In reply to the posts, my comments for what they are worth include:
flap gates are good is they can be maintained. it is more common for them to be forgotten and then get leaks rendering them pretty much useless. if they are in a location where it is difficult and costly to access there could...
You may want to ensure there is some slop in the inverted syphon so that any rubbish that enters the pipe ends up at one end or the other for maintenance.
You may want to lower the invert of the pit at the inlet to the syphon so that there is room for settling material to collect in one point...
RDK is correct on the issue with smaller bars at closer spacing as the placement of the concrete around the bars becomes difficult. The other issue is the difficulty in tieing the bars together when placed closer together. If a small spacing is required a welded mesh reinforcement would assist...
A good source of info for calculating wave heights is the ACES (Automated Coastal Engineering System) from the Waterways Experiment Station at the Corps of Engineers in the USA. Although the document is extensive it is quite user friendly and has a number of ways to estimate wave heights and the...
I once heard of a gret rule of thumb that actually involves your thumb (one suggestion on where the term comes from)
In soil mechanics you can use your thumb to evaluate the compaction of a material (usually clay) by pressing your thumb into the compacted surface.
If your thumb sinks all the...
I thought I would reply to my own request rather than re- entering it. Hopefully there is some one who can help me on this issue.
I was thinking it was something to do with Q=VA as the velocity of the water increases with gravity the area has to reduce. But, at what point does the area become...
I agree with Krautso. if you are working along the contour (or close to the contour) you can construct the emabnkment in lifts allowing for a flat working surface to comapct as you go along. trying to compact on a slope is difficult and vehicles such as scapers and sheeps foot rollers have...
jebbo2:
the limiting velocities in pipes is more restricted by the pipe lining material and the available head to create the velocity in the first place.
I am unsure what the FDOT suggests but here in victoria, australia the limts go up to 4m/s. Velocities over abut 2.5m/s should be looked at...
I know of some irrigation pipeline manufacturers in Australia who manufacture several different versions of collars for HDPE pipe. Some use a curtain and stell band around the pipe to secure the sheet. Others use a two piece bolt together HDPE rectangle with an opening the size of the outer...
I was wondering if anyonw knew a formula for the situation when you have free falling water, such as a waterfall to indicate the point where sheet flow becomes droplets?
I know it is a function of flow depth and velocity, but was hoping for some sort of formula to enusre it does not happen.
I...
Another thing that may be worth considering is the effect of the water flow on the long grass. The force of the water in the channel can "push over" the grass so it lays flat on the bed and banks of the channel effectively reducing the manning's n value. For a well grassed channel i...