Why Does Concrete Settle?
Concrete settles for many reasons, like poor compaction, bad site conditions, poor drainage, and tree roots. The most common reason for this issue is when rainwater or water from gutters washes away dirt from under your sidewalk or driveway. That creates voids or pockets beneath the concrete, which causes it to settle.
Another reason is clay-rich soil, which expands and contracts as per its moisture level. When the soil is saturated with water, it expands. And when it dries out, it shrinks. Thus, the frequent change in moisture results in unstable soil, which causes the concrete to move and sink.
Concrete Leveling Using Polyjacking