i would just drill 2 holes--- 18" x 36'', fill with 3500 mix concrete, set anchor bolts, or once concrete sets use a hiliti drill and use some 3/4 x 6 redheads with a 3/4 x 10 x 10 base plate, will be plenty
I assume that cost isn't a big concern in this case (as long as we don't speak of a million dollars), so I can send you the Anchor Bolts Engineering Standard that we used, back in my days of erector engineer, in the construction of a new oil refinery in the province of Mendoza, Argentina. 60 mph, or more, winds are frequent in the region, and most important, the province of Mendoza is a Grade 4 Earthquake Zone, which means that the worst earthquakes on earth can occur there. The last one happened in 1944.
A lot of anchor bolts types are depicted on that Engineering Standard, all of them designed for Grade 4 earthquake. I can send you a copy and you may choose the one that suites you better. However, it's not in electronic format, just printed, so I'll send it by Priority Air Mail. If you agree, send me a Private Message through this Forum with your mailing address. Depending on which city of the USA you live in, it'll take 6 - 10 days to reach you.
Of course, there will be no charge at all. It'll be a pleasure to be of service to you.
Giovanni S. Crisi
Sao Paulo - Brazil
Gotta love this forum! Thanks for all the replies. Yes, it is in the area south of Fayetteville, WV and the sign itself will be located about 7 miles south of the Gorge itself. I am now thinking about going the bolts in concrete route, similar to what I have seen on other signs around here. That way, I can pour the concrete and set the bolts one day, and then erect the sign after it cures. With the nuts above and below the plate, I should be able to level and adjust things just fine. As far as erection goes, I think I am going to assemble a crew of friends and do it Amish style. It's only 430 or so pounds..... PM's sent to all who so graciously offered extra help, if you ever want to come and see some of the best whitewater in the east, give me a call, I'm a better raft guide than I am a welder.
If You keep the top of the concrete above grade, You won't get the rusting that comes along with soil contact. The bolted base sounds like a good idea to Me as well.
For what it's worth, you will notice that the electric utility industry typically set their columns on double-nut anchor bolts with no grout below the baseplate. Their theory is to allow air to circulate below the baseplate and preclude rust. As long as the space between the top of concrete and bottom of baseplate is no more that 1 1/2 times the bolt diameter, bolt bending should not be an issue.
I would love to hit the whitewater again but old age is keepin' me and the wifey on dry land. We loved the Class 5's on the American River!