×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

Bridge Foundations Over Granite Railway Cutting

Bridge Foundations Over Granite Railway Cutting

Bridge Foundations Over Granite Railway Cutting

(OP)
Hi,

As part of my final year at University I am performing a slope stability assessment of a 1.5km railway cutting, varying in height from 6-10m. The cutting runs through slightly weathered, strong, homogeneous granite and is capped with a 1-6m layer of boulder clay. The occasional faulted zone appears in the cutting but no significant stability problems have been identified.

The (currently disused) line is soon to be upgraded to a dual track system and the cutting therefore requires widening by approximately 2m. Due to the proximity of private propety either side of the cutting it has been decided to cut each slope face back by 1m, rather than taking the full 2m from just one face.

I am still in the early stages of analysing the data which I have collected - triaxial and shear disc tests have been arranged and scanline data is currently being input into a rockslope stability analysis program, so until I get these results back I won't know if any significant stability problems exist.

My report will be focussing on the excavatability of the granite within the cutting and the any subsequent slope stability problems which would be created by the widening process. I will also be looking at the bearing capacity of the granite either side of the cutting to asses the possibility of constructing a large footbridge across the railway.

I have set off in the usual direction - have reported on the geology, the structure etc but am now at the stage of assessing the rock mass. All we have been taught since I have been at University for the general classification of a rock mass is the use of various rock mass rating systems such as Bienawski etc.

However, I am aware that various new systems, such as GSI etc are beginning to appear which are supposed to offer a more accurate assessment of the rock mass for construction purposes and which avoid over-engineering, which apparently commonly occurs with the older systems.

Does anyone have any opinion on this matter? Is there a particular rock mass classification scheme which gives particularly good results with rock slope faces? How much better are these newer systems?

Also, as of yet I have found very little info regarding the construction of footbridge foundations directly onto the granite (at the site of the bridge <1m of overburden exists above the granite). If anyone can point me in the right direction I would be very grateful!

If anyone has any other thoughts as to what else I could include in my project I would love to hear them.

Many thanks!

:)

RE: Bridge Foundations Over Granite Railway Cutting

Best wishes to you during your final year of school, and to the success of your project.  At this time I am not able to offer useful input to your project.  However, I would be interested to know which rock slope stability program you are using to analyze your data.

Rockjoint
Rockjoint@yahoo.com

Rockjoint
rockjoint@yahoo.com

RE: Bridge Foundations Over Granite Railway Cutting

(OP)
Thanks for your support Rockjoint,

At the moment I am using Rocscience's "Dips" program to analyse the scnaline data which I have collected for the cutting.

Have found it good to use so far, it seems easy to use and have seen some impressive results.

Am slowly getting there with my project - only six weeks until it needs to be handed in!

Thanks for your comment.

Llessur

RE: Bridge Foundations Over Granite Railway Cutting

I am familiar with DIPS.  I have used ROCKPACK (Dr. Skip Watts: http://www.radford.edu/~geol-web/GeoFacCFW.htm, http://www.rockware.com/catalog/pages/rockpack.html). It is the best program for stability analysis of rock slopes that I have encountered (I am a little biased, as Skip was my major advisor).  Check out the links to find out more.

Also: check out http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-1-2908/c-4.pdf for a brief overview of classifications.  I am not very familiar with newer systems, but I intend to learn.

Good luck,

Rockjoint
rockjoint@yahoo.com

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close