钢吊车梁上部区域裂缝的现场调查及其加固方法研究

根据现有资料 ,分析了内蒙古包头钢铁公司出轧厂某车间钢吊车梁裂缝发生的原因 ,找出了偏心荷载是产生裂缝的主要原因。在此基础上 ,提出了以增加吊车梁截面的方法 ,在梁的两侧用角钢和高强度螺栓进行加固 ,并在裂缝尖端处钻孔 ,防止裂缝的继续发展及其他措施。为了解加固效果 ,现场实测了吊车梁在垂直荷载作用下角钢中的应力大小和相应措施位置腹板中的应力大小。结果表明 ,加固效果良好 。

关于重级工作制焊接钢吊车梁上部区域疲劳问题的探讨

钢吊车梁上部区域疲劳破坏在重级或特重级工作制的厂房中时有发生,我国现行规范规定对处于受压区的吊车梁上部区域可不进行疲劳计算,这与实际中频繁出现的吊车梁上部区域疲劳破坏现象不符。虽然对钢吊车梁上部区域疲劳问题的研究在某些方面取得阶段性进展,但目前尚未形成一套系统、合理的研究成果,为新建工程和加固设计提供有力的理论支撑。本文以最大剪应力理论为基础,以国内外有关的研究资料为依据,建立吊车梁上部区域最大剪应力疲劳计算模型,并结合实例对其合理性进行论证。

广州地区正常汉族人群股骨颈中段上部骨密度测量结果分析

目的：通过测量广州地区正常汉族人群的股骨颈上部区域骨密度（ bone mineral density， BMD），确定本地区股骨颈上部区域骨密度的正常参考值，并探讨其随年龄变化的规律。方法使用美国Lunar公司生产的DPX型双能X线骨密度仪（ dual－energy x－ray absorptiometer，DXA）对广州地区20岁以上汉族健康人1342例（男648人，女694人）双侧股骨近端BMD进行测定。按不同性别29岁及以下、70岁及以上各为一个年龄组，30～69岁每5岁分为一年龄组，得出骨密度均值、标准差及累计丢失百分率。结果①广州地区男、女性双侧股骨上部1／2区域骨密度峰值（ peak bone density，PBD）均出现在20～29岁年龄组；此后，随年龄增长BMD降低，女性BMD在45岁后加速下降，男性无加速下降倾向。②广州地区双侧股骨颈中段上部1／2区域骨质疏松症的诊断参考值：男性为0．627 g／cm2，女性为0．487 g／cm2。结论股骨上部1／2区域是检测骨质疏松的敏感部位，其BMD测量值具有良好的年龄相关性，且女性骨质丢失增速出现年龄更早。

Numerical simulation of protection range in exploiting the upper protective layer with a bow pseudo-incline technique

The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the roles of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the upper-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline teelmique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.

谦比希深部开拓-693m水平隔离矿柱的稳定性分析

本文主要针对谦比希铜矿主矿体-700 m水平以上充填区域和-700 m水平以下深部开拓崩落法开采对应区域矿柱留设的安全稳定性,用经验公式法和工程类比法进行对比分析,同时根据分析结果结合生产实际现状提出了保证措施和建议。

The Exploration of Reasons Why Southeast Asia Countries Have Strong Insecurity About the Rise of China

The word, “China’ rise”, has highlighted the rapidity and suddenness of China’s development, and the Southeast Asia region, both in history and in reality, has a close relationship with China. In face of the giant’s rise, some Southeast Asia countries have reduced their sense of certainty and control over this external environment, which causes their insecurity. The reasons of this phenomenon include the factor of history, ideology, geopolitics, overseas Chinese and extraterritorial states intervention. We should go start with national and ideological barriers, combine the analysis of the sense of certainty and control, to understand the underlying causes of insecurity.

抗浮锚杆受力特性及布置方式的分析与设计

抗浮锚杆设计时应考虑上部结构荷载分布、基础形式、上部结构及基础刚度等因素对锚杆受力均匀性的影响,地下室结构的整体和局部变形是锚杆受力的根本原因。通过建立包含上部结构、基础和锚杆的整体有限元模型来进行抗浮计算和分析,得到了抗浮锚杆的受力特点和分布规律,同时给出了锚杆的合理布置原则。上部结构荷载影响区域决定了锚杆的布置,设计中应仔细分析该区域的范围和基底压力的大小及分布,以确保锚杆受力的合理性、均匀性及安全性;基础底板构件设计时,锚杆可视为其弹簧支座。