> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/loading-stg/loads-stg/inf-surf-based-llbrce-stg.md). # Inf. Surf Based LL/BR/CE \[STG] The effects of Live Load, Braking Load, and Centrifugal Load in OpenBrIM are calculated using the generated Influence Surfaces. The defined roadway is considered the boundary for applying Live Loads and is further utilized for Influence Surface definitions. To satisfy the requirements under extreme conditions, engineers must calculate the maximum and minimum reaction forces and moments at supports. To address such cases, Influence Surfaces are generated and used in the calculations of Live Load, Braking Load, and Centrifugal Load effects on the structure. After running the analysis for varying load locations, the user is presented with the following results: 1. Minimum/maximum force for selected Fenode/FELine/FESurface or composite elements. 2. Minimum/maximum stress for selected Fenode/FELine/FESurface or composite elements. Such analyses are also supported for rails on OpenBrIM. For a detailed explanation of each library object, refer to the relevant section of the documentation. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/loading-stg/loads-stg/inf-surf-based-llbrce-stg.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.