The wave energy of the ocean is one of the natural resources that cannot be ignored. The oscillating water column (OWC) wave energy converter is a promising technology due to its simplicity and reliability. For the convenience of construction, OWC devices are often installed on the sidewall near the coast. Therefore, this research analyzes a similar OWC device combined with a water surface-piercing vertical plate and an end-upright wall. Furthermore, the seabed near the shore is not a flat topography. Hence, in addition to considering the case of a flat bottom, this work also analyzes the impact of the sea bottom with a step or a sloped structure on the wave motions. The solitary wave is generated to impact the simplified OWC device to analyze its maximal runup in front plate and maximal water level in the hollow zone of OWC.