施工过程中地下管线的定位及其测量.doc

英文资料翻译及原文1、译 文施工过程中地下管线的定位及其测量精确的定位地下管线和查明其相关联的故障，不论是天然气、石油输送管道，还是废水、废物排放管道，对于管线业主和工程师来说都是一个最大的挑战。虽然管线定位和管线测漏技术经过若干年的发展，但它们仍有其局限性。幸运的是，现在新技术的产生和发展意味着管线探测工人有了更多的可行的选择方法。但是为什么管线定位技术如此重要？这主要归结为两点：时间和金钱。市政公司花费大量的财力去完成街道工程，其中花费最大的是开挖洞口，以提供资料去定位和处理故障。每个开挖地点都花费数百英镑，首先找到正确的开挖地点比作多次试验经济的多。所以说积累试验法是一个经济的方法。存在这样一个现实，大部分的管线业主主要想知道所有地下管线资源详细的精确的位置，而这个极好的目的是非常棘手的，常常是不可能实现的。例如，数据会很快过时。假想有这样一个情况，在公司的资料上清楚地记录着有沿着村庄路两旁许多年前安装的天然气管道。然而，由于新公路的施工，这些管道现在在双线车道的下面。这个变化即使是那在世的最初标记员也不会发现；最终结果是当管线业主或它的承包人去查找故障或提供资料时，他们只有一个模糊的视线去观察。这主要是解决地下空间的逐渐紧凑与管理它们的问题。当这项工程被一个市政或交通运输公司承包时，他们需要确定管线或电缆是否被邻近的机构不经意的破坏。虽然修理偶然挖断的一套电缆是非常昂贵的，但重要的是不要忘记全局的健康和安全。不同的定位方法管线定位方法的范围从低技术到高科技发展。在这个范围的底部和末端是现存的传统的方法，是非常经济和容易看得见的，是相当基础的。在过去几十年，需要很多经验的基本频率法的解决方案是非常流行的。它分为两种方法：被动源无线电探测法和主动源无线电探测法。被动源探测法是基于金属管线自动再辐射信号被探测到。地下管线的定位可用手携式无线电探测仪追踪。这种方法是十分简单和相当有效的，但它的缺点是：必须是金属管线而且带有足够强的无线电信号，而实际中常常不是这样的。主动源探测法是应用发射机激发管道信号，或将它放置在管道需要探测的位置。然后，工程师提着接收机沿着管道走，它可接收信号同时发出能增强信号的嘟嘟响声。这个方法是非常有效的，它也会探测在密集区域的其他任何管线和电缆。今天的管线工程师对被动源电磁定位法是非常熟悉的。被动源电磁定位在许多国家变得日益普遍，尤其在美国。这个方法完全不同于以前的方法，因为它不依赖于管线自身。相反，在安装过程中，每隔一定间距在管线的关键点，如交叉点，就有一个塑料接口。这个接口通常是球形的，也可是其他形状的，它包括一个用于标记流度朝向的标志天线。当管线工程师需要精确定位时，手携式管线定位仪可选择一个高的精度。每个标志通常对应一种颜色，例如蓝色表示水管，黄色表示天然气输送管。为了避免一些在安装过程中的混淆，每种管道也对应一种细微差别的频率，例如水管是145.7千赫，天然气输送管是83千赫，污水管是121.6千赫。这就意味着工程师不仅能探测到自己需要探测的管道，还能探测到同一区域的其他管道。一项新定位技术的产生所有的系统都被认为是目前较好的，但它们仍有其局限，因为所有的方法只是告诉工程师管线（或故障）在哪儿，其具体的就没有了。这将会被新出现的地下管线定位技术所改变。例如，有新技术如卫星测量、超声波测量和地质雷达，它们都是十分精确的，但成本价价比较高昂。另一种方法是ID标记系统，目前也被应用。基本上，它是被动源地磁定位技术的延伸。与以前定位技术不同的是，它可提供用户管线更详细的情况。安装了这个有经验的球状标记，用户可从每个球的记录中重新得到相当详细的情况。如参考编码，交叉点的标记、意图、埋深和何时安装的等等。每个标记球包括一个金属卷和一个特定用途集成电路，它们被丙二醇、乙二醇和水的混合物包围者。它们是可被微生物分解的，对人类、野生物和环境是无害的。这个球形标记的外壳是用高密度的聚乙烯制成的。当工程师或承包人在安装过程中将球下降到电缆沟时，他们可用一个手携的仪器去记录相关的情况。每个球形标记有一个10位数的序列号，并且可将长达256字节的数据储存在手携式探测仪的球形标记中。容量为64字节的数据被用于储存序列号和标记；其余的可被使用者用一系列的描述方法根据其使用详细要求定义。使用者在仪器顶端的小液晶显示屏绘图界面定义一系列描述方法。这些资料可被下载到手提电脑或个人电脑中，然后转入到中心数据库。工程师也可以进入用户可定义模板系统，所以一个市政公司或承包人必须保证使用该仪器的人遵守同样的规则。仪器用这种方法尽可能的储存大量标记数据，然后通过一个标准的RS232串行接口下载到手提电脑的合适位置。其他的有用属性是寻求包含扫描两种同步频率的标记，能够使承包人每次找到多于一种的球形标记。一个球形标记可以读到探测器5英尺或1.5米远的地方。这个仪器用标准的AA电池可运行24小时。ID标记方法的好处是，经过多年后，不管记录被谨慎保存没有，一个非常详细的管线网历史记录被创建和维修，它包括修理、扩充的详细资料等等。如果不幸的是计算机系统崩溃，这种情况可利用手携式探测仪收回球形标记中的地图和与它们关联的数据去重新建立数据库。当然，这样的方法收集数以千计的资料是非常耗时的，但总比失去全部的资料好。在英国，天然气管道与民用航空的应用试验已经起步。然而，ID标记技术的加法对现有标记系统是如此的新，以致于现在公共的个人历史记录还没形成。3M，现在定位技术最前线的公司之一，已经从ID标记系统的使用团体中得到一些积极的反馈。这是一个公正的低风险的投资，而且系统成本费少于1000英镑。此外，所有的工程师可分享相同的手携式仪器（他们不许要每天使用它），每天工作的只是球形标记，它们是在大部分管道工程逐渐零星购买的。随着管线业主降低业务预算压力的渐增，精确管线定位无疑扮演一个重要的角色。同时传统的方法占有它们的位置，新的定位技术可以帮助公司节省时间和更进一步减少成本费。PAUL WARD是欧洲3M测量和试验系统的销售部执行经理，他是管线定位中使用无线电信号和球形标记的先驱。他在3M已经29年了，专攻电信和仪器测试市场。他最初的背景是电力工业。在过去的15年，他负责试验测量系统。2、原 文Underground pipeline locationby Paul Ward3M Test & Measurement Systems, Bracknell, UKAccurately pinpointing underground pipes, as well as any associated faults, has long been one of the biggest challenges for pipeline owners and engineers, whether gas, oil, water or waste. And although pipe- and fault-location techniques have been around for some time, they have tended to have their limitations. Fortunately, new developments now mean that pipeline workers now have a far greater choice of methods available to them.But why is the ability to locate pipes so important anyway? This comes down to two simple words: time and money. Utility companies can spend fortunes carrying out streetworks, where one of the most expensive elements is digging holes, whether to extend existing services or to locate and deal with faults. Each hole costs hundreds of pounds, so it makes sound economic sense to dig in the right spot on the first try, rather than making several attempts. Trial and error is a costly policy.It could be argued that, surely, most pipeline owners maintain detailed and accurate records of all underground resources, but this is often not the case, even when the best intentions are involved. For instance, records can become quickly out of date. Imagine a situation where gas pipes were years ago installed to run alongside the side of a village road and clearly marked as such on the companys records. However, thanks to new roads being constructed, these same pipes are now under a dual carriageway. The chances are that even the original above-ground marker - if there was one was ploughed up); the net result is that when the pipeline owner or its contractor has cause to locate a fault, or extend the services, they now only have a hazy idea where to look.Then there is the whole problem of sharing increasingly-cramped underground space with other services. When work is being carried out by one utility or transport company, then it needs to be sure that it is not going to inadvertently damage the pipes or cables of any organization in the same vicinity. Accidentally cutting through a set of cables can be an expensive problem to fix and, of course, it is important not to forget the whole issue of health and safety,Different location methods The range of pipe-location methods ranges from the very low tech to the very high tech. At the bottom end of the scale are good old-fashioned above-ground methods, cheap and easily visible, but rather basic. Rather more sophisticated are the range of frequency-based solutions that have become increasingly prevalent over the past decade or so. These divide into two groups: passive radio detection and active radio detection.The concept of passive detection is based on the fact that any metallic pipe naturally picks up and reradiates a signal. The location and path of an underground pipe can be tracked using hand-held radio signal detection devices. This approach is simple and relatively effective, but does have its drawbacks: it depends on pipes being metallic and on them radiating a sufficiently strong signal, which may not always be the case. In the case of active detection, a signal is applied to the pipe using a transmitter unit which can be clipped on to a pipe, or placed over the point where the pipeline is expected to be .The engineer then walks along holding a receiver which detects the signal and emits a beeping sound that increases in relation to the signals strength. Again, this system is relatively effective, but will also detect any other pipes or cables in the immediate area.Todays pipeline engineers will also be familiar with passive electronic location, which is becoming increasingly common in many countries, and is particularly strong in the USA. The concept takes a completely different approach to previous methods, because it does not depend on the pipe itself. Instead, during the installation process, plastic markers are placed alongside the pipe at key points such as junctions, or at regular intervals. The markers are usually ball-shaped, but can take other forms, and contain a fluid which is used to orientate the markers antenna.When the pipeline engineer needs to be accurately located thereafter, a hand-held device can be used with a high degree of accuracy. Each marker is usually allocated a different color, for example blue for water and yellow for gas, to avoid any confusion during installation, and will each respond to a slightly different frequency; for example,145.7kHz for water, 83.kHz for gas, and 121,6kHz for wastewater. This means that the engineer can not only detect his own pipes, but those in the same area.A new generation of location technologyAll the systems described so far perform their job well, but still have their limitations, because all they do is tell the engineer where the pipe (or fault) is located, but little else. This is now changing with the advent of a new generation of underground-location technology. For instance, there are systems that use satellite, sonic surveying, or downward-looking radar that are extremely accurate, although they have a price tag to match.Another method that has beer introduced recently is ID marker systems which, in essence, are an extension to the existing concept of passive electronic location. Where these differ to previous types of location technique is that they provide the user with far more detailed levels of information. By making the In ball markers more sophisticated, the user can record and later retrieve considerable information from each ball, such as the reference number, what junction it marks, what the purpose of that junction is, the depth, when it was installed, and by whom.Each marker ball contains a metal coil and an ASIC (application-specific integrated circuit), surrounded by a mixture of propylene glycol and water, a biodegradable solution that is not harmful for humans, wildlife, or the environment. The outer shell of the ball marker is made out of high-density polyethylene. When the engineer or contractor drops the balls into the trench during the installation process, they use a hand-held locator to record the relevant information. Each marker ball has a 10-digit serial number and up to 256 bits of data per marker ball can be stored by the accompanying hand-held locator. 64 bits of the data capacity are used for the serial number and marker; the rest can be defined according to the risers particular requirements, using a series of description fields on the hand-held by the user, who is guided by a series of description fields on the small LCD graphical user interface on the top of the locator. This information can then be downloaded on to a laptop or PC, and can then be transferred to a central database. The engineer can also enter user-definable templates into the system, so a utility company or contractor can ensure that anyone using the locator follows the same rules. A locator should be able to store dozens of marker records in this way before downloading to an on-site laptop through a standard RS232 serial port.Other useful features to look out for include the ability to scan two marker frequencies simultaneously, enabling the contractor to look for more than one kind of marker ball or utility at a time. A marker ball can be read up to 5ft, or 1,5m, from the locator probe, and the locator is able to run for 24 hours using standard AA batteries.The benefit of the ID marker method is that, over a number of years, an extremely-detailed history of a pipeline network can be created and maintained, regardless of how carefully records have been kept or not, including details of repairs, extensions and so on. In the unfortunate event of the computer system being wiped out, this information could be built from scratch by taking the hand-held locator back out into the field, to map the marker balls and their associated data. Of course, if thousands of records were involved this would be time-consuming, but better than having lost this information altogether.Gas-pipeline and civil-aviation application trials are already underway in the UK. However, the addition of the ID marker technology to the existing marker system is so new that public case histories have yet to emerge. That said, 3M, which is one of the companies at the foref