Need advice on sheeting and shoring design

[bgrove]

I have recently been given the assignment of helping a local contractor with temporary sheeting and shoring design. It's been a few years since I have worked in this area of engineering and I'm just looking for some helpful hints to get me on the right track. When tackling a new design process the first step I like to take is getting all the best references and computer program. I have done my own research and I have found some old text books and the AASHTO guides "construction handbook for bridge temporary works" and "guide design specifications for bridge temporary works". I have also done some research into computer programs and have recently found a program called ct-shoring that I am thinking about purchasing. The bottom line is I am looking for some good hands on practical design examples and a good computer program to help me out. Can anyone out there give me some advice on this topic? If it helps here is some more specific info on the job: it's for a contractor doing bridge work in PA on a PENNDOT project. Any help would be appreciated!

 

[jheidt2543]

You might contact Pile Buck, Inc. of Jupiter, FL, USA. The have a lot of information and some software regarding sheet piling and retaining walls. Check the web for their site too.

 

[DRC1]

I have both the CT- Shoring and the SPW-911 (shoring program published by Pile Buck)I use the CT Shoring more because it is more flexible for non standard loadings. However if you have not done a lot of design work in this area and the problem is fairly straight forward, the SPW-911 may be easier to use. Both make nice reports. Pile Buck also publishes a book on sheeting design which is a very good reference for sheeting design and worth having if you are getting into this.

A word of caution, as you may know from your previous experience, desiging sheeting is a different process than desiging other retaining walls. I would urge you to spend some time reviewing the sheeting design manual before you start and having an engineer who is familar with this type of work review the design when you finish.

Good Luck!

 

[PEinc]

bgrove,

Although I have both programs, I would recommend CT-Shoring over SPW911. SPW911 is not really intended up for soldier beams and lagging. It is basically a sheet pile design program. It does, however, handle C-Phi soils while CT-Shoring handles only cohesionless soil unless you manually calculate and enter the pressure diagrams for the cohesive soils. I agree with DRC1 about reading the program's manual. You need to know the methods and assumptions used in the program.

I've done many, many sheeting designs for PENNDOT projects. Be careful. PENNDOT usually tells you what soil values to design with. PENNDOT also usually specifies using the LRFD method for design. I am not aware of any sheeting design program that works with LRFD.

Are you using steel sheeting? Soldier beams? Braces? Tieback anchors? Where in PA is the project? What is the S.R. number?

 

[bgrove]

First of all I would like to say thanks to everyone who responded. I have considered all of the advice and I have taken a few steps already. I have on order the pile buck design manual and SPW911 program as suggested. I have also begun developing my own spread sheets based on the LFD AASHTO methods. PEinc you have brought up a point that I was going to touch on about LRFD design. I feel like I have a good handle on the LFD design but I am not at all familiar with the LRFD methods the new AASHTO and DM-4 do not seem as clear cut as the old LFD methods. For instance there are no given pressure diagrams for cantilevered walls with no tie backs for different soil conditions? Are we to assume the pressure distributions are the same as the ones given in the LFD AASHTO chapter 5.6? Do you know of any good manuals that have examples for LRFD design? As for your question of the location of this job I am not sure yet? We are not sure if we are getting the job but we wanted to start putting a preliminary game plan together for design in case we do start doing this work. We figured eventually we will have construction services on a job which will require this type of design review so we might as well get ready for it now. Typically we have worked with PENNDOT Districts 6-0,8-0,5-0,4-0. Do some Districts require LRFD while others don't?

 

[PEinc]

bgrove,

There is no consistency between PennDOT Districts for sheeting design but the trend is toward LRFD. I am not aware of any available LRFD sheeting design manuals or programs. You are treading on relatively new ground. FHWA and AASHTO are pushing the design method. Don't forget what I said about the PennDOT specified soil design properties. Good luck.

 

[Focht3]

LRFD makes even less sense for retaining walls. These things need to be thought out in a consistent, thorough manner. And they aren't.

An easy prediction - either:[ol][li]FHWA and AASHTO will develop a rational design method for LRFD, or[li]FHWA and AASHTO will back off the LRFD push after some well-publicized wall failures.[/ol]I'm counting on the second one, myself.



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