Site Challenges of RM Clayton WRC-Video

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Video Summary

The RM Clayton wastewater treatment plant expansion in Atlanta increased capacity from 240 to roughly 320–350 million gallons per day. The $53 million design-build project required a deep excavation beside an operating plant, with limited access, undocumented existing foundations and utilities, and highly variable rock conditions.<br /><br />A major challenge emerged when large rock wedges began sliding from the excavation face. Mapping revealed unfavorable joint sets, prompting extensive rock bolting, mesh, shotcrete, and careful blasting. The team also supported existing structures and high-voltage utilities, and underpinned settlement-sensitive equipment and a stairwell using micropiles and reinforced concrete.<br /><br />Because the project moved quickly, designs were completed in about four weeks, and geotechnical conditions were assessed using construction equipment already on site. Key lessons included verifying rock-cut stability in the field, obtaining reliable as-built information, maintaining engineering oversight during construction, and addressing worker safety early. Conservative underpinning protected critical equipment without disrupting treatment operations.

Keywords

wastewater treatment plant

deep excavation

rock bolting

micropiles

construction safety

geotechnical engineering