30 2 2011 6 GLOBAL GEOLOGY Vol. 30 No. 2 Jun. 2011 1004-5589 2011 02-0289 - 07 1 1 2 3 4 4 1. 130026 2. 130026 3. 110015 4. 430074 45 cm 100% ` TU447 A doi 10. 3969 /j. issn. 1004-5589. 2011. 02. 020 Consolidation properties of dredger fill under surcharge preloading in coast region of Tianjin ZHANG Ying 1 WANG Qing 1 WANG Yu-jie 2 MA Jun-hua 3 YANG Jing 4 WANG Ji-liang 4 1. College of Construction Engineering Jilin University Changchun 130026 China 2. Testing Scientific Experiments Center Jilin University Changchun 130026 China 3. Shenyang Design and Research Institute Sino-coal Engineering Group Shenyang 110015 China 4. The Three Gorges Investigation Institute Co. Ltd Wuhan 430074 China Abstract Dredger fill making roads is an effective way to solve the land shortage in coastal areas. In order to quicken drainage consolidition and shorten the construction period of dredger fill taken the dredger fill in coast region of Tianjing as studied object the basic properties and subsidence characteristics of dredger fill in Tianjin were studied by water subsidence and laboratory tests without external force self-weight consolidation. The consolidation and subsidence characteristics of dredger fill in Tianjin has been obtained through the quantitative analysis of the consolidation degree and velocity and its evaluation. The results showed that the graduated compression constant amplitude waterhead inhabited the formation of low permeability soil to some extent. The consolidation degree closed to 100% when the waterhead was 45 cm. The consolidation degree was better with the closer distence from drain. The permeability decreased and the soil tended to consolidation when the accumulation load increased. Key words surcharge preloading dredger fill settlement pore water pressure consolidation properties 2010-07-29 2011-03-21 40372122 40911120044 20111014.
290 30 1 2 3 4 1 1 3 3 3 24 h 3 0. 1 cm 3 3 4 3 1 3 848. 45 cm 2 51 cm 196 271 cm 3 30 cm 35 cm 40 cm 45 cm 3 5 cm 17. 5 cm 30 cm 1 2 3 2 Fig. 1 Self-made settlement instrument device 5-7 1 1 2. 5 2 2. 1 8
2 291 1 1 0. 005 ~ 0. 007 5 mm 9 Table 1 1 Grain size composition of experimental soils < 0. 005 0. 005 ~ 0. 075 0. 075 ~ 0. 1 0. 1 ~ 0. 25 0. 25 ~ 0. 5 0. 5 ~ 2 > 2 a 1. 36 84. 51 10. 38 2. 62 0. 27 0. 61 0. 25 b 41. 7 44. 13 10. 30 2. 9 0. 27 0. 65 0. 05 a. b. mm. Table 2 /% 2 Comprehensive result of physical and chemical properties of dredger fill /% W L /% W p PH Ip /19. 1 /mmol 100g - 1 /% 250 52. 58 23. 97 28. 61 8. 1 16. 875 1. 01 2. 2 2 Ip 28. 61-1. 01% 3 2 Fig. 2 Log curve of settlement and time 30 cm 35 cm 40 cm 45 cm 2 35 cm 3. 1 2 5 d 84. 9 d 30 cm 1 15 d
292 30 v = S i +1 - S i / t i +1 - t i 1 S i + 1 S i t i + 1 t i Table 3 i = 1 2 10 3 Setting parameters table of consolidation degree solution α β S 1 /cm S 2 /cm S 3 /cm t 1 /min t 2 /min 1 0. 000102 26. 92 27. 84 27. 94 1322 23161 α = 1. 3 Fig. 3 Log curve of settlement rate and time 3 4 10 d Fig. 4 Change of consolidation degree under whole pressure 4 11 2 7 d 12 13 27 420 min 35 cm U = 1 - αe -βt 2 35 cm 4 45 cm 100% 3 t 1 t 2 t 3 t 3 - t 2 = t 2 14 - t 1 S 1 S 2 S 3 3 40 cm 45 cm 3. 2 35 cm
2 293 35 cm 3 5 6 Fig. 5 25. 7% ~ 26. 3% 1. 1% ~ 4. 5% 0. 75% ~ 2. 4% 0. 91% ~ 2. 1% 3. 3 5 Change curves of pore pressure under natural settlement stage 7 Fig. 6 6 Change curves of pore pressure under seepage drainage stage Fig. 7 different load levels 6 h 7 1 560 min 14 d 0. 2 cm 15 372 ml /d 22 d 16. 2 d 5 6 1 30 cm 45 cm 3 2 7 Relation curves of time and displacement under
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