SDR-35 is to light for this application. I wouldn't go any thinner than SDR-21. Ductile Iron should also be considered. Include a proper bedding detail and enough inspection to make sure the installation is correct. With 30' of cover and railroad sidings on top, any failure or deformation...
I don't use the sliding resistance of the soil for two reasons:
1. The worst case may occur during construction, before there is any backfill.
2. I practice in an area with clay soils that in dry weather may shrink and pull away fron the walls, reducing the friction.
Some additional concrete...
I see no need for an acceleration lane. Traffic from the side road will wait for a gap in traffic before entering. The deceleration lane or right turn only lane is a good idea.
Your last statement and question: "I figure that when pump is not on gravity flow will push as a siphon into manhole. When the pump comes on what will happen...Will it pull with a vacume?"
The pump will not pull a vacuum, it will cause a back pressure on the check valve until the valve fails...
My company went through a similar situation when working as City Engineer. We were regularly requested to provide copies of documents that the City already had. A phone call to us was less work (for them) then going to their files and locating what they needed. This continued for a while...
I have done a lot of subdivision design, and we are usually required to submit calculations for the storm sewer and storm water detention design. These calculations are almost always reviewed in detail by the city engineering staff.
I work for a private consultant that does many municipal projects. We have encountered companies that have copied our plans and specs on projects that are out for bid and have made them available online. We've had to contact these companies and tell them to stop reproducing our copyrighted...
You could try electronically tracing the pipe to find out where it originates. I am surprised that there isn't some indication of the excavation that would have been done to install the pipe. Some possibilites for a source that wouldn't show up immediately with dye testing: sump pump for...
Neenah Foundry Co. has done actual tests on their grates, both in curb flow and ponding. You should be able to access this data from their web site and select a grate that is similar to the one your ae evaluating.
You describe this as a main highway, which suggests that it is owned by the Virginia DOT. Since you are going to need a DOT permit for the work, go to them to discuss the project ASAP. They will tell you how they want traffic control to be done and will probably have standard details to use.
Regarding Option 3 (Surveyor. I don't know where you live, but all of states that I have knowledge of require a substantial amount of experience working with a licensed surveyor before you would be eligible to take the licensing exam. You should check into this before you make your choice...
Delta#1 = 90d47m55s
Delta#2 = 121d46m10s
These are the differences between the end angle and the start angle, which are the bearings of the tangents.
T = tangent lengths of the curves. These lengths are sometimes needed for staking but probably aren't necessary fot the small curves described...
The existing 4" is to small even for a service. It should be at least 6" diameter. The slope of 0.10% is much to flat. The usual design is a flow velocity of 2 fps for the pipe flowing full. I don't understand how this would have been permitted
I would suggest replacing all of the sewer with...
