Trenchless Pipeline Installation Methods and Their Pros and Cons

它是轻描淡写的，即与飞行管道安装方法相关的益处远远超过缺陷。然而，最吸引人的因素是它的事实是它不需要破坏交通，阻挡整个道路部分或挖掘整个道路来获得完成的工作。发射和接收坑是大多数这些方法中唯一需要的挖掘。

Trenchless technology offers a variety of methods for the installation of different pipe sizes and types, depending on location, soil type and depth of penetration. Some of the trenchless pipeline installation methods are horizontal directional drilling (HDD), horizontal auger boring (HAB), pipe jacking, pipe ramming and impact moling. All these methods have proved to be time and cost effective when compared to the trenching methods. However, these methods come with some advantages and disadvantages, knowing which will help gain a better understanding of which method will be most beneficial for a particular project.

水平定向钻孔（HDD）

HDD is a steerable tunneling method and is a two-stage process i.e. the pilot bore and the back reaming process, and can be used for small and large diameter pipelines. The optimum angle for the rig carriage incline to push the drill rod for drilling the pilot bore is 12° but the adjustment can be done anywhere between 5° and 30°. This method requires the use of a lubricant known as drilling mud, usually, bentonite that is circulated in the pilot bore as the drilling progresses. The drilling fluid facilitates the removal of the drill cuttings and also stabilizes the borehole.

水平定向钻井优点

There are several pros when installing pipelines using HDD. A major advantage is a minimum impact this method has to environmentally sensitive areas such as wetlands, estuaries, rivers and lakes. It is also a fast method of pipeline installation and enables the operators to accomplish creditable accuracy even when crossings are complicated. Continuous monitoring and control during the operation allow operators to navigate in constrained spaces between existing utility lines. Drilling can even be carried out at greater depths to bypass existing utilities altogether and requires only one launching shaft at the entry point and one reception shaft at the exit point.

水平定向钻孔Cons

The cons of HDD are not many but are significant. HDD operation can be carried out only by highly skilled operators and the cost of equipment and machinery requires the project to be of sufficient bore length to be profitable.

水平螺旋钻（HAB）

HAB utilizes a casing system fitted with a cutting head and rotating auger that is jacked into the earth from the launching shaft. As the auger proceeds, it transmits torque to the cutting head. The soil cuttings generated from the cutting head are transmitted back to the launch pit via the rotating augers. Once the casing and auger are in the earth, the next set of casing and auger blades are attached to the previous casing and auger and the process is continued to the reception shaft.

Horizontal Auger Boring Pros

The major advantage of HAB is that the casing installation and excavation are carried out simultaneously. It only requires two pits, one for launching and one for excavation. The method is suitable for all types of soil except for mixed soils containing boulders.

水平螺旋钻无聊缺点

常常是有considerab不利le investment in equipment because the method calls for availability of different sizes of cutting heads and augers for the varying casing sizes.

Pipe Ramming

Pipe ramming is carried out by using a percussive hammer attached to the end of the pipe or casing that pushes it into the soil. The leading edge of the pipe or casing creates the borehole and installs the pipe. The spoil enters the pipe and is removed after the installation is complete.

管道撞击售卖所

The advantage of pipe ramming is that the method is very economical and does not require expensive equipment. The pipe can be installed either as one piece or in segments and can be installed in almost any type of soil. It is best suited to medium sized pipes and for shorter lengths.

管道撞击

The major disadvantage of pipe ramming is that there is no control over the line and grade of installation. There is also the chance of the pipe deflecting if met with hard obstructions like hard boulders that are larger than the casing. This method can only be used for steel pipes because of the percussive nature of the installation. The ranges of pipe size that can be installed using this method are limited from 2” to 55”.

Impact Moling

Also known as the compression method, the installation is carried out by pushing or pulling the pipe through the borehole created by a mole. The mole is a streamlined tool in the shape of a bullet and is propelled using a power source. The energy is transferred to the mole by compressed air or hydraulic mechanism which allows the mole to propel through the ground. Once the borehole is complete the mole is removed and the pipe to be installed can be pushed or pulled through.

影响莫林格披面

Impact moling is very advantageous for small diameter pipelines requiring short installation lengths. The method does not require any expensive equipment and can be used to install any kind of utility line, making it an economic method. The moling process helps in compressing the soil around the mole thus stabilizing the borehole.

Impact Moling Cons

Impact moling has some disadvantages such as inaccuracy in line and grade since the system is unguided. This can cause damage to existing utility lines that have not been detected before the start of the project. Pipe sizes that can be installed is limited to 6” or less though some techniques allow for larger sizes, and installation length is limited to 60 feet though some techniques allow up to 200 feet.

磁力安装工具箱中可用的各种方法足以满足安装现场存在的不同类型的土壤和环境条件。在所有这些方法中，最重要的是，最重要的是项目现场决定适合该项目的最佳方法和设备的岩土性调查。通过使用桥接方法可以节省的整体成本和时间是相当大的，这就是为什么它成为许多承包商手中的重要工具，无论是管道安装还是康复。