There are three primary methods for laying underground cables, each with its own advantages and applications:

1. Direct Burial: The cable is laid directly in a trench, often surrounded by a layer of sand or thermal backfill for protection and heat dissipation.

2. Laying in Ducts: Cables are pulled through pre-installed pipes or ducts, which are themselves buried in a trench. This method offers enhanced protection and makes future maintenance easier.

3. Trenchless Installation: Techniques such as Horizontal Directional Drilling (HDD) or boring are used to install cables or ducts without the need for an open trench.