Driven pile foundations consist of long, strong members driven into the ground to support structures where soil conditions are poor or unstable near the surface. Piles transmit loads through weak soil strata to firmer soil or rock at greater depth. Common pile types include steel pipe piles, steel H-piles, concrete piles (precast or prestressed), and timber piles. Pile selection depends on soil conditions, load requirements, corrosion environment, and cost considerations. Steel piles are strong, durable, and can withstand high driving forces. Steel H-piles have a wide flange shape that efficiently resists bending. Concrete piles are durable and provide good bearing capacity but are heavier to handle. Timber piles are economical but have limited durability and load capacity compared to steel or concrete. The piling contractor determines the required pile size, length, and spacing through soil investigation and structural design. Pile-driving equipment including diesel hammers, vibratory drivers, or hydraulic presses drive the piles into the ground. Noise and vibration from pile driving must be managed to avoid damage to nearby structures and excessive disturbance. Driving monitoring includes measuring hammer blows and movement to verify the pile has adequate bearing capacity. Pile capacity is often verified by dynamic testing or static load testing. Piles may be left in place to serve as permanent supports (bearing piles) or may be cut off at the ground surface and connected with a pile cap (cap beams). Pile caps are concrete beams connecting multiple piles and distributing loads to the piles. Connection of the structure to pile caps is through anchor bolts or embedded connection plates.