Explain Boring and its Methods

Boring refers to the process of creating holes or excavations in the ground to collect soil samples, gather information about the subsurface conditions, or install various types of foundations, utilities, or structures. Boring is a crucial technique in geotechnical engineering, environmental studies, construction, and geological investigations. It provides insights into the composition, properties, and behavior of the soil beneath the surface. There are several methods used for boring soil:

Auger Boring: 

• Auger boring is the simplest method of boring using hand drilling. 
• It can be used on shallow foundations up to 5 meters or so. 
• This method is generally used for cohesive and soft soils above the water table. 
• This boring method isn’t suitable for hard soil. 
• However, it's often used for preliminary investigations and to gather undisturbed soil samples for analysis.

Wash Boring: 

• Wash boring is the fastest and simplest method to make holes in all types of soil except rock and boulders. The process consists of casing, drilling, and chiseling. 
• The water is forced under pressure through the hollow bit, and the chisel starts chopping the soil. Disintegrated particles travel upward through angular space. 
• This method is simple and cost-effective for shallow boreholes in unconsolidated soils.

                    

Shell and auger boring: 

• This method involves the use of different tools for boring purposes. When dealing with soft to stiff clay, a cylindrical auger is employed, comprising a hollow tube with a diameter ranging from 75 to 200mm and featuring a cutting edge at its base. 
• This method facilitates vertical boring of up to 200mm in diameter and 25m in depth through manual rig application. 
• By utilizing mechanical rigs, borehole depths can be extended to 50m. At regular intervals or when encountering strata changes, soil samples are retrieved. 
• These samples are subsequently subjected to laboratory tests, enabling the identification of soil types and the determination of subsoil properties at various depths.

Rotary Drilling: 

• The rotary drilling method can be used for both soil and rocks. 
• A hole of 50mm to 200mm diameter can be made. 
• The rotary drilling methods are used to obtain the rock pores. A diamond bit or steel bit is used for drilling in this method, so this method is also called pore drilling. 
• It's a versatile method suitable for a wide range of soil types, from soft clays to hard rocks, and allows for both shallow and deep excavations.

Percussion drilling: 

• This method is used for making holes in rock, boulders, and other hard strata. 
• The heavy chisel is lifted and dropped vertically, which makes the rock pulverized, and when mixed with water, it forms slurry, which is further pumped out through a sand pipe. 
• This method can be used for any material. Materials at the bottom are distributed by a heavy blow. 
• It's less common today due to the availability of more efficient drilling techniques.

Sonic Drilling: 

• Sonic drilling is a method that uses high-frequency vibrations to break up soil and extract core samples. 
• It's especially useful in deep and hard soils because it causes little damage to the surrounding ground.