Complex sentence: The peak horizontal acceleration (PHA) is the most commonly used type of ground acceleration in engineering applications, and is often used within building codes and plotted on seismic hazard maps.
Split into simpler sentences: The peak horizontal acceleration (PHA) is the most commonly used type of ground acceleration in engineering applications. It is often used within earthquake engineering (including seismic building codes) and it is commonly plotted on seismic hazard maps.