引导镗孔方法：飞行员

这试点管引导镗孔方法通常用于当今城市的电缆，管道或导管。这boring设备使用指导系统，该指导系统可以更高的准确性而不是其他隧道选项。（读Guided Boring Machine Maintenance Checklist。)

了解所需的设备，需要什么评估，如果该方法适合他们的需求，则可以帮助项目规划者了解的福利和限制。（读规划过程：如何为一个绝抗项目做准备。)

What Equipment Is Required for the Pilot Tube Guided Boring Method?

这guided boring method使用各种设备来完成镗型飞行员。设备的大小和精确组合取决于项目的性质。但是，每个引导的镗孔方法都需要一个杰克框架。

框架容纳圆筒，以在帮助确保管道沿正确的方向移动时将管子推动到位。框架安装在entrance pit项目一起guided boring machine(GBM).

Additional to the jacking frame, there is a power pack to run the drill. These power packs are often hydraulically powered using the hydraulic fluid to help cool the diesel engine. The packs which use an electric motor do not use liquid to cool the motor. The packs vary in size from 75 horsepower up to 200 horsepower to control the jack.

A guidance system is necessary to ensure that the cutting goes as planned. The operator controls the angle of the剪头通过指导系统。该系统由经纬仪组成，并具有带有照明LED目标和相机的远程专注。

计算机允许操作员每隔几秒钟记录移动时控制切割头。

All guided boring method pilot tubes required some form of cutting or reaming head. Some projects,就像2016年在明尼阿波利斯完成的那个，使用8英尺的16英尺轴来制造先导管。

这起挂管道is formed by vitrified clay, which housed the cutter head and the reaming head. (Read这History of Vitrified Clay Pipe in Trenchless Installation。)

这reaming head followed the pilot tube to make the hole more significant for the final pipeline to slide in place.

What Field Evaluations are Necessary?

在开始引导无聊之前，工人必须收集土壤样品to determine what type of soil is in the area. Traditionalauger boring方法不利于交叉混合条件。如果操作员知道预期的预期，则导向镗孔方法可以适应不同的土壤类型。

Soil conditions for guided boring the dirt should be easily displaceable. It works well for wit sand, caliche, or clay. The cutter head is capable of grinding through small boulders, but not more significant, denser rock. It is not suitable for use below the groundwater table.

这same soil investigations used forhorizontal directional drilling(HDD) projects should be conducted for pilot tube guided boring methods. These tests should include samples from several positions along the boring track.

在埃德蒙顿加拿大, engineers check six drilling indices to ensure they can identify the soil transitions throughout the drive length.

What type of Pipeline Uses the Pilot Tube Method?

Most subterranean pipeline installations can use the pilot tube method. The method works for lengths up to around 500 feet (or 152.4 meters), and pipes can have diameters of up to approximately 60 inches. While it works for most utilities, it is not the choice for installing new sanitary andstorm sewers。它是水，天然气，电力和电信线路的选择。

Guided boring is an idea for lines that need to lay relatively close to the surface. Pilot tube methods work at depths around four feet or more. While other ways, such as HDD, require greater depth.

As there is little to no fracking involved in pilot tube guided boring, there is minimal disruption to the surrounding structures.

What Are the Benefits and Limitations of the Guided Boring Method?

As with all drilling methods, there are benefits and risks that engineers must weigh when deciding on how to proceed with the project. The following benefits and risks are just a few that should be considered during the planning phase of any project where guided boring may work.

Benefits

这re are many benefits of using pilot tube guided boring methods. The first of which is versatility. The equipment works with a wide variety of conditions. If the operator knows what type of soil is along the digging track, they can adjust the cutting speed and direction as needed.

An additional benefit is an accuracy provided by the guided boring method. With the onboard guiding system, operators can follow the cutting head, with an acceptable margin or error. The cutting head is continuously monitored for accuracy.

Finally, the environmental impact of using guided boring methods is less than traditional drilling methods. There is little to no damage to the surrounding soil. There is a smaller footprint with little in the way of greenhouse gases being admitted.

Limitations

Pilot tube guided boring methods are an optimal choice for installing underground utility lines. However, even the best options have some limitations. One such restriction is while it works on multiple types of soil, it is not suitable for the ground with copious amounts of gravel, rock, or medium to large boulders, which is why a soil survey is essential before the start of the project.

Rocky ground conditions can cause the pilot tube to deflect off course and affect the guided boring’s overall accuracy. The soil should be above the area’s水桌子。

此外，有多少算子可以使用导游的镗孔系统。这些器件不设计用于钻孔超过600到700线性脚。最好将驱动器放在400英尺以下的最高精度。

我们学到了什么

试点管引导镗孔方法有助于确保孔稳定和精确。市政当局可以使用这种技术在不扰乱周围的土壤和生态系统的情况下铺设新的地下公用事业。

尽管有很少的局限性，具有适当的规划和土壤调查，但这种方法可能是一个地区新电气，水和电信线的最佳选择。