登入
選單
返回
Google圖書搜尋
Experience with Relative Density as a Construction Control Criterion
DJ. Leary
RJ. Woodward
出版
ASTM International
, 1973
URL
http://books.google.com.hk/books?id=nD54zgEACAAJ&hl=&source=gbs_api
註釋
Limitations of several, shallow and deep, direct and indirect methods to obtain relative densities are discussed, and opinions are given concerning the use of these methods for construction control purposes. Experience from two earthwork projects are given for: (1) direct methods--conventional sand cone and water balloon, cutting cylinder, manually excavated pit, and Denison sampler; and (2) indirect methods--nuclear, standard plate load test, standard penetration test, and static cone penetration test. Some of these methods proved satisfactory as a means of obtaining relative densities, others did not. The water-balloon method was found more suitable than the sand-cone method. Reference curves were effective in some cases. Use of 6-in.diameter cutting cylinders to obtain field dry unit weights was found unsatisfactory for sand containing gravel. Relative densities obtained from measurements of individual layers from a manually excavated pit were found to be greater than those obtained from the water-balloon method. Dry unit weights obtained from Denison samples gave reasonable relative density values. Relative densities from nuclear methods are only approximate. Use of the standard plate load test to obtain relative densities was not successful. High standard penetration resistances resulting from residual lateral stresses were obtained in sand fill compacted in layers by vibratory compactors and lead to very high inferred relative densities. Static cone penetration resistances give qualitative measures of relative density of completed earthwork and are useful in evaluating uniformity of compaction.