Allen specializes in geotechnical and geostructural engineering in Thornton Tomasetti's Forensics practice, helping clients understand the causes of damage and performance issues. He has decades of experience in design and investigations for buildings, industrial facilities, and critical infrastructure. Allen works across complex subsurface geologic conditions including sands, clays, marl, and rock. His expertise includes analyzing and evaluating soil-structure interaction, foundations, earthen systems and soil-retaining structures, site conditions, and structural distress.