土工格室形式与填料类型对公路地基承载力的影响

为研究土工格室形式与填料类型对加固公路地基承载能力的影响,在模型试验箱内以土工格室焊距、高度及填料类型为变量,增加土工格室加固地基顶部的压力,测量土工格室加固地基下方和附近的土压力变化及加固地基顶部的沉降,对土工格室层荷载从垂直向水平的有效传递进行评价,研究加固地基内部应力状态和表面变形特性。结果表明：土工格室的布设使加固地基产生了柔性筏基作用,可均化传递来自上部结构的应力,与未加固结构层相比其最大土压力降低了50%～60%;土工格室的加入使结构层承载能力显著提升,在最优加固效果下,极限承载能力增加了4～8倍;格室焊距与高度对结构层承载能力有一定影响,格室高度越高、焊距越小其加固效果越好;选择砾石为填料时,格室宽高比为1∶0.8时加固效果最好;填料选择黏土时,格室形式的宽高比为1∶1.2时加固效果最优。     

土工格室柔性结构体系工程应用施工技术研究

土工格室是一种新型的土工合成材料,由其组成的柔性结构体系在工程中的应用效果与施工工艺和质量验收标准密切相关,然而,至今尚无较为完整与系统的施工工艺。文章结合近年来土工格室在柔性搭板处治差异沉降技术、柔性筏基加固软弱地基技术、生态柔性挡墙应用技术等方面大量的工程应用实际,系统总结了土工格室柔性结构体系在公路工程应用中的施工工艺与质量验收标准,以期为推广应用提供依据。     

土工格室加筋粘性土的强度特性研究

对土工格室（三维立体加筋材料）加筋粘性土的强度进行了试验研究，在加筋率相同的条件下，将土工格室中筋土与筋材平铺加筋土及无筋土的强度进行了对比研究，找出了土工格室加筋粘性土抗剪强度增加的原因，探明了土工格室加筋土的工作机理。     

土工格室加筋边坡大模型试验研究

对土工格室加筋边坡,进行了考虑加筋量变化的大模型对比试验研究,对边坡变形、加筋边坡中土体受力特征以及加筋体中土工格室本身的受力等问题,进行了探讨.研究表明,与一般平面型土工合成材料通过材料与土的摩擦力来提高边坡的稳定性不同,土工格室加筋边坡主要是依靠土工格室对土体的约束作用来提高边坡稳定性,加筋区复合土体整体性较强.     

土工格室界面特性与处治路堤现场试验分析

拉拔试验能更好的反映加筋土结构中筋材的加筋行为,采用自制的拉拔试验装置来测试高填方路堤的现场砂粒填料与土工格室的界面特性参数,分析土工格室与土的界面摩擦作用,进一步研究土工格室的加筋机理。结合工程实例,对土工格室处治高填方路堤进行现场试验,分析格室在路堤横断面的受力特点以及格室的加筋性能。试验结果表明:土工格室拉拔受力是一个渐进式的过程,随着拉拔位移继续增大,格室后面几排网格依次受到填料的阻力,拉拔界面的剪应力呈台阶式的上升;格室与填料的界面摩擦角大于填料本身的摩擦角,且拉拔系数K大于1.0,格室加筋性能远优其他平面材料的加筋性能;在路堤横断面方向,格室承受拉应力;在新旧路堤搭接处,格室受拉应力最大,是重点需要处治的位置。研究表明格室能有效的约束路堤土的侧向变形,同时土工格室所在层位起到了扩散荷载的作用。     

清伊高速公路土工格室加固粉土地基试验研究

以新疆清水河至伊宁高速公路为依托工程,结合粉土物理力学特性,提出了采用土工格室对粉土地基进行加固的方法.通过对土工格室加固粉土地基开展地基承载力、室内剪切、水分迁移等试验分析,论证了土工格室加固粉土地基的可行性,为新疆粉土地区公路设计提供了切实可行的技术依据.     

土工格室在高陡岩质边坡防护体系中的应用

基于张季如提出的土工格室稳定分析模型,将其应用于京张高铁坡率为1:0.3的高陡岩质边坡工程中,计算分析了不同坡率和固土深度工况下对土工格室材料强度的要求,并对边坡土工格室表面监测数据进行分析.结果表明:高强度的土工格室可在坡率小于1:1.0的边坡上应用,而对于不同坡率的防护体系,土工格室强度要求尚需通过计算确定.     

高强土工格室挡墙在高速公路拓宽中的研究

通过在一高速公路拓宽工程中的土工格室加筋挡墙沉降、深层水平位移、剖面沉降与墙背土压力现场试验监测,结果表明：土工格室挡墙具有较强的抗拉与抗剪强度,整体性较好,不均匀沉降较小,适宜在征地拆迁困难的高速公路拓宽工程中使用。     

土工格室处治山区高填方加宽路堤试验研究

结合高速公路拓宽工程,采用弹塑性三维数值方法,借助三维薄膜单元模拟土工格室,分析山区高填方加宽路堤的位移与沉降规律,提出优化的格室处治方案,同时进行了现场试验,分析格室处治后路堤深层侧向位移与沉降规律。结果表明:数值模拟与现场试验结果规律相符,高填方路堤在加宽路基自重荷载作用下竖向位移主要集中在加宽路堤的中上部,侧向位移从路基顶面到底部逐渐减少。受上部路堤土俯冲荷载作用,加宽路堤底部侧向位移相对附近土体较大。格室可有效减少高填方加宽路堤的侧向变形及扩散荷载传递。     

土工格室生态挡墙工程性状分析

应用Marc软件,通过模拟土工格室生态挡墙墙体、加筋层与填土的相互作用,对生态挡墙墙背的位移和应力性状进行分析,并结合实体工程进行墙背侧向土压力测试。结果表明:土工格室生态挡墙在外荷载的作用下,除了刚体位移之外,还会发生挠曲变形,具有柔性支挡结构的特点;墙背侧向土压力随着距墙顶距离的增大而增大;数值计算与现场测试得到的墙背侧向土压力变化规律一致,表明本文采用的数值模型是合理的。     

Handling Characteristics of Car-Trailer Systems; A State-of-the-Art Survey

Work relevant to the state of the art as regards passenger cars towing trailers is referenced and reviewed. Not only included is the very limited amount of work specifically dealing with passenger cars towing trailers, but also reviewed is the much larger body of work having a bearing on car-trailer systems. Topics included are aerodynamic forces, tire forces, the compliance concept, relevant work on vehicles without trailers, vehicles with trailers, and the role of the driver. The types of stability problems exhibited by car-trailer systems are discussed.

The state of the art as regards ability to predict vehicle response to specific steering inputs is shown to be fairly advanced. Recent significant advances include the appearance of experimental data useful for validating theoretical models. However, the state of the art as regards definition of what constitute desirable handling characteristics is still at a primitive stage, largely because of a lack of understanding of the roles played by drivers as part of the vehicle -driver - environment systems.

Throughout the review an effort was made to point out topic areas where it is likely that significant future contributions to the state of the art can be made. These areas are reviewed in the conclusions.     

Advanced Control Methods for Automotive Applications

This paper reviews key developments in applications of advanced control methods to automotive systems. Such applications appear in many aspects of vehicle controls. We will examine representative application areas, which include engines, suspension systems, traction systems, steering systems and those for automated highway systems (AHS). Each area is examined from the viewpoint of modeling and control algorithm development. Useful control theories for automotive application are briefly reviewed for better understanding of the applicability of these theories.     

Advanced Control Methods for Automotive Applications

SUMMARY

This paper reviews key developments in applications of advanced control methods to automotive systems. Such applications appear in many aspects of vehicle controls. We will examine representative application areas, which include engines, suspension systems, traction systems, steering systems and those for automated highway systems (AHS). Each area is examined from the viewpoint of modeling and control algorithm development. Useful control theories for automotive application are briefly reviewed for better understanding of the applicability of these theories.     

Is vehicle ownership in urban india influenced by the availability of high quality dedicated public transit systems?

As India's economy grows, so too does the number of people who can afford to own vehicles. A downside of this rapid increase in private vehicle ownership is a corresponding increase in traffic congestion, air pollution, and carbon emissions. Although affordability may be one reason for the shift toward commuting via private vehicles, another contributing factor could be the quality of public transportation. The objective of this paper is to determine whether private vehicle ownership in large urban areas in India is influenced by the presence of high quality dedicated public transit systems. Consumer expenditure survey data acquired from the National Sample Survey Office (NSSO) for the year 2009–2010 were used to develop a vehicle ownership model for 26 Indian cities with a population of at least one million. The results show that the availability of public transportation has a negative correlation to motorcycle/moped ownership but has no strong effect on car ownership. These results should encourage governments in developing economies to invest in high-quality dedicated public transit systems.     

Traffic Simulation with Consideration of Driver Models,Theory and Examples

SUMMARY

In the last five years the IKA (Institut für Kraftfahrwesen Aachen) and BMW created the microscopic traffic simulation program PELOPS. It simulates the traffic flow on motorways with a specific view on vehicle affairs. One application for PELOPS was the assessment of ACC (Adaptive Cruise Control) systems inside the PROMETHEUS program. It was shown, that PELOPS is a powerful tool for the analysis of new technologies. A new research period will extend the use of ACC about the functionality in urban areas. This requires an extension of PELOPS about some specific models. With this extension it is possible, to analyse new traffic technologies for the individual vehicles or the infrastructure. In a first step, PELOPS is extended about functions for suburban areas. This effects mainly the modelling of the driver behaviour. The driver behaviour is related to the traffic situation. In contrast to the normal traffic flow on motorways, the driver has to stop and go in the suburban area, he has to control lower distances and he has to react on other vehicles on cross-roads. New concepts for these functions are included in PELOPS and calibrated by detailed traffic data from a video observation and floating car measurements in the surrounding of Aachen. Based on the traffic measurement near Aachen, different scenarios are simulated to improve the traffic flow and to relieve the environment. These scenarios include ACC systems, inter-vehicle-communication and intelligent traffic lights. The paper shows some information's about the simulation technic and the results from the described analysis.     

现代汽车车载自诊断系统效率的分析

现代汽车车载自诊断(OBD)系统存在一个OBD不能监测出故障(误诊)的区域，该区域定义为自诊断系统的“盲区”。产生自诊断盲区时，汽车使用性能开始下降。汽车OBD系统产生的盲区主要受电子连接及布线技术、汽车传感器质量和执行器性能、汽车接地技术等凶素的影响。     

浅谈AB PLC数据交换技术应用

文章针对白车身焊装车间工艺复杂、控制系统布局分散、PLC系统之间通讯需求大等问题,在焊装车间原有设备的基础上,利用PLC数据交换技术,建立PLC控制系统之间远程数据通信功能,实现车间各区域联动生产,提高生产效率。     

Dynamic Interactions Between Travelling Vehicles and Guideway Systems

The technical state-of-the-art of ground transportation vehicles interacting with flexible, perturbed guideway systems is reviewed with emphasis on high-speed passenger-carrying systems. Currently available modelling, analysis, and simulation techniques as well as parametric results illustrating the dominant interaction dynamics are summarized. Experimental studies and correlations of field data with analytical results are described and areas in which further research is required are identified.     

Adhesion estimation at the wheel–rail interface using advanced model-based filtering

The railway industry in the UK is currently expanding the use of condition monitoring of railway vehicles. These systems can be used to improve maintenance procedures or could potentially be used to monitor current vehicle running conditions without the use of cost prohibitive sensors. This paper looks at a novel method for the online detection of areas of low adhesion in the wheel/rail contact that cause significant disruption to the running of a network, particularly in the autumn season. The proposed method uses a Kalman–Bucy filter to estimate the creep forces in the wheel–rail contact area; post-processing is then applied to provide information indicative of the actual adhesion level. The algorithm uses data that, in practice, would be available from a set of modest cost inertial sensors mounted on the vehicle bogie and wheel-sets. The efficacy of the approach is demonstrated using simulation data from a nonlinear dynamic model of the vehicle and its track interface.     

自动驾驶系统交通规则符合性仿真验证方法

随着自动驾驶技术的不断发展，高级别自动驾驶车辆逐步在限定区域开展实际道路测试，确保和提高自动驾驶系统安全驾驶能力是当前研究、测试和工程开发的热点难点。面对自动驾驶车辆将长期与人类驾驶车辆混行，并与其他交通参与者遵守同样交通规则的现实需要，提出一种验证和测试自动驾驶系统交通规则符合性的方法，以期降低多车混行条件下的交通安全风险。针对各类交通法律法规语义自动解析技术瓶颈，提出规范化-逻辑化两阶段交通规则数字化模型，基于改进谓词度量时序逻辑框架(Metric Temporal Logic，MTL)，将自然语言交通规则转换为命题、逻辑连接词和时序算子组成的逻辑编码，生成了自动驾驶系统可理解、可执行、可验证的数字化交通规则，并构建了交通规则命题的分级分类体系。提出了一套基于自动驾驶车辆高精度运动轨迹的交通规则符合性验证算法，并搭建仿真试验平台，在高速公路交通场景下开展了试验验证。理论分析与试验表明：精简命题空间、新增时序算子和谓词逻辑词等改进有效提高了原有MTL框架的时间表现能力，解决了时序逻辑性不足等问题，大幅提高了交通规则数字化转换效率，对地方性交通法规和未来交通法规修订提供了良好的兼容性。提出的交通规则符合性验证方法及试验平台可以有效测试自动驾驶系统对现有交通规则的遵守能力，相关成果对提高自动驾驶系统安全性能和未来混行交通安全管控水平具有重要意义。