Using RAS Mapper as a GIS Tool Part 1: Removing Bridge Decks from Terrain Surfaces This is the first in a three-part series on using RAS Mapper as a GIS tool. In this post we’ll cover the removal of bridge decks from terrain data. This topic comes up fairly frequently, since LiDAR data may be […]
Situation: Advances in HEC-RAS now allow for improved simulation of overbanks using 2D Flow Areas. Coupled 1D/2D models where 1D cross-sections represent the bank-to-bank cross-section data and 2D flow areas represent overbank areas has greatly improved the accuracy and robustness of HEC-RAS models. This is particularly the case in flat, urban areas with significant overbank […]
Take a look at the water surface profile in Figure 1 below. The two profiles are for Class A low flow (subcritical throughout) with identical boundary conditions, flow conditions, and geometry. The only difference is the bridge modeling approach: the blue line is calculated using the energy method; the red line is calculated using the […]
***Update: I received a few very important comments about this post that I want to share. First, and this is very important: These methods are not meant to be used to do any kind of detailed bridge design or bridge scour analysis (contraction, abutment, or pier scour). The methods I present in this post are […]
Here’s a video of pressure and weir flow yesterday at a bridge near my house. This was brought on by some very intense rainfall over a short period of time. What do you think the weir coefficient would be? ‘Tis the season in many parts of the world for heavy rains and high water. This […]