Influence Line & Surface Analysis

Influence surfaces extend the notion of an influence line onto a 2D surface and are used for plate-deck models. In LARSA 4D, influence lines & surfaces include algorithms to automatically find the worst-case live load scenarios by positioning vehicles and uniform lane loads to maximize the effect.

LARSA 4D Influence Surface Analysis Video

Unique Features

Special algorithms for vehicle loading produce faster and more accurate results when more than two vehicles are placed on a lane or deck surface.

Influence surface design lanes can include UDL without vehicle loading to promote flexibility in creating load combinations.

Centrifugal force factors adjusts vehicle wheel magnitudes, and multiple factors can apply on different segments of a single influence surface.

Supports curved bridges and skewed bridge decks.

Variable axle spacing, variable wheel spacing.

Parallel solver takes advantage of multi-CPU and multi-core machines.

Supported Codes

LARSA 4D provides tools that can be applied to any live load design code, including AASHTO LRFD, AASHTO LFD, BS5400, and Indian Roads Congress. The vehicle load patterns for these codes come preloaded in LARSA 4D, and additional as well as custom vehicle load patterns can be entered.