fire lanes needed - temp c/o approved

06/18/98 407 - Final - courtesy inspection - Denice - call 1st ###-####

RETAINING WALL EVALUATION by Jim Rogers Developer has cut into the toe of an existing slope and constructed a wall composed of manufactured blocks. I don't know if the intent was to build an actual retaining wall or if this is to function as a decorative wall. Although the wall is about 4 - 5 feet in vertical height; because of the slope above the property and what appears to be other utilities (sewer line??) buried in the slope, it should be designed as a retaining wall. Because the back of the homes are very close to the wall, around 10 feet or so, failure of the wall and slope could cause extensive damage. Suggestions are: 1. An engineering analysis of the slope from the toe of the wall to the top of the canal above the property should be made to determine slope stability. This would include a Unified Soil Classification of the soil, moisture content and other soil engineering properties. 2. If the analysis indicates a Factor of Safety (FOS) less than 1.5, an engineered retaining wall will probably be necessary. I do no believe the existing wall is sufficient to support the slope for the following reasons. A. The foundation of the wall is constructed of material that appears to be road base and although it may supply adequate support for the vertical load of the wall, it supplies no lateral support in which to resist the driving forces of the slope above the wall. In addition, as ground saturation below and above the wall occurs because of landscape irrigation, vertical settlement and distoration of the wall will take place. B. It looks as if frictional forces are the only thing which ties the wall into the gravel foundation, which is above the grass line. If the gravel erodes from under the wall, settlement and failure of the wall may occur. It appears some erosion of the gravel is already occuring. The above is based on a visual examination of the wall. I would have a few questions concerning how the wall was constucted. 1. Is each lift of blocks tied into the back fill with a geo-grid? If so, how far back into the fill does the grid extend? 2. What was the compacted density of the soil behind the wall? 3. What was the compacted density of the gravel foundation which supports the wall, how thick is it, is the bottom layer of the retaining wall blocks tied into the gravel foundation, and if so, what was used? Is the gravel foundation supported and seperated from the sub-grade on a geotextile? Was the sub-grade compacted and to what density? 4. Was an analysis of the wall made to determine if it supplied sufficient resisting forces greater than the slope driving force? Last - The geotextile under the gravel mulch above the wall only provides a slip plane for the mulch to move down slope on. This is already occuring. The gravel mulch will be a constant maintance problem to the owners.

/ / 301 - FRAM-OK FRAMING

02/20/98 301 - wrong insp requisted framing is what should have been req insp. c/n are complet and framing is approved.

12/30/97 301 - READY AT 4:00 FDN -OK FOUNDATION ì