driveway edge repair

[ultrarunner]

My thought also. You do need to do it the right way the first time, the existing road going away would not be the right way and surely end up costing more.

Living in Georgia, we hear of slides in Cal. often when you get big rains. Is this common around your area of California?

I hope you will update the post as you work on a solution.

MarkV

Well, yes and no.

We can go for years under water rationing and then we get a wet year at 165% over the course of a few years and all bets are off.

The SF Bay Area has slides in every communtiy... some affect roads and others newer subdivisons.

 

[beeforty]

You look like typical Santa Cruz Mountains type slide. They are more like big sand dunes with redwood trees growing on them. :laughing: Water sinks to a solid layer then goes down hill and "lubricates" the bottom of the bank, then like the song.."slip sliding away.." Then the water comes out

 

[mpowrd]

beeforty: You're spot on. That's in the Santa Cruz Mountains above Los Gatos.

Update:
Based on info here and similar assessment by a couple of contractors out here, I took a 2-phase approach to getting things stabilized.

First, I got two loads of about 1/3 yard of 3/4" crushed rock in bags (all I can carry in an Explorer) and filled the muddy area on the uphill side so traffic can drive well off the undercut slide area. That allowed some exiting tenants to get moved out and the new ones moved in without damaging the driveway any further.

Second, I had a contractor friend that does excavator and tree work for me come in and build a wall of burlap bags filled with base rock and cement. These were anchored with 4' rebar driven down through them. We then backfilled with base rock wet down and hand-tamped into the unsupported slide area. Looks good enough now to last through our dry summer with traffic staying on the uphill side. We added some additional base rock over the 3/4" crush I laid down so we have a very driveable surface.

Third step will be a more permanent solution with drilled footings reenforced with I-beams or similar and a proper poured concrete wall and then rebuild the driveway bed and repave it. That will need some engineering consultation, time for the soil to dry out, and a source of funds.

Thanks to everyone for your help. Pictures through phase 2 are attached.

 

[beenthere]

If there isn't a culvert under that drive where it washed out, then there certainly should be.
The last pic shows the hillside above the drive that has to have water come off it when it rains. It should get collected in a ditch above the drive and pass under, through a culvert. Then down hill in a ditch or culvert to get to the next lower levels.

Hope your fix works well for you.

 

[gwjd]

would some rock baskets filed with large rock in 2 levels down hill then a culvert or other drain then fill with rock repave .......

just an idea sounds cheaper than concreat beams and wall

also sounds more permanent .....

 

[Egon]

Interesting site to evaluate and design for an keep it within a reasonable budget.

Without any real knowledge of the site or soil stabilization design I'll make some comments.

Water content of the soil appears to be the culprit. The whole hill is liable to slip again at a deeper level and further back into the hill. An action like this would most likely take any piles with it as they would be included in the slide volume.

As suggestions go diversions of water at the top may help. Horizontal bores at the base and higher intervals may also help drain the water.

Increase the amount of dirt at the base may help anchor the side hill or prevent it from sliding. Doing this would probably involve starting at the top of the hill and side dozing dirt till the road grade is reached.

If the temporary fix looks like it will hold up take a wait and see attitude.

The pile idea bothers me for some reason. Maybe it's the cost to do it properly??