San Francisco Home Foundation Case Study Zero Lot Line ...

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The Challenge e Client had pur- chased a lot in San Francisco for a new home. As is typical of many City lots, there was a zero lot line condition: on one side there was an exist- ing home right at the property line and at 2 others, the edge of the foundation was right at the sidewalk. e plans called for excavating below both the founda- tion of the neighboring house and the City sidewalks. Action: e adjacent foundation was sta- bilized by hand-digging alongside and under the adjacent foundation and installing underpinning pits, before the mass excavation phase. Because the soils were type 1 it was not necessary to place shoring in between the shoring pits and it was also possible to make unshored vertical cuts at the sidewalk sides. e foundation was then installed by placing drainage and water- proofing membranes directly against the cuts and shoring, and shotcreting the foundation walls. Case Study Zero Lot Line Foundation Job San Francisco Home Foundation RWR Construction Inc. 200 Gary Place, San Rafael, CA 94901 (415) 457-5658 www.RWR-inc.com Unshored cuts in type 1 soil at City sidewalks Underpinning pits exposed along property line

Transcript of San Francisco Home Foundation Case Study Zero Lot Line ...

Page 1: San Francisco Home Foundation Case Study Zero Lot Line ...

The ChallengeThe Client had pur-chased a lot in San Francisco for a new home. As is typical of many City lots, there was a zero lot line condition: on one side there was an exist-ing home right at the property line and at 2 others, the edge of the foundation was right at the sidewalk. The plans called for excavating below both the founda-tion of the neighboring house and the City sidewalks.

Action:The adjacent foundation was sta-bilized by hand-digging alongside and under the adjacent foundation and installing underpinning pits, before the mass excavation phase. Because the soils were type 1 it was not necessary to place shoring in between the shoring pits and it was also possible to make unshored vertical cuts at the sidewalk sides.The foundation was then installed by placing drainage and water-proofing membranes directly against the cuts and shoring, and shotcreting the foundation walls.

Case Study

Zero Lot Line Foundation Job

San Francisco Home Foundation

RWR Construction Inc. 200 Gary Place, San Rafael, CA 94901 (415) 457-5658 www.RWR-inc.com

Unshored cuts in type 1 soil at City sidewalks

Underpinning pits exposed along property line

Page 2: San Francisco Home Foundation Case Study Zero Lot Line ...

Results: Because of the techniques used, it was not necessary to over-excavate for double-sided forms and the excava-tion and foundation work were completed without any distress to the surrounding properties.

Case Study

Zero lot line foundation job

RWR Construction Inc. 200 Gary Place, San Rafael, CA 94901 (415) 457-5658 www.RWR-inc.com

San Francisco Home Foundation

Shotcreting the foundation walls

Excavation with waterproofing membranes and reinforcing steel installed

Above grade back forms with mud sills attached, ready for shotcrete