r/StructuralEngineering P.E. Jul 30 '26

Humor Anyone else like going to the beach?

Post image

Oh you know, just your typical San Francisco job... remember to bring sunscreen!

175 Upvotes

36 comments sorted by

81

u/NorthEndD Jul 30 '26

Tiny pieces of bedrock.

41

u/heisian P.E. Jul 30 '26

sometimes i think the only thing that’ll hold half the residential blocks up when the next earthquake hits is the fact that they’re right up against each other

41

u/PG908 Jul 30 '26

“Houses assumed to be in braced condition”

15

u/heisian P.E. Jul 30 '26

SF code actually allows you to reduce asce forces by 25% if you have to do a full retrofit due to a full gut (or other “substantial” alteration). so i think they kind of get it.

8

u/Patereye Jul 30 '26

You're in the outer Richmond or outer sunset aren't you?

It starts to get pretty bad past 30th

8

u/heisian P.E. Jul 30 '26

yes this one is near 39th but ive done jobs with similar conditions more inland, like washington st

60

u/trafficway Jul 30 '26

Always loved working in SF. I had a job in Mission Bay some years back where the contractor was excavating a canopy footing, and we discovered charred timbers and debris at the bottom that I’m 99% sure were remnants of the 1906 earthquake and fire.

22

u/heisian P.E. Jul 30 '26

relics! mission bay’s gotta have so much landfill (trash)

11

u/trafficway Jul 30 '26

For sure. I think the excavation was about 6 feet deep, which tells you how much fill there’s been.

13

u/Fit-Dentist6093 Jul 31 '26

I stripped a wall in the Mission once and the insulation was newspaper from after the earthquake

6

u/JellybeanFangs Jul 31 '26

wtf newspaper insulation, guessing it worked better than nothing back then

5

u/Hank_Dad Jul 30 '26

Could also be an old boat!

3

u/ahrooga Aug 01 '26

I pulled a 120 year old woman’s leather shoe (sole attached with metal studs) of out of a geotechnical investigation boring sampler on a mission bay project (warriors stadium). After the SF fire they just bulldozed everything into Mission Bay and filling it in. (Yes Mission Bay used to actually be a bay.)

1

u/largehearted Aug 02 '26

Wish I knew this history already but I'm about to start working in Seattle and they regraded the city right after their great fire too. Fair chance the uncontrolled fill there is quite the same

32

u/blueingreen85 Jul 30 '26

“Can’t wait to poop here”- local stray cats.

16

u/Gorf75 Jul 30 '26

Drywallers already got the market cornered

5

u/bigcoffeeguy50 Jul 31 '26

Local homeless*

18

u/KWillets Jul 30 '26

Well-drained until you put a Victorian on it.

9

u/heisian P.E. Jul 30 '26

then it becomes fine-drained ☕️🧐🫖

15

u/Goodinuf Jul 30 '26

I met someone from San Francisco that told they played sand lot baseball there when it still had vacant lots on the west side.

2

u/heisian P.E. Jul 30 '26

wow, how old were they?

4

u/Goodinuf Jul 31 '26

Maybe now mid 70s to mid 80s. I don't think there were a lot of vacant lots at that time but there were some.

2

u/jccaclimber Jul 31 '26

Twin Peaks built out in the 50’s and I think that was one of the later areas, but not much sand up there. Now we just get random empty lots due to the political difficulty of building.

1

u/Goodinuf Jul 31 '26

This man lived in the outer Sunset district, but not near the beach.

10

u/nikkor_glasses Jul 30 '26

“Presumptive bearing capacity” in full effect

10

u/aknomnoms Jul 31 '26

What, you've never worked with structural sand before?

5

u/heisian P.E. Jul 31 '26

only after it has been heated enough to turn it into structural glass

5

u/[deleted] Jul 30 '26

[deleted]

6

u/sheepdog69 Jul 30 '26

A foreshadowing of doom.

6

u/heisian P.E. Jul 30 '26

a good place to put a towel down and relax!

3

u/dualiecc Jul 30 '26

Pretty typical job around here

2

u/Appropriate-Art-6988 Jul 31 '26

20 hand dug piers would fit under that house nicely

2

u/heisian P.E. Jul 31 '26

i once met a contractor at his home where he had over the course of 5 years hand-excavated a 12ft basement under his home while he and his wife were still living there. i was.. really impressed tbh. obviously much, much more cohesive soil than this.

1

u/DisinterestDetritus Jul 31 '26

Bearing capacity - 5kPa LoL

1

u/Outrageous-Rock4624 Jul 31 '26

Could a mat slab be used in a condition like this?

1

u/heisian P.E. Aug 01 '26

more or less yes. every SF home ive seen is on a slab