Boring does not allow direct admittance to the subsoil and subsequently, holes are bored into the ground. This can be done by power augers or by hand augers. Practically auger boring is a decision or an instrument as we say in general language which supports us in developing a borehole into the ground.
There are several different hand-operated augers and power operated ones too. Two different types of hand-operated augers are helical type and post hole augers. With the most popular method being posted hole type. The bottom part of it is pressed into the ground and handles provided at the top are used to rotate the augers, During the continuous process of pressing and simultaneous rotation the auger is then gently driven in the ground. After some time when auger reaches a finite depth it is completely filled with soil it is taken out of the ground surface and the soil is then removed from the auger.
Hand operated augers can make holes the depth of around 30m. The use of suffers in boring is suitable for all types of soil except gravels and boulders. To add more auger boring is the cheapest way to advance a borehole into the ground. Another type of auger hollow stem auger is the type of device that acts as its own casing. It can bore a hole rapidly up to a depth of 60m.
According to Simon from Allen Watson “In general cases, we prefer auger boring where the sides of the borehole can stand without external supports.” Generally, auger boring is used in fields where it is then not necessary to bore a hole more any deeper than 6m. This method is extensively used in cases as soil investigation works for railroad, highway or airport construction where the depth of borehole is usually less than 6m.
In case of situations when deeper holes are to be bored into the ground, power augers will be used. The diameter of augers used varies from 75mm to 300mm and they are often used in cohesive soils. If large augers are required, trucks mounted with auger type drilling machines are used. However, this method can be very expensive and not reasonable unless the project in which it is used is very large and vital.
A trenchless method of installing clay or concrete jacking pipes can also be used with a high degree of accuracy. The process is primarily used for the construction of gravity sewers where traditional methods would either not be feasible due to surface obstructions or that the depth of installation required increased cost about that of auger boring.
Compact auger boring system designed to exit from a manhole and small pits. It obtained its accuracy in line and level by pushing a hollow rod fitted with an illuminated target at the rear of the inclined faced cutting head. The target is viewed on a monitor through the theodolite in the pit bottom set to the required pipe centerline.