×
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

lateral load from drilled shaft on mse walls

lateral load from drilled shaft on mse walls

lateral load from drilled shaft on mse walls

(OP)
can anyone advise me on the best procedure to take the results from LPILE or COM624 and convert it to soil pressures that could be transmitted to a mechanically stabilized earth wall?

RE: lateral load from drilled shaft on mse walls

You could look at the shear in the drilled pier.  As the shear in the pier decreases, that load must be transferred to the soil.  If you take the load on that leaves the pier per foot of depth and divide it by the pier diameter that would give you a pressure.

RE: lateral load from drilled shaft on mse walls

What is the origin of the lateral load? Do you have a sketch to help in visualizing?

RE: lateral load from drilled shaft on mse walls

(OP)
the MSE wall is a wrap around bridge abutment; lateral loading comes though the piles which support the bridge abutment.  actually, i found out that COM624 has a result called "soil resist" which i never appreciated for 20 years until just now.  it is the interaction of the pile structure and the soil, the "p" in the famous "p-y" curves where "y" is the deflection of the pile.  in effect, p is like a little spring constant, so from there one can get the force in the soil at various depths along the pile.

RE: lateral load from drilled shaft on mse walls

actually Lpile and COM624 give you the soil reactions with depth. The soil reaction is in units of Force per unit length of the pile. That number is the resultant force and is calculated as the integration of the stress bulb around the pile (including the active and passive stresses). So theoretically, that would be the resultant force per unit length that the soil would fell when the pile is laterally loaded.  

RE: lateral load from drilled shaft on mse walls

(OP)
great, six06; so if i have regularly spaced soil reactions i can integrate them along the pile within the zone of interest and get a lateral force?

RE: lateral load from drilled shaft on mse walls

not really,  the number that lpile gives you is already the resultant soil reaction (distributed force). So, i would see what those reactions are, see if their values are reasonable, and come with an approximate force on the wall. You have to consider that the way these forces are calculated are a little bit tricky and could lead on values way over (or under) the reality.

RE: lateral load from drilled shaft on mse walls

There are many ways to get your lateral loads.  I never use the spring anology method.  In real life the soils are surrounding the pier or pile continuously.  There is no gap in lateral soil support.

The best I have seen is the method proposed by Budhu and Davis 1986 and 1987 and before that Teng.  

The following equation works for granular soils.  You can compute your lateral load by equating it to the area of a triangle.  The embedded length minus the "ignore passive resistance" height is L, pier diameter is B, and the base of the triangle is 3*Gamma*B*Kp*L.  The area would give you your lateral load directly.

However if you have a Moment in addition to the lateral load, then it may be faster to compute the required embedment by obtaining the following Teng paper:

"Tapered Steel Poles - Caisson Foundation Design" Prepared by Teng and Associates, July 1969    

To get the Budhu and Davis method look at Amazon for "Foundations and Earth Retaining Structures" book by Budhu.    It comes with APILES program that is very useful.                
 

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