The effect of soaking on the top and bottom CBR value of a sub-base is studied in this paper. Fourteen CBR samples were prepared at 95% relative modified AASHTO compaction .Two CBR samples were prepared for each soaking period of 0,4,7,14,30 and 60 days. These samples were prepared and compacted mechanically in the laboratory. The first group was tested in case of unsoaked while the second group was tested in case of soaking. The results showed that, a significant drop in the CBR for top and

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... tom due to the soaking was observed compared with natural case due to softening of soil particles Which means that the bearing capacity of subbase soil decrease with increase of soaking time. Most of decrease in soaked CBR value is pronounced inthe first days for top and bottom CBR, respectively. And it dropped to 20% and23%value for top and bottom after 60 days soaking period and this drop is in full of weakness of soil with soaking. ‫ر‬ ‫اور‬ ‫ال‬ ‫ار‬ ‫ر‬ ‫اس‬ ‫ت‬ ‫ا‬ ‫درا‬ ‫اث‬ ‫ھذا‬ ‫دم‬ ‫ر‬ ‫ادة‬ ‫و‬ ‫ط‬ ‫اور‬ ‫ال‬ ‫ار‬ ‫رات‬ ‫ل‬ sub-base ‫ادم‬ ‫اطرق‬ ‫راض‬. ‫درا‬ ‫ر‬ ‫ار‬ ‫رة‬ ‫ر‬ ‫م‬ ‫اور‬ ‫ال‬ 14 ‫درھ‬ ‫رص‬ ‫وذج‬ 95 % ‫و‬ ‫دل‬ ‫ا‬ ‫و‬ ‫ا‬ ‫رص‬ ‫ن‬ ‫رة‬ ‫ل‬ ‫وذن‬ ‫ر‬ ‫م‬ ‫د‬ ‫ھ‬ ‫رات‬ ‫ا‬ ‫ذه‬ ‫ھ‬ ‫ان‬ ‫و‬ ‫ر‬) 0 ‫و‬ 4 ‫و‬ 7 ‫و‬ 14 ‫و‬ 30 , ‫و‬ 60 ‫وم‬ .(‫م‬ ‫و‬ ‫ار‬ ‫ر‬ ‫و‬ ‫رھ‬ ‫م‬ ‫اذج‬ ‫ھذة‬ ‫وان‬ ‫او‬ ‫و‬ ‫ص‬ , ‫ر‬ ‫اورة‬ ‫ادا‬ ‫ء‬ ‫ت‬ ‫و‬ ‫ا‬ ‫واو‬ ‫ارو‬ ‫رات‬ ‫وا‬ ‫اض‬ ‫وظ‬ ‫د‬ ‫اور‬ ‫ال‬ ‫وادة‬ ‫اط‬ ‫ن‬ ‫ل‬ ‫دث‬ ‫د‬ ‫ان‬ ‫ظم‬ ‫و‬ ‫ار‬ ‫رات‬ ‫زدة‬ ‫ت‬ ‫د‬ ‫اس‬ ‫ت‬ ‫ر‬ ‫ال‬ ‫ان‬ ‫وادة‬ ‫اط‬ ‫ن‬ ‫ل‬ ‫ر‬ ‫او‬ ‫ام‬. ‫ا‬ ‫ال‬ ‫ات‬ ‫د‬ 20 % ‫و‬ 23 % ‫رور‬ ‫د‬ ‫ادة‬ ‫و‬ ‫اط‬ ‫ن‬ ‫ل‬ 60 ‫ء‬ ‫ورة‬ ‫وم‬. ‫ار‬ ‫ف‬ ‫ا‬ ‫ود‬ ‫اض‬ ‫ھذا‬ ‫اء‬ ‫رات‬ ‫رھ‬ .