{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "Signal Foundation Design Zones are intended to provide guidance, with respect to geology, influencing design requirments for constructing and installing signal...", "description": "

This dataset contains polygon features digitizied from the Louisiana Geological Survey, <\/SPAN>Geologic Map of Louisiana <\/SPAN>(Snead and Mc Culloh, 1984), depicting the surface geology of the State of Louisiana. The dataset was digitized from a 1:500,000 scale source matp by the US Geological Survey, Biological Resources Division, National Wetlands Research Center. It does not include point or line features such as faults, ceniers, or cap rock.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "summary": "Signal Foundation Design Zones are intended to provide guidance, with respect to geology, influencing design requirments for constructing and installing signal...", "title": "LADOTD Signal Foundation Design Zones", "tags": [ "LADOTD", "Louisiana Department of Transportation and Development", "signal foundataion design", "surface geology", "design zone" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 500000, "maxScale": 5000, "spatialReference": "", "accessInformation": "Digitized by the US Geological Survey, Biological Resource Division, National Wetlands Research Center from the Geologic Map of Louisiana, developed by the Louisiana Geological Survey (Snead and Mc Culloh, 1984).", "licenseInfo": "

Signal Foundation Design Zone Usage Notes<\/SPAN><\/SPAN><\/P>

1. Foundation Design Zones are based on the <\/SPAN><\/SPAN>Geologic Map of Louisian<\/SPAN><\/SPAN>a, published by the Louisiana Geological Survey (Snead and Mc Culloh, 1984). The source data were mapped t a scale of 1:500,000 and may not be sufficiently accurate to support distinctions near mapped boundaries. Local geological variations are likely due to human activities or natural events. <\/SPAN><\/SPAN><\/P>

2. The zone map is intended to assist in sizing foundation for selected signal poles and should not be viewed as a substitute of engineering judgment or proper design. <\/SPAN><\/SPAN><\/P>

3. Some soils such as gravel or cemented soils may not be amenable to the conventional drilled shaft construction. Exercise caution and seek confirmation of the soil conditions during design and/or during shaft excavation. <\/SPAN><\/SPAN><\/P>

Zone 1<\/SPAN><\/SPAN>- Alluvial soils formed by the Red River, the Ouachita River, the Atchafalaya River, and the Mississippi River. Assumed average soil shear strength is at least 250 pounds per square foot (psf).<\/SPAN><\/SPAN><\/P>

Zone 2<\/SPAN><\/SPAN>- Pleistocene age Prairie Terraces deposits. Assumed average soil shear strength is at least 500 psf.<\/SPAN><\/SPAN><\/P>

Zone 3<\/SPAN><\/SPAN>- Pleistocene age or older deposits other than Zone 2. Assumed averaged shear strength is at least 1,000 psf. <\/SPAN><\/SPAN><\/P>

Zone 4<\/SPAN><\/SPAN>- Mostly coastal marsh and sand/gravel deposits. Special design is required for the signal pole within this zone.<\/SPAN><\/SPAN><\/P>

Zone M<\/SPAN><\/SPAN>- Mississippi River, unsuitable for signal foundations.<\/SPAN><\/SPAN><\/P>

Zone W<\/SPAN><\/SPAN>- Water, unsuitable for signal foundations.<\/SPAN><\/SPAN><\/P>

Construction Notes<\/SPAN><\/SPAN><\/P>

1. If groundwater is encountered during foundation excavation and no cave in is observed, the groundwater should be pumped out prior to steel cage placement. The water remains in the excavation should be no more than ½ inch.<\/SPAN><\/SPAN><\/P>

2. If groundwater is encountered during foundation excavation and cave in is observed, the excavation should be ceased. Contact the project engineer immediately. Should the caving is excessive, backfill the excavation immediately.<\/SPAN><\/SPAN><\/P>

3. Free fall concrete is allowed for dry holes only. The concrete shall be placed with a hopper or a tremie. When free fall method is used, control the concrete to fall vertically without contacting shaft wall or steel cage to prevent segregation.<\/SPAN><\/SPAN><\/P>

4. Concrete placement with a tremie is required if excessive groundwater (more than 6 inches accumulation) is encountered. <\/SPAN><\/SPAN><\/P>

5. When the soil conditions are suspected to be different than those described in the Foundation DEsign Zone, contact the Project Engineer immediately to evaluate the suitability of the foundation design.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>" }