This is an archived newsletter. Click to learn what RetainPro can do for you..

Quarterly Newsletter - Spring 2011
Dear Colleague:

This is our 22nd quarterly newsletter and now goes to over 4,000 of you! We value each of you and thank you for your continued support.

About these newsletters

If you joined us since the winter newsletter, these quarterly newsletters keep you up-to-date on changes and enhancements to Retain Pro. You can view all previous newsletters from the NEWSLETTERS link on our home page. There is valuable information in each of them, particularly Tech Topics.

The latest release for Retain Pro 9 is 9.25

It's available now via AutoUpdate or downloadable from For what's changed see Retain Pro 9 Advisor on our home page.

In this Newsletter

Retain Pro is now a division of ENERCALC, INC.

Retain Pro Software has been acquired by ENERCALC, Inc. As most of you know Retain Pro was originally authored in 1992 by Michael Brooks, SE, who founded ENERCALC in 1983. Then since 1992 Retain Pro has been managed by Hugh Brooks, SE, who is responsible for its extensive development over the past 20 years. ENERCALC is familiar to most of you - over 60% of Retain Pro users are also ENERCALC users. With this transition Michael Brooks and his staff at ENERCALC have exciting plans for continued enhancements to Retain Pro and look forward to serving you. Phone, fax, email, and website all stay the same.

Basics of Retaining Wall Design, 9th Edition.

The all new 9th edition is now available for ordering! Shipping begins July 25th. Expanded and updated on nearly every page, it will be a valuable reference! We are offering Retain Pro 9 users a discount to $49 until August 31st. (Regular $69.95) For more information and ordering: (HBA Publications is owned and managed by Hugh Brooks).

Some building codes are available online

We're repeating this in case you missed it on our last newsletter: Here is a link for regional codes: Errata for IBC '09 and supplements to the 2010 California Building Code are available on this link:

IBC 2012 is here!

Already? It seems like we just bought IBC '09! It's available now from or for $117.50. Ouch! And you might as well spend another $33.11 for their book of "Significant changes...". We'll report what's new that affects retaining walls in our next newsletter.

Plan Review Agencies

Over 200 city, county, state, and federal plan review agencies now have Retain Pro. We offer a free copy upon request. It must be used for design review only; not for commercials use. It can be requested by selecting that option under Order Options at

Still using Retain Pro 2007?

Reminder: If you're still using Retain Pro 2007 you need to renew your license to continue receiving support and program updates. You are missing many new features and code updates to IBC '09 and CBC '10. To upgrade your license to Retain Pro 9 for $195 go to and get immediate download after ordering.

Technical Topics

Restrained walls caution: Our restrained wall module was intended for cases where the upper lateral restraint was at or near the top of the wall, such as a "basement" wall. Some of you are inputting a lower height to this support and higher lateral forces above the support. This can result in a negative reaction at the stem base which the program cannot now handle. If your result shows a negative reaction at the stem base, or an indication of ####, you will need to revise your conditions to avoid a negative base reaction or supplement you design with hand calculations. We will provide programming to handle this condition in a future release.

Had a crash or lost your PAC? We get many calls asking for their Product Activation Code (PAC) so they can re-install or install on a new computer. We can look it up for you but you can retrieve it yourself at Just click on Retrieve Product Activation Code.

Torque shear in grade beams between C.I.P drilled piers. The torsional shear is overly conservative because the critical section should be away from the center of the pier by half the pier diameter plus the transverse "d" distance for the footing. We will fix this in the next release but in the meantime just reduce the torsional shear by the ratio [(0.5 pier spacing) - (0.5 pier diameter) - (footing transverse "d")] / [0.5 (pier spacing)]. This reduction may make the footing adequate without torsional reinforcing. per AC1 11.5.1 (a)

Adjacent footing lateral pressures. For point or line load surcharges Retain Pro uses the Boussinesq equation. This requires inputting a value for Poisson's Ratio which can be conservatively taken as 0.5 for usual sand and gravel backfill material but your geotechnical engineer can help with this important value. Another widely used equation for the resulting lateral pressure are those in NAVFAC-DM 7.2 which does not require Poisson's Ratio. Results from these and other theories can vary by 30% or more and adding to this dilemma are in-situ tests that differ considerably. So use judgment and allow leeway when assessing the effect of these lateral loads. If the adjacent footing is farther from the wall than the height from top of footing to bottom of the adjacent load then you can probably ignore it.

If we didn't respond to your email

If we do not respond to your email within two business days please resend. Some emails are inadvertently overlooked.

Are you not the intended recipient of these newsletter?

If you are not the intended recipient for your company please pass this along. Or update your company's contact email address at

Suggestions and comments?

We value your suggestions and comments! Send them to

With best regards,


Hugh Brooks, P.E., S.E.
Retain Pro Software

Remember our special offer to Retain Pro 9 users: Just $49 (regular $69.95) to order the all-new 9th Edition of Basics of Retaining Wall Design. To order:

You are receiving this email because you are a Retain Pro user or have downloaded a demo and asked to be on our email list. This email list is for our use only to provide you with information, but if you do not want to receive future copies just email me at and on the subject line type "Cancel", and don't forget to include your company name and email address where you received this.
© 2011 Retain Pro Software div. ENERCALC, Inc. All Rights Reserved.