基于ANSYS的沉降后浇带裂缝成因分析

为了有效治理沉降后浇带裂缝引起的地下工程漏水问题,以云南某工程为例,使用理论分析与有限元软件ANSYS建立参数模型相结合的方法对后浇带裂缝进行分析,探究后浇带裂缝成因及发展趋势,结果表明:该工程后浇带在荷载作用下产生裂缝的理论最大宽度为0.1 mm,潜在的裂缝发展区域的发展值均小于0.3 mm,实际工程中无须对潜在裂缝...     

用后浇带控制超长钢筋混凝土水池裂缝的探讨

从理论和实践两方面提出用后浇带的方法,可以达到控制混凝土水池裂缝,取消或扩大永久伸缩缝间距的目的,同时介绍了后浇设计原则和施工方法,以及注意事项。     

人防工程温度后浇带间距设计与计算

<正>1问题的提出在现浇钢筋混凝土结构中,为了防止由于温差而产生的裂缝,通常采用伸缩缝和温度后浇带。温度后浇带是一种扩大伸缩间距和取消结构中永久伸缩缝的有效措施,它是施工期间保留的临时性温度收缩变形缝,保留一定时间后,再进行填充封闭。在地下工程中,因为有利于防水和方便维护,     

新浇混凝土爆破振动损伤累积机制试验研究

为揭示新浇混凝土爆破振动损伤累积机制,设计并开展新浇混凝土爆破振动损伤累积模拟试验。首先测量超声波波速,并计算损伤值;然后利用试验结果和损伤断裂力学原理,分析新浇混凝土振动损伤累积规律与机制。结果表明:受振混凝土超声波速变化经历快速增长、缓慢增长、降低和稳定4个阶段;损伤值在第一阶段快速减小,进入第2阶段后损伤劣化效应显现,损伤值随着振动次数的增加先快速增加、后缓慢增加;受振混凝土中的峰值波速和稳定波速均低于基准混凝土的相应波速,高强混凝土损伤累积劣化效应较普通混凝土明显。新浇混凝土振动损伤累积是原生微裂纹尖端局部损伤变形、微裂纹和细观裂纹扩展的结果。     

要临危不惧 不能临阵脱逃

8月13日,衡阳探矿机械厂铸造车间浇注班正在紧张地浇注。天车工吊来装满铁水的浇包(半吨直筒形倾嘴浇包),由两个浇注工面对面操作,一人负责转动手轮倾斜浇包,另一人负责操纵手柄平衡浇包。不料浇包出了故障,转动困难。2人赶紧用力转动手轮、手柄,由于用力过猛,手轮突然转动起来,在惯性作用力下,浇包向一面急骤倾斜,火红的铁水从浇包中流到地上。此时,负责操纵手柄的人见势不妙,撒手就跑。浇包失去平衡,向相反方向倾斜,铁水又从相反方向流到烤芯班的一些工件上,情况万分危急!幸而负责转动手轮的那个浇注工临危不惧,用尽全身力量坚持扶住手轮,…     

红钢平板吊钩的改进

我厂炼钢车间铸钢工段一直用链条排钩吊运脱膜的红钢。装卸两处各由四名工人在800℃左右高温下用手工挂钩和摘钩,不仅效率低,也不安全。为改善炉后浇钢工人的劳动条件,我们设计制造了一台自动挂取平板的吊钩(简称“红钢”吊钩)。经过一段时间的试用,效果很好,深受浇钢工人欢迎。     

磁型铸造新工艺

磁型铸造是一种不用型 砂的铸造新工艺,自一九七 O年以来,我国济南、开封、 北京、上海、重庆、兰州、 长春等地的工厂、科研单位 和学校开展了磁型铸造的试 验研究工作。到目前为止, 已初步掌握磁型铸造的气化 馍、耐火涂料和磁型铸造设 备等方面有关技术关键。开 封市的磁型铸造组、五机部 53所和济南铸锻机械研究所 共同试浇了小批钳身铸铁 件;北京市永定机械厂试浇了轮毂铸钢件;开封地区柴油机厂试浇了X195型柴油机球墨铸铁曲轴;甘肃省高中压阀门厂和长春市阀门厂试浇了铸钢阀体;北京市医疗器械厂试浇了冷冻机上的薄壁(三毫米)铸铁件等…     

模板支设引发的伤亡事故

1工程概况 中国银行苏州市分行综合业务楼(苏州市干将路,工程,总建筑面积为31000m2,土建总预算造价为2249万元.该工程±0.00以上7层,高25m,地下负一层.结构形式为后张法预应力框架结构.整幢大楼分为东西二个楼,中间设后浇带断开.西楼中央768m2范围从3层楼面到7层屋顶为共享空间.共享空间顶为井字梁(宽0.5m,高2m),梁网配玻璃,自重650t,且高出7层楼顶3m.由张家港建筑安装总公司(一级施工资质)驻该市分公司承建.     

X实业公司“6&#183;17”较大伤亡事故

事故经过： 2007年6月16日22时43分,第X-1267炉炉料装料进1号初炼炉进行熔炼。17日0时56分完成初炼作业。出钢前钢水温度1641℃,接本炉钢水的钢水包为6#包。1时45分钢水包吊到LF钢水包精炼炉进行精炼,2时45分完成精炼,钢水包被吊上连铸机浇注台位,此时钢水温度1640℃。2时55分左右,顺利牵引滑板打开水口开浇。开浇30．40秒后浇注工感觉浇速太快,便收小水口,突然包内部分钢水、钢渣从钢水包上沿飞溅而出,使当时在操作平台上的赵&#215;等4名操作工先后灼伤死亡,引流工吴&#215;被烫伤。事故直接经济损失：300万元。     

多级机站通风系统在武山铜矿的应用

介绍了武山铜矿北矿带西部通风系统实施多级机站改造的技术和方法,及改造后的效果。     

高危行业事故应急科技服务实用性平台研究

针对当前我国高危行业应急平台建设中存在事故应急救援决策支撑弱、应急救援服务能力差的缺陷,以“江苏省高危行业事故应急科技服务平台”项目为背景,提出高危行业事故应急科技服务平台的总体建设架构;并以此为基础提出建立应急信息共享,预案可视化与推演,事故后果分析模拟,应急救援决策支持,应急咨询、培训、评估,事故现场快速监测六大子平台。以期利用VR、GIS、人工智能等先进技术,从功能、系统、体系三个层面完善高危行业事故应急科技服务平台建设内容,从而为政府门提供应急决策支持、为企业和社会公众提供应急科技服务。     

我国工业防尘技术面临的新课题

文章分析了我国现阶段粉尘危害的严重状况,提出必须迅速提出高强度采掘作业、强致害粉尘作业、非铀矿山及乡镇企业生产中粉尘危害控制的有效方法;努力提高我国对无组织排放烟尘源及呼吸性粉尘的控制水平,努力降低粉尘控制装备的投资及能耗,逐步扭转我国工业粉尘危害的现状。     

清洁生产审核工作职能定位探讨

清洁生产审核工作职能是清洁生产审核工作存在和发展的基础,也是实施清洁生产战略的具体工作指针。在论述对清洁生产审核职能定位必要性的同时,建设性地提出了清洁生产审核职能定位的具体涵义和内容,从而为清洁生产审核工作的深入开展和今后的发展提供理论上的借鉴。     

建筑材料及制品燃烧性能试验规范概述

建筑材料和制品燃烧性试验规范对保证建筑物内人的生命安全和财产安全是极为重要的。笔者对美国、加拿大、欧盟、日本以及中国的建筑材料燃烧性能试验规范进行分析、比较和综述。通过研究认为美国和加拿大对建筑材料燃烧性能的要求和试验方法基本相似,他们主要针对材料的燃烧性、火焰传播进行检测;欧盟于2001年颁布了新的燃烧性分级体系,该分级体系包括专门针对铺地材料部分和针对其他所有建筑构件材料和产品部门;日本采用锥形量热计法(ISO5660)将内装饰材料分为不燃、准不燃和阻燃材料3个等级;我国对建筑材料的试验方法包括不燃性试验方法、墙和天花板内装饰材料的三级分级体系和铺地材料两级分级体系。     

The risk of whiplash injury in the rear seat compared to the front seat in rear impacts

One hundred ninety-five rear impacts with both front- and rear-seat occupants in the struck car, where at least one occupant sustained permanent disability, were selected for study. There was a significantly higher disability risk for the female rear-seat occupant compared with the male driver. Furthermore, a higher risk was found for female rear-seat occupants compared with female front-seat passengers. The disability risk for occupants of the driver's seat was three times higher for females than for males, and four times higher for females in the rear seat. In the future, test methods should consider the risk of whiplash injury in both the front and the rear seat.     

Michigan's graduated driver licensing program: evaluation of the first four years

INTRODUCTION: To evaluate the four-year outcome of Michigan's graduated driver licensing (GDL) program, motor-vehicle crash data for 16-year-old drivers in 1996 (pre-GDL), and 1998-2001 (post-GDL) were analyzed. METHOD: Relative risks and 95% confidence intervals for several crash types were computed, and pre-post-GDL population-based crash rates were compared. Reductions in crash risks among 16-year-olds previously found in 1998 and 1999 were generally maintained in 2000 and 2001. RESULTS: Reductions in crash risk among 16-year-olds from 1996 to 2001 were 29% for all, 44% for fatal, 38% each for nonfatal-injury and fatal-plus-nonfatal-injury, 32% for day, 31% for evening, 59% for night, 32% for single-vehicle, and 28% for multi-vehicle crashes. Even after adjusting for more general population-wide changes among drivers 25 years and older that might have contributed to changes in 16-year-old crash risk, reductions remained impressive (19% for all crashes in 2001). IMPACT ON INDUSTRY: As one approach to reducing teenage motor-vehicle morbidity and mortality, GDL remains promising.     

城市天然气管道半定量风险评估方法研究

以实现天然气管道风险评估资源的合理分配，确定天然气管道定量风险评估的重点为目标，改进燃气管道风险评估方法的肯特模型，探求城市天然气管道的半定量风险评估方法；分析了城市埋地天然气管道失效可能性与失效后果的影响因子，并研究其评分标准；分别给出了城市天然气管道失效可能性与失效后果的等级划分标准，并运用半定量风险矩阵进行燃气管道单元的风险初步排序，以确定高风险管道单元；对城市天然气管道进行半定量风险评估，可为识别管道沿线高风险后果区域、风险动态排序、风险预警及制定事故应急预案等提供科学依据和方法指导，具有重要的工程应用价值。     

安全生产大数据的5W2H采集法及其模式研究

为从安全生产大数据中挖掘安全规律并最终提炼安全生产基础原理,首先在对安全生产大数据的定义及其内涵进一步阐释基础上,提出安全生产大数据采集的定义,并将其分解为3个过程;然后提出安全生产大数据的5W2H采集法,并对其内涵(采集原因,使用主体、采集者及采集对象,采集数据类型,采集边界,采集时间,采集数据量及其采集方法）进行详细分析;最后以思维路径为主、过程路径和技术路径为辅,建立安全生产大数据采集的一般模式。结果表明,安全生产大数据采集模式的研究可为安全生产大数据的存储、处理及其应用提供基础。     

Relationships of frontal offset crash test results to real-world driver fatality rates

In a study of the relationship between Insurance Institute for Highway Safety frontal offset crash test ratings and real-world fatality rates, there was a clear trend for better-rated vehicles to have lower driver fatality risk, although the correlation was not uniform across all vehicle groups or statistically significant in all cases. For all types of crashes combined, fatality rates per registered vehicle were generally lower for vehicles rated good than for vehicles rated poor, but rates for acceptable and marginal vehicles were not always within this range. A more precise examination of fatality risk was accomplished by comparing driver outcomes in fatal two-vehicle crashes. When a rated vehicle collided with a nonrated vehicle, the fatality risk for the rated vehicle driver was highest for poorly rated vehicles, then progressively smaller for vehicles with marginal, acceptable, or good ratings. For two-vehicle crashes of similar vehicles rated good and poor, the odds of driver fatality was 34 percent lower for the good vehicle than for the poor vehicle, but this estimate was not statistically significant. Finally, in head-on crashes of rated vehicles, the estimated odds of driver fatality was approximately 74 percent lower for the good vehicle than for the poor vehicle, with confidence limits ranging from 28 to 91 percent.     

Safety distances for hydrogen filling stations

In the context of spatial planning the Dutch Ministry of Housing, Spatial Planning and the Environment asked the Centre for External Safety of the National Institute for Public Health and the Environment (RIVM) to advice on safe distances pertaining to hydrogen filling stations. The RIVM made use of failure modeling and parameters for calculating the distance in detail. An imaginary hydrogen filling station for cars is used in the determination of ‘external safety’ or third party distances for the installations and the pipe work for three different sizes of hydrogen filling stations. For several failure scenarios ‘effect’ distances are calculated for car filling at 350 and 700 bar. Safe distances of filling stations from locations where people live and work appear to be similar for compressed hydrogen, gasoline/petrol and compressed natural gas. Safe distances for LPG are greater. A filling unit for hydrogen can be placed at gasoline/petrol-filling stations without increasing safety distances.