公路盐渍土路基处理与病害防治策略

盐渍土在我国的分布区域非常广泛,尤其是在沿海地区,盐渍土由于自身的盐胀性和腐蚀性会对公路路基造成很大的破坏.因此,公路盐渍土路基的防腐蚀处理和病害防治对保证公路工程的建设质量具有重要意义.基于此,本文对公路盐渍土路基的病害成因进行了简要的分析,并提出了相应的防治策略.     

路面雷达在高速公路施工质量控制中的应用

控制高速公路的施工质量是保证其日后正常运营的关键.选取某在建高速公路一试验段,用路面雷达和介电常数测试仪进行路基和路面的测试,并对路基进行灌砂法试验,对路面进行钻孔取芯来验证.结果发现,路面雷达计算介电常数与含水量、湿密度和压实度之间都具有很好的相关性,其计算的基层和面层厚度与取芯厚度非常接近,并与介电常数测试仪的测试数据也有很好的相关性.因此,路面雷达可以对高速公路的路基和路面的施工质量进行检测和控制.     

市政道路施工中路基路面压实技术分析

市政道路工程建设的路基路面压实工程是整个市政道路工程中的重要基础,在建设过程中起到了很好的组成效果与组成作用,工程的质量好坏可以直接关系到整个工程的应用寿命,因此,在市政工程路基路面压实工程的施工过程中,施工单位应当做好对路基路面压实工程中施工技术的有效运用,确保工程项目的质量,进而实现工程经济效益的最大化。本文就着重针对市政道路工程的路基路面压实工程施工技术的有效运用进行分析,主要从路基路面压实工程的施工技术方面进行讨论,进一步为我国市政道路工程的有效建设与质量发展提供建议。     

浅析油田道路桥梁沉降段路基路面施工技术

最近的几年中我国社会经济水平得到了飞速发展,道路桥梁工程的施工规模不断扩大,施工数量不断增多,道路桥梁的安全问题变得越来越重要。想要保障道路桥梁施工整体质量,道路桥梁沉降段路基路面施工技术是其中的重点内容,是保障道路桥梁施工安全、可靠的关键。本文主要阐述了道路桥梁路基路面出现沉降现象会造成的危害,分析研究影响油田道路桥梁施工出现沉降的主要因素,介绍了油田道路桥梁沉降段路基路面的施工技术要点,促进道路桥梁工程更加安全、优质的服务。     

高速公路工程施工中软基处理关键技术分析

在高速公路施工中若不能有效对软土路基进行处理,将直接导致工程建设进度的延缓,为高速公路建设产生负面影响.高速公路施工过程中,软土路基施工量约为高速公路工程施工的三分之一,所以必须合理分析软基处理关键技术,以优化高速公路工程施工效果.     

路基施工技术分析及特殊路基处理探讨

路基作为道路结构的承重基础,它的施工质量决定道路的使用年限、维修费用等。本文先对路基施工技术进行分析,然后探讨了一些特殊路基的处理。     

盐渍土地区地基处理及基础防腐应用策略

对于盐渍土地区进行房屋工程建设,土壤能够对工程建设效果产生一定影响,特别是地基防腐在其中占据重要地位.本文通过对盐渍土对于房屋建筑的危害进行分析,并阐述盐渍土地区地基处理及基础防腐应用策略,以供参考.     

探地雷达在公路路基路面检测中的应用

简述了探地雷达检测公路路基路面厚度的基本原理和检测方法。应用美国GSSI公司TerraSIRchSIR-3000探地雷达系统,对连霍高速公路三门峡段路基路面厚度进行了无损检测。计算得出公路路基路面各检测层的平均厚度和标准差,同时通过探地雷达交互式解释方法可以绘制连续清晰的厚度曲线图,有利于探地雷达厚度检测成果的进一步精细解释。     

软基加固施工技术在道路施工中的应用

针对软土地基的主要特点和道路建设施工要求,介绍了几种在软土路基建设工程中的加固施工技术,并简要的分析了这几种方法在道路施工中的的结构特点、应用环境及主要技术使用条件,同时也考虑到道路地基处理风险,并根据此应用方法对于目前各地区项目施工提出新的发展方向。     

路基压缩强度的剪切波速评价

为了保证路基的施工质量,以水泥改良粉土、粉质黏土为研究对象,通过室内三轴剪切和波速检测试验,研究了影响路基压缩强度与剪切波速的因素,证明了剪切波速与路基压缩强度的相关性,为路基品质检测提供了技术依据。研究发现:一定试验条件下路基压缩强度与剪切波速变化规律基本一致,压缩强度及剪切波速随水泥剂量、龄期的增加逐渐提高;当黏粒含量范围为18%～22%时,改良土强度及波速较大。研究结果为路基的品质检测提供了技术依据。     

Approach to identify cracking in asphalt pavement using GPR and infrared thermographic methods: Preliminary findings

Pavement condition is a factor of major interest due to its direct contribution to safety and comfort of the users of the road. Consequently, road inspections imply the evaluation of different parameters such as roughness of the pavement, skid resistance, and presence and condition of cracks. Although the first two parameters can be quantitatively evaluated with different sensors, the latter is usually only qualitatively assessed by visual inspection. This paper deals with this drawback through the combined application of Ground Penetrating Radar and Infrared Thermography to the detection and characterization of cracks in pavement and their origins.     

Non-invasive moisture monitoring within an earth embankment — a precursor to failure

An experimental monitoring system is described using electrical resistivity as a proxy for imaging changing moisture content distribution in engineered earthworks. The approach is illustrated using a case history concerning a road embankment constructed of tropical red soil in western Kenya.Tropical red soils have highly variable properties, governed by their soil fabric and mineralogy. As earthworks materials, their geotechnical behaviour is extremely sensitive to changes in moisture content and compaction. The relationship between moisture content and electrical resistivity was established in the laboratory on core obtained using a monitored drilling and sampling technique.The non-invasive nature of electrical resistivity surveys was exploited in the design of a monitoring system placed below the pavement in the topmost layers of compacted soil. Monitoring over a period of 18 months is reported, starting prior to the construction of the pavement following the completion of soil compaction. Initially substantial variability in moisture content was inferred from surface monitoring, and even larger changes were seen in corresponding downhole measurements.The moisture content within the body of the embankment stabilised after six months, while a moist layer ‘trapped’ beneath the pavement dissipated over the following 10 months. Two surveys were undertaken during the ‘December rains’; they showed large changes in moisture content had occurred quickly in the surface layers on one side of the embankment. This area subsequently failed as a small landslip and was remediated by additional drainage.     

处于盐渍土和盐湖环境下建筑物的腐蚀与防护现状

盐湖水和盐渍土环境下的腐蚀问题包含有氯离子对钢的腐蚀,还包含硫酸根离子和镁离子对混凝土结构的破坏。本文介绍了中国盐湖和盐渍土区域分布情况,盐湖水和盐渍土对结构物的腐蚀特征和腐蚀造成的危害,综述了目前国内防治盐湖水和盐渍土腐蚀的措施现状以及理论研究现状。情况表明,需要继续对盐渍土和盐湖地区的结构物的腐蚀与防护开展深入的研究。     

Relating tensile, bending, and shear test data of asphalt binders to pavement performance

Eight different asphalt binders representing a wide range of applications for pavement construction were tested in uniaxial tension, bending, and shear stresses. Theoretical analyses were performed in this study to convert the data from the three engineering tests to stiffness moduli for predicting pavement performance. At low temperatures, high asphalt stiffness may induce pavement thermal cracking; thus, the allowable maximum stiffness was set at 1,000 MPa. At high temperatures, low asphalt stiffness may lead to pavement rutting (ruts in the road); master curves were constructed to rank the potential for rutting in the asphalts. All three viscoelastic functions were shown to be interchangeable within the linear viscoelastic region. When subjected to large deformation in the direct tension test, asphalt binders behaved nonlinear viscoelastic in which the data under bending, shear and tension modes were not comparable. The asphalts were, however, found to exhibit linear viscoelasticity up to the failure point in the steady-state strain region.     

Validation of mobile LiDAR surveying for measuring pavement layer thicknesses and volumes

Mobile LiDAR surveying is currently one of the most popular topics in road inspections. This non-destructive technology is suitable for collecting infrastructure inspection data related to 3D geometry and radiometry. Ground penetrating radar (GPR) is traditionally used to measure pavement thickness, though this technique requires reference data (cores) when surveying in a ground-coupled configuration.Within this work, a new alternative method to GPR has been studied for determining pavement layer thicknesses and volumes. We analyze the performance of mobile LiDAR technology in this scope and test its accuracy compared to the results obtained with a ground-coupled 2.3-GHz GPR antenna. The findings presented here are based on field data collected from the Ourense–Celanova highway, in Northwestern Galicia. The results showed the potential of the Lynx Mobile Mapper to obtain the designed pavement thickness of newly constructed roadways with errors that are always less than 1.5 cm.     

路面铣刨机用聚晶金刚石截齿头的研制

采用纳米结合剂梯度过渡层连接技术,在六面顶压机上合成路面铣刨机用聚晶金刚石截齿头。采用砂轮修整和落锤冲击的方法进行耐磨性、抗冲击性和耐热性等3方面的测试。结果表明:所合成的聚晶金刚石截齿头磨耗比大于25万,抗冲击韧性为1220 J;在750℃保温1.5h的条件下,具有很好的热稳定性;制成的路面铣刨机截齿,在铣刨沥青混凝土路面时,使用寿命是硬质合金截齿的6倍。      

岩溶隧道涌突水灾害源类型及灾害防治分析

近年来,我国交通基础建设逐步向地质条件复杂的西部岩溶地区发展.在岩溶地区隧道施工期间,由于工程地质条件的复杂性和外在因素的扰动,极易诱发涌突水等地质灾害.本文通过分析岩溶隧道的突涌水灾害案例,从灾害源的角度将突涌水灾害划分为裂隙型、管道型、溶洞型、其他型4种类型,并对每种涌突水灾害提出了具体的灾害防治措施.     

Determination of the Test Methods Sensitive to Free Mica Content in Aggregate Fine Fractions

The detrimental influence of mica rich aggregates on structural deterioration of road pavement has been discussed in the literature for over a half century. This negative effect is of great importance especially for regions with crystalline, mica-rich bedrock and temperate, subarctic climates. Recent investigations reveal that elevated fractions of free mica particles in unbound granular materials, used in road constructions, greatly reduce bearing capacity and influence the hydraulic behavior of the road structure. Despite the awareness of mica’s potential harmful effect, the absence of properly adapted analytical methods is noticeable. The scope of the current study was to test two possible analytical methods which, are susceptible to mica content and could be used as an indicating technique for quantitative determination of free mica particles in unbound granular materials. Two standard methods: Sand equivalent test and methylene blue (MB) test were assumed as the most sensitive to mica presence. The rock samples used in the tests are representative for the common crushed rock aggregates for construction purposes with different contents of mica. Both methods showed susceptibility to mica content and gave strong correlation in terms of mica content. The result of the MB test can be explained by the schistose structure of mica particles and the ability of mica to absorb liquids. Another important explanation is the increased reaction surface of mica particles, which leads to an increase in the total reaction surface of the sample. The receptiveness of the sand equivalent test to mica content could be caused by the ability of mica to stay in suspension due to its flake-shaped grains.