These quarterly newsletters are intended to keep you informed of changes in Retain Pro and give pointers for its use. Updates on technical issues are also given.

These newsletters are sent to all version 2007 users and to users of earlier versions (to encourage you to upgrade!). Your receiving them depends, of course, upon our having your current email address - if you change your email address, or want to redirect it to someone else in your firm, it's easy to make the change on our Support page.

Previous newsletters - this is our 13th - can all be retrieved from our home page by clicking on NEWSLETTERS. There is valuable information in them, particularly the Technical Topics sections.

Thanks to all of you...

In a few weeks Retain Pro will begin its 18^th year! We are now serving over 4,000 design professionals, including nearly 200 City, County, State, and Federal plan review agencies. We hope we are serving you well and making the task of retaining wall design easier - much easier! We strive to make Retain Pro an effective time-saving tool, with the accuracy you expect, and the features you need.

New AutoUpdate now available

A new update, release 2007P, is now available. Click "Yes" when prompted to check for updates (version 2007 only). Alternatively, you can retrieve it from Settings > AutoUpdate, or download it from www.retainpro.com/downloads. It contains a number of enhancements, clarifications, and yes, a few minor bug fixes. All revisions are described on our Support page.

Revised Users Manual

A revised User's Manual (December, 2008), is available for download in pdf format from within the program under Help & Tutorials. Revisions are minor, but it does include the expanded Installation Procedures which is also available for download from our home page - and you should have these instructions for reference!

How's the recession affecting your firm?

To find out how your peers see their outlook for 2009, we've placed a brief survey on our home page asking whether your firm foresees 2009 as: More work, About the same as 2008, Significantly less work, or Drastically less. The results can be viewed, and will be interesting!

Technical Topics

Seismic design update
Help is coming for those in seismic prone areas who object to having to design low-risk retaining walls for code mandated seismic forces. Both CBC '07 and IBC '06 can be interpreted as requiring seismic design for all retaining walls. This has caused quite an outcry from designers since it adds design time for the engineer and significant construction cost for the owner. Some jurisdictions are requiring seismic design even for a four foot wall! Building code subcommittees are responding with revised policies.

Reportedly, the City of Los Angeles now has a policy:
"An analysis and determination of the lateral pressure on basement and retaining walls due to
earthquake motion will not be required for walls up to 12 feet height. Walls exceeding 12 feet in height, including stacked retaining walls, where one or more walls are surcharging another wall and combined height exceeds 12 feet will require analysis".

"Retaining walls greater than 8 feet (for non-R-3) or 12 feet (for R-3) in height shall be designed for seismic lateral force in addition to all horizontal and vertical loads. Seismic forces shall be specified in a geotechnical investigation prepared by a licensed geotechnical engineer", and further: "The building official at any time and based on site specific information may require the preparation and submittal of a geotechnical report for any project, even if it meets the exemption criteria specified above."

We understand other jurisdictions are planning a 6 foot height threshold.

Clearly this needs a major effort to decide on reasonable criteria. Perhaps theory needs adjustment. The most compelling argument for code change is the lack of evidence of seismic damage from earthquake events. In our last newsletter to over 4,000 Retain Pro users we asked for reports of observed seismic damage to retaining walls. We received only three responses. Each was from an engineer who had done extensive inspections following the Loma Prieta and /or Northridge earthquakes (one was an insurance company inspector), and none reported any observed damage. Obviously this excludes instances of shoddily built and unreinforced freestanding walls.

If seismic design is required, the generally accepted kh value for input into the Mononobe-Okabe equation (used in Retain Pro) is: k_h = S_DS / 2.5. See IBC '06, Section1802.2.7(2). Also, NEHRP '03 Part 2:Commentary, Section 7.5.1.

Many of you will have opinions on this important issue. Please post them on our User Tech Forum on our home page (www.retainpro.com) under the post titled SEISMIC DESIGN COMMENTS.

Caution about using the vertical component

On the OPTIONS screen (sub-tab under Criteria) there are three checkbox choices for using the vertical component of active pressure: To reduce soil pressure; to increase sliding resistance; and to increase overturning resistance. We recommend using this vertical force only for overturning resistance (bottom checkbox). This is in accord with recommendations in most texts. For level surcharge, all boxes should be unchecked, which is the default.

Verifying results

Nearly any questioned result can be easily checked by a five-minute hand calculation. This is easier and faster (and a good exercise!) than using CalcTrac, which is a feature we may drop. Additionally, the User's Manual contains 12 varied design examples, each with corresponding Retain Pro reports. Retain Pro is not a "black box" except to an inexperienced user. Use of the software assumes you have the expertise to easily check any questioned result based upon the input displayed. It is very unlikely you will find errors, but when reported and verified they are promptly fixed.

Requesting technical support

If you email us for tech support please include your name, company, phone, and you must include your registration number (RP-xxxxxxx).

Installation procedures

Our new license management system allows us to keep track of your activations (and prevent unauthorized use of the software!) and can better assist you if you have a problem. Although extra steps are required for installation, you should have no difficulty if you follow the Installation Procedures which are posted on our home page. You should print these nine pages which cover situations you may encounter, and keep them handy for reference.

Changed your email address? Let us know!

It's easy to change your email address for out database: On our Support page just click on "Change email address". You will need your original email address (the one you gave us when ordering) and your password. This will assure that you (or the intended person in your organization) will receive these newsletters and any bulletins we issue. It also allows access to our online Users Forum - many important announcements are first posted there.

Suggestions and comments.

If you have suggestions, comments, or corrections on these newsletters, or a technical item to contribute, we want to hear from you. Email me at hbrooks@retainpro.com.

With best wishes for the holidays - and for 2009!