I believe VAD is correct. In the case of an earthquake the soil around the structure may not provide sufficient support to the pier, as it could move independently of the piers. Consequently, the pier would not have lateral support. Therefore, it is necessary to tie them together to ensure...
The correct way of modelling this problem is how RWF7437 or bltseattle suggested.
Gravity flow is pushed by the difference in total energy, so what will happen here is that the flow will build up a head to push the flow through the pipe. This will happen even when the pipe is not flowing full...
I suggest the following document for a very useful explanation of the SCS unit hydrograph method:
www.info.usda.gov/CED/ftp/CED/neh630-ch10.pdf
Once you understand the method, then you can apply a computer model such as HydroCAD.
What you will find in hydrograph methods, is that the...
I believe that it makes more sense to design the overall system taking into account the concept of minor and major systems: the minor system conveys the more frequent storms, say up to a 5-year storm, and the major system is designed so that the 100-year storm can be conveyed safely. This...
Don't let the structural scare you, I know what I'm talking about (15 years of hydraulic engineering practice on top of 10 years as structural):
In the standard step method, the calculations proceed from downstream to upstream for subcritical flow and vice versa for supercritical flow.
If the...
I design retaining walls using spreadsheets or MathCAD. In all cases, though, I have to do a trial-and-error method to arrive at the structure dimensions. Some structural manuals will give you some general ideas based on past problems.
Usually the rain part on rain-on-snow events is less intense than for usual runoff calculations. This is because the large, high intensity storms occur during the non-frozen part of the year. So in effect, you should calculate the n-year storm using peak rainfall data applicable for the months...
I agree with Iha. Do you have photos of the reach? The Manning equation will give you an approximation, but would not be correct in a reach where the flow is gradually variable.
For practical purposes, the 101-year flood is equal to the 100-year flood is equal to the 99-year flood. We must not forget that the 100-year flood is the flood that has a probability of 0.01 of being equalled or exceeded in one year. However, in most cases we don't have enough records to...
I agree with bltseattle. Most of the time the problem is due to the program not being able to converge to a solution on the section downstream of the crossing.
In addition to more sections, you should check the elevations you input for the ineffective flow areas on each side of the culvert...
The first thing that should be done is to provide intermediate supports to reduce the beam spans. From your description, you have a "failed" support structure, which may be still working due to redistribution of the load.
It is reasonable to assume that the dynamic torque will be transmitted...
I suggest that you contact the local university's Civil Engineering Department. The structures section likely has the required data, or data from which you could develop the S1 and S2 values.
gman1,
For dams the headwater and the tailwater numenclature are as explained by flame. However, it seems that for floodwalls there is no consistency in numenclature. My own inclination is to call the "headwater" where the water is, and "tailwater" where I want it to go.
In the case of a...
