San Francisco : Architect and Engineer, Inc · leaf 498
the pumps. The rock surface was composed of shale,sandy shale and sandstone, the sandy shalepredominating and being interspersed byridges of sandstone which formed decidedsteps in the foundation. It was necessaryto step the shale at several places in orderto break any decided slopes. The rocksloped… … FIG. -BED ROCK IN COFFER DAM 96 ARCHITECT AND ENGINEER, Febr 1930 Before pouring of concrete commenced,the remaining 168 tons of scrap rail wereunloaded. The foundation was carefullycleaned and, after erecting footing formsagainst the inside of the cofferdam wales,the surface of the rock was…
Architecture · Building
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