×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

(OP)
Just wondering what other do here.

Working on a project with a 13' tall daylight basement. the building is rectaugular, 140'X60'. Really I have (4) shearwalls for earth loading on the 140 foot side, each wall is roughly 15' long.

The at service at rest pressure is really high at 65pcf. I started by designing the wall as a foundation wall (pinned at top) but that service reaction is 2700#/ft. to transfer that force I need a deck attachment of 2500#/ft (possible on an elevated composite slab but stretching the limit of the system). Also I would need drags to transfer the force into the 15' walls, and that connection for drag force into the wall would be messy.

Next option is to simply design the wall as a cantilevered retaining wall and not worry about transfering force into the slab, but my footing get to be large to stop sliding.

I know the obvious answer is to use soil nails or something, but I am wondering what others do in this situation, Thanks

RE: DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

Build a key under the cantilever retaining wall or thicken the footing for pressure on the non-retained face of the footing.  Analyze the shear walls as sharing the load with the cantilever footing (similar to a concrete buried tank with the edges and bottom fixed, top hinged or free).

RE: DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

I have used keys before and they help quite a bit for sliding.  If you do design the wall as a cantilever, make sure that load does not get transfered floor/roof system as it will not be designed for that force.  Depending on your shear wall orientation, maybe consider designing the walls horizontally, not vertically.

RE: DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

In this case we typically (residential applications), design the wall as cantilevered with a key as necessary and ask that the backfill be compacted to 90% BEFORE the floor diaphragm is connected to the wall, if it is attached at all.  Also, your slab may be able to help you in the sliding problem.

RE: DAYLIGHT BASEMENT ELEVATED FLOOR REACTIONS

Can you analyze the wall as a rectangular plate fixed on three sides and free at the top? I just did that with a 15' tall fondation wall with soil pressures of 55 pcf.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources