Foundation Stakeout Conflict with an ADA Ramp
A mast arm pole with a 45-ft arm is planned for the southeast corner of an intersection. The survey crew stakes the foundation at station 12+45, 6 ft behind the face of curb. The existing ADA ramp has a 5-ft-wide landing, and the proposed 42-in-diameter foundation would leave its edge about 18 in inside the landing. The anchor bolt template has been set, but the inspector notices the arm-facing direction is rotated 90 degrees from the plan. It points down the side street rather than over the mainline. At the 8-ft excavation depth, the bottom contains soft, dark material that looks like fill, not the stiff clay described in the geotechnical report, which assumes 2,000 psf bearing capacity. The concrete truck is 45 minutes out, and the crew wants to pour.
1. What is the problem with the foundation location relative to the ADA ramp, and what is the correct process to resolve it?
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The foundation intrudes into the accessible landing, reducing clear width and creating a protruding hazard. That is not acceptable without redesign. Check the plan dimensions and the applicable ADA/protruding-object and clear-width requirements, then evaluate options: shift the pole behind the landing, enlarge or reshape the ramp landing, or relocate the ramp. Each option changes the arm reach and signal-head visibility, so the layout must be rechecked. The resolution requires engineer and owner approval and likely an ADA review; it is not a field decision. Stake a revised location, verify it by survey, and do not excavate or pour until the revised location is approved in writing.
2. The anchor bolt template is rotated 90 degrees. What checks and actions are required before the pour?
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Before placing concrete, verify the template orientation against the plan: the arm should extend over the roadway it signals. Check the plan north arrow, the station and offset, the conduit stub-up location and orientation, and the anchor bolt spacing, projection, and level. If the template is wrong, reset it and recheck. Use a template that holds the bolts rigidly during the pour, and recheck orientation and elevation immediately after finishing. A rotated template would put the mast arm over the wrong approach and could make the pole unusable, so this is a hold point, not something to correct later.
3. The excavation bottom shows soft fill rather than the expected bearing material. What should happen before concrete is placed?
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Stop and notify the engineer and geotechnical representative. The bearing material differs from the basis of design, so the foundation may need over-excavation and replacement with suitable fill or flowable fill, or it may need redesign. Document the depth and extent with photos and elevations, and obtain written direction before pouring. Pouring on soft fill risks settlement, pole lean, and long-term signal misalignment. Because the concrete truck is close, the correct decision is to hold the pour and accept schedule delay rather than place concrete on unverified bearing material.