路桥毕业设计外文翻译--浅析公路路基边坡防护
软土路基外文翻译--论公路路基施工技术
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论公路路基施工技术1引言公路路基施工是整个公路施工工程的关键所在，稍有偏差，将给整个工程埋下质量隐患。
例如，在公路施工中常会遇到诸如软土路基，黄土路基等不良路基，如不加以特别处理，会引起填方路堤施工后沉降或不均匀沉陷，路面纵横坡变碎，平整度下降，导致行车颠簸等，严重影响公路的正常使用，造成大量的人力、物力、财力浪费。
因此，路基施工应根据施工当地地形、地质状况、公路等级、所在地区的气候、结合施工填挖方平衡等来选择施工方法。
2路基填压公路路基的强度和稳定性很大程度取决于路基填料的性质及其压实的程度。
从现有条件出发，改进填土要求和压实条件是保证路基质量经济有效的方法。
2.1路基填料现行《公路路基设计规范》（以下简称规范）规定了对路基填料的要求。
对路基填料的最小强度和最大粒径给了量化的标准，采用承载比实验（CBR）值表征路基土的强度，引入了路床的概念。
对上路床的填料提出了限制条件，高速公路和一级公路路面底以下0cm-30cm的路床填料，其CBR值应大于8，对下路床及下面的填土也给出相应的规定值。
2.2路基压实当前路基施工，普遍采用了大吨位的压路机，碾压效果有了明显的改善。
对于提高路基土的压实度起了很好的作用。
规范规定高速公路和一级公路路面底面以下80cm－150cm部分的上路堤其压实度必须≥95％，对其它等级公路当铺筑高级路面时，其压实度亦应按高速公路和一级公路的标准采用。
浅析公路施工中的边坡防护技术
浅析公路施工中的边坡防护技术摘要：公路施工中的边坡防护技术是公路防护技术的重要组成部分，也是公路防护中的难点技术。
从公路养护和人民群众的切身利益出发，都应该加强公路施工中的边坡防护技术研究。
本文试从对于道路的边坡防护形式、边坡防护和加固要点及主要施工工艺、道路边坡防护设计稳定性的基本原则等三个方面论述公路施工中的边坡防护技术。
关键词：道路施工边坡防护技术探析Abstract: highway slope protection technology is an important component of the road protection and also the difficulty in the technology. From the highway maintenance and the vital interests of the people set out, should strengthen the construction of highway slope protection technology research. This paper tries to road slope protection form of side slope protection and reinforcement points and main construction technology, road slope protection design stability of the basic principles and so on three aspects in the construction of highway slope protection technology.Keywords: road construction slope protection technology in this paper1.道路边坡防护的基本形式1.1关于浆砌片石护坡浆砌片石护坡是工程中坡面防护应用最多的方法，主要有片石护坡和片石护面墙两种方式。
浅议高速公路路基边坡植物防护
浅议高速公路路基边坡植物防护摘要：本文结合工作实际，介绍了高速公路路基边坡植物防护的功能与特点，并就当前边坡植物防护技术进行了简要的分析与探讨。
关键字：高速公路；边坡；植物防护Shallow discussion freeway roadbed slope plant protectionShangZhiLin hangzhou yuhang district people's government star bridge street office 311199Pick to: this paper according to the practice, this paper introduces the highway subgrade slope protection function and characteristics of the plants, the slope plant protection technology isbriefly analysed and discussed.Key word: highways; and Slope; Plant protection前言：近年来，随着我国经济的发展和城市化进程的加快，高速公路作为一种现代化的公路运输通道在当今社会经济体系中正发挥这越来越重要的作用。
截止2012年初，我国高速公路总里程已达8.5万公里，在近几十年中取得了辉煌的成绩。
然而与此同时，高速公路在建设过程中不仅较大的破坏了原有植被，还导致了大量山体和地面裸露，给自然环境带来了灾难和隐患。
高速公路路基边坡的植物防护工作，能最大化的减少水土流失和生态破坏，并保护和美化了环境。
一、高速公路边坡防护常用措施对高速公路边坡的防护，主要是保护路基边坡的表面能免受日照、降水、风力和温度等自然因素的破坏，从而提高边坡的稳定性，在我国高速公路建设中受到了广泛的重视与应用。
边坡防护常用的措施包括了工程防护和植物防护两大类。
公路路基的边坡防护技术浅析
公路路基的边坡防护技术浅析作为国民经济与社会发展的重要基础设施，公路事业在改革开放后也得到了极大的发展。
路基边坡防护施工作为公路工程建设的重要组成部分，其技术水平的高低将直接影响到公路工程的整体质量，甚至影响到公路事业的可持续发展。
为此，在公路工程建设中相关部门及施工单位必须重视路基边坡防护施工，做好施工准备工作，采取科学有效的措施，有效提升施工质量，实现公路建设的社会效益与经济效益。
一、路基边坡防治的概况为保证路基稳定，在路基两侧做成的具有一定坡度的坡面叫边坡。
边坡受到破坏与路基使用的填料有着明显的关系。
砂性的路基比粘性的路基更容易受到雨水的冲刷破坏。
高处的路基比地处的路基更容易受到流水冲刷。
压实的路基要比压实轻的路基更加耐冲刷。
路基边坡出现坍塌现象主要表现在砂石的滑动、落石以及流动性的坍塌。
这三种情况可以单独出现同时也能够共同发生。
二、二、公路路基边坡防护施工技术的应用1、生物防护生物防护大致可分为三种类型：植树防护、植草防护和覆盖草皮防护。
其中，植树主要用于下边坡，属传统生物防护形式；而植草或覆盖草皮防护是近年来在高速公路上才兴起的两种绿色防护形式。
其优点是能在短期内恢复公路沿线的绿色景观和防止边坡冲刷，但养护费用高，要随时保持绿色有一定困难，不适宜用于上边坡以及荒山野外的高速公路的防护工程。
（1）挂网客土喷播防护在进行坡面排水问题处理时，应考虑的问题有坡面径流和涌水。
在坡面上设置一定量的泄水管，可以将涌水引至坡底；在坡面上设置好平台排水设施，将水从坡面的两边排出，也可将水引至坡底。
对于坡面上存在的植物，如果没有对施工造成妨碍，应进行适当的保留。
坡面应保证有一定的粗糙度，为此可以在坡面上修造一些凹凸粗糙面，这样可以使植物顺利地在上面生长，起到吸附基材，防止基材流失的作用。
在进行喷射施工时，应自上而下对坡面进行喷射，喷口应尽量与坡面保持垂直，距离控制在0.8～1m之间，各处喷射厚度保持均匀。
道路路面毕业设计外文翻译
毕业论文（外文翻译）（2012届）学院名称土木与水利工程学院专业（班级）土木工程七班姓名（学号）李小润（20083650）指导教师扈惠敏系（教研室）负责人方诗圣PavementHighway pavements are divided into two main categories: rigitand flexible.The wearing surfaceof a rigid pavement is usually constructed of Portland cement concrete such that it acts like a beam over any irregularities in the underlying supporting material.The wearing surface of flexible pavements, on the other hand, is usually constructed of bituminous material such that they remain in contact with the underlying material even when minor irregularities occur.Flexible pavements usually consist of a bituminous surface underlaid with a layer of granular material and a layer of a suitable mixture of coarse and fine materials.Coarse aggregatesFine aggregatesTraffic loads are transferred by the wearing surface to the underlying supporting materials through the interlocking of aggregates, the frictionaleffect of the granular materials, and the cohesion of the fine materials.Flexible pavements are further divided into three subgroups: high type, intermediate type, and low type. High-type pavements have wearing surfaces that adequately support the expected traffic load without visible distress due to fatigue and are not susceptible to weather conditions.Intermediate-type pavements have wearing surfaces that range from surface treated to those with qualities just below that of high-type pavements. Low-type pavements are used mainly for low-cost roads and have wearing surfaces that range from untreated to loose natural materials to surface-treated earth.✹The components of a flexible pavement include the subgradeor prepared roadbed, the subbase, basecourse, and the surface course (Fig.11.1).✹Upper surface courseMiddle surface courseLower surface courseThe performance of the pavement depends on the satisfactory performance of each component, which requires proper evaluation of the properties of each component separately.✹The subgrade is usually the natural material located along the horizontal alignment of the pavement and serves as the foundation of the pavement structure.✹The subgrademay also consist of a layer of selected borrow materials, well compacted to prescribedspecifications.✹Compacting plantCompaction deviceCompactnessIt may be necessary to treat the subgrade material to achieve certain strength properties required for the type of pavement being constructed.Located immediately above the subgrade, the subbase component consists of a superior quality to that which generally is used for subgrade construction. The requirements for subbase materials are usually given in terms of the gradation, plastic characteristics, and strength. When the quality of the subgrade material meets the requirements of the subbase material, the subbase component may be omitted.In cases where suitable subbase material is not readily available ,the available material can be treated with other materials to achieve the necessary properties. This process of treating soils to improve their engineering properties is know as stabilization.✹The base course lies immediately above the subbase. It is placed immediately above the subgrade if a subbase course is not used.✹This course usually consists of granular materials such as crushed stone, crushed or uncrushed.The specifications for base course materials usually include stricter requirements than those for subbase materials, particularly with respect to their plasticity, gradation, and strength.Materials that do not have the required properties can be used as base materials if they are properly stabilized with Portland cement, asphalt, or lime .In some cases, high-quality base course materials may also be treated with asphalt or Portland cement to improve the stiffness characteristics of heavy-duty pavementsThe surface course is the upper course of the road pavement and is constructed immediately above the base course. The surface course in flexible pavement usually consists of a mixture of mineral aggregates and asphaltic materials.It should be capable of withstanding high tire pressures, resisting the abrasive forces due to traffic, providing a skid-resistant driving surface, and preventing the penetration of surface water into the underlying layers.✹The thickness of the wearing surface can vary from 3 in. to more than 6 in.（inch，英寸，2.54cm）, depending on the expected traffic on the pavement.It was shown that the quality of the surface course of a flexible pavement depends on the mix design of the asphalt concrete used.✹Rigid highway pavements usually are constructed to carry heavy traffic loads, although they have been used for residential and local roads. Properly designed and constructed rigid pavements have long service lives and usually are less expensive to maintain than the flexible pavements.✹The Portland cement concrete commonly used for rigid pavements consists of Portland cement, coarse aggregate, fine aggregate, and water. Steel reinforcing rods may or may not be used, depending on the type of pavement being constructed.Rigid highway pavements be divided into three general type: plain concrete pavements, simply reinforced concrete pavements, and continuously reinforced concrete pavement. The definition of each pavement type is related to the amount of reinforcement used.Plain concrete pavement has no temperature steel or dowels for load transfer.However, steel tie bars are often used to provide a hingeeffect at longitudinal joints and to prevent the opening of these joints. Plain concrete pavements are used mainly on low-volume highways or when cement-stabilized soils are used as subbase.Joints are placed at relatively shorter distances (10 to 20 ft) than with the other types of concrete pavements to reduce the amount of cracking.In some case, the transverse joints of plain concrete pavements are skewed about 4 to 5 ft in plan, such that only one wheel of a vehicle passes through the joint at a time. This helps to provide a smoother ride.Simply reinforced concrete pavements have dowels for the transfer of traffic loads across joints, with these joints spaced at larger distances, ranging from 30 to 100 ft. Temperature steel is used throughout the slab, with the amount dependent on the length of the slab. Tie bars are also commonly used in longitudinal joints.Continuously reinforced concrete pavements have no transverse joints, except construction joints or expansion joints when they are necessary at specific positions, such as at bridges.These pavements have a relatively high percentage of steel, with the minimum usually at 0.6 percent of the cross section of the slab. They also contain tie bars across the longitudinal joints.h/2h/25~10cm填缝料 横向施工缝构造填缝料平缝加拉杆型Bituminous Surface CoursesThe bituminous surface course has to provide resistance to the effects of repeated loading by tyres and to the effects of the environment.✹In addition, it must offer adequate skid resistance in wet weather as well as comfortable vehicle ride. It must also be resistant to rutting and to cracking.✹It is also desirable that surface course is impermeable, except in the case of porous asphalt.Hot rolled asphalt (HRA) is a gapgraded material with less coarse aggregate. In fact it is essentially a bitumen/fine aggregate/filler mortar into which some coarse aggregate is placed.The mechanical propertiesare dominated by those of the mortar. This material has been extensively used as the wearing course on major road in the UK, though its use has recently declined as new materials have been introduced.✹It provides a durablelayer with good resistance to cracking and one which is relatively easy to compact. The coarse aggregate content is low (typically 30%) which results in the compacted mixture having a smooth surface. Accordingly, the skid resistance is inadequate and precoated chippings are rolled into the surface at the time of laying to correct this deficiency.In Scotland, HRA wearing course remains the preferred wearing course on trunk roads including motorway but，since 1999 thin surfacings have been the preferred option in England and Wales. Since 1999 in Northern Ireland, HRA wearing course and thin surfacings are the preferred permitted options.Porous asphalt (PA) is a uniformly graded material which is designed to provide large air voids so that water can drain to the verges within the layer thickness. If the wearing course is to be effective, the basecourse below must be waterproof and the PA must have the ability to retain its open textured properties with time.Thick binder films are required to resist water damage and ageing of the binder. In use, this material minimizes vehicle spray, provides a quiet ride and lower rolling resistance to traffic than dense mixtures.✹It is often specified for environmental reasons but stone mastic asphalt (SMA) and special thin surfacings are generally favoured in current UK practice.There have been high profile instances where a PA wearing course has failed early in its life. The Highways Agency does not recommend the use of a PA at traffic levels above 6000 commercial vehicles per day.✹Asphaltic concrete and dense bitumen macadam (DBM) are continuously graded mixtures similar in principle to the DBMs used in roadbases and basecourses but with smaller maximum particle sizes. Asphaltic concrete tends to have a slightlydenser grading and is used for road surfaces throughout the world with the excepting of the UK.✹It is more difficult to meet UK skid resistance Standards with DBMs than HRA, SMA or PA. This problem can be resolves by providing a separate surface treatment but doing so generally makes DBM economically unattractive.✹Stone mastic asphalt (SMA) material was pioneeredin Germany and Scandinavia and is now widely used in the UK. SMA has a coarse, aggregrate skeleton, like PA, but the voids are filled with a fine aggregate/filler /bitumen mortar.✹In mixtures using penetration grade bitumen , fibres are added to hold the bitumen within the mixture (to prevent “binder drainage”).Bitumen✹oil bitumen( earth oil)✹natural bitumen✹TarWhere a polymer modified bitumen is used, there is generally no need for fibres. SMA is a gap-graded material with good resistance to rutting and high durability. modified bitumen✹SBS✹SBR✹PE\EV A✹It differs from HRA in that the mortar is designed to just fill the voids in the coarse aggregate whereas, in HRA, coarse aggregate is introduced into the mortar and does not provide a continous stone matrix. The higher stone content HRAs ,however, are rather similar to SMA but are not wide used as wearing courses in the UK, being preferred for roadbase and basecourse construction.A variety of thin and what were called ultra thin surfacings (nowadays, the tendency is to use the term ‘thin surfacings’ for both thin and ultra thin surfacings ) have been introduced in recent years, principally as a result of development work concentrated in France.These materials vary in their detailed constituents but usually have an aggregate grading similar to SMA and often incorporate a polymer modified bitumen.They may be used over a high stiffness roadbase and basecourse or used for resurfacing of existing pavements. For heavy duty pavements (i .e those designed to have a useful life of forty years), the maintenance philosophy is one of minimum lane occupancy, which only allows time for replacement of the wearing course to these ‘long life’ pavement structures. The new generation of th in surfacings allows this to be conveniently achieved.The various generic mixture types described above can be compared with respect to their mechanical properties and durability characteristics by reference to Fig.12.1. This shows, in principle, how low stone content HRA, asphaltic concrete, SMA and PA mixtures mobilize resistance to loading by traffic.Asphaltic concrete (Fig.12.1a)) presents something of a compromise when well designed, since the dense aggregate grading can offer good resistance to the shear stresses which cause rutting, while an adequate binder content will provide reasonable resistance to the tensile stresses which cause cracking.In general, the role of the aggregate dominates. DBMs tend to have less dense gradings and properties which, therefore, tend towards good rutting resistance andaway from good crack resistance.HRA (Fig.12.1b)) offers particularly good resistance to cracking through the binder rich mortar between the coarse aggregate particles. This also provides good durability but the lack of coarse aggregate content inhibits resistance to rutting.SMA and PA are shown in the same diagram ( Fig.c)) to emphasis the dominant role the coarse aggregate. In both case, well coated stone is used. In PA, the void space remains available for drainage of water, whilst in SMA, the space is occupied by a fine aggregate/ filler/ bitumen/ fibre mortar.Both materials offer good rutting resistance through the coarse aggregate content. The tensile strength of PA is low whilst that of SMA is probably adequate but little mechanical testing data have been reported to date.Drainage for Road and Airports✹Provision of adequate drainage is important factor in the location and geometric design of road and airports. Drainage facilities on any highway, street and airport should adequately provide for the flow of water away from the surface of the pavement to properly designed channels.Inadequate drainage will eventually result in serious damage to the structure.✹In addition, traffic may be slowed by accumulated water on the pavement, and accidents may occur as a result of hydroplaning and loss of visibility from splash and spray. The importance of adequate drainage is recognized in the amount of highway construction dollars allocated to drainage facilities. About25 percent of highway construction dollars are spent for erosion control anddrainage structures, such as culverts, bridges, channels, and ditches.✹Highway Drainage Structures✹One of the main concerns of the highway engineer is to provide an adequate size structure, such that the waterway opening is sufficiently large to discharge the expected flow of water.Inadequately sized structures can result in water impounding, which may lead to failure of the adjacent sections of the highway due to embankments being submerged in water for long periods.✹The two general categories of drainage structures are major and minor. Major structures are those with clear spans greater than 20 feet, whereas minor structures are those with clear spans of 20 feet or less .✹Major structures are usually large bridges, although multiple-span culverts may also be included in this class. Minor structures include small bridges and culverts.Emphasis is placed on selecting the span and vertical clearancerequirements for major structures. The bridge deck should be located above the high water mark .The clearance above the high water mark depends on whether the waterway is navigable ✹If the waterway is navigable, the clearance above the high water mark should allow the largest ship using the channel to pass underneath the bridge without colliding with the bridge deck. The clearance height, type, and spacing of piers also depend on the probability of ice jams and the extentto which floating logs and debris appear on the waterway during high water.✹An examination of the banks on either side of the waterway will indicate the location of the high water mark, since this is usually associated with signs of erosion and debris deposits. Local residents, who have lived near and observed the waterway during flood stages over a number of years, can also give reliable information on the location of the high water mark. Stream gauges that have been installed in the waterway for many years can also provide data that can be used to locate the high water mark.Minor structures, consisting of short-span bridges and culverts, are the predominant type of drainage structures on highways. Although openings for these structures are not designed to be adequate for the worst flood conditions, they shouldbe large enough to accommodate the flow conditions that might occur during the normal life expectancy of the structure.✹Provision should also be made for preventing clogging of the structure due to floating debris and large boulders rolling from the banks of steep channels.✹Culverts are made of different materials and in different shapes. Materials used to construct culverts include concrete（reinforced and unreinforced）, corrugated steel, and corrugatedaluminum. Other materials may also be used to line the interiorof the culvert to prevent corrosion and abrasionor to reduce hydraulic resistance. For example, asphaltic concrete may be used to line corrugated metal culverts. The different shapes normally used in culvert construction include circular, rectangular (box), elliptical, pipe arch, metal box, and arch.✹The drainage problem is increased in these areas primarily for two reasons: the impervious nature of the area creates a very high runoff; and there is little room for natural water courses. It is often necessary to collect the entire storm water into a system of pipes and transmit it over considerable distances before it can be loosed again as surface runoff. This collection and transmission further increase the problem, since all of the water must be collected with virtually no pending, thus eliminating any natural storage; and through increased velocity the peak runoffs are reached more quickly.Also, the shorter times of peaks cause the system to be more sensitive to short-duration,high intensive rainfall.Storm sewers,like culverts and bridges,are designed for storms of various intensity-return-period relationships, depending upon the economy and amount of ponding that can be tolerated.✹Airport Drainage✹The problem of providing proper drainage facilities for airports is similar in many ways to that of highways and streets. However, because of the large and relatively flat surface involved, the varying soil conditions, the absence of natural water courses and possible side ditches, and the greater concentration of discharge at the terminus of the construction area, some phases of the problem are more complex. For the average airport the over-all area to be drained is relatively large and an extensive drainage system is required. The magnitude of such a system makes it even more imperative that sound engineering principles based on all of the best available data be used to ensure the most economical design.Overdesigning of facilities results in excessive money investment with no return, and underdesigning can result in conditions hazardous to the air traffic using the airport. In order to ensure surfaces that are smooth, firm, stable, and reasonably free from flooding, it is necessary to provide a system which will do several things.It must collect and remove the surface water from the airport surfaces; intercept and remove surface water flowing toward the airport from adjacent areas; collect and remove any excessive subsurface water beneath the surface of the airport facilities and in many cases lower the ground-water table; and provide protection against erosion of the sloping areas.路面公路的路面被分为两类：刚性的和柔性的。
浅谈公路路基边坡防护应遵守的几项原则
浅谈公路路基边坡防护应遵守的几项原则Introduction to highway subgrade slope protection shall comply with the principles 随着我国公路建立迅猛开展，对公路路基的防护显得越来越重要。
路基在水、风、冰冻等自然要素的长期作用下，经常发作边坡的表土剥落和构成冲沟曾经滑塌等变形和毁坏，下面简单引见一下在公路路基边坡防护上的一些观念。
Along with our country highway to establish rapid, of highway subgrade protection is more and more important. Subgrade in the natural elements such as water, wind, frost, under the long-term effects of often attack constitute gully slope surface soil peeling off and once the deformation and damage, so as the following simple introduce you some ideas on highway subgrade slope protection.公路路基边坡防护应恪守以下准绳：Highway subgrade slope protection should abide by the following criterion:“综合设计、因地制宜、以防为主、确保施工”是边坡综合防护设计的根本准绳。
（2）路基防护应依照设计、施工与养护相分离的准绳，深化调查研讨，依据当地气候环境、工程地质和资料等状况，量体裁衣因地制宜，选用恰当的工程类型或采取综合措施，以保证路基的稳定。
不要随便取消或减少必要的防护工程措施，而给养护遗留繁重的工作量。
二级公路毕业设计外文文献
外文资料及翻译Effects of Design Features on Rigid Pavement PerformanceThe performance of rigid pavements is affected by a variety of design features, including slab thickness, base type, joint spacing, reinforcement, joint orientation, load trans fer, dowel bar coatings, longitudinal joint design, joint sealant, tied concrete shoulders ,and subdrainage . A study was made by ERES Consultants, Inc. under FHWA contract on the effects of these features on rigid pavement performance . Ninety-five pavemen tsections located in four major climatic regions were thoroughly evaluated . The following conclusions, which provide some revealing insights into pavement performance, are abstracted from the report (Smith et al., 1990a).Slab Thickness The effect of slab thickness on pavement performance was significant.It was found that increasing slab thickness reduced transverse and longitudinal cracking in all cases. This effect was much more pronounced for thinner slabs than fo rthicker slabs . It was not possible to compare the performance of the thinner slabs and the thicker slabs directly, because the thick slabs were all constructed directly on th esubgrade and the thinner slabs were all constructed on a base course .Increasing the thickness of slab did not appear to reduce joint spalling or join tfaulting . Thick slabs placed directly on the subgrade, especially in wet climates an dexposed to heavy traffic, faulted as much as thin slabs constructed on a base course .Base Type Base types, including base/slab interface friction, base stiffness, base erodibility, and base permeability, seemed to have a great effect on the performance of jointed concrete pavements . The major performance indicators, which were affected by variations in base type, were transverse and longitudinal cracking, joint spalling, and faulting .The worst performing base type, consisted of the cement-treated or soil cement bases, which tended to exhibit excessive pumping, faulting, and cracking. This is most likely due to the impervious nature of the base, which traps moisture and yet can brea- k down and contribute to the movement of fines beneath the slab .The use of lean concrete bases generally produced poor performance . Large curl -ing and warping stresses have been associated with slabs constructed over lean concrete bases. These stresses result in considerable transverse and longitudinal cracking of the slab . The poor performance of these bases can also be attributed to a bathtub design, in which moisture is trapped within the pavement cross section .Dense-graded asphalt-treated base courses ranged in performance from very poor to good. The fact that these types of bases were often constructed as a bathtub design contributed to their poor performance . This improper design often resulted in severe cracking, faulting, and pumping.The construction of thicker slabs directly on the subgrade with no base resulted In a pavement that performed marginally. These pavements were especially susceptible to faulting, even under low traffic levels.Pavements constructed over aggregate bases had varied performance, but were generally in the fair to very good category. In general, the more open-graded the aggregate,the better the performance . An advantage of aggregate bases is that they contribute the least to the high curling and warping stresses in the slab . Even though aggregate bases are not open-graded, they are more permeable and have a lower friction factor than stabilized bases .The best bases in terms of pavement performance were the permeable bases . Typical base courses have permeabilities ranging from 0 to less than 1 ft/day (0 .3 m/day) ; good permeable bases have permeabilities up to 1000 ft/day (305 m/day) . Specific areas of concern were the high corner deflections and the low load transfer exhibited by the permeable bases . These can affect their long-term performance, so the use of dowel bars might be required . An unexpected benefit of using permeable bases was the reduction in "D" cracking on pavements susceptible to this type of distress .Slab Length For JPCP, the length of slabs investigated ranged from 7 .75 to 30 ft(2.4to9.1m). It was found that reducing the slab length decreased both the magnitude of the joint faulting and the amount of transverse cracking. On pavements with random joint spacings, slabs with joint spacings greater than 18 ft (5.5 m) experienced more transverse cracking than did the shorter slabs .For JRCP, the length of slabs investigated ranged from 21 to 78 ft (6 .4 to 23 .9 m) .Generally, shorter joint spacings performed better, as measured by the deteriorated transverse cracks, joint faulting, and joint spalling . However, several JRCP with long joint spacings performed quite well . In particular, the long jointed pavements in New Jersey, which were constructed with expansion joints, displayed excellent performance .An examination of the stiffness of foundation was made through the use of the radius of relative stiffness, f . Generally speaking, when the ratio L/E, where L is the length of slab, was greater than 5, transverse cracking occurred more frequently . Thisfactor was further examined for different base types . It was found that stiffer base courses required shorter joint spacings to reduce or eliminate transverse cracking .Reinforcement The amount of steel reinforcement appeared to have an effect in controlling the amount of deteriorated transverse cracking . Pavement sections with less than 0.1% reinforcing steel often displayed significant deteriorated transverse cracking.A minimum of 0 .1% reinforcing steel is therefore recommended, with larger amounts required for more severe climate and longer slabs.Joint Orientation Conventional wisdom has it that skewed joints prevent the application of two wheel loads to the joint at the same time and thus can reduce load-associated distresses . The results from the limited sample size in this study were ambiguous, but all of the nondoweled sections with skewed joints had a lower PSR than similar designs with perpendicular joints . The available data provide no definite conclusions on the effectiveness of skewing transverse joints for nondoweled slabs . Skewed joints are not believed to provide any benefit to doweled slabs.Load Transfer Dowel bars were found to be effective in reducing the amount of joint faulting when compared with nondoweled sections of comparable designs. The diameter of dowels had an effect on performance, because larger diameter bars provided better load transfer and control of faulting under heavy traffic than did smaller dowels.It appeared that a minimum dowel diameter of 1 .25 in . (32 mm) was necessary to provide good performance .Nondoweled JPCP slabs generally developed significant faulting, regardless of pavement design or climate . This effect was somewhat mitigated by the use of permeable bases. However, the sections in this group had a much lower number of accumulated ESAL, so no definite conclusions can be drawn yet .Dowel Bar Coatings Corrosion-resistant coatings are needed to protect dowels from the adverse effects of moisture and deicing chemicals .While most of the sections in this study did not contain corrosion-resistant dowel bars, those that did generally exhibited enhanced performance. Very little deteriorated transverse cracking was identified on these sections. In fact, one section in New Jersey with stainless steel-clad dowel bars was performing satisfactorily after 36 years of service .Longitudinal Joint Design The longitudinal joint design was found to be a critical design element.Both inadequate forming techniques and insufficient depths of joint can contribute to the development of longitudinal cracking . There was evidence of the ad vantage of sawing the joints over the use of inserts . The depth of longitudinal joints is generally recommended to be one-third of the actual, notdesigned, slab thickness, but might have to be greater when stabilized bases are used .Joint Sealant Joint sealing appeared to have a beneficial effect on performance . This was particularly true in harsh climates with excessive amounts of moisture . Preformed compression sealants were shown to perform well for more than 15 years under heavy traffic.Except where "D" cracking occurred, pavement sections containing preformed sealants generally exhibited little joint spalling and were in good overall conditions.Rubberized asphalt joint sealants showed good performance for 5 to 7 years.Tied Concrete Shoulders It is generally believed that tied concrete shoulders can reduce edge stresses and corner deflections by providing more lateral supports to the mainline pavement, thus improving pavement performance . Surprisingly, this study showed that, although tied concrete shoulders performed better than asphalt shoulders,many of the tied shoulders were not designed properly and actually contributed to poor performance of the mainline pavement . The tiebars were spaced too far apart ,sometimes at a spacing of 40 in.(1016 mm), and were not strategically located near slab corners to provide adequate support . In some cases, tied concrete shoulders were constructed over a stabilized dense-graded base in a bathtub design, resulting in the poor performance of mainline pavement.Subdrainage The provision of positive subdrainage, either in the form of longitudinal edge drains or the combination of a drainage layer and edge drains, generally reduced the amount of faulting and spalling related to "D" cracking . With few exceptions, the load-associated distresses, especially faulting and transverse cracking, decreased as the drainage characteristics improved . The overall pavement performance can be improved by using an open-graded base or restricting the percentage of fines . A filter layer must be placed below the permeable base, and regular maintenance of the outlets must be provided .译文结构特点对刚性路面性能的影响刚性路面的性能受种种结构特点的影响，如板厚、基层类型、接缝间距、钢筋用量、接风方向、荷载传递、传力杆涂层、纵缝设计、接缝填封料、有拉杆混凝土道肩和地下排水等。
公路路基边坡防护
浅谈公路路基边坡防护摘要：近年来，我国的交通运输业得到了迅速发展，高速公路建设作为公路交通的现代化主要标志，也取得了很大的成就。
路基是公路的重要组成部分，它的稳定性是保证公路正常使用的基本条件。
由于自然和人为因素的影响，路基边坡的崩塌、滑坡和剥落等损坏现象时有发生，因此，高等级公路路基边坡的施工及养护质量越来越多地引起施工、养护单位和管理部门的重视。
中图分类号： u213.1+3 文献标识码： a 文章编号：一、边坡的防护具有一定的要求：1.根据当地气候环境、工程地质和施工材料等情况，因地制宜、就地取材，选用适当的工程类型，以保证公路路基的稳定。
2.对于冲刷防护，一般在水流流速不大及水流破坏作用较弱地段的沿河路基边坡设置防护工程以抵抗水流的冲刷。
3.坡面防护要求防护的边坡有足够的稳定性。
二、边坡的防护类型及其适用条件：路基边坡防护根据所建地域的不同大致可分为坡面防护和沿河路基防护。
1.坡面防护：主要是保护路基边坡表面免受雨水冲刷，减缓温差及温度变化的影响，防止和延缓软弱岩土表面的风化、碎裂、剥蚀演变进程，从而保护路基边坡的整体稳定性，在一定程度上还可美化路容，协调自然环境。
它包括植物防护、骨架植物防护、圬工防护和土工织物防护。
⑴植物防护：包括种草、铺草皮、植树三种。
①种草防护适用于边坡稳定，坡面受雨水冲刷轻微，且易于草类生长的路堤与路堑边坡。
用以防止表面水土流失，固结表土，增强路基的稳定性。
边坡上己扎根的种草防护，可容许缓流水短时冲刷。
选用草籽应注意当地的土壤和气候条件，通常应以容易生长、根部发达、叶茎低矮、枝叶茂密或有匍匐茎的多年生草种为宜，常用的月白茅草、毛鸭嘴、鱼肩草、果圆、雀稗、鼠尾草和小冠。
最好采用几种草籽混合播种，使之生成一个良好的覆盖层。
种植时草籽宜掺砂或与土粒拌和，使之播种均匀，播种时间以气候温暖、温度较大的季节为宜。
当前推广使用的两种新方法是湿式喷播技术和客土喷播技术。
②铺草皮适用于需要迅速绿化的土质边坡。
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浅析公路路基边坡防护摘要：本文通过分析公路路基边坡的破坏形式及原因，分析了路基边坡防护设计原则，详细介绍了公路边坡的防护方法，以保证路基的稳定和防治各种路基病害，确保公路的正常使用品质及投资效益。
关键词：公路路基边坡防护路基防护是保证路基强度和稳定性的重要措施之一,防护的重点是路基边坡,由于地形的变化,适路设计标高与天然地面标高的相互关系不同,会出现高于天然地面的填方路基即路堤、低于天然地面的挖方路基即路堑和介于前两者之间的半填半挖路基。
由岩土体填挖而成的路基,改变了原地层的天然平衡状态,且暴露于自然环境中,长期受各种自然因素的影响,岩土体的物理力学性质会发生较大的变化,引起岩土体变形、移动,破坏边坡的稳定,甚至导致一系列环境地质问题和生态环境问题,如崩塌滑坡、泥石流、土壤侵蚀和植被破坏等。
因此为保证路基的稳定和防治各种路基病害,除做好路基排水工作外,还需结合当地水文、地质及材料等情况,采取有效措施,对各类土、石边坡进行必要的防护。
一、边坡破坏形式及原因路基边坡的滑塌是最常见的路基病害之一,根据边坡土质类别、破坏原因和规模不同,主要破坏形式为溜方、滑坡、剥落和碎落崩塌四种。
溜方是由于少量土体沿土质边坡向下移动所形成,即边坡上薄的表层土下溜,通常是由于降水、降雨等流动水冲刷边坡或施工不当而引起的。
滑坡是指一部分土体在重力作用下沿边坡的某一滑动面滑动,主要是因土体的稳定性不足引起的。
路堤边坡发生滑坡的主要原因是边坡坡度过陡或坡脚被挖空,或填土层次安排不合适等;路堑边坡发生滑坡的主要原因是边坡高度和坡度与天然岩土层次的性质不相适应。
剥落和碎落是指边坡风化岩层表面,在各种外界环境的影响下使表层岩石从坡而上剥落下来的破坏形式。
崩塌通常是指较大的石块脱离边坡表面沿坡而滚落下来。
二、路基边坡防护设计原则公路边坡沿公路分布的范围广,对自然环境的破坏范围大,如果在防护的同时,能够注意保护环境和创造环境,采用适当的绿化防护方法来进行,则会使公路具有安全、舒适、美观、与环境相协调等特点,也将会产生可观的经济效益、社会效益和生态效益。
因此,边坡设计应遵循“安全绿色、水土保持、恢复自然、环保之路”的设计原则。
三、路基边坡防护方法1.植草防护。
植物防护则是在边坡上种植草或植树,以减缓边坡上的水流速度,利用植物根系固结边坡表层土壤以减轻冲刷,从而达到保护边坡的作用。
植物防护不仅可以美化公路环境,调节边坡的湿温,起到固结和稳定边坡的作用,而且又比较简单、经济。
植草防护应选择根系发达、茎矮叶茂耐旱草种,严禁采用生长在泥沼地的草皮。
直接植草护坡方法如下:其一,在土质坡面上用草籽、肥料、水拌和,直接喷洒在坡面上,优点是方法简单、施工方便、成本较低,但易受风雨的侵蚀;其二,在修整好的坡面上,将粘土、种子、肥料、水等混合物用喷浆机直接喷射于坡面,与原土壤粘合,种子发芽后便会植根于边坡土壤中,形成整体保护。
上述两种方法在植草初期,应免受风雨的侵蚀,可覆盖纤维网,由于坡面没有任何的加筋处理,在暴雨和径流的冲蚀下极易导致坡面破坏,因此一般应在每年3-5月进行。
2.工程防护。
工程防护主要是针对不适宜植物生长的土质填、挖方边坡或风化严重、节理发育不良的岩石路基边坡等,采取工程防护措施即设置人工构造物防护。
3.干砌片石。
干砌片石适用于保护边坡免受大气降水和地面径流的侵害,以及保护浸水路堤边坡免受水流冲刷。
对严重潮湿或有冻害的路段、长期承受主动土压力地段一般不宜采用干砌片石防护,可用于下边坡中的土质边坡防护,坡度为1:1.5-1:2。
4.浆砌片石。
浆砌片石设置在浸水路堤及可能发生坡面被冲刷的土质边坡,应做好排水与防护的结合,否则不宜采用。
当水流速度较大时(如4-5m/s),波浪作用较强,以及河流可能有流木及其他撞击物等冲击作用时,宜采用浆砌片石防护,必要时可与浸水挡墙或护面墙同时设置。
浆砌片石护坡优点是耐久性较好,适宜防护不同控制边坡中的岩土层和不同位置的边坡,且造价适中,故适用于上下边坡中的一般坡面。
5.拱式、网格防护。
这种防护方式克服了鱼鳞状砌石防护排水抗冲刷能力弱和污工量大的特点,最大限度地绿化坡面,外观较好,在高填方、长直线的护坡段,能达到美化、绿化的双重效果,是近年来公路防护常用的方法之一。
缺点是施上较繁琐,劳动强度大,对坡面要求严格,拱内必须填土植草或进行其他工程防护,否则易被雨水冲蚀。
6.预制块铺砌防护。
这是目前高速公路上应用较多的护坡方法之一,由于预制块的规格一致,易于施工,外观整齐,最大限度地减少了坡面防护对植草绿化的依赖性,即使坡面绿化效果不好,也不容易造成太严重的冲刷现象,所以,目前大多数高速公路采用这种方式,缺点是造价高,施工难度大。
7.喷射混凝土防护。
喷射混凝土法分为素喷法和锚喷法。
素喷法为直接将高标号砂浆喷射在大致平整的岩面上,使坡面易松散的颗粒得以稳固,保证行车及行人的安全。
它用于表层易松散的风化岩面。
锚喷法,其工作原理是利用锚杆将滑动体固定在山体上,以锚杆约束山体的滑动,并在滑动体表面锚头上加挂钢筋网并喷射混凝土,在滑动体表面形成钢筋混凝土板体结构,这样可以将松散的岩石固定为一个整体,以达到彻底根治滑坡的目的。
锚喷法适用于大部分岩石土和碎石土等地质结构山体和易产生滑坡地段,它可预防早期滑坡的产生。
只要产生滑动的区域面积不很大,滑动层不很厚,都可以采用此方法。
此外,对于边坡破坏较严重的情况,如出现塌方、滑坡以及可能出现失稳等,必须采取相应的措施来确保边坡的稳定性(强度方面)和安全性(变形方面)。
根据边坡的不良工程地质特征和滑坡加固治理与防护工程特点,主要选取适用性强、易于操作、工程负效应小的措施,如抗滑桩、锚杆(索)、挡土墙、削坡和灌浆等,使其分别适用于不同塌方、滑坡的物理力学条件和地质条件。
参考文献[1]黄建明.浅析高速公路路基边坡防护的施工-以甬金分离立交桥6#、7#墩施工为例[J].科技创新导报,2009,(2):.[2]钮震雨余俊美.浅探公路工程质量通病及其预控措施[J].江西建材,2007,(4):.[3]于跃王慧贤安震.高速公路路基边坡防护浅析[J].黑龙江交通科技,2007,(12):12,14.According to the highway subgrade slope protection[abstract] this article through the analysis of road foundation slope failure forms and reasons, analyzes the roadbed slope protection design principles, detailed introduces the highway slope protection method, in order to guarantee the stability of roadbed and prevention and control of all kinds of roadbed disease, to ensure the normal use of the highway quality and benefit of investment[key words] highway subgrade slope protectionRoadbed protection is to guarantee the stability of roadbed strength and one of the important measures, protection is the focus of the embankment slope, the change of the terrain, ShiLu design elevation and natural ground conductivity of the relationship between different, there will be higher than that of the natural ground embankment fill subgrade construction of the ground below natural excavated one that cut and between the two and a half between fill subgrade in geotechnical engineering by half to dig into roadbed fill dug, change the original layer of the natural balance, and exposed to a natural environment, long-term affected by various natural factors, the physical and mechanical properties of rock mass will been great changes, cause rock mass deformation mobile, destroy the stability of the slope, and even cause a series of geological environment problems and the ecological environment problems, such as collapse landslides of soil erosion and damage to vegetation, etc .So to ensure the stability of roadbed and prevention and control of all kinds of roadbed disease, in addition to the drainage roadbed, still need to be combined with the local hydrological geology and material of case, take effective measures to all kinds of soil ShiBianPo necessary protection.Firstly,a slope failure forms and reasonsEmbankment slope of the slump is one of the most common roadbed disease, according to slope soil category damage reason and scale is different, the main failure form of slip party peel and broken down landslide collapse four slip party is due to a small soil slope moves down along the soil formed, namely the slope of thin surface soil slip under, it is often due to rainfall precipitation and flowing water erosion caused by improper slope or construction of the landslide is refers to the part of the gravity of soil slope under one of the sliding surface sliding, mainly because of the soil slope of embankment caused by inadequate stability of landslide is the main reason of the side slope steep or spend change clearly feet are hollow, or filling levels arrangement inappropriate, etc.; Cut slope is the main reason of the landslide slope height and slope and natural geotechnical levels of nature does not adapt spalling and broken down is refers to the slope rock weathering surface. In different kinds of external environment under the influence of the top rock slope and peeling off from the destroy form of collapse usually refers to the larger stones out along the slope surface slope and tumble down.second，Embankment slope protection design principlesHighway slope distribution along the road of the range, the destruction of the environment of natural range, if in the protection, and can also pay attention to protect the environment and create the environment, the adoption of appropriate green protective method, can make highway has safe and comfortable and beautiful in harmony with the environment and other characteristics, which will create considerable economic benefit and social benefit of ecological benefit so, slope design should follow the safety of soil and water conservation and restoration of natural green environmental protection of the way the design principlesthirdly，embankment slope protection method1.The plant grass protection plant protection in the slope is planted on grass or trees to slow down the slope of flow velocity, the use of plant root consolidation of surface soil slope to reduce erosion, so as to achieve the function of the slope protection plant protection not only can beautification highway environment, adjust the temperature wet slope, consolidation and the stability of the slope play a role, and simple economic.Plant grass protection should choose the root system developed stem short and leafy drought tolerant grass seed, it is strictly prohibited to the growth in mud to clear the implanted directly into the grass slope protection method are as follows: firstly, in the soil slope surface water mixing with seed fertilizer, direct sprayed in the slope surface, the advantage is simple convenient construction cost is low, but vulnerable to wind erosion; Secondly, in dressing good slope surface, will clay fertilizer water with seed mixture of spray directly injection machine in the slope, and the soil adhesion, seed will rooted in soil slope, forming overall protection of the two methods in plant grass at the initial stage, the rain should be from erosion, fabric covered, because no slope reinforcement treatment in heavy rains and runoff erosion of the slope easily result in damage, and therefore should be in commonly 3-5 months each year.2. Engineering protection engineering protection is mainly aimed at not suitable for the growth of plant soil slope excavation or weathering fill joints growth of serious adverse rock embankment slope, take engineering protection measures that is setting artificial slope protection.3. Do PianShi build by laying bricks or stones do build by laying bricks or stones PianShi is designed to protect the slope from atmospheric precipitation and runoff violations, and protect water embankment slope from flow erosion of severe cold wet or sections of long-term bear active earth pressure area should not be commonly use dry build by laying bricks or stones PianShi protection, and can be used in the soil slope under the slope protection, slope of 1:1. 5-2-1..4. Pulp PianShi plasma build by laying bricks or stones PianShi build by laying bricks or stones set in immersion embankment and possible washed the soil slopesurface slope, should do well in the combination of drainage and protection, otherwise not be used as the water velocity is (such as in 4-5 m/s), wave action is stronger, and rivers flow and other wood may have hit content to wait impact, appropriate USES plasma build by laying bricks or stones PianShi protection, when necessary and water retaining wall or HuMianQiang also set pulp PianShi build by laying bricks or stones advantage is good durability slope protection, which is suitable for the protection of the different control slope rock layer and different locations of the slope, and moderate cost, it is applicable to the general up and down the slope slope5. Arch type grid protection this protection way been overcome the QiShi protection drainage anti-scouring ability weak and the large amount of work the characteristics, the maximum slope greening, appearance is better, in long lines of the high fill slope section, can achieve beautification greening double effect, road protection in recent years is the commonly used method shortcoming is one of the more tedious;, labor strength, strict requirements on slope surface, within the filled soil arch must be planting grass or other engineering protection, or to be rain erosion.6. Precast block slabs protection this is the current highway slope protection method widely applied one, because of the specifications of the precast block consistent, easy construction, neat appearance, minimizes the slope protection on plant grass greening dependence, even if the slope greening the result is bad, it is not easy to cause too serious erosion phenomenon, so, at the moment, most of the highway that way, defect is cost is high, difficult construction.7. Jet concrete protective jet concrete method into meat spray method and shotcreting method for directly spray method, high standard in the formation of the mortar injection roughly sheared off, make easy to loose particles slope stably, ensure running and pedestrian safety it used for surface layer of rock bolting and easy to loose by law, the working principle is to use sliding body will be fixed in the mountain, the mountain to the constraints of sliding, and in the sliding body surface anchor head and sprayed concrete use steel mesh, sliding body surface formation in reinforced concrete board body structure, so can will loose rock fixed for a whole, in order to achieve the purpose of cure landslide shotcreting act applies to most of the rock soil and rock soil and other geological structure mountain and produce landslide location, it can prevent the generation of landslide early as long as produce sliding area is not very big, Sliding layer is very thick, all can use this methodIn addition, the slope destruction for serious, such as a landslide and collapse may appear instability, etc, must adopt corresponding measures to ensure the stability of the slope (strength) and safety (deformation) according to slope of bad engineering geological characteristics of the landslide reinforcement management and protection and the features of the project, the main selection applicability is easy to operation of small negative effect on the engineering measures, such as anti-slide pile retaining bolt (cable) cutting slope and grouting, make its are used in different collapse of thephysical and mechanical landslide conditions and geological conditions References:[1] HuangJianMing. According to the highway subgrade construction of the side slope protection in highway overpass 6 gold separation # 7 # pier construction, for example [J]. Science and technology innovation herald, 2009, (2).[2] NiuZhenYu, the more beautiful. Shallow ground the highway engineering quality problems and its control counter measures [J]. Jiangxi building materials, 2007, (4).[3] to jump, WangHuiXian, AnZhen. Highway subgrade shallow slope protection [J]. J heilongjiang transportation science and technology, 2007, (12).。