Commercial Retaining Wall

[globe trekker]

I have a "new" business that is proposing to install a retaining wall that is at

least 5.5 ft. in height ( varies from one end along the length ), ...reasonably

non-expansive soil, ...soil compressive strength at least 2,000 psi,

...Seismic Design area "B".

The GC of record has proposed to install " ...landscaping timbers, ...reinforced

concrete or decorative block", with no details or plans submitted.

In the IRC, Section R404.1.3, Note #2 requires a wall supporting more than

48 inches of unbalanced fill that does not have lateral support at the top

or bottom, to be designed by a [ competent ] RDP.

Is there a correlating section in the IBC? Does a 1 ft. height differential

require designed plans, ...2 ft., ...3 ft., etc.? Any information / guidance would

be greatly appreciated.

Thank ya'll!!

.

 

[MarkRandall]

SECTION 1610SOIL LATERAL LOADS

1610.1 General. Foundation walls and retaining walls shall be

designed to resist lateral soil loads.

This section pretty much says it all! Have them show you the design.

 

[fatboy]

I'd go back to the exceptions for required permits, retaining walls less than 4" do not require a permit. (I'm winging it, no code books at home) So, over 4' a permit is required, and details also. If they can't comply with the prescriptive IBC code, engineer's plans required.

 

[MarkRandall]

105.2 Work exempt from permit.4. Retaining walls that are not over 4 feet (1219 mm) in

height measured from the bottom of the footing to

the top of the wall, unless supporting a surcharge or

impounding Class I, II or IlIA liquids.

Section Fatboy references, but since it's over 4', have them show you the engineered design.

Note that the 4' measures from bottom of footing to top of wall, not the retainage from one side to the other.

 

[globe trekker]

"This section pretty much says it all! Have them show you the design."

"I'd go back to the exceptions for required permits, retaining walls less than 4" do notrequire a permit. ( I'm winging it, no code books at home ).So, over 4' a permit is required,

and details also. If they can't comply with the prescriptive IBC code, engineer's plans required."

Excellent!

.

 

[Paul Sweet]

Some of these systems are pre-engineered, and the manufacturers have tables showing how much soil reinforcing is required for different heights, soil types, and surcharges.

 

[MarkRandall]

Yes, many modular retaining wall systems have tables, but we're still at the same conclusion, they need to provide the the engineering or (tables) to show compliance.