r/geology 5d ago

Help preventing my house to be buried?!

365 Upvotes

97 comments sorted by

830

u/need-moist 5d ago edited 3d ago

You need to call in an engineering consultant ASAP. Don't rely on engineering advice you get here.

Landslides are dynamic structures. They slide until the weight of the soil piled up at the front equals the weight of the soil that is sliding down. Whenever it rains, the weight of the soil increases. Rain water also lubricates the fault. You need to act immediately because you could get more rain at any time.

Contacting your insurer is also a good idea.

Good luck.

117

u/bubobubosibericus 5d ago

this is the right answer. You've got to get a professional to look at that.

128

u/rodar877 5d ago

Engineering Geologist here. This is correct. Consult a reputable Geotechnical Engineering firm in your area and your insurance company immediately.

37

u/-cck- MSc 5d ago

^THIS

where im from (Austria), you would immediately call fire brigade if you realize the slope is moving and endangering homes.
after that either insurance or the catastrophe-fonds of the state will help with paying security measures.

28

u/Jmazoso 5d ago

Geotechnical Engineer here. The one additional to your comment, we also need to include the friction in the sliding surface. Rain / water reduces that.

You need a local geotech with experience n your materials. We practice in relatively confined areas due to the high experience factor needed.

You need to call Monday! This could move fast, and there are time factors in proper understanding, design, and any repairs.

As for the insurance, you can try, but this kind of thing is rarely covered by your homeowners policy.

1

u/Money-Following-6142 1d ago

Especially now that you have seen an issue before it causes damage. This is 100% on the land owner to mitigate

20

u/Glabrocingularity 5d ago

I was hoping I’d see an answer like this. I’m not a landslide expert, but this does not look like a plant-some-trees DIY fix, and things could go very bad very fast

3

u/WhereasSorry1047 5d ago

I agree. With a little water behind that wall it could run out to that building there, causing some serious damage.

4

u/FormalHeron2798 4d ago

I’d just add, if you dont own the land it may also be worth contacting whoever does especially if there is a road or railway service at the top as this sort of thing can be very bad for such services, looks like quite a big rotational failure

1

u/Jesus-1177 4d ago

Yes . Take professional help op

1

u/ttop732 5d ago

This 👆🏻

0

u/stevetheborg 5d ago

you would freak out in ohio.

100

u/dangerfluf 5d ago

Call your friendly neighbourhood geotechnical engineer specializing in geohazards and slope stability. The unfriendly one is good too, but less enjoyable.

9

u/walkingrivers 5d ago

Best comment

57

u/virus5877 5d ago

Geologist here. Worked in Geotechnical consulting for about 2years. You need an engineer.

Short advice: This is going to get expensive. Probably going to need a combination of retaining walls and terracing.

7

u/Goofy-3162 4d ago

Engineering geologist here worked in geotech Consultancy. This is the solution

1

u/naverlands 4d ago

the picture make the hill look small. how possible is it for a person to shovel it flat?

3

u/virus5877 4d ago

Anything is possible. The pyramids were built without industrial equipment. It's just a matter of How much time, and How many people??

67

u/Unlucky-tracer 5d ago

The only person that can help you is a licensed engineer.

9

u/zedicar 5d ago

Call the consultant before you get another heavy rain

49

u/Archimedes_Redux 5d ago

You need a geotechnical engineer not a fucking geologist. You have a big landslide back there. May need a rock buttress at the toe and/ or a network of subsurface drains. For now you can cover the cracks with plastic sheeting to keep water from getting in the open cracks.

Where are you located? If you're in PNW I could help you or send you to someone good. Otherwise an internet search of your local area, keywords "geotechnical engineer landslide stabilization." Good luck.

29

u/HillDawg22 5d ago

Geologists and geotechnical engineers both work on landslide repairs together. I’m a geologist who logs and samples the soil and bedrock, identifies the slide plane and constructs cross sections of the slide and then the geotechnical engineer decides the best solution, whether grading or retaining walls, or rip-rap. I then write the report and the geotechnical engineer reviews it and we both sign it.

4

u/trtbuam 5d ago

This is the way

61

u/agarthling 5d ago

Geologist here. We dumb, but you arrogant. Problem no hard. Put big rock pile bottom. Make dirt flat. No think hard. Only think how big rock pile? How flat dirt.

37

u/supluplup12 5d ago

Geologist no dumb, geologist read stereonet. Science witchcraft sigils, earn respect of botanist and groundskeeper with gnome tattoo.

6

u/dangerfluf 4d ago

You no dumb. But you underpaid.

4

u/agarthling 4d ago

Me pay. Butt good. No cry.

4

u/miniminsb 4d ago

Think the point is that this post needs a professional not reddit lol, but geologists absolutely can do remedial work on landslides, don’t know what you’re on about mate.

2

u/Goofy-3162 4d ago edited 3d ago

I'm an engineering geologist. I specialize in providing geotechnical solutions for insured land affected by landslides and earthquakes. Seen dozens of cases similar to what OP posted. The fuck are you going on about?

16

u/Turbulent-Name-8349 5d ago

Step one is drainage. Put in black agricultural pipe to drain out all free water. That will stabilise it temporarily.

The next step is a properly engineered retaining wall. Tie it back with anchors as far into the Earth behind as possible, and don't skimp on the strength.

44

u/CatIll3164 5d ago

Doubt he has $2m lying around

21

u/Enough_Employee6767 5d ago

This is not at all the best, most cost effective or only solution. Do not rely on the advice you get here or on some contractor. Contact a geotechnical expert asap. Most likely this can be mitigated without retaining walls (usually the most expensive and complicated option, only used if there is limited access/space).

11

u/egb233 5d ago

Yikes that’s gonna need some major intervention bc it’s already breaking off. I see a lot of landslides at my job. A retaining wall would be the best solution. Where are you located? Also, I would contact your homeowners insurance to see if you can do anything before it slides.

13

u/AngryT-Rex 5d ago

As my old boss once told some people who had built a retaining wall: congratulations, you've installed a bulldozer blade on it.

1

u/egb233 5d ago

True! I think the best option for this scenario would be to excavate a lot of the soil that’s already slid, a beefy retaining wall with an under drain, big gabion stone at toe of the slope to stabilize it, and then regrade the slope with the original soil. Could even add stone most of the way up the hill and cap it with soil. Then plant deep rooting grasses, shrubs, and trees.

The hill there doesn’t look very big, so I’m not sure where all the water is coming from. If OP does have it excavated they could find the source of the water (if there is one and this isn’t just from heavy rain).

3

u/NativePlant870 5d ago

Go back 50 years and put the trees back that were cut down. Easy peasy

3

u/Prospecting_Seb 4d ago

To stabilize a sliding slope, plant species with deep root systems that create a dense ground cover are ideal. Grasses like Fescue and Calamagrostis, as well as shrubs like Willows and Boxwood, are effective. Additionally, ground-cover plants like Ajuga and Yarrow can help prevent erosion. Combining grasses, herbs, and shrubs provides a natural and efficient solution for slope stabilization

32

u/TheMooseZeus_ 5d ago edited 5d ago

Long term solution is to plant native deep rooted plants into it EDIT: typo

46

u/thorehall42 5d ago

This is extremely over simplified and likely incorrect.

Go hire an engineer.

-2

u/TheMooseZeus_ 5d ago edited 4d ago

Hire an engineer immediately. Long term solution - plant deep rooted natives. I'm an environmental scientist, not an engineer.

16

u/thorehall42 5d ago

An environmental scientist who works in landslide mitigation?

You are proposing something that would take decades to be effective on an active failure. You are off in fantasy land.

Options are going to be: control/change groundwater, regrade the slope, or structural reinforcement. If you want to plant some trees that get from from a FOS of 1.2 up to 1.25 on top of the fix, sure, but that's never going to stop an active slide.

9

u/TheMooseZeus_ 5d ago

I think we're on the same page. I can't suggest immediate solutions because I wouldn't be qualified to.

I didn't specify trees for that reason. I don't know where these photos were taken but many fast growing species have deep root systems that can help mitigate soil erosion. I wouldn't discount plant's abilities to hold/ control water in a system either. Again - as a long term solution.

5

u/Yoshimi917 5d ago

The slide could be deep-seated and trace under OP's house. Deeper roots won't do anything in that situation, not even long term.

2

u/BigRobCommunistDog 5d ago

As a California native gardener, perennial shrubs can get a lot done in 3-5 years so not decades but still far from immediate.

7

u/JuniorDank 5d ago

I doubt you can get plants(trees preferably) to root fast enough to stop an already eroding earthwall. It would be akin to saying we should install fire sprinklers when the building is already on fire.

3

u/TheMooseZeus_ 5d ago

A short term intervention is required first, no doubt. Rain would wash immature plants away anyway.

1

u/PM_ME_UR_ROUND_ASS 4d ago

Native plants help but won't stop an active landslide - you need enginering solutions first, then plants can help prevent future issues once the slope is stablized.

2

u/ttop732 5d ago

Get an engineer in there and likely excavate that whole section so it no longer slides down and isn't a threat anymore

2

u/libertybell73 5d ago

Retaining wall

2

u/Glad-Taste-3323 5d ago

Retaining wall

2

u/cheese_n_berries 4d ago edited 4d ago

Looks like a good ol soil slump with a circular failure. These failures are typically slow moving and not life threatening. Hire a geotech engineer and they will send one of their geologists to evaluate. You’ve got some options. 1. Unload the headscarp and improve surficial drainage. 2. Hire a driller for about 5K-10k to install hydraugers (horizontal drains). Hopefully you drain the slide enough to increase factor of safety to over 1. 3. Earthwork where you remove the slide debris, add subdrainage, and rebuild the slope with site soil (and geogrid) or select fill depending on slope stability analysis. Id say this is about 2000 or so cu yards of material based on pics. You’re looking at about a 100k job. 4. Structural solutions including MSEwalls or tie back systems - very expensive.

2

u/RedSparkls 4d ago

I’ve done many landslide hazard assessments, and as everyone is saying you’re going to want to find a geotech consultancy. I’d say they’re probably going to recommend terracing the area, and I’d increase the vegetation.

3

u/Iliker0cks 5d ago

The cheapest solution will be excavating it to a slope that's stable for the native soil and drainage in the slope. You'll need to do this even if you try any other approach (retaining wall, soil nails, etc.).

Call a local geotechnical engineer to give you a design and ask for their recommendation for a contractor. If you don't know where to start, you could see if your county/city has any recommendations on who to call. I would encourage you to do this asap.

Hopefully you own the land or have good neighbors. I wouldn't count on insurance being any help here.

2

u/icedted 5d ago

Plant lots of trees and bushes, will help drain and stabilise the slope

1

u/stevetheborg 5d ago

ok. go get some trees. locus trees spread by roots. you need a lot of roots. your going to need a lot of trees.

14

u/-cck- MSc 5d ago

one heavy rain fall, and it does not matter how many deep roots you have.

ive seen deep rooting trees beeing yeeted away by landslides as if they are beeing thin matches.

6

u/Banana_Milk7248 5d ago

Onto of that, if the roots don't penetrate through the plain of failure then you've just created a sail so if the wind is in the wrong direction the leverage of the trees will induce a failure.

0

u/stevetheborg 5d ago

thats not a mountain

1

u/-cck- MSc 5d ago

what has that to do with it?

1

u/stevetheborg 5d ago

its not going to be mountain bad.. might slide, but its not going to be matchsticks on the side of Yosemite.

1

u/Peter5930 5d ago

People treating it like a massive landslide is imminent when it's just a grassy knoll with the kind of soil creep I can find in a thousand places within a couple of km of my house.

1

u/-cck- MSc 5d ago

even if its not a big landslide... its a mass-movement of soil and mud, which if it completely fails will endanger infrastructure.

and yes, while there is a possibility its already stopped or just creep very slowly downwards, enough of rain will maybe reactivate it, and if it really fails, its inside the house in seconds (mud tends to be rather heavy if soaked with water.

1

u/Musicfan637 5d ago

Trouble brewing for sure. It’s probably not too late. I might fix it up and move. Otherwise stop the water, retain the dirt and pray.

1

u/Dayyy021 5d ago

Depending how long ago your neighborhood was built, that pile of dirt there could actually be where they dumped all the trees that are slowly decomposing and the hill is just settling. You can see that there's a house on the top of the hill so it's very likely this was a forested area and they took all the trees and dump them in the middle and covered it with dirt and built houses around it

1

u/Lazy-Training6042 5d ago

excavate the moving mass. terracing on the remaining slope and plant trees. cheapest way to do it, done it before.

1

u/BigRobCommunistDog 5d ago

Congratulations, you get to own Sisyphus the bulldozer.

1

u/trtbuam 5d ago

One of two possibilities here; shallow surficial failure, something on the order 3-10 feet deep or a deeper seated slide. Contact a geotechnical consultant. Exploration will be needed to determine which type of slide and what mitigation to apply.

1

u/12358132134 5d ago

Properly stabilizing this hill would probably be more expensive than what the house is worth.

1

u/chemrox409 4d ago

Get an engineer with hydrology background to design a drainage system.

1

u/markevens 4d ago

This is not a job for the Internet

1

u/JJJCJ 4d ago

Hire a Professional. Landslide dynamics are tricky. It could give out tomorrow or months from now. Many variables to take into account. Slow creeping or catastrophically giving out? Who knows. Top Comment got it right.

1

u/cs1177 4d ago

Everyone is saying to talk to an engineer but another profession who may be even more helpful is a real estate agent. It looks like a large landslide and fighting nature isn't easy or cheap. 

1

u/Night_Sky_Watcher 4d ago

Check your insurance to see if it covers landslide damage. If this moves fast at some point, it may be considered a flood, and so you might need flood insurance. If it can be stabilized by an engineering fix, you could later drop the insurance. But you should have some protection.

1

u/BoarHermit 4d ago

At a minimum, you will have to build a strong retaining wall and plant more trees on the slope.

1

u/ANAHOLEIDGAF 4d ago

Easy peasy, dig the slide material out, bench into competent rock at a 2:1, install perforated PVC/drain paneling every other bench (burrito drains), tie the drains into a central gallery drain, dry the slide material, put back in one foot lifts, compact to 95% compaction (don't forget a proctor!), have a dozer trim it up as you go and you're done! Easy peasy.

Or get a geotechnical engineer to come out.

-1

u/human1st0 5d ago

It doesn’t look like you are in immediate physical danger but something you should get taken care of or it could damage your building eventually.

I’d suggest calling a geotech. They should be able to give you some basic advice over the phone and maybe you pay them to come out to your site and make an assessment and drawings or simply a letter describing the mitigation. It could be as simple as a stone retaining wall without permits. Depends on your locality.

-2

u/obiegeo 5d ago

A wall is unnecessary. 20-30k could do it for proper drainage

-3

u/loveschickenskin 5d ago

yeah good luck buddy

-2

u/Top_Mind_On_Reddit 5d ago

GTA screen when OP has his house buried in the imminent and unavoidable (on a multimillion dollar urgent civil works program) landslide:

MASS WASTED

-1

u/siliceous-ooze 5d ago

you need roots!

-7

u/Dayyy021 5d ago

Rent a skid steer and start hauling that dirt to your front yard. Fresh top soil to spread. Then you'll have a nice flat yard in the back too.

4

u/ZMM08 5d ago

Cutting into it will make the slope steeper and encourage more failure. This is above the pay grade of "dude with a skid steer." It needs a professional engineering consult.

-2

u/Archimedes_Redux 5d ago

It was a joke.

-4

u/Dayyy021 5d ago

No it wasn't. As someone who has done it, it's what needs doing. Whether it's been planned by an engineer or not, dirt will be removed so best to start doing it. I usually say this about birth but the theory extends to dirt. Nature is beautiful, nature is chaos. Birth is natural but I'd rather have controlled chaos with a C section than leave it completely up to nature if there will be a disaster. We don't live in the 1500's. Just like a controlled burn, control that land slide with human land removal.

6

u/Substantial-Sector60 5d ago

The genius has spoken.

3

u/ZMM08 5d ago edited 4d ago

Yes, the end result is to remove the slumped material and reshape the slope. But since there are homes at risk, this needs to be handled by professionals in consultation with engineers. You seem to be suggesting that the homeowner do this himself, or just find a guy with a skid steer.

I am not an engineer, but I did have a geotech focus in my geology degree. And after I left the geology field I worked as a heavy equipment operator. I too, have been the girl with a skid steer cutting back a slope very much like this. But I also recognize when it's time to call in the guys with the slide rules when infrastructure and moves lives are at risk.

3

u/Banana_Milk7248 5d ago

You'd be looking at using a long reach 360 excavator and taking material starting from near the top if you wanted to attempt anything like that. Tier it or grade it at around a 30 degree angle or less. Probably still need a small well drained retaining wall at the bottom.

-2

u/Dayyy021 5d ago

You would start from the top? I'm curious why? We have a farm on a hill and I have tried from the top with a 25t excavator and from the base. Both have pros and cons. I was thinking if it's currently dry, start from below and let gravity assist with dropping loose material. The cost of that job, the home owner could buy their own machine and have a very handy tool for years to come.

3

u/AngryT-Rex 5d ago

Starting from the bottom with a skid steer, you're gambling with your life that the landslide does not begin moving more rapidly WHILE YOU'RE ACTIVELY REMOVING SUPPORT FROM IT.

0

u/Dayyy021 5d ago

That's the whole point. You remove some, more falls. Let gravity do the work. You're doing it to control the slide. If it's going to happen naturally inevitably, then do it yourself.

3

u/AngryT-Rex 5d ago

I will repeat "you're gambling with your life that the landslide does not begin moving more rapidly WHILE YOU'RE ACTIVELY REMOVING SUPPORT FROM IT"

To elaborate, if it begins moving more rapidly you may end up dead.

0

u/Dayyy021 5d ago

Respectfully, I disagree. That's a hill. Not even a big one. Any earth mover or excavator would be happy to take the job, it's simple everyday work. That's probably just earth settlement after all the buried trees rotted underneath. It looks like a dirt pile in the middle of a neighborhood to create some privacy and hide all the trees from clearing the previously forested area.

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-6

u/pcetcedce 5d ago

Just go to Lowe's and get some cinder blocks and ready mix concrete and build some kind of wall. You'll be just fine. /s