Experimental Study of Effects of Static and Cyclic Loads on Compaction of Sand

• Main Authors: Chao, Chi-Kit, 周志傑
• Other Authors: Fang, Yung-Show
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/4a62gt

碩士 === 國立交通大學 === 土木工程系所 === 106 === This thesis presented experimental data on the relative density distribution with depth due to compaction with different static and cyclic stresses. A variable-mass vibratory plate compactor was designed and constructed. Compaction tests were conducted on the surface of a 1.5 m  1.5 m  1.5 m soil specimen with different static and cyclic stresses. Air-dry Ottawa sand was used as fill material. The relative density of the uncompacted fill was about 24  1.8 %. Surface settlement of the fill was measured with a laser distance meter. Before testing, soil density cups were buried in the cohesionless specimen to investigate the distribution of relative density with depth. The static normal stresses applied were 1.9, 4.9 and 9.1 kN/m2, and the cyclic normal stresses applied were 10.1, 20.3 and 30.2 kN/m2. Based on the experimental results, it was found that the magnitude of applied static and cyclic normal stresses effectively increased the soil density in the fill. The peak relative density increased with both increasing static and cyclic stresses. The effective compaction depth increased with both the static and cyclic stresses. For tests with a constant cyclic stress 30.2 kN/m2, the effective depth of compaction varied from 0.21 to 0.32 m. These values were in good agreement with the lift thickness of 0.20 to 0.25 m for coarse-grained soil compacted by a vibratory baseplate compactor, as suggested by US Navy design manual DM 7-2. Measured surface settlement slightly increased with increasing static normal stress, and significantly increased with increasing cyclic normal stress