45T旋挖钻机变幅机构液压缸设计【含CAD图纸、说明书】
附 录国内外当前形势下旋挖钻机的发展前景随着全球经济的快速发展,继续扩大对基础设施的范围,以人为本和保护,直到不断加强基础设施,特别是现浇混凝土桩的桩位与环境有关的法律和规章的设想基础他几乎取代了空间应用范围广泛的基本基础。扶轮社是因为其效率高,污染少,更多的全面发展的功能特点,以满足钻机在就地演员,在国内建设的需要,混凝土桩已被广泛使用。 旋挖钻机的旋挖钻机在英国除了各扶轮社分销业务的斗争中,我们需要短期和长期螺旋螺杆钻分布,长城钻井套管安装符合动摇抓斗控制设备等 - 将套管施工;抓斗与地下连续墙伸缩杆指导,对硬岩破碎施工直接到户;进行更换后的植物和Jet建设的是建设周期;配置可以液压锤,振动锤,柴油锤了一系列其他形式的桩等施工。 旋挖钻机一般适用粘土,粉土,砂土,淤泥土,回填土一些碎石,结石形成。对于第一个大型动态扭矩和自动锁定伸展台内,可在该路口施工用的风钻杆。为了适应旋挖钻机的施工要求安装底盘和配电设备,大扭矩输出,灵活,多功能,高效率建设。目前,最大的旋挖钻机钻孔直径3米,在120m高(主要是40米) ,最大钻孔扭矩620kNm最大钻孔深度。 20世纪90年代末,中国旋挖钻机的业主,只有约100个,2002年,中国进口的100台旋挖钻机,为2003年底的最后期限,中国曾在2004年年底之前,41万台钻机旋挖350-400 ,旋挖钻机41万台450-500。 扶轮社在全台钻机和旋转钻机斗争制定了关于第二次世界大战的基础上,美国开发的第一台旋转式CALWELD斗争中,短螺旋。 20世纪50年代,法国贝诺托桩基础施工将用于在全钻机,而欧洲国家在其产品组合,不断改进,成为今天的多功能机型发展。岩土意大利从美国公司,将被安装在卡车和第一附属于欧洲引进钻机履带式起重机,固定动力头,无法安装套管,是难以适应硬层施工在1960年德国和Gaiercigaite维尔特同时,公司开发的第一台可移动式的力量。鲍尔在1975年德国公司的发展与伸缩钻杆钻机配备BG7,直接从钻机底盘与动力配置可以达到锁定压缩钻杆钻探,钻井扭矩,可在接近实现砾石和岩石钻探。 日本进口从1960年CALWELD旋挖钻机,这是发达国家15 - H的加藤生产钻机美国。之后支持在1974年能抓住动摇控制设备和钻机,挖掘机在1965年日立建机采用液压钻机设备安装与底盘,开发了液压履带起重机底盘由液压马达驱动钻机的发展。日立建机于1980年和岩土工程公司共同开发和扩大,以提高桩端承载力的建筑领域。鲍尔加入德国和日立建机与住友建机旋挖钻机的联盟,以进一步促进日本的技术的发展。日本的旋挖钻机扭矩比欧洲同类产品低。 目前,主要的外国制造商的旋挖钻机:德国:宝华,利勃海尔,德尔马格在尊重的MGF,意大利SoilMec,旋转,巨细胞病毒,B200E是IMT,ENTEGO;西班牙:拉马达。日本:日本汽车,日立,住友,加藤,芬兰:JUNTTAN,汤姆洛克;:超支美国,英国:BSP的英格索兰,其他。 天津探矿机械厂1984年从美国RDI的公司所造成的第一辆车旋挖钻机。 1988年北京城建机械厂仿制岩土工程公司隶属1.5米直径的旋转钻机。郑州调查机械厂于1994年引进英国公司BSP的附件旋转钻机,1998年泰有限公司和上海合作组装BG15.1999鲍尔哈尔滨通用公司和徐州工程机械工程机械公司已开发出旋转钻机和依恋型旋转钻机。新华社在2001年开发出巨大的力量旋转钻机首次成功。经过2003年3月1日,旋挖钻机数减少智力厂商已下线,产销两旺。 目前,旋挖钻机的主要制造商:湖南山河智能,湖南,3月1日,徐工集团,中联重科,徐州东说,一个巨大的,鲍尔天津,石家庄,煤炭,连云港黄海哈尔滨普遍,内蒙古北方南汽,宇通汽车时代,山东鑫,郑州勘探。 据如扭矩的旋挖钻机,主要的技术参数,孔直径,钻孔深度,发动机功率,质量组件可以分为三类小型,中型和大型。 目前,国外旋挖钻机包括欧洲平行四边形连杆加方柱独立的代表,履带式起重机附着日本代表。 欧洲的独立具有以下特点旋转钻机: (1)由一个或多个液压驱动动力头,一个用于鲍尔,邓勇,速度为代表的低,非高速相反。在其他地区,Medtech公司,卡萨内由一个动态运作的第一大代表的两个变量由一个高速反演此外小型电动驱动电机,有一种一厢情愿的种族分类,直接通过行星齿轮减速机,以实现快速逆转引发领土。第三,结构简单,液压管道,以便低成本,留下了复杂的液压控制管,传动复杂,容易发生故障,成本高。 (2)钻杆与机锁摩擦。间歇性锁到另一台机器和机架。钻杆摩擦对普通地层钻进,为钻孔机锁硬地层。工作旋挖钻机,钻杆紧张和压缩时间,剪切,扭转,弯曲应力及其他复合材料。欧阳距离拉旋挖钻机钻杆的特殊的高强度合金用无缝钢管生产厂家。设计和制造有一些特殊的要求。要做到这一点重量轻,扭矩,磨损,寿命长。 (3)柱箱形结构,刚性好,重量轻。使用一个正方形槽磨损无缝管,促进扭矩传输。这里有三个机构组成一个平行四边形支持一个小三角结构,其特点是不同的,可以将一孔,折叠,降低运输高度和长度。前面的缺点是附加的重量稍微稳定,不能超扭矩。对于一个三角结构,鲍尔代表,特点是简单,稳定,能承受高扭矩。缺点是运到包装,耗时和需要援助的起重设备,第三个公司拉马达,意大利,具有较高的代表性,同时还支持三角结构,起了辅助油箱飞机,也可以折叠最主要的一块,与上述两种结构类型的优势,新颖,经济实用。 (4)旋挖钻机的关键部件吊装,根据下一个洞钻钻钻工具,旋转倾销) ,主要的市场容量,结构和旋挖钻机的钻机每个周期(建筑特色功能非常重要,对钻井的主要市场销量的生活绳长度事故的概率水平钻井效率是紧密相关的。欧洲的旋挖钻机已经停止了和权力钻杆到与绳装置,以防止损坏任意司法第一次接触。特别是Medtech公司旋挖钻机的公司,主要绞车意大利鼓容量大,单绳缠绕,以加强对该部队的常数,不重叠绳滚动,从而减少钢丝绳磨损,延长钢丝绳寿命。国外旋挖钻机提升更好地利用非旋转弹性绳,以提高生活。 (5)为底盘测功机(可用横向扩展与支腿,专业堆后,3列的支持,宝华,建华等);旋转钻机专业底盘(横向伸缩式底盘,SOILMEC,B200E,拉马达等);履带起重机底盘(利勃海尔);履带式推土机的底盘(车长在这里增加后方支腿,设备独立是IMT在尊重,MGF的);汽车底盘(改善流动性,主要是在城市地区或要求快速施工的使用不同的场合,如旋转,巨细胞病毒,SOILMEC其他。 ) 可变履带间距的底盘,低重心和可调重量的设计和布局,确保大局的稳定,满足更广泛的轨道交通需求,降低地面的压力,比上攀爬,以确保传输所需的钻井现场机械性能的能力。 (6)机械和电气设计功能整合 一个匹配引擎和负荷(降低燃油消耗,减少噪音) ,电子控制系统; 乙,手动和自动切换控制列的垂直度(垂直孔保证度)自动缠绕系统; ,精度高,旋转钻井转储位置(以防止桩变形)控制技术; 研发,钻孔深度(以防止绳子和确认洞太深)测量和显示系统; 五,故障与起动负荷(绞车过卷)检测,并显示报警信息系统; 男,一个工作(预激活状态一块之前自动) ,动画和虚拟仪器显示系统; G号,全球定位系统和移动电话(及时快速地接触)传输系统; H型进入(提高桩过程)反馈,记录,打印系统; (7)适应各种建筑机械集团 一般用于大口径旋挖钻机螺旋和旋挖斗争,除了钻机模块化设计的多种用途,而且还以适应建设分配如下: 欧杰(CFA)的演练,以及 - 抓斗完全控制,液压抓斗地下连续墙,液压锤,振动锤等。日本生产的主要是附加到主旋挖钻机。事实上,这不仅是对起重机底盘就像一个起重机,一台起重机的外观,液压系统的设计按照旋挖钻机的特点。附旋挖钻机是一个多用途(即钻机,最重要的特点,也可用于起重机)的工作范围,并可以设置为安装设备,扩大其缺点是第一个动态扭矩太小,压不长,垂直钻机良好的自我为零。近年来,国内使用的方法和消化,吸收国外先进技术的基础上不断创新,手段,它已经开发了旋挖钻机,如山脉,类型多样,河流和湖泊,徐工集团,致力于发展最终钻进;盘旋3月1日重型机械,煤炭和其他盘旋石家庄发展的挖掘机钻机结束。国内虽然国外产品旋挖钻机的整体水平仍远远落后,但主要性能已接近国际先进水平,价格明显优于热从2003年下半年,国内旋挖钻机市场已经从进口到飞机取得了飞机。 目前,中国制造的旋挖钻机品种单一,大多数产品的扭矩是180 - 220kNm使用者的选择权较小,然后,根据我们的统计80-85桩径在1200以下的不超过40米的深度,在未来,可以发挥多功能旋挖钻机的最大优势,而不是片面的适合我国国情的发展条件和注重扭矩,以满足国内旋挖钻机的施工要求低价格。而在日本旋挖钻机100kNm以下就是一个例子。二手不少日本进口旋挖钻机,用户也很良好的效果。 为提高桩基础施工质量的具体方法,桩负荷承载能力和增强城市环境法规,严格执行,混合物灌注桩几乎取代了其他基础设施,成为使用最广泛的基础,国内和国外钻井作业钻孔机(反周期,各类旋挖钻机,全套管一) ,这个比例是完全不同的,在国外大直径混凝土灌注桩施工中,旋挖钻机一般占了三分之二以上。反向循环钻机在欧洲市场几乎不再使用,国内钻井机械产品中反循环钻机的产量,近90。 旋挖钻机,因为安装的功率,输出扭矩,轴向压力,灵活性,高效率,环保及其他特点的不同施工钻在我国大部分地区,为适应地质条件成为建设合适的基础设施项目孔最佳操作机器。近年来,北京地铁,环网,特别是青藏铁路,奥运场馆,新机场客运大楼和其他重大项目正在建设资金,旋挖钻机高效,环保,高效率优势的认可。 随着改革的逐步深化和开放,对国内市场经济的需求,使得铁路公路和水路运输,城市公共设施及土木工程,水利,电力设施,港口建设和机场的桩基础施工机械快速发展潜在的巨大市场已经出现了。仅铁路建设,中国将在2005年接获的新项目,2020年铁路建设总投资超过2亿元。高速客运专线等作为武器,今年数百议员,西点太多,如北京,天津进入一个高速客运专线的运作超过60桥梁,桥桩的直径最合适的旋挖钻机建设,这是青藏铁路后,旋挖钻机在铁路建设较大规模的应用。 旋挖钻机和北部中国建筑技术已在南部迅速蔓延,尤其是东南沿海地区由于地层较软,深桩一般较大,旋挖钻机成孔困难,主要还是反循环钻机。其实与其他建筑设备在该区域的一些旋挖钻机,有旋挖钻机,套管钻机联合建设;另一种方法是使用振动在中国已被广泛用于促进桩锤成孔钢管在软土,由浙江大学,宁波金华兰溪电厂,福建宁德电厂建设已证明是可行的。 旋挖钻机是近几年大规模的应用,我们有没有相应的产品标准已用于旋挖钻机施工规范编制,没有系统的方法,技术培训不足,有待进一步研究的基本理论,旋挖钻机并结合土木工程施工技术紧密合作。研制旋挖钻机的设计技术人员应与桩基础施工,对旋挖钻机的工程技术人员使用熟悉的应该有它的工作原理的理解和操作的性能,为此,中国工程机械工业协会将和有关科研单位,主机生产厂家和建设部门在执行有关的旋挖(的工作原理,液压技术,机电控制技术的基本结构装配,安全规则等)的技术培训,构建经验交流和其他活动,及时制定旋挖钻机产品标准和相关标准,促进机械化和旋挖钻机产品的开发。Rotary drilling rig in the current situation and prospect of development at home and abroadWith the rapid development of the global economy, continuing to broaden the scope of infrastructure, people-oriented and the idea of protecting the environment-related laws and regulations until the continually strengthening the infrastructure, especially the piles of cast-in-place concrete pile foundation he has almost replaced the basic foundation for a wide range of applications of space. Rotary drilling rig because of its high efficiency and less pollution, more functional features of the comprehensive development to meet the needs of the cast-in-place concrete piles in the domestic construction has been widely used. The rotary drilling rig for Rotary Drilling Rig English, in addition to various Rotary distribution operations struggle, we need the distribution of short and long helical screw drilling, casing installation Wall Drilling meet shaken grab control devices and so on - will casing construction; Grab with telescopic rod guide for the underground continuous wall, with DTH for hard rock crusher construction; Be carried out after the replacement of plant and Jet Construction is the construction cycle; Configuration can hydraulic hammer, vibratory hammer, diesel hammer out a pile of other forms, such as construction. Rotary drilling rig generally applicable clay, silt, sand, silt soil, and back fill with some gravel, stone formation. For the first large dynamic torque and automatic locking stretching drill pipe inside the rig, which can be used in construction of the intersection of breeze. In order to meet the construction requirements of rotary drilling rig is installed chassis and power distribution equipment, and large torque output, flexible, multi-purpose, the construction of high efficiency. Currently, the biggest auger drill hole diameter of 3m, the largest drilling depth of 120m (mainly 40m), the largest drilling torque 620kNm. The end of the 1990s, China rotary drilling rig owners, only around 100, in 2002, China imported 100 auger drill Taiwan, the deadline for the end of 2003, China had 410,000 rotary drilling rig 350-400 to Taiwan until the end of 2004, 410,000 of rotary drilling rig to Taiwan 450-500. Rotary drilling rig in the full-rig and the rig rotary struggle developed on the basis of the Second World War, the United States developed the first rotary CALWELD struggle, the short auger. 20th Century 1950s, France BENOTO Pile Foundation Construction will be used in full-rigs, while the European countries to its portfolio and constantly improved and developed into todays multi-function models. Italy geotechnical companies from the United States, will be installed on the first truck and crawler crane attached to the introduction of the European rig, the head of fixed power and is unable to install the casing, and it is difficult to adapt the hard layer construction, in 1960 Germany and Gaiercigaite Vildt Meanwhile, the company developed the first movable type force. Bauer German company in 1975 to develop a drill pipe equipped with a telescopic BG7 rig, the rig directly from the chassis, with the impetus to lock configuration can achieve compression drill pipe drilling, drilling torque, can be achieved at the close of gravel and rock drilling. Japan imported from the United States in 1960 CALWELD rotary drilling rig, which was developed 15-H Kato production rig. After supporting the development of a shaken can grab control devices and the rig, built in 1965 Hitachi excavator machine using hydraulic pressure device chassis fitted with rigs, in 1974 developed a hydraulic crawler crane chassis rig driven by hydraulic motors. Hitachi Construction Machinery in 1980 and geotechnical companies to co-develop and expand to improve the bearing capacity of the end of pile construction field. Bauer joined Germany and the Hitachi Construction Machinery alliance with Sumitomo Construction Machinery rotary drilling rig to further promote the development of technology in Japan. Japans torque rotary drilling rig smaller than similar products in Europe. At present, major foreign manufacturers of rotary drilling rig : Germany : BAUER, LIEBHERR, Delmag, In respect of, MGF, Italy SoilMec, spin, CMV, B200E, IMT, ENTEGO; Spain : LLAMADA. Japan : Japanese Vehicle, HITACHI, Sumitomo, Kato; Finland : JUNTTAN, TAMROCK; : APE United States, the United Kingdom : BSP Ingersoll-Rand; other. Tianjin Machinery Plant prospecting 1984 RDI companies from the United States caused the first vehicle rotary drilling rig. 1988 Beijing Urban Construction Machinery Plant imitation of geotechnical engineering company attached 1.5m diameter rotary drill rig. Zhengzhou investigation Machinery Plant in 1994 to introduce British companies BSP attachment rotary drill rig, 1998 Tai Co. Ltd. and Shanghai Cooperation assembly BG15.1999 Bauer Harbin universal Xuzhou Construction Machinery Corporation and construction machinery company has developed a rotary drill rig and attachment type rotary drilling rig. Xinhua tremendous power in 2001 developed the first successful rotary drilling rig. After March 1 2003, reduced intellectual auger drill several manufacturers have come off the assembly line, sell very well. At present, the rotary drilling rig major manufacturers : Hunan Shanhe intellectual, Hunan, March 1, XCMG, Zoomlion, Xuzhou East that, a huge, Bauer Tianjin, Shijiazhuang, coal, Lianyungang Yellow Harbin universal, Inner Mongolia North gasoline and YUTONG South car era, Shandong Xin, Zhengzhou prospecting. According to the main technical parameters of rotary drilling rig, such as torque, the hole diameter and drilling depth, engine power, quality components can be divided into three types of small, medium and large. At present, foreign rotary drilling rig consists of representatives of the European parallelogram linkage plus square column stand-alone, Japan representative of the crawler crane attachment. Europes independence rotary drill rig with the following features : (1) dynamic head by one or more hydraulic drive, one for Bauer, represented by Tang Yong, speed is low, not high-speed reverse. In the other territories, Medtech, Kasane represented by the dynamic operation of the first large one to two variable displacement motors driven by the addition of a high-speed inversion small motor-driven, there is a category of wishful race, directly through the planetary gear reducer to achieve rapid reversal thrown territories. The third simple structure, hydraulic piping to facilitate low-cost, behind a complex hydraulic control tube, drive complex and prone fault, and high cost. (2) of drill pipe into friction with machine-locking. Intermittent lock into another machine and rack. Friction Drill Pipe stratigraphic drilling for ordinary, hard formation for the drilling machine-locking. Auger drill work, drill pipe a time of tension and compression, shear, torsion, bending stress and other composites. Ouyang distance stretching drill pipe auger drill used by special high-strength alloy seamless tube manufacturers. Design and manufacture have some special requirements. This can be achieved lightweight, Torque, wear, longer life expectancy. (3) Column box structure, rigid, light weight. Use a square chute wear seamless pipe, facilitate the transmission of torque. Here are three supporting bodies form a parallelogram to a small triangular structure, it is varied in its characteristics, can put an orifice, folded, lower transport height and length. Front drawback is the weight attached slightly stability, can not afford super torque. For a triangular structure, as represented by Bauer, are characterized by simple, stable, able to withstand high torque. Drawback is transported to the package, time-consuming and need assistance lifting equipment, the third company to Llamada, Italy, features high-represented, while also supporting the triangular structure, starting with auxiliary fuel tanks planes, can also uppermost piece of folded, with the advantages of the above two types of structures, novel, economical and practical. (4) Hoisting of rotary drilling rig in the key components, according to rotary drilling rig construction characteristics of the rig each cycle (on the next hole drilling-drilling-drilling tools-rotary-dumping), the main market volume, the structure and functions are very important, and the drilling efficiency of the level of drilling accident probabilities of life rope length with the main market volumes are closely related. Europe rotary drilling rig has since stopped and power drill pipe to the first contact with the rope device to prevent damage to arbitrary justice. Italy in particular Medtech rotary drilling rig company, the main winch drum of large capacity, single rope winding order to enhance force constant, non-overlapping rope rolling, thereby reducing the rope wear to extend the life of the wire rope. Foreign rotary drilling rig Hoist better use of non-rotating flexible rope to enhance life. (5) Professional pile into chassis dynamometer (available horizontal expansion, with outrigger after, the three-column support, BAUER, BSP, etc.); Rotary drilling rig professional chassis (horizontal telescoping chassis, SOILMEC, B200E, LLAMADA etc.); Crawler crane chassis (LIEBHERR); Crawler excavators chassis (rear car length Here increase outrigger, the device independent, IMT, In respect of, MGF); Automobile chassis (to improve mobility, mainly in urban areas or require the use of the rapid construction of occasions, such as spin, CMV, SOILMEC other. ) Tracked variable spacing chassis, low center of gravity and the weight of adjustable design and layout, ensuring the overall stability, meet the transport requirements of wider track and lower ground pressure and superior climbing ability than to ensure that the rig site transfer required mechanical properties. (6) the functional integration of mechanical and electrical design A matching engine and load (lower fuel consumption, reduced noise), the electronic control system; B, manual and automatic switching control column vertical degrees (vertical hole-assurance degrees) Auto entangled system; C, high precision rotary drilling dump location (to prevent pile deformation) control technology; D, drilling depth (up to prevent rope and confirmation hole too deep) measurement and display system; E., fault (with load starting, winch off Volume) detection, alarm and display information system; F, a state of a piece of work (pre-activated automatically before), animation and virtual instrument display system; G, GPS and mobile phone (rapid contact place in a timely manner) transmission system; H-into the process of (raising pile) feedback, records, printing systems; (7) adapt to a variety of construction machinery group Generally used in large-diameter auger drill helix and Rotary Drilling struggle, in addition to the multi-purpose use of modular design rigs, but also to accommodate the construction allocation is as follows : Auger (CFA) drill, and - grab full control, hydraulic grab diaphragm walls, hydraulic hammers, and other vibratory hammer. Japanese-produced mainly Attached to the main rotary drilling rig. In fact, it is not only the chassis of the crane, just like the appearance of a crane, a platform crane, hydraulic systems are designed in accordance with the characteristics of rotary drilling rig. Attached rotary drilling rig is the most important feature of a multi-purpose (ie, for drilling rigs, cranes can also be used) operating range, and can be set to install equipment to expand its shortcoming is the first dynamic torque is too small, not long pressurized, the vertical drilling rigs good self-nil. In recent years, domestic use ways and means with digestion and absorption of advanced foreign technology, based on constant innovation, it has developed a variety of types of rotary drilling rig, such as mountains, rivers and lakes, XCMG group dedicated to the development of end-drilling; circled March 1 heavy machinery, coal and other Shijiazhuang Development circled the end of the excavator drilling rig. Domestic rotary drilling rig While the overall level of foreign products still lags far behind, but the main performance has approached the international advanced level, prices significantly superior thermal, from the second half of 2003, domestic rotary drilling rig market has changed from being imported into airplanes have made airplanes. Currently, China-made rotary drilling rig varieties single most products torque is 180-220kNm users the option of a smaller, and then, according to our statistics of 80%-85% Piles Drive in 1200 following a depth of not more than 40m, in the future, could play a rotary drilling rig multifunctional the greatest advantage, not one-sided emphasis on torque conditions for the development suited to our national conditions, to meet the construction requirements of low prices of domestic rotary drilling rig. Most rotary drilling rig in Japan 100kNm following is an example. Many Japanese imports of second-hand rotary drilling rig, the user is also very good results. Concrete for improving the quality of the pile foundation construction methods, the Pile load bearing capacity of enhanced and the urban environment and regulations strictly implemented, mixtures Pile almost replaced the other infrastructure, become the most widely used foundation, and the domestic and foreign Drilling operations all kinds of Drilling Machine (Anti-cycle, spin drilling rig, a full set of Tube), the ratio is utterly different, in the large foreign diameter Concrete Pile Construction, spin drilling rig usually accounts for over two thirds. Reverse cycle drill in the European market is almost no longer use and domestic Drilling Machine products in which Reverse Circulation drilling rig the yield, nearly 90% of. Rotary drilling rig, because of installed power, output torque, axial pressure, flexibility, the construction of high efficiency, environmental protection and other features of different drill, in most parts of our country to adapt to the geological conditions become suitable for building infrastructure projects hole best operating machinery. In recent years, Beijing Metro, ring networks, especially the Qinghai-Tibet Railway, Olympic venues, the capital of the new airport terminal building and other major projects under construction, rotary drilling rig efficiency, environmental protection, high efficiency advantages recognized. With the gradual deepening of reform and opening up, the demand for the domestic market economy makes rail highway and waterway transport, urban public facilities and civil engineering, water conservancy, electricity facilities, port construction and the rapid development of the airport Pile Foundation Construction Machinery potentially huge market has emerged. Only railway construction, China will on a number of new projects in 2005, total investment in railway construction in 2020 to more than two trillion yuan. This year hundreds of high-speed passenger lines, such as weapons, Mr West Point too, such as Beijing and Tianjin into operation of a high-speed passenger lanes for more than 60% of bridge, the bridge piling most suitable diameter rotary drilling rig construction, which is the Qinghai-Tibet Railway after rotary dr
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