浅谈桥梁病害及其检查、养护的必要性

重型车辆日益增加,加之修建年代久远的桥梁设计荷载等级较低,使现有许多桥梁出现破损、裂缝等病害。以本地区为例,对衡水市桥梁的现有病害进行了描述及成因分析,论证了桥梁检查及养护的必要性。     

Diagnostic value of diffuse and peripheral lung lesions by transbronchial lung biopsy

Objective To evaluate the diagnostic value of transbronchial lung biopsy (TBLB) via bronchoscope for lung diffuse lesions and peripheral pulmonary lesions. Methods The results of TBLB were retrospectively analyzed from 256 diagnoses of unknown patients with lung diffuse lesions or peripheral lung lesions. Results Eighty-nine final diagnosis cases via TBLB only once, the diagnostic rate of double lung diffuse lesions was the highest, [51.06% (24/47)], local non-nodule lesions, nodule lesions, cavity lesions were 33.33%(23/69), 29.91%(35/117), and 28.57%(4/14), respectively. Among 24 diagnostic cases of double lung diffuse lesions, there were 6 cases of pneumonia of pulmonary tuberculosis, 9 cases of lung carcinoma, 7 cases of adenecarcinoma; 6 cases of pneumonia, 2 cases of fungous infection, and 1 case of lung hemosiderusis. The diagnostic yield about 58 cases of local lesions was low, among which non-nodule lesions accounted for 33.33% and nodule lesions accounted for 29.91%. In 89 cases of peripheral lung lesions with histological diagnosis, lung carcinoma and pulmonary tuberculosis were frequent diseases, which accounted for 86.52%. Conclusion TBLB is a reliable, safe, effective and repeatable operation method in diagnosis of lung diffuse lesions and peripheral pulmonary lesions.     

路面竣工后弯沉实测标准探讨——以G312南京段为例

针对现行的《公路沥青路面设计规范》中有关弯沉计算存在的问题,根据动态控制的观点,路面结构层的实测代表弯沉值应以其下一层的实测代表弯沉值为基础进行反算,并通过偏差分析,了解其层间接触状态,计算实际层底弯拉应力,预估其疲劳寿命。     

轿车白车身优化设计研究

建立了国产某轿车白车身有限元模型,计算得出白车身低阶振动固有频率和固有振型.进行了振动固有频率对壳体厚度等结构参数的灵敏度分析,在灵敏度分析的基础上,选取灵敏部件进行了结构优化设计.     

大连市金州湾二桥主桥桥型方案选择

介绍了大连市金州湾二桥主桥的三个设计方案,即预应力混凝土斜拉桥方案、自锚式悬索桥方案、自锚式斜拉-悬索协作体系桥方案.分别从施工难易程度、经济适用性和外观造型等方面进行综合比较分析,认为自锚式斜拉-悬索协作体系桥方案最适合在此处实施,推荐其为本工程的首选方案.     

"国家高速公路网"规划中值得关注的几个问题

高速公路网的规划建没是中国公路交通现代化最显著的特征之一。阐述了过去20多年高速公路发展对国家社会经济和综合运输发展所产生的积极影响．同时指出可通过法律手段确保。国家高速公路网”规划建设的有效实施和建设资金来源。进一步对“国家高速公路网”在未来综合运输中的定位给出了描述．认为：三级路网整合的门到门运输优势和增强干线运输竞争力应成为21世纪中国公路交通现代化不可分割的整体概念。最后．认为。国家高速公路网”规划与原有高速公路网的对应关系、规模问题和通过城市的连接关系等是“国家高速公路网”规划的关键问题。     

新型1000t/h散粮卸船机

2005年6月14日,华澄实业有限公司为日本日立公司配套、为我国营口港制造的1000t／h连续式散粮卸船机安全抵港。     

交通产业结构调整的宏观动态优化模型

指出了交通产业的结构组成和影响因素,从宏观、中观、微观三个结构层次,分析了交通产业的合理结构和变化趋势,明确了我国交通产业结构调整的目标和主要措施,从而从宏观角度建立了交通产业结构的动态优化模型,为我国交通产业的结构调整提供一定的理论参考.     

沥青胶结料路用性能分级评价分析

为探讨不同沥青胶结料分级体系对于沥青材料的评价有效性,对不同沥青材料进行不同分级试验评价,结果表明PG性能分级对于沥青材料流变性的区分优于针入度分级和黏度分级。     

Analytical solutions for three-dimensional stability of limited slopes

A method of three-dimensional limited slope stability analysis is presented here based on the upper-bound theorem of the limit analysis approach. A rotating collapse mechanism is considered in which energy dissipation takes place along curve velocity discontinuities. In the frictional soils, the failure surface has the shape of logarithm helicoids, with track outline defined by log-spirals. In the cohesive soils, the shape of the failure surface is torus. Angle is considered at slope top, and the critical height is less than top with no inclination. Numerical results of the proposed algorithm are presented in the form of nondimensional graphs. Some examples illustrate the practical use of the results.