I've been tasked with monitoring potential land movement/ impacts along a soon-to-be constructed road project. The intital phase of the project is to install some initial fill materials, in this case known as test berms, and check for loading impacts thru the use of settlement plates. 2 months out of the year, the area looks like a rice paddy. The following 2.5 months the hay emerges and it's a hayfield, barely above water. The base material is highly organic- basically peat-. the settlement plates is basically a slamdunk. My concern is the part of the task of monitoring for soil movement at the right of way line.
What would be the best material to use of the monitor stations? I'm going to be monitoring at least monthly, which means at least some of the time the positions will be inundated.
my plan so far.
use pressure-treated "2x4"- 6'0", cut pointed, and driven into the peat 4 -4.5 feet and attaching a reflective sheet tgt, near the top. I also will install a hub@ tack w/ whisker approx 4 feet away for a tattle tale, buddy. This will hopefully, verify true displacement in the event of tilting of the 2X4" due to side pressure. I don't figure on putting any iron pins in the peat because i don't think i can be garunteed that they wont sink on their own.
a few other parameters. avwerage distance from control to the monitor points will be less than 250'.
total number of monitor sites - approx 15. every 400'+/- for 2000 meters of frontage.
planned istrumentation will be an S6 robot.
Your thoughts?
I wish you all the luck. Sounds like you have a great control placement concept anyway. I myself have one in the same type monitoring projects, except with structures. I will be using the VX Spatial Station and applied 40mm targets to relative locations along the structures (MSE Walls and Road surfaces)_ then scanning using the VX capabilities for the road surface.
Let me know how it works. Are you planning on using the Monitoring software or data records? We have used records in the past and will be trying the Trimble Monitor add on in the Trimble Controller (TSC3 w/Access) and Trimble 4D Office Software. Let me know how your results turn out!
AzClif
The soil horizontal movement may be unequal at various depths, so you should plan your monitoring with that in mind. Perhaps if you take inclinometer angles on the faces of the 2x4's as well as your reflector positions, you can then compute the position of the surface and subsurface points?
How much shrink/swell should you expect because of seasonal change? temperature change? moisture change?
How should you construct your monument to best reflect your client's needs?
Let us know what you think of the Access monitoring add-on and the 4D software. I've been trying to get info out of my dealer about 4D without much luck.
Doug
