完整版道路工程专业3000字外文翻译

1、软土路基处理方法概述摘要：软土路基的加固有很多种方法， 本文对常用的几种方法从加以解释对其加 固机理, 作用,作用范围以及个别的工程实例的阐述 . 新型的加固材料以及新工艺 的开发和利用对提高软土路基的加固技术水平所起的重要作用等做以简单的阐 述.在道路工程中经常会遇到软土路基， 由于高速公路、 高速铁路的发展， 对地 基的承载能力要求越来越高， 天然的软土地基远远不能满足这些高档次的构造物 对地基承载力的要求。20世纪8090年代，由于人口膨胀土地资源日益紧张， 同时软土路基加固的技术也有了长足的发展， 经济条件有所改善， 各种软土加固 理论得到了充分的应用与验证， 软基加固技术也得到长足发

2、展， 在不同的领域里 均有涉猎；到 20 世纪 90 年代以后 , 各种各样的软基处理技术已广泛地应用在各 种道路工程中。地基中常见的软土， 一般是指处于软朔或者流朔状态下的粘性土。 其特点是 天然含水量大、孔隙比大、压缩系数高、强度低，并具有蠕变性、触变性等特殊 的工程地质性质， 工程地质条件较差。 选用软土作为路基应用， 必须提出切实可 行的技术措施。 这种土质如在施工中出现在路基填土或桥涵构造物基础中， 最佳 含水量不易把握， 极难达到规定的压实度值， 满足不了相应的密实度要求， 在通 车后，往往会发生路基失稳或过量沉陷。其危害性显而易见 , 故禁止采用。在软 土地基上修筑路堤， 特别是

3、桥头引道， 如不采取有效的加固措施， 就会产生不同 程度的坍滑或沉陷，导致公路破坏或不能正常使用即所说的桥头跳车。一般地， 除要确保新填筑路基的密实度以减少沉降外， 包括原地面的地基总沉降必须达到 基本稳定，沉降量大致达到总沉降量的 80%以上时，才容许铺路面。软土地基沉 降严重时，不仅增加填方数量， 而且沉降或水平位移对临近填土的桥台、 挡土墙、 涵洞，甚至对附近的住宅、 农田以及路线的技术标准都会产生很大的影响。 为此， 根据地基土的工程特性，选用适当的处理措施。经过长期的实践，在公路、铁路 中形成了多种形式的软土地基处理方法， 结合很多的施工企业多年施工经验及有 关专家学者的论述进行总结

4、归纳如下：1 换填垫层法当软弱土层厚度不很大时， 可将路基面以下处理范围内的软弱土层部分或全 部挖除，然后换填强度较大的土或其它稳定性能好、无侵蚀性的材料 （ 通常是渗 水性好的中粗砂）称为换填或垫层法。此法处理的经济实用高度为 23m如果 软弱土层厚度过大， 则采用换填法会增加弃方与取土方量而增大工程成本。 通过 换填具有较高抗剪强度的地基土， 从而达到增强地基承载力的目的， 满足构筑物 对地基的要求。主要加固方法有换填、抛石挤淤、垫层、强夯挤淤几种。垫层法 根据材料的不同可分为砂 （ 砾石 ） 垫层、碎石垫层、 粉煤灰垫层、干渣垫层、土（灰 土、二灰 ） 垫层。代表方法有砂垫层法及换填法。

5、砂砾垫层：当路堤高度小于极限高度的 2 倍，软土层较薄， 填筑材料比较困 难，或雨季施工时，采用砂砾 （砂） 垫层，在填土与基底之间设一排水面，从而使 地基在受到填土荷载后， 迅速地将地基土中的孔隙水排出， 加快固结速度， 提高 地基的承载力，减少沉降，防止地基局部剪切变形。要注意控制填土速度，所用 的材料为含泥量不大于5%勺洁净中粗砂，或最大粒径小于 5cm的天然级配砂 砾。换填法：在软土厚度不大于 2m 时，利用渗水性材料 （砂砾或碎石 ）进行置换 填土，可以降低压缩性，提高承载力，提高抗剪强度，减少沉降量，改善动力特 性，加速土层的排水固结。它的特点是施工工艺简单，但费用比较高。抛石挤淤

6、：当软土或沼泽土位于水下，更换土施工困难，且厚度小于3m，表层无硬壳、 基底含水量超过液限、 路堤自重可以挤出的软土之上， 排水比较困 难时，采用抛片石（直径一般不小于30cm）挤淤的方法。从中部开始抛石，逐渐 向两边延伸，挤出淤泥，提高路基强度。2 深层密实法采用爆破、夯击、挤压和振动及加入抗剪强度高的材料等方法，对地基深层 的软弱土体进行振密和挤密的地基加固方法称为深层密实法。适用于软土厚 度3m的中厚软土的加固，分布面积广的软基加固处理，其加固深度可达到30m 通过振动、挤压使地基中土体密实、 固结，并利用加入的具有高抗剪强度的桩体 材料置换部分软弱土体中的三相 （气相、液相与固相 ）部

7、分， 形成复合地基， 达到 提高抗剪强度的目的。主要加固方法：强夯法、土（或灰土、粉煤灰加石灰 ）桩法、砂桩法、爆破法、 碎石桩法（振冲置换法）、石灰桩法、水泥粉煤灰碎石桩（CFG桩法）、粉喷桩法、 旋喷桩法。代表方法有碎石桩法、强夯法、水泥粉煤灰碎石桩法、粉喷桩法。强夯法：对于砂土地基及含水量在一定范围内的软弱粘性土地基， 可采用重 锤夯实或强夯。 它的基本原理是： 土层在巨大的冲击能作用下， 土中产生很大的 压力和冲击波，致使土体局部压缩， 夯击点周围一定深度内产生裂隙良好的排水 通道，使土中的孔隙水 （气）顺利排出，土体迅速固结。 强夯后地基承载力可提高 34倍，压缩性可降低200%-1

8、000%其佳夯击能：从理论上讲，在最佳夯击能 作用下，地基土中出现的孔隙水压力达到土的自重压力， 这样的夯击能称最佳夯 击能。因此可根据孔隙水压力的叠加值来确定最佳夯击能。 在砂性土中， 孔隙水 压力增长及消散过程仅为几分钟， 因此孔隙水压力不能随夯击能增加而叠加， 可 根据最大孔隙水压力增量与夯击次数关系来确定最佳夯击能。 兰海高速公路某滑 坡体的堆积破碎泥岩堆积物厚度 412M从土样的土工试验报告可知为低液限黏 土含水量 29.820.2,凝聚力 13.812.2KPA,内摩擦角 13.8202挤密砂桩、碎石桩加固法：属于复合地基的一种，当软土层较厚，换填处理 比较困难，地基土属于非饱和粘

9、性土或砂土时，采用挤密砂桩或碎石桩加固法， 可以使地基土密实，容重增加，孔隙比减少，防止砂土在地震或受震动时液化， 提高地基土的抗剪强度和水平抵抗力， 减少固结沉降， 使地基变均匀， 起到置换、 挤密、排水作用，防止地基产生滑动破坏，提前完成沉降，减少沉降差。3 排水固结法在软土地基上加压并配合内部排水， 加速软土地基的排水， 加快软土固结的 处理方法称为排水固结法。 适用于处理各类淤泥、 淤泥质粘土及冲填等饱和粘性 土地基。软土地基在附加荷载的作用下，逐渐排出孔隙水，使孔隙比减小，产生 固结变形。 在这个过程中， 随着土体超静孔隙水压力的逐渐扩散， 土的有效应力 增加，并使沉降提前完成或提高

10、沉降速度。主要加固方法： 堆载预压法、 砂井法、袋装砂井、 真空预压法、 电渗排水法、 降低地下水位法、塑料排水板法。预压处理：分为超载预压、等载预压和欠载预压等，其施工工艺简单，但工 期较长，超载预压的时间一般为 6 个月，通常与排水处理地基相结合使用。 广州 市新窑南路道路工程就是利用堆载法加固软土路基的 . 新窑南路道路工程起点为 广州大道K4+600,终点为北山村K11+700,全长约7KM道路沿线地层结构自上而 下分别为 : 地壳硬壳包括松散状杂填土 , 素填土和软塑状耕土 , 厚度为 0.402.20; 软土层包括流塑状淤泥和淤泥质土 , 厚度为 1.519.39, 沿线厚度变化大

11、 ;下伏层 包括粘性土和砂层堆载预压时间从1995年到2003年，大约78年.袋装砂井：对于软土厚度大、 路堤稳定、 填土高的软土路基， 采用袋装砂井， 可增加软土竖直方向的排水能力，缩短水平方向的排水距离，加速软土的强度。 砂袋灌入砂后， 砂井可采用锤击法或振动法施工。 它的施工工艺复杂， 费用相对 较高，所用的时间较长， 可采用矩形或梅花形布桩。 珠江地区某市公路的地质 勘探表明，地基土质分布比较均匀，除表层 1。0m左右耕植土外，接着为8.6m 厚的高含水量、 高压缩性、低强度， 高含粘性的超软弱淤泥。 第三层为厚约 1.0m 的贝壳粉砂土；第四层又为7.6m厚的淤泥质粘土；以下分别是

12、0.5m厚粘土和 3.0m厚粉细砂。往下为击数（SPT大于19击的含砾粗砂层，再往下土质更好。 地基土质为20m左右深厚的淤泥，含水量高达 85.7%,十字板剪切强度仅4Kpa, 且淤泥分布深度大致由前方向后方陆域倾斜， 前浅后深， 前方相对有利。 在这样 大面积超软弱的淤泥地基上筑路需作软基深层处理，以防止施工期软基沉降缓 慢，引起工程完工后仍有较大剩余沉降量，同时不致因加载引起地基失稳破坏。这一带因软基不当而出现工程质量或安全事故是较常见的，就设计采用7cm袋装砂井加砂垫层堆载预压排水固结进行软基加固，目的是通过打设砂井使第二、 四层淤泥土排水固结后， 土质强度获得提高、 减少工程投产后的

13、沉降， 保证工程 的正常使用，满足工程设计要求。塑料排水板：排水原理与袋装砂井相同，由于是工厂制作，它的质量稳定、 重量轻、运输保管方便，施工工艺比较简单，投入劳力少，费用相对较低，并且 渗滤吸水性好，具有一定的强度和延伸率，对土的扰动小，预压时间较长，在工 程中得到广泛应用，但对于提高土层的抗剪能力不如袋装砂井。Overview of Soft Subgrade Treatme ntAbstract: The rei nforceme nt of soft soil roadbed There are many ways, several to explai n the rei nforce

14、me nt mecha nism of the role, scope, and in dividual project example elaborati on. New rein forceme nt materials and new tech no logy developmentand utilization of soft subgrade reinforcementplayed animportant role to do with the simple description.Whe n road works are ofte n encoun tered in soft so

15、il subgrade, the carry ing capacity of the foundation have become increasingly demanding due to the developme nt of highway, railway, n atural soft ground is far from meeti ng these high-grade structures are the foundation bearing force requirements. 1980s and 1990s, due to population expansion of l

16、and resources are becoming in creas in gly ten se, soft soil subgrade rein forceme nt tech no logy has made great progress, and econo mic con diti ons have improved, a variety of soft soil reinforcement theory has been fully Application and verification of soft base rei nforceme nt tech no logy has

17、made rapid progress in differe nt areas are covered; to the 1990s, a variety of soft foun dati on treatme nt tech no logy has bee n widely used in various road projects.Foun dati on in soft soil,usually in soft new moon or under the state of the flow of new moon of the clay. Which is characterized b

18、y the natural water content, void ratio, compressibility factor, low strength and creep, thixotropy, and other special engineering geological properties, poor engineering geological conditions. Selection of soft soil roadbed application must be put forward practical measures.Soil, such as in the con

19、 structi on of the base of the emba nkme nt or bridge and culvert structures, optimum moisture content is not easy to grasp, is extremely difficult to achieve the required degree of compact ion can not meet the den sity requireme nts after the ope ning, ofte n a roadbed in stability or excessive set

20、tleme nt. Its obvious dan gers, therefore prohibit ing the use. Con struct ion of emba nkme nt on soft ground, especially Bridge Approach, if not take effective measures for the rein forceme nt, it will have vary ing degrees ofcollapse slip or subside nee, result ing in road damage or is not work in

21、g is known as the Bump. In gen eral, i n additi on to en sure that the new subgrade Using den sity to reduce the settleme nt In additi on, the total settleme nts of the foundations of the original ground must meet the basic stability of the settlement roughly more than 80% of the total settlement am

22、ount, to allow resurfac ing. Serious settleme nt of soft ground, not on ly to in crease the amount of fill, and subsidence or horizontal displacement of the bridge near the filling, retaining walls, culverts, and even the technical standards of the nearby residential, farmland, and the route will ha

23、ve a huge impact .To this end, accord ing to the engin eeri ng properties of foun dati on soil, the select ion of appropriate measures to deal with. After a long practice, the formatio n of roads, railways, various forms of soft ground, comb ined with a lot of con struct ion compa nies many years of

24、 experie nce in con structi on and related experts and scholars discussed summarized as follows:1 replaceme nt cushi on methodWhe n the thick ness of the soft soil, soft soil below the subgrade surface with in part or all of the excavati on, the n cha nge to fill the greater in ten sity of soil or o

25、ther stability, non-erosive materials (usually good water permeability in coarse sand) called Replaceme nt Cushi oning. This econo mical and practical method to deal with the height of 2 to 3m, if the thickness of the soft soil is too large, the n using the replaceme nt method will in crease the dis

26、posable side and dug side content and in crease the cost of the project.Replaceme nt higher shear stre ngth of soil, so as to achieve the goal of enhanced foundation bearing capacity to meet the requirements of the structures on the foun dati on.Rei nforceme nt Method Replaceme nt, Sto ne Fill, cush

27、i on, COMPACTED silt several. Cushi oning accord ing to the differe nt materials can be divided into the sand (gravel) cushion, gravel pads, fly ash cushion, the cushion of dry residue, soil (dust, ash) cushi on. Represe ntatives of sand cushi on method and replaceme nt method.Gravel cushion: when t

28、he embankment height is less than 2 times the limit height, soft soil layer is thi n, the filli ng material is more difficult, or rai ny seas on, con struct ion, gravel (sa nd) cushi on betwee n the fill and the baseme nt to set up a drain age face, so that the foun datio n by filli ng load in the f

29、oun dati on soil pore water discharge speed to accelerate the con solidati on to improve the beari ng capacity of foundations, reduce sedimentation, to prevent the foundation of local shear deformation. Pay attention to controlling the filling speed, the materials used to clean coarse sand with mud

30、is not more than 5%, or maximum particle size less than 5cm natural gradation gravel.Replacement Method: water permeability material (gravel or crushed stone) in the soft soil thickness is not greater than 2m, filling replacement can reduce the compressi on to in crease beari ng capacity, shear stre

31、 ngth, and reduce the settlement to improve the dynamic characteristics accelerate soil con solidati on by drain age. It is characterized by the con struct ion process is simple, but the cost is relatively high.Stone Fill: When the soft soil or marsh soil located underwater, replace the soil con str

32、ucti on difficulties, and the thick ness is less tha n 3m, the surface without a hard shell, the substrate water content over liquid limit, embankment above the weight of the soft soil that can be squeezed out, drain age more difficult whe n using cast stone tablets (diameter gen erally less tha n 3

33、0cm) to squeeze the depositi on method. Start from the middle of the rubble, gradually exte nding to the sides, out of mud, to improve the subgrade stre ngth.2 deep compact ion ,The use of blasti ng, compact ing, extrusi on and vibrati on and join the high shear strength of materials, etc., the foun

34、dation of deep soft soil density vibrati on and compact ion of the foun datio n rein forceme nt method is called deep compact ion. For soft soil thick ness 3m thick soft soil rein forceme nt, distributi on of a wide area of soft Rein forceme nt process ing, has con solidated its depth is up to 30m.V

35、ibration, squeezing ground Turkey body dense consolidation, and added with high shear strength of the pile materialreplacement of part of the soft soil of the three-phase (gas, liquid and solid phase) porti on to form a composite foun dati on, to improve the shear stre ngth of purpose.Main reinforce

36、ment methods: dynamic compaction,soil (or dust, fly ashplus lime) piles, sand piles, blasting, gravel pile (vibration and substitution method), lime piles, cement, fly ash gravel pile pile (CFG), the DJM France, jet grouting piles. On behalf of rubble piles, dynamic compaction, cement and fly ash gr

37、avel piles, DJM Fran ce.The dyn amic compact ion method can be used to hammer compact ion or dyn amic compacti on: sand foun dati on and the water content in a range of soft clay foundation. Its basic principle is: the soil under the huge impact in the soil to produce a lot of pressure and shock wav

38、e, resulting in the soil of local compression, tamping points around within a certain depth to produce the fissures good drain age cha nn el, so that the soil pore water (gas) discharged smoothly, the rapid consolidation of soil. Dynamic compaction, foundation beari ng capacity can be in creased 3-4

39、 times, compressi on can be reduced from 200% to 1000%.Good ram is able to hit: In theory, the best tamping can function in the foundation soil pore water pressure reaches the soil weight pressure, such tamping energy known as the best tamping energy. Therefore, according to the superposition of the

40、 pore water pressure value to determine the best tamping energy. In sandy soil, the growth and dissipation of pore water pressure of only a few minu tes, the pore water pressure can not be with the tamp ing can in crease and overlay, the maximum pore water pressure in creme nt and the nu mber of tam

41、p ing relatio ns to determ ine the best tamp ing can. Sea highway Iandslide accumulation of broken mudstone deposits thick ness of 4 12M from the soil samples of the soil test report shows that for low liquid limit clay con tai nin g.Water 29.8 to 20.2, the cohesive ness 13.8 12.2KPA internal fricti

42、on angle of 13.8 20.2.Sand compaction piles, rubble pile reinforcement method: a kind ofcomposite foun dati on, thick soft soil replaceme nt to han die the more difficult, the foun dati on soil is un saturated cohesive soil or sand, sand compact ion piles or broken Shizhuang reinforcement method, th

43、e foundation soil compacting bulk den sity in creased, pores less tha n to preve nt liquefacti on of sand in the earthquake or by vibration and improve the foundation soil shear strength and the level of resista nee, reduc ing the con solidati on settleme nt, so that the foun dati on to cha nge un i

44、form , play replaceme nt, compact ion, drain age and to prevent the foundation to produce sliding failure, completed ahead of the settleme nt to reduce the differe ntial settleme nt.3 drain age con solidati on methodPressure on the soft ground and in line with in ternal drain age, accelerate the dra

45、in age of the soft ground, speed up the process ing of soft soil con solidati onknown as drain age con solidati on method. For saturatedcohesive soil foundation in handling all types of mud, silt clay and red fill. Soft ground in the role of the additi on al load is gradually passed to the pore wate

46、r, the void ratio decreases, resulting in consolidation deformation. In this process, with the gradual diffusi on of excess pore water pressure in soil, soil effective stress, and settleme nt in adva nee or improve the settli ng velocity.Reinforcement methods: heap preloading method sand wells Franc

47、e, packed sand, vacuum preloading method, electro-osmosis water method, dewateri ng method, plastic drain age plate method.Preload ing: divided into the surcharge preload ing, set Preloadi ng and less preload ing, the con structi on process is simple, but a Ion ger durati on, surcharge preload ing t

48、ime is gen erally six mon ths, usually used in conjunction with wastewater treatme nt foun dati on . New kil n South Road, Guan gzhou City, road works is to use a heap load reinforcement of soft soil roadbed. New kiln South Road road works start ing point for Guan gzhou Ave nue K4, +600, and finish

49、at North Village K11, to +700, total length of about 7KM road along the stratigraphic architecture were as follows: the crust hard shell loose, miscellaneous fill, fill factors, and soft plastic like cultivated soil, thickness of0.40 to 2.20; soft layers including the flow of plastic-like silt and s

50、ilty soil, thickness of 1.51 9.39, along thickness variation; underlying layer of cohesive soil and sand heap preload ing time from 1995 to 2003, about 7 to 8 years.Packed sand: soft soil subgrade for soft soil thickness, embankment stability, high filli ng, packed san d, in crease the soft soil the

51、 vertical drain age capacity, shorte n the horiz on tal direct ion of the drain age dista nee, accelerate the soft soil stre ngth. Sand bags poured into the sand, sand wells can be used to hammering or vibration method of construction.Complexity of itscon struct ion process, the relatively high cost

52、, used for a long time, can be rectangular or plum-shaped cloth pile. Geological Survey of the Pearl River area of a city road show that the foundation soil is more evenly distributed, surface 0m about Cultivate soil, then a 8.6m thick high water content, high compression, low-intensity, high content of viscous super-weak sludge. The third layer is thick and 1.0m shell