Slope and Ground Mov't Repairs
Slope and Ground Mov't Repairs
(OP)
Hello!
I am working on a slope and ground movement assignment caused by fat clay and high groundwater. The toe of the slope is adjacent to a concrete sidewalk which has uplifted (buckled) and the ground movement even extended into the streets. Due to the amount of underground utilities beneath the sidewalk and the heavy rain during the winter, excavating the area by removing the clayey soil and replacing with gravel and installing a drainage system is not what I want to do at the moment.
Are there better alternative temperary repairs that someone could recommend to stablize the toe for the time being without having to excavate during the wet weather season?
Thank you,
-gingerbread
I am working on a slope and ground movement assignment caused by fat clay and high groundwater. The toe of the slope is adjacent to a concrete sidewalk which has uplifted (buckled) and the ground movement even extended into the streets. Due to the amount of underground utilities beneath the sidewalk and the heavy rain during the winter, excavating the area by removing the clayey soil and replacing with gravel and installing a drainage system is not what I want to do at the moment.
Are there better alternative temperary repairs that someone could recommend to stablize the toe for the time being without having to excavate during the wet weather season?
Thank you,
-gingerbread





RE: Slope and Ground Mov't Repairs
A temporary fix maybe to increase the toe support by placing a surcharge load on the toe (I.e placing 1m x 1m x 1m cocncrete blocks). The amount of blocks required could required could be calculate by modelling a surcharge loading in SLIDE. A FOS >1.2 would be appropriate for temporary support
RE: Slope and Ground Mov't Repairs
Again, if you can, try to quickly unload the crest of the slope and if you are having heavy rains, we have seen in the tropics the use of membranes placed on the slope to keep the water out of it. This will reduce the driving force. Are there any "springs" breaking out into the slope face? Would horizontal drains into the slope be useful? (short term might consider drains under vacuum to pull down the phreatic surface quicker - if the phreatic surface is high at equilibrium).
Just some thoughts - sorry if it seems a bit disjointed . . . but as I was writing, things from past projects just seemed to be popping into my mind . . .
RE: Slope and Ground Mov't Repairs
I think a starting point would be some boreholes to asses parameters such as shear strength, cohesion and current ground water level. I would then do a stability analysis to asses various stability solutions.
If you could supply a cross section with borehole information it could help develop the geotechnical model. I'm sure you would get some better feedback then
RE: Slope and Ground Mov't Repairs
Thank you both for contributing solutions to my question. I Do have some laboratory testing data from the soils collected from the slope that I can use for a stability model(s). I will supply some more information later such as a cross section with soils paraneters to better illustrate the condition in the field.
RE: Slope and Ground Mov't Repairs
RE: Slope and Ground Mov't Repairs
If it is shallow type failure. Blocks could be an idea. An improvement in this could be to place 1.5m high blocks right at the toe and place some hsrdfill behind to add further surcharge. These blocks can be rented for relatively cheap. Sliding and overturning failure should be ok in the short term
RE: Slope and Ground Mov't Repairs
After studying the slope and sidewalk issue further, it appears water from the hillside (maybe even naturally occuring springs) is a major problem. The uplift in the sidewalk is most likely due to the water from the hillside mixing the fat clay. The plan is to install a drainage system on the slope and at the toe (underneath the sidewalk) and connecting the drains to the existing city's drainage inlet to discharge the water. By removing the water, I think, will eliminate much of the problems.
RE: Slope and Ground Mov't Repairs