花岗岩地层中盾构掘进效率影响因素研究

为了定量对比盾构掘进花岗岩地层时的掘进效率,提出一种表征掘进效率的特征参数,并依托深圳市城市轨道交通8号线一期工程进行掘进试验和地层参数现场量测,分析了各影响因素和掘进效率的相关性,提出了针对不同地层的掘进效率控制措施.研究结果表明:岩石的单轴抗压强度和岩体的完整性系数均与掘进效率负相关,可用幂函数近似表达地层参数和掘进效率之间的经验关系;可用反比例函数近似表达掘进效率与总推力之间的经验关系,总推力对掘进效率的影响程度随地层坚硬程度的升高而降低;低推力高转速的掘进参数组合在微风化地层中效率较高,中等风化地层中总推力、刀盘转速分别为14000±1000 kN、1.6±0.1 rpm时掘进效率较高,可以通过牺牲掘进效率的方法来在该掘进速率水平上短期内提高掘进速率.     

关于沥青混凝土路面的常见病害及防治措施

沥青混凝土路面主要应用于公路的面层,由于沥青混凝土材料本身的差异,以及受设计、施工水平的影响,沥青路面常常出现松散、脱皮、冻胀翻浆、水破坏、沉陷、开裂、泛油、坑槽等病害。这些病害的出现严重影响了路面行车速度、行车安全、加大了汽车磨损、缩短了沥青路面的使用寿命,使行车不畅,行成交通压力,造成道路使用年限缩短。本文具体结合工程项目阐述沥青混凝土的施工工艺、病害分析及防治措施。     

单片机在无线通讯中的应用

采用可工作于433 MHz频段的无线射频收发模块n RF9E5,通过内嵌8051单片机C语言编程,实现多通道、短距离的数据传输。并在近距离范围内验证了所设计的无线通讯模式的可靠性和准确性。     

Application of digital image correlation method to in-situ dynamic strain measurement

Application of digital image correlation (DIC) method to determination of in-situ dynamic strain is presented in this study. Firstly, an integrative software is programmed based on the DIC algorithms and point-wise least-squares fitting technique. Then, simulated speckle images are generated to study the computational accuracy of this software. The experimental setup and procedures for measuring in-situ dynamic strain through both DIC and strain gauge are proposed. The DIC results are close to those measured by strain gauge. This fact reveals that DIC is a practical and effective tool for in-situ dynamic strain measurement. Finally, the full-field in-situ dynamic strain of another specimen is measured by DIC, and the overall distribution of the strain in the measurement area is clearly shown.     

铁尾矿粉在道路工程中的应用研究

以绍兴某尾矿坝堆积的铁尾矿粉为背景,利用石灰和黏性土进行改良再生,使复合尾矿粉满足路用性能要求,同时对其施工工艺进行改良,通过试验验证了复合铁尾矿粉完全可以满足道路路用要求;为类似尾矿粉的综合利用提供了借鉴方案,既减轻了固体废弃物对生态环境的污染,又可以减少对土地资源的占用以及减轻对库区下游人民生命财产的危害,同时还可以取得明显的社会效益和经济效益。     

Characteristics analysis for travel behavior of transportation hub passengers using mobile phone data

The travel behavior of passengers from the transportation hub within the city area is critical for travel demand analysis, security monitoring, and supporting traffic facilities designing. However, the traditional methods used to study the travel behavior of the passengers inside the city are time and labor consuming. The records of the cellular communication provide a potential huge data source for this study to follow the movement of passengers. This study focuses on the passengers’ travel behavior of the Hongqiao transportation hub in Shanghai, China, utilizing the mobile phone data. First, a systematic and novel method is presented to extract the trip information from the mobile phone data. Several key travel characteristics of passengers, including passengers traveling inside the city and between cities, are analyzed and compared. The results show that the proposed method is effective to obtain the travel trajectories of mobile phone users. Besides, the travel behavior of incity passengers and external passengers are quite different. Then, the correlation analysis of the passengers’ travel trajectories is provided to research the availability of the comprehensive area. Moreover, the results of the correlation analysis further indicate that the comprehensive area of the Hongqiao hub plays a relatively important role in passengers’ daily travel.

     

浅谈公路装配式桥梁桥面横坡

公路桥梁尤其是山区公路桥梁,受到平面线型指标限制,桥面横坡常不是标准横坡,既有标准横坡也有等超高段单向坡,甚至需要在一跨两端出现反向横坡。装配式桥梁以其受力简单、施工周期短和施工便捷等优点在公路桥梁中得到广泛应用。在设计阶段合理选择适当的梁顶横坡对桥梁受力和经济有着不可忽视的影响。但是实际桥梁设计中,由于设计人员水平参差不齐,往往会造成桥梁处于不利的受力状态和造成经济上浪费。本文针对公路装配式桥梁常见的四种桥面横坡调整,从施工便捷和经济安全的角度总结四种桥面横坡形成机制。     

电控转向系统直流电机实时故障诊断方法

作为电动助力转向系统和线控转向系统执行元件的电动机,其可靠运行对电控转向汽车的行驶安全至关重要.本文中通过建立永磁直流电机模型和运用带有遗忘因子的递推最小二乘法,提出了一种电控转向系统直流电机故障诊断方法.线控转向实车试验验证的结果表明,该方法可准确、实时地诊断直流电机故障,为电控转向系统的容错控制奠定基础.     

掺混甲烷对乙烯层流预混火焰炭烟形貌的影响

针对掺混甲烷的乙烯层流火焰中的炭烟颗粒从形貌角度进行了研究,构建了具有相同当量比(2.07)、火焰温度、气体流速的层流预混乙烯火焰和掺混甲烷的乙烯火焰,并各自选取了3个高度进行热泳探针取样,采用TEM和AFM方法对各个工况的炭烟颗粒粒径分布、平均粒径、平均体积当量球径进行了对比。发现少量的甲烷掺混会令乙烯火焰中炭烟颗粒的尺寸变大,而当甲烷掺混量变多时该现象消失。而通过对颗粒的圆度、球度和分形维数计算和分析,发现即使是很小的颗粒也具有相似的不规则形状,这一现象广泛存在于各种火焰和各种大小的颗粒中,不受掺混比的影响,并且越大的颗粒结构越松散。