Sunday, May 12, 2013

Basement Crawl Space Excavation

The owner of a small home wanted to excavate the basement crawl space in order to expand the living space. This project involved devising a method to convey soil out of the crawl space & to lower cement back into the excavated space. Access to the space was limited by slopes & trees near basement windows. Access was available only through a small window in the carport. The owner did not want to disturb the brick walls or the concrete driveway. 


The solution was a dolly on a track at an angle to reach up from the basement to a tandem dump truck box in the carport. The track has  a weighted support that allows removal of a section of the track. Removal allows closing the basement window & pedestrian access to the front door.






The dolly is raised or lowered by a cable, & a snap allows dolly to be used as a wheelbarrow or to be replaced by a flat bed for large rocks, blocks or boxes. 




The track has sides & a center guide to keep the dolly in place & a end to catch the front wheels of the dolly as it dumps into the truck. 





The dolly is raised & lowered by cable. The dolly's forward motion is stopped after a dump by a rope snapped to the rear of the dolly. The rope is also used to pull the dolly back up to the track after a dump. The dolly is made from a wheelbarrow & salvaged wheels. The end is cut away to facilitate the dump. 





The rear wheels are wide apart and remain on the main while the closer forward wheels drop when dumping.





The carport provides weather protection and a critical structure to support the track, the dolly cable from the boat winch & the winch motors.






The cable winch raises or lowers the dolly is attached to a boat winch driven by 2 motors.






A large plywood pulley, sized to provide the appropriate cable speed, is bolted to the boat winch.






The operators position at the window shows the dolly with a full load, the limiting & lifting rope & the up & down motor control switches. Although the load for each trip of the dolly appears small, approximately 30 cubic yards of material  was removed in two weeks.





The soil under the foundation was solid clay. The clay was cut away intermittently to create footings & supports for the foundation. 








The space between the supports was excavated & infilled to create a new basement foundation.






 

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