road design 3

[sfmech]

I have project engineering experience and I am from mechanical background. Can someone explain what inputs ate to be given to civil dept. For road design in chemical plant. I just need to know about the inputs and outputs of road design. The outputs will be drawings, I suppose.

 

[oldestguy]

First: Where is it to go? If you cannot provide a map, they will have to do a survey and prepare their plan and profiles from information on the ground.

Next: What kind of soil is there? The civil group has to show where test borings need to be made to provide that. there may have to be a separate contract with a test boring company, not likely the civil group capability.

Next: How many trucks a day?

Next: What are the truck axle loads or perhaps just truck types and capacities?
Perhaps some limits to construction accessibility known ahead of rime, such as restricted areas.

Is there a preference as to pavement type?

 

[fel3]

Also…

(a) Is the road to be one-way/one lane (e.g. a loop road, similar to what you find in a lot of campgrounds), two-way/two-lane (probably the most typical design), or something else? The owner may have specific criteria for how traffic moves around the site. If not, the design team (including, but not limited to, the civil) should sit down and figure this out and present it to the owner for approval or modification.
(b) Is the roadway width limited to just the travel lanes (e.g. a two-lane road might be 24' wide to accommodate two 12-foot lanes) or is a shoulder desired and, if so, how wide?
(c) Are turnouts needed at various locations? Some of the prisons I have designed have had one-lane exterior patrol roads with turnouts at each guard tower. The purpose of these turnouts is to allow one or two vehicles to be parked on pavement but out of the traveled way.
(d) What types and sizes of trucks will be using this road? Truck turning radii affects horizontal curve alignments and intersection designs. In any event, the smallest design vehicle will most likely be the largest fire truck operated by the local fire department and they should be able to provide that information. Along these lines, you may also have fire hydrants that are remote from the main circulation roadways. If so, it may be necessary to provide paved fire truck access to these fire hydrants. Fire truck access does not have to be paved per NFPA (I have used gravel), but many fire departments require it.
(e) What is the maximum speed for the road? For a private project, this might come from the owner or the civil might recommend a design value.

In addition, the project will almost certainly require one or more paved parking lots. The local agency should have minimum parking standards that will apply, but if not the owner should have some idea of how many passenger and other vehicles to accommodate. I did the civil design for an ethanol plant about ten years ago and the owner's parking requirements far exceeded the local agency's requirements. We also made the parking spaces slightly over-sized at the owner's request to better accommodate dualie four-door pickups.

Because each project and each site is different, there are many other questions a savvy civil is going to want answers to regarding the on-site roads and parking areas. Where such answers are not available (or haven't yet been decided), the savvy civil will be able to come up with reasonable suggestions.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[bimr]

Inputs:

[ol 1]
[li]Site factors and constraints (To determine the constraints which may impact on the location for the proposed works and the design. What side of site is available for access, is the site flat or rolling?, etc.)[/li]
[li]Procurement of investigations and surveys[/li]
[li]Geotechnical investigation[/li]
[li]Topographical survey[/li]
[li]Locations and requirements of existing and new services (Location size and capacity of the existing water supply, surface water and sewage disposal and the likely additional requirements for the project. These services impact the location and road design)[/li]
[li]Archaeology, special conservation areas, protected structures, environmental, etc. (identification of potential impacts)[/li]
[li]Scope of essential work required to existing infrastructure (potential offsite work to existing roads, etc. for connections)[/li]
[li]Consultation with agencies and authorities have jurisdiction that will approve project particulars[/li]
[li]Traffic study (for plant site and connection to off site highway)[/li]
[li]Site (Check the property conditions of sale for burdens, easements, and particular conditions. In all cases the site boundaries should be confirmed.[/li]
[/ol]

 

[oldestguy]

Even if this is a negotiated construction job, you should have a set of plans and specifications as if it were bid. Sometimes the purchasing departments of large companies have some "cover their a##" wording in standard purchase orders. Be aware that this can greatly increase the cost of the job. No contractor in his right mind will stick his neck out without some coverage by insurance for these requirements.

Arrangements for construction inspection are recommended for any job, since corners can be cut and unforeseen conditions may come up requiring re-negotiating.

The specifications usually have a section on payment to the contractor, in steps, with final payment after approval and acceptance.

 

[BUGGAR]

Why not ask the Civil Department what they need to fulfill their responsibilities?