下,还存在有管理的标准化程度不高,地震重点项目专题档案管理较弱和档案信息化管理有待加强等问题,并针对这些问题提出了几点建议。     

多层建筑多维基础隔震体系的研究

地震灾害是自然灾害之首,地震造成的建筑物破坏倒塌是人员伤亡财产损失的主因,特别是在小城镇、农村,大量的未纳入抗震管理也无抗震措施的多层建筑,面临诸多地震安全隐患,多维隔震体系是多层建筑地震安全的有效保障,从建筑物基础下部的垫层隔震到基础上部的滑移隔震层,再会同基础周边的隔震带,三种隔震方法在三个方面综合互补共同作用,使建筑基础底部到建筑周边都能阻隔消减地震波对建筑结构产生的影响,以达到隔震的目的。     

蒸压加气混凝土砌块砌体承重墙抗震性能研究综述

介绍了蒸压加气混凝土砌块砌体承重墙抗震性能研究的新进展,包括试验研究结论、有限元分析结果。指出采用足尺试件进行试验研究、采用设芯柱的方法提高此类新型承重墙体的抗震性能、建立本构模型等是今后需要进一步研究的内容。     

烟气湿法脱硫装置吸收塔抗震计算与研究

通过研究火电厂烟气湿法脱硫喷淋式吸收塔的抗震计算理论,结合工作实际,提出吸收塔抗震计算的简化方法。     

采用sPn震相确定陕西宁强M≥4.0级地震震源深度

在震中距大于170km范围内,西安数字地震遥测台网可记录到较清晰的sPn震相.本文给出了精度较高的采用sPn和Pn确定地震深度的方法,并将其用于西安地震遥测台网记录的陕西宁强M≥4.0地震序列的sPn震相,得到较为精确的地震震源深度.     

考虑液固耦合储液罐非线性地震反应分析

利用ADINA有限元软件研究了考虑液固耦合的立式圆筒形锚固储液罐非线性地震反应.通过分析计算1000m3储液罐自振特性,储液罐的加速度峰值沿罐壁高度变化趋势,罐壁的应力分布等反应,初步揭示其破坏机理,分析结果为储液罐的抗震设计提供重要的参考依据.     

油包水型乳化液水击波速的分析

水击驻波场处理油包水型乳化液是一门新兴工艺,稳定驻波场的存在是破乳的关键,而水击压力波波速在驻波场形成中起着重要的作用。因此,为了更精确的求解水击波速,从W/O型乳化液两相流产生水击现象的特点出发,根据流体力学的连续性原理,推导其水击波波速的表达式,并与经典单相流水击波波速公式进行对比,通过MATLAB仿真分析与对比验...