摘要
振動夯實砂樁及動力夯實法分別應用於永安及麥寮兩處海埔新生地改良工程都能達到改良土壤工程性質的效果。但是振動夯實砂樁的改良成效，由於受地層中細粒含量影響，較諸日本實用經驗為低。經比較試驗結果，以浚填海砂及優良級配河砂做為夯實砂樁打設時之回填料均能獲得相似的改良成效，似可考慮不須再嚴格要求回填砂料之規格。動力夯實應用於麥寮新生地之經驗顯示深度影響係數偏低，必須使用較大能量方能達到須改良深度，而改良過程產生的壓縮量雖然與國外案例相符，但是SPT N及CPT QC兩項貫入阻力都偏低，原因尚待進一步探討。此外，兩則案例都指出改良後細粒含量大幅增加，尤以動力夯實法最為明顯。是否因此造成改良後貫入阻力值較國外經驗為低，亦值得探討。
並列摘要
Sand compaction pile and dynamic compaction methods were respectively applied to ground improvements for newly reclaimed lands in Yungan and Mailiao, Taiwan and the results were satisfactory. However, due to the higher fine contents in the strata, less remarkable effect of improvement was achieved when using sand compaction pile method in Yungan than in Japan. Comparison of the test results revealed that both sea sand and well graded river sand could be used as the fill material for sand compaction pile method. As both types of material yielded similar degree of improvement; therefore, strict specification for sand fill material seemed to be unnecessary.Results of application of dynamic compaction in Mailiao site showed that the depth influence coefficient was low, and larger compaction energy was required to achieve expected depth of improvement. Although ground settlement induced by the improvement was much the same as in other cases abroad, the post improvement SPT-N value and CPT-Qc resistance were comparatively low. Further study is required to elaborate the cause of such phenomenon. In addition, both cases showed that the fine contents increased after the improvements and such increase was especially noticeable in the case of dynamic compaction method. Further investigation should be carried out to determine whether increase in fine contents may cause lower post improvement cone resistance in domestic cases than in foreign cases.