大厚度水泥稳定碎石基层层间有限元模拟分析

大厚度水泥稳定碎石基层分层施工使得基层由设计中的整体受力变为两薄层受力,层间接触的存在降低了基层的路用性能,从而降低了整个路面结构的使用性能。文章采用有限元软件ABAQUS,分别对两种不同工况下(分层施工和全厚式施工)的大厚度水泥稳定碎石基层路面进行路表弯沉、面层底面和基层底面的最大主应力、土基顶部最小主应变及面层底面最大剪应力等指标的有限元模拟,分析不同工况的大厚度水泥稳定碎石基层路面的荷载响应。     

大厚度水泥稳定碎石基层施工质量控制探讨

为解决大厚度水泥稳定碎石基层施工中不易压实的问题,文章以崇左至水口高速公路为例,针对大厚度水泥稳定碎石基层成型后崩边、边部线形不顺直、底部不密实、平整度较差等问题,介绍了29cm大厚度水泥稳定碎石基层施工工艺,并从原材料及配合比,混合料生产、摊铺、碾压等方面介绍质量控制要点。经现场检测表明,该型大厚度水泥稳定碎石基层摊铺效果好,各路用性能满足要求。     

大厚度水泥稳定碎石基层施工技术研究

文章结合YJ高速公路工程实例,对大厚度水泥稳定碎石基层施工技术进行研究,通过方案比选、试铺路段试验等方法,对大厚度水泥稳定碎石基层中的拌合、摊铺、碾压作业等施工技术进行深入探讨,从而得出其最优的施工方案。结果表明:该工程采用大厚度水泥稳定碎石基层施工技术在平整度、强度等方面均能满足工程要求。     

水泥稳定碎石基层的施工质量控制

水泥稳定碎石基层作为路基与面层之间的半刚性过渡层,在力的传递上起到了承上启下的作用.结合施工实践,对水泥稳定碎石基层的施工质量控制措施进行了总结和归纳,提出了改善水泥稳定碎石施工质量的技术措施.     

厚层水泥稳定级配碎石压实标准及检测方法研究

我国水泥稳定级配碎石混合料应用已有二十余年,在施工工艺方面均是常规施工方法,碾压厚度20cm左右,近几年来,随着施工机械设备功率的提高,厚层水泥稳定级配碎石在各地高等级公路中均有应用,但对于厚层水泥稳定级配碎石的压实度控制标砖和检测方法没有明确要求,本文通过G16丹锡高速赤峰段厚层水泥稳定级配碎石试验段施工,对厚层水泥稳定级配碎石的压实度控制标准和检测方法进行研究。     

祥周至龙邦公路路面大修施工质量控制

文章以祥周至龙邦二级公路路面大修工程为例,介绍采用旧路油面层和水泥稳定碎石基层进行再生利用的大修施工方案,从细粒式沥青混凝土上面层、沥青碎石再生料下面层（AM-16）、沥青碎石封油层、水泥稳定碎石再生基层等方面阐述了路面各结构层施工技术要求和质量控制要点。     

广西大厚度水稳基层施工技术前景探讨

文章针对广西高等级沥青路面基层施工技术进行探讨,分析了水泥稳定碎石基层施工工艺存在的问题,结合国内外研究及实体工程应用现状,总结阐述了大厚度水稳基层施工技术的工程应用历程及技术的可行性;将《公路路面基层施工技术细则》(2015版)与大厚度水稳基层施工进行对比解读,发现现行规范部分条例不能满足大厚度水稳基层施工要求,因此,区域性地推广大厚度水稳基层技术需要相应的标准或指南配套实施。     

高原路面工程水泥稳定碎石基层施工质量控制

在高原路面工程中,水泥稳定碎石基层的施工是一个至关重要的阶段,需要严格的质量控制措施。分析高原路面工程水泥稳定碎石基层施工工艺流程及施工常见问题,阐述高原路面工程水泥稳定碎石基层施工质量控制要素,提出高原路面工程水泥稳定碎石基层施工质量评估,为优化高原路面工程中水泥稳定碎石基层施工提供参考。     

大厚度水泥碎石整体强度的影响分析

大厚度水泥碎石可以采用连续施工和间断施工两种方法。文章通过铺筑试验路,检测FWD、钻芯强度,比较这两种不同施工方法对路基整体结构强度的影响,得出在层间浇洒水泥净浆的连续施工方法对提高基层整体强度效果最好。     

水泥稳定碎石基层施工质量控制探讨

文章分析了采用传统施工方法进行水泥稳定碎石基层施工存在的一些质量通病及对沥青路面造成的病害,并结合广西柳南高速公路改扩建工程实例,介绍了水泥稳定碎石基层施工的新工艺、新方法,探讨了水泥稳定碎石基层施工的质量控制措施。     

基于DSP/GPRS的长输管道阴极保护在线监测系统的设计

针对人工巡检长输管道阴极保护的不足,设计了一种长输管道阴极保护在线监测系统.整个系统分为硬件部分和软件部分.硬件部分基于DSP和GPRS技术,实现管道阴极保护电位的在线测量和信息的传输.软件部分基于VC ++,实现数据的接收、保存和计算机辅助分析.现场试验表明:研制的在线监测系统实时性好、可靠性高.     

浅谈我国中小企业成本控制

企业是以盈利为目的的社会团体,追求的是经营利润最大化,其开展各项活动的最终目标是实现企业价值最大化,而进行成本控制则是实现这一目标的重要手段。我国的大部分中小型企业成本控制程度较差,生产效率较低,运作流程较混乱,所以生产成本均较高,对企业内部成本控制进行科学、合理的整顿,在生产成本控制方面大有潜力可挖。本文从中小企业成本控制的重要性入手,对中小企业成本控制中存在的一些问题进行分析,试探讨成本控制的有效方法。     

管道污垢监测装置的研究进展

介绍了管道污垢的种类,并对国内外目前较流行的污垢监测设备进行了分析。污垢广泛存在于各种工业生产过程中,使管道截面积减小,设备处理能力降低,能耗增加,甚至使管道破裂,带来巨大的经济损失。污垢的形成是个复杂的过程,现阶段的研究处在实验阶段,没有形成完整的理论体系,污垢监测装置的研发显得尤为重要。采用合理、经济的监测装置有利于除垢、防垢工作的进行。国内污垢监测装置的开发起步较晚,技术水平还不太成熟,通过对不同污垢监测装置的分析比较,可以促进国内污垢监测水平的提高。     

储罐机械清洗设备清洗工艺与应用

清洗作业是储罐运行中的一项重要工作,可保证储罐的正常运行。介绍了储罐机械清洗技术工作原理,储罐机械清洗较人工清洗具有显著的优势。介绍了清洗设备主要构成,分析了原油储罐清洗的主要工艺流程。结合吐哈油库20#原油储罐油质的特点和现场具体情况,制定了专项清洗方案,给出此次原油储罐清洗的具体工艺流程。应用上述工艺流程,能够更快更好地满足储罐的清洗要求,节省了人力、物力和财力,创造更多的效益。     

Driving behaviour models enabling the simulation of Advanced Driving Assistance Systems: revisiting the Action Point paradigm

In the field of Intelligent Transportation Systems (ITS), one of the most promising sub-functions is that of Advanced Driver Assistance Systems (ADAS). Development of an effective ADAS, and one that is able to gain drivers’ acceptance, hinges on the development of a human-like car-following model, and this is particularly important in order to ensure the driver is always ‘in the (vehicle control) loop’ and is able to recover control safely in any situation where the ADAS may release control. One of the most commonly used models of car-following is that of the Action Point (AP) (psychophysical) paradigm. However, while this is widely used in both micro-simulation models and behavioural research, the approach is not without its weaknesses. One of these, the potential redundancy of some of the identified APs, is examined in this paper and its basic structure validated using microscopic driving behaviour collected on thirteen subjects in Italy. Another weakness in practical application of the Action Point theory is the identification of appropriate thresholds, accounting for the perception, reaction and adjustment of relative speed (or spacing) from the leading vehicle. This article shows that this identification is problematic if the Action Point paradigm is analysed in a traditional way (car-following spirals), while it is easier if the phenomenon is analysed in terms of car-following ‘waves’, related to Time To Collision (TTC) or the inverse of TTC. Within this new interpretative framework, the observed action points can be observed to follow a characteristically linear pattern. The identification of the most significant variables to be taken into account, and their characterisation by means of a simple linear pattern, allows for the formulation of more efficient real-time applications, thereby contributing to the development and diffusion of emerging on-board technologies in the field of vehicle control and driver’s assistance.     

Optimal vehicle trajectory planning in the context of cooperative merging on highways

One of the main triggers of traffic congestion on highways is vehicle merging at on-ramps. The development of automated procedures for cooperative vehicle merging is aimed to ensure safety and alleviate congestion problems. In this work, a longitudinal trajectory planning methodology is presented, developed to assist the merging of vehicles on highways; it achieves safe and traffic-efficient merging, while minimizing the engine effort and passenger discomfort through the minimization of acceleration and its first and second derivatives during the merging maneuver. The problem is formulated as a finite-horizon optimal control problem and is solved analytically. This enables the solution to be stored on-board, saving computational time and rendering the methodology suitable for practical applications. The tunable weights, used for taking into account the different optimization criteria, may serve as parameters to match the individual driver’s preferences. The proposed methodology is first developed for a pair of cooperating vehicles, a merging one and its putative leader. Moreover, an alternative solution procedure via a time-variant Linear-Quadratic Regulator approach is also presented. A Model Predictive Control (MPC) scheme is utilized to compensate possible disturbances in the trajectories of the cooperating vehicles, whereby the analytical optimal solution is applied repeatedly in real time, using updated measurements, until the merging procedure is actually finalized. Subsequently, the methodology is generalized for a set of vehicles inside the merging area. Various numerical simulations illustrate the validity and applicability of the method.     

高压燃气管道储气能力分析

高压燃气管道储气能力与两端压力和管长有着密切的联系.为了得到高压管道的储气量与压力和管长的关系,利用稳态仿真模型,采用四阶龙格-库塔法对模型进行求解,对求出的沿线压力进行线性拟合,得到沿线压力变化公式.结合储气定义推导出储气量与管长的关系式,并得到实例验证.从关系式来看,当管长等于最优管长时储气量最大.     

基于神经网络的无信号路口人车交通行为预测分析

以无信号灯路口人车交通行为为研究对象,对行人和机动车辆在无信号灯路口的整体交通行为进行分类预测。在对路口现场交通情况进行拍摄后,用电脑的分帧技术对所需要的数据进行提取和分类,而后建立BP神经网络模型,确定神经网络的输入变量与输出变量。将样本数据导入神经网络并进行训练和测试后,得出行人和车辆过街类型的分类准确率,并且通过准确率所达到的标准来证明了BP神经网络模型的可行性。     

Optimizing sustainable feeder bus operation considering realistic networks and heterogeneous demand

A mathematical model is developed to optimize social and fiscal sustainable operation of a feeder bus system considering realistic network and heterogeneous demand. The objective total profit is a nonlinear, mixed integer function, which is maximized by optimizing the number of stops, headway, and fare. The stops are located which maximize the ridership. The demand elasticity for the bus service is dependent on passengers' access distance, wait time, in‐vehicle time, and fare. An optimization algorithm is developed to search for the optimal solution that maximizes the profit. The modeling approach is applied to planning a bus transit system within Woodbridge, New Jersey. Copyright © 2011 John Wiley & Sons, Ltd.     

输油站场管道腐蚀调查与分析

输油气站场管道敷设复杂,且多数没有实施区域性阴极保护,存在腐蚀风险。选择输油气站场典型腐蚀调查点,通过外观检查、厚度测试、漏点检测、粘结力测试及缺陷点活性评价,对某输油站场防腐层、保温层性能及管道腐蚀情况进行调查。结果表明：生产区管道防腐层失效严重,管体腐蚀,最大腐蚀坑深2.18 mm;立管出入土界面也存在腐蚀。文中分析了腐蚀原因,给出了站场维护维修建议。