Developing a physics-based model for post-earthquake ignitions

Earthquakes not only cause damages by shaking, but secondary disasters like fire following earthquake (FFE), tsunami, liquefaction, land slide etc. also cause large-scale losses. In some cases, FFEs result in losses more than shaking do as seen in the 1906 San Francisco earthquake and the 1923 Kanto earthquake. FFEs are generally caused by strong ground shakings. Strong shakings damage the structures and infrastructures. As a consequence of earthquake, many ignitions can occur due to damaged gas systems and electrical systems, overturning of electrical appliances and heating equipments and falling of flammable materials from shelves in structures. In addition to interior structure ignitions, damaged infrastructure elements such as gas pipelines and electric transmission lines can also cause ignitions. Some of these ignitions spread due to amount of fuel load (combustible materials), construction material, direction and speed of wind etc. in the environment and they can turn into large urban conflagrations. This paper proposes a physics-based post-earthquake fire ignition model in order to estimate number and location of ignitions in urban areas.