Zarinkelk Engineering Services Inc. will move its offices to a new location next month and plans to double its employee count over the next year. The Houston-based civil and structural consulting engineering company plans to hire around 15 new employees — mid-level engineers as well as recent college graduates — to its roster and is moving downtown mid-October to Caroline Street. The firm has worked on a variety of high-profile projects including three segments of the Grand Parkway and multiple…