LARSA 4D LARSA 4D is an advanced analysis and design program for 3D structures with “4D” time-effects, with special tools for bridge projects. It is based on a rock-solid analysis engine and has an intuitive and modern user interface for Microsoft Windows. Features include 3D post-tensioning tendons, seismic and inelastic elements, bridge geometry coordinate systems, influence surfaces, and extremely powerful macro capabilities such as integration with Microsoft Excel. LARSA Section Composer LARSA Section Composer is used to model the cross-section properties of arbitrary shaped sections which may include rebar, nonprismatic variation (haunches), and composite materials. Its analysis capabilities include moment curvature analysis, ultimate strength analysis, and torsion constant computation for sections of any shape. Its parametric and formula-based approach to shape templates and nonprismatic variation define the product as unique in the industry.