ACI 230.1R-09 Report on Soil Cement

ACI 230.1R-09 Report on Soil Cement. Reservoir in eastern Colorado in 1951 (Holtz and Walker 1962). The test-section location along the southeast shore of the reservoir was selected because of severe natural service conditions created by waves, ice, and more than 140 freezing-and-thawing cycles per year. After 10 years of observing the test section, the USBR was convinced of its suitability and specified soil cement in 1961 as an alternative to riprap for slope protection on Merritt Dam, NE, and later at Cheney Dam, KS (Coffey and Jones 1961). Soil cement was bid at less than 50% of the cost of riprap, and produced a total savings of more than $1 million for the two projects. Performance of these early projects has been good (Casias and Howard 1984). Although some repairs have been required for both Merritt and Cheney Dams, the cost of the repairs was far less than the cost savings realized by using soil cement over riprap. In addition, the repair costs may have been less than if riprap had been used (Casias and Howard 1984). The original test section at Bonny Reservoir has required very little maintenance and still exists today, over 50 years later (Fig. 3.5). Since 1961, more than 400 major soil cement slope protection projects have been built in the United States and Canada. In addition to upstream facing of dams, soil cement has provided slope protection for channels, spillways, coastal shorelines, and highway and railroad embankments. For slopes exposed to moderate to severe wave action (effective fetch greater than 1000 ft [300 m]) or debris- carrying, rapid-flowing water, the soil cement is usually placed in successive 6 to 9 in. (150 to 230 mm) thick hori- zontal layers 6 to 9 ft (1.8 to 2.7 m) wide, adjacent to the slope. This is referred to as stair-step slope protection (Fig. 3.6). For less severe applications, such as those associated with small reservoirs, ditches, and lagoons, the slope protection may consist of single or multiple 6 to 9 in. (150 to 230 mm) thick layers of soil cement placed parallel to the slope face. 3.5—Liners Soil cement has served as a low-permeability lining mate- rial for more than 40 years. During the mid-1950s, a number of 1 to 2 acre (0.4 to 0.8 hectare) farm reservoirs in southern California were lined with 4 to 6 in. (100 to 150 mm) thick soil cement. The...