The use of lightweight foam soil material as backfill for embankment and bridge deck is one of the effective ways to dispose of roadbed settlement diseases. How to predict the fatigue life of lightweight foam soil is the current research hotspot, which is of great significance for the in-depth study of its deformation properties and the enhancement of durability. In this paper, different machine learning methods are used to learn to predict the fatigue life of lightweight foam soil under cyclic loading, and the prediction results between different models are compared and analyzed, and the results show that the support vector machine method is more accurate and applicable for the prediction of the service life of lightweight soil in air bubbles.

Tunnel excavation in weak surrounding rock areas is prone to landslide accidents, and the use of high-pressure rotary piles to pre-strengthen the soil in the local area can enhance the strength and bearing capacity of the surrounding rock. Discrete lattice spring model is established with the three-dimensional morphology modeling system of the rotary pile reinforcement. It is used to quantitatively characterize the reinforcement effects of high-pressure rotary piles, to analyze the influence of the reinforcement ratio and reinforcement function. The results show that compared with the deformation of unreinforced stratum, the high-pressure rotary pile can better control the ground surface settlement. The larger the reinforcement ratio is, the better the reinforcement effect of the rotary spray pile is, especially with the increase in reinforcement ratio, the contact between individual piles bites to form a row of piles, which can significantly improve the ability of the formation to resist deformation. Under the same reinforcement situation, the square root type reinforcement function has the best reinforcement effect, the line function has the middle reinforcement effect, and the quadratic type reinforcement function has the worst effect.

The performance of RAP material directly affects the engineering effect of pavement recycling technology. In this study, the performance of high content RAP recycled mixture was analyzed. Through the extraction and screening of RAP materials, it was found that the viscosity of old asphalt increased significantly, the softening point decreased, and the coarse aggregate was refined seriously. The high, low temperature and water stability of high content plant mixed recycled ATB-25 mixture were studied through laboratory tests with different regenerants. The results showed that, compared with the control group, the dynamic stability, freeze-thaw splitting strength ratio and the maximum flexural tensile strain increase rate were: Type A regenerant: 27.48%, 29.45%, 35.71%; Type B regenerant: 16.76%, 21.28%, 38.96%. Comparing the effects of the two kinds of regenerants, after adding Type A regenerant, the mixture has the best high-temperature and water stability, and Type B regenerant is better than Type A regenerant in improving the low-temperature performance. The high, low temperature and water stability of the mixture after adding the regenerant can meet the specification requirements.

Most of the existing slope protection methods of subgrade slopes in retention areas were mortar rubble masonry pavement, which had a poor ecological effect. Under the action of long-term wind and sun, local damage was easy to occur and even led to the overall instability of the slope. Based on the design principles of environmental protection, economy, landscape, and safety and durability, a new ecological slope protection technology was developed. The new technology was resistant to erosion, soak, and salinity, which not only ensured the safety of the roadbed slope but also focused on ecological green, achieving the dual objectives of safety and ecology. The technology was applied to the Jinshi Expressway in Tianjin. By establishing the numerical model of the slope with or without protection, the variation rule of the stability of the subgrade slope and the distribution of the plastic zone inside the subgrade during the rise and fall of water level on both sides were obtained. The stability coefficient of the roadbed with protection was higher than that of the unprotected state, which showed that the new ecological slope protection not only could improve the overall stability of the roadbed but also reduce the range of the plastic zone and the displacement at the foot of the slope, therefore the protective effect was good.

In response to the phenomenon that road maintenance construction activities may have a certain impact on passing vehicles and generate additional carbon emissions, based on the Tianjin Avenue Restoration and Maintenance Project, a recommended list of carbon emission factors is proposed. A traffic impact carbon emission calculation model is used to calculate the traffic impact carbon emissions of the supporting project, analyze the characteristics of traffic impact carbon emissions composition, and explore the hot spots of traffic impact carbon emissions of maintenance projects, propose emission reduction strategies for road maintenance engineering traffic organization.

In recent years, a three-dimensional numerical simulation has been widely used in the analysis of slope stability. In this paper, a landslide is used as the engineering background, and the FLAC3D software is used to analyze the stable state of the landslide. The relationship between the displacement and the time step of the point is analyzed. The position of the sliding surface is simulated, and the stable state of the landslide is comprehensively evaluated, thereby providing a meaningful experience for other similar projects.

我国已建成较为完备的公路体系和城市路网.新的道路建设需要在保证质量的基础上逐步实现道路的绿色可持续发展.现依托重庆地区某沿江城市道路改建工程,在旧路病害调研的基础上,根据当地工程建设经验,借鉴国外长寿命路面设计理论,参考公路和城镇道路相关设计规范,采用路面结构批处理分析技术和有限单元数值模拟方法,提出适宜于高温多雨区的城市道路长寿命沥青路面结构.其研究成果对于相同气候地区的城市道路建设具有一定的参考价值.

为了分析半刚性沥青路面建设过程的碳排放,本文采用生命周期理论,将半刚性沥青路面建设过程进行了阶段划分,建立了碳排放定量计算模型,结合津石高速公路某段建设工程案例,量化了半刚性沥青路面建设过程碳排放,分析了碳排放特征,识别了关键碳排放源,并对比分析了"油改气"技术的减排效益.研究结果表明,半刚性沥青路面建设期的碳排放主要来源于原材料生产阶段,生石灰和水泥的生产为该阶段主要的碳排放来源;施工现场的碳排放主要来源于场外加工阶段,沥青混合料制拌过程产生了较大的碳排放;采用"油改气"技术减排效益显著,相较于使用重油减排率达28.14％.

通过室内土常规试验、土水特征曲线试验和非饱和土强度试验,得到天然土体的基本物理力学性质、非饱和石灰改良土的土水特性和强度特性.在土水特性方面,结合压力板仪、WP4C仪和饱和盐溶液3种测试方法分析含水率、孔隙比以及饱和度与吸力之间的关系,并通过VG模型对广吸力范围内石灰改良土饱和度与吸力关系曲线进行拟合,且拟合精度高;在强度特性方面,三轴试验结果表明试样的黏聚力随吸力的增大而增大,三轴试样的内摩擦角随吸力增大的变化并不明显.研究成果可为实际工程中路基边坡稳定性研究提供较为可靠的非饱和数据.

The transportation industry is a key area of greenhouse gas emission reduction in China, and the construction of highway asphalt pavement generates a large amount of carbon dioxide, which is the focus of emission reduction. By analyzing the characteristics of carbon emission during asphalt pavement construction, the calculation method of carbon emission during asphalt pavement construction is studied by LCA, and the carbon emission and heat source in the whole construction process are obtained based on a highway case. The results show that in the process of asphalt pavement construction, the total emission in the raw material production stage and mixing stage is up to 92.23%. The emission reduction measures are mainly to actively use clean fuel and improve the efficiency of production equipment. During the paving of water stabilized base / subbase, the carbon emission in the production stage of raw materials is as high as 90% of the total amount, and the emission reduction measures are mainly low-carbon cement.

边坡防护方案的确定是公路设计阶段的重要环节,决策结果的客观性、科学性直接影响公路全寿命周期的安全.目前滞洪区高速公路生态边坡方案的决策以定向的经验判断为主,缺乏定量理论评价.为此,基于二元定量比较法、熵权法、灰靶决策理论,构建了一种滞洪区高速公路生态边坡评价决策模型.该模型从经济、技术、社会三方面综合考虑生态边坡方案决策的多种因素,选取11个评价指标构建指标体系;利用熵权法对指标权重进行计算,降低人为主观因素影响,并结合灰靶理论计算各评价方案靶心距,进行优劣排序决策最优方案.最后以津石高速公路生态边坡方案决策为例,对上述方法进行了应用验证.实践结果表明,该评价模型能较为准确的评价滞洪区高速公路生态边坡方案的优劣程度,具有一定的合理性和可行性.

As one of the most critical functions of traffic information infrastructure, traffic information perception could provide essential data and decision-making support for traffic application scenarios such as traffic situation prediction and signal control. Currently, the common traffic information perception means mainly include geomagnetic coil, radar, video, infrared, etc., but these single traffic information perception devices generally lack of comprehensive information perception and high accuracy. In this paper, the traffic information perception technology based on the radar and video fusion is investigated, which organically integrates the detection data of millimeter wave radar and visual sensors. A large-scale, accurate and comprehensive traffic information perception is realized with the purpose of establishing the foundation for the development of intelligent and informative traffic.

为应对山区地质复杂区公路勘察效率低、安全风险高的局面,探讨基于无人机遥感技术的公路不良地质判识技术框架、应用方法.首先系统介绍无人机技术原理及其优势,并探讨无人机遥感不良地质判识的流程方法.以现场案例为基础,重点介绍利用无人机遥感技术在崩塌、滑坡、泥石流等不良地质判识中的应用.结果表明:①利用无人机遥感进行勘察精度较高,相比于人工勘察可降低安全风险,提高勘察效率,提升数据时效性及可靠性;②可快速构建三维模型,突破传统二维不良地质体解译技术,提升了不良地质识别精度;③利用构建的不良地质体三维模型,可对不良地质体的空间特征进行量测,为方案的选择与处理提供可靠的数据.

针对目前公路路面传统维修技术难以满足养护需求的情况,提出了高等级公路高聚物注浆快速修复技术,阐述了高聚物注浆材料特点、注浆机理及注浆技术优势.根据不同病害特点,重点介绍了半刚性基层高聚物注浆快速修复技术及施工工艺,为高等级公路路面快速、无损修复提供了可靠的技术手段,对于提升养护水平、降低养护成本有重要现实意义.

伴随我国交通基础设施的大力建设,道路地基处理技术逐步有了较多研究成果和成功实践经验,新技术、新方法层出不穷.总结了几种常用的道路地基处理技术的特点和研究进展,并探讨近几年较为典型的地基处理新技术、新方法;以相关标准规范的编制、修订情况为基础,分析道路地基处理标准化的建设情况,并展望道路地基处理技术应用发展趋势.

在分形理论的基础上,构建了宾汉流体在多孔介质中的扩散模型,分析了浆液黏度、浆液初始剪切力和受注介质孔隙结构特征(孔隙度)对浆液扩散规律的影响,以便为注浆在岩土工程灾害治理中的合理设计提供技术支撑.结果 表明:(1)当孔隙通道的曲折度分形维数DT为1.5时,浆液扩散压力随着扩散距离的增加呈非线性迅速减小趋势,而当DT为1.0时,浆液扩散压力随着扩散距离的增加无明显变化;(2)当DT较大时,浆液压力损耗随着浆液初始剪切力的增加呈非线性迅速减小趋势,而当DT较小时,在相同条件下,浆液压力损耗随浆液初始剪切力的增加无明显变化;(3)浆液压力损耗随着受注介质孔隙度的增加呈现先急剧减小、后缓慢减小的趋势.

针对信号交叉口行人过街溢出轨迹建模,选择商业区作为数据采集点,从而保证足够的行人数据量,采用视频采集技术获取行人过街的时空数据,得到行人过街轨迹.基于Weibull(韦布尔)模型建立行人在3个穿越区域的穿越位置分布模型,进而连接3个穿越区域的穿越位置得到行人过街轨迹.利用轨迹模型进行信号交叉口行人过街安全护栏的长度设计,该方法操作简单、实用性强,且该设计可有效降低行人与机动车的冲突,提高行人过街的安全性,改善信号交叉口行人及机动车的运行秩序,为交叉口安全设计提供理论支持.

引言 当前大多数工业大型厂房中用电耗电量主要为风机、泵类等设备.因此经常出现风机、水泵负载率长期偏低或负荷经常变动且幅值较大e,通常采用高效的调速技术改变电动机转速,从而达到节电目的.其中,以引风机最为突出,大部分厂房中的引风机因功率较大,需采用高压电机,当前最广泛的调速方式为对高压变频调速及斩波内馈调速.