• Vibration


• Impact

Various compaction equipments are -

1. Smooth wheel roller


2. Pneumatic tired roller


3. Sheep foot roller


4. Vibratory roller equipment –
   1. i. Dropping weight type
   
   
   2. Pulsating hydraulic type .

1. Smooth wheel roller – Smooth wheel roller compacts the soil by applying pressure on it . It is used for coarse grained soil and spread in thin layer . For find grained soil , they are not effective . These rollers are only useful in smoothing the upper layer , whereas bottom layer normally remains loose .


2. Pneumatic tired roller – Pneumatic tired roller used the principle of ___________ action to effect the compaction below the surface . They are generally self – propelled . The rear tires are spaced in such a way they travel over the surfaces between the front tires . Thus the roller produces compaction of the whole surface . The parameters which determine the compacting ability of pneumatic rollers are –
1. Wheel load