Sự Nén Không Đều của Đất và Ảnh Hưởng của Hiệu Ứng Tắc Nghẽn Tương Ứng trong Quá Trình Nén Chân Không

International Journal of Geosynthetics and Ground Engineering - Tập 8 - Trang 1-11 - 2022
Peng Wang1, Jianfeng Wu2, Xueyan Ge1, Fan Chen1, Xiaotian Yang3
1College of Architecture and Civil Engineering, Wenzhou University, Wenzhou, China
2Zhejiang Inestitute of Communications CO.,LTD, Hangzhou, China
3First Company of China Construction Eighth Engineering Division Ltd, Jinan, China

Tóm tắt

Sự nén không đồng nhất của đất xúc không dưới tình trạng nén chân không và hiệu ứng tắc nghẽn tương ứng đã được nghiên cứu thông qua các thử nghiệm liên tiếp. Độ ẩm và hệ số thấm của đất ở các khoảng cách và thời gian nén khác nhau đã được đo trong quá trình nén chân không. Khối lượng và tốc độ thoát nước trong các thử nghiệm cũng đã được ghi nhận. Kết quả thử nghiệm cho thấy đất đồng nhất trở nên không đồng nhất khi quá trình nén chân không bắt đầu. Hệ số thấm của đất gần ranh giới thoát nước giảm từ 50 đến 100 lần ngay từ đầu quá trình nén chân không, dẫn đến hiệu ứng tắc nghẽn nghiêm trọng, làm giảm tốc độ thoát nước của đất khoảng 90% tại cùng thời điểm đó. Sự không đồng nhất và hiệu ứng tắc nghẽn của đất đạt giá trị cực đại sau 24–48 giờ nén chân không trong các trường hợp khác nhau. Dựa trên kết quả thử nghiệm và thuyết Ruth, một số yếu tố như độ ẩm thấp hơn, hàm lượng muối cao hơn, áp suất chân không thấp hơn và chất phụ gia keo tụ đã làm giảm hiệu ứng tắc nghẽn và làm cho đất trở nên đồng nhất hơn sau khi nén. Cuối cùng, sự so sánh giữa kết quả thử nghiệm và kết quả phân tích đã làm rõ rằng sự không đồng nhất và hiệu ứng tắc nghẽn cần được xem xét trong quá trình nén của đất dưới điều kiện nén chân không.

Từ khóa

#sự nén không đều #hiệu ứng tắc nghẽn #nén chân không #độ thấm #độ ẩm đất

Tài liệu tham khảo

Hansbo, S. (1981). Consolidation of fine-grained soils by prefabricated drains. Proc of the ICSMFE 3: 677–682. Pyrah IC (1996) One dimensional consolidation of layered soils. Geotechnique 45(3):555–560 Xie KH, Xie XY, Wen J (2002) A study on one-dimensional nonlinear consolidation of double-layered soil. Comput Geotech 29(2):151–168 Basu D, Prezzi PBM (2006) Analytical solutions for consolidation aided by vertical drains. Geomech Geoeng 1(1):63–71 Walker R, Indraratna B (2006) Vertical drain consolidation with parabolic distribution of permeability in smear zone. J Geotech Geoenviron Eng 132(7):937–941 Chen GH, Xie KH, Cheng YF, Xu Y (2011) Analytical solutions for consolidation of sand-drained ground considering variation of permeability coefficient in smeared zone. J Zhejiang University Eng Sci 45(4):665–670 Indraratna B, Zhong R, Fox PJ, Rujikiatkamjorn C (2016) Large-strain vacuum-assisted consolidation with non-Darcian radial flow incorporating varying permeability and compressibility. J Geotech Geoenviron Eng 143(1):04016088 Nguyen BP, Do TH, KimL YT (2020) Large-strain analysis of vertical drain-improved soft deposit consolidation considering smear zone, well resistance, and creep effects. Comput Geotech 123:103602 Pu HF, Yang P, Lu MM, Zhou Y, Chen JN (2020) Piecewise-linear large-strain model for radial consolidation with non-Darcian flow and general constitutive relationships. Comput Geotech 118:103327 Imai G, Tang Y (1992) A constitutive equation of one-dimensional consolidation derived from inter-connected tests. Soils Found 32(2):83–96 Watabe Y, Udaka K, Kobayashi M, Tabata T, Emura T (2008) Effects of friction and thickness on long-term consolidation behavior of Osaka Bay clays. Soils Found 48(4):547–561 Zhou Y, Chai JC (2017) Equivalent sear effect due to non-uniform consolidation surrounding a PVD. Geotechnique 25:101–110 Zhou Y, Khoteja D, Xu F (2019) Numerical study: influences of local radial consolidation for soft clay. Soil Mech Found Eng 56(3):157–163 Zhou Y, Xu F (2021) A novel semi-analytical method for evaluating average consolidation degree of a two-soil-layer deposit. Bull Eng Geol Env 81:13 Indraratna B, Rujikiatkamjorn C, Baral P, Ameratunga J (2019) Performance of marine clay stabilised with vacuum pressure: based on Queensland experience. J Rock Mech Geotech Eng 11(3):598–611 López-Acosta NP, Espinosa-Santiago AL, Pineda-Núñez VM, Ossa A, Mendoza MJ, Ovando-Shelley E, Botero E (2019) Performance of a test embankment on very soft clayey soil improved with drain-to-drain vacuum preloading technology. Geotext Geomembr 47(5):618–631 Stoltz G, Delmas P, Barral C (2019) Comparison of the behaviour of various geotextilesused in the filtration of clayey sludge: an experimental study. Geotext Geomembr 47(2):230–242 Wang P, Gu BW, Yang H, Yang XT, Yu Z (2021) Analysis method for consolidation of soil under vacuum preloading assisted by air booster. Mar Georesour Geotechnol. https://doi.org/10.1080/1064119X.2021.2001611 Wang, P., Yang, X.T., Zhang, J., Ge, X.Y. 2022. Vacuum consolidation of soil: clogging effect, varying permeability and compressibility. Proceedings of the Institution of Civil Engineers—Geotechnical Engineering. https://doi.org/10.1680/jgeen.21.00237. Chen L, Zhang FH, Li ZP, An YY, Li YL (2016) Experimental study on radial consolidation of soil around drainage plate. Chin J Geotech Eng 38(1):163–168 Lei HY, Lu HB, Liu JJ, Zheng G (2017) Experimental study of the clogging of dredger fills under vacuum preloading. Int J Geomech 17(12):04017117 Shi L, Wang QQ, Xu SL, Pan XD, Sun HL, Cai YQ (2018) Numerical study on clogging of prefabricated vertical drain in slurry under vacuum loading. Granular Matter 20(4):74 Shi L, Jiang JW, Wang QQ, Xu SL, Yuan ZH, Pan XD (2021) Numerical study on movements of soil particles forming clogging layer during vacuum preloading of dredged slurry. Granular Matter 23:92 Deng YF, Liu L, Cui YJ, Feng Q, Chen X, He N (2019) Colloid effect on clogging mechanism of hydraulic reclamation mud improved by vacuum preloading. Can Geotech J 56(5):611–620 Cai YQ, Xie ZW, Wang J, Wang P, Geng XY (2017) A new approach of vacuum preloading with booster PVDs to improve deep marine clay strata. Can Geotech J 54(4):547–560 Hu XP, Zhang WK, Fu HT, Wang J, Ni JF (2021) Clogging effect of prefabricated horizontal drains in dredged soil by air booster vacuum consolidation. Geotext Geomembr 49(6):1529–1538 Fu HT, Cai YQ, Wang J, Wang P (2017) Experimental study on the combined application of vacuum preloading-variable-spacing electro-osmosis to soft ground improvement. Geosynth Int 24(1):72–81 Lei HY, Hu Y, Lei SH, Qi ZY, Xu YG (2019) Analysis of microstructure characteristics of air-booster vacuum preloading for ultra-soft dredger fills. Rock Soil Mech 40(S1):32–40 Wang J, Cai YQ, Ma JJ, Chu J, Fu HT, Wang P, Jin YW (2016) Improved vacuum preloading method for consolidation of dredged clay-slurry fill. J Geotech Geoenviron Eng 142(11):06016012 Mishra PN, Scheuermann A (2021) Ventilated well method for efficient dewatering of soft soils: experimental investigations. J Geotech Geoenviron Eng 147(11):04021112 Fu HT, Chai JC (2020) Performance of a winged PVD (WPVD) for vacuum consolidation of soft clayey deposits. Transp Geotech 24:1–9 Chai JC, Saito A, Hino T, Negami T (2022) Behaviour of winged PVD and the method for calculating its induced degree of consolidation. Int J Geosynth Ground Eng. https://doi.org/10.1007/s40891-022-00394-y Wang P, Han YB, Wang J, Cai YQ, Geng XY (2019) Deformation characteristics of soil between prefabricated vertical drains under vacuum preloading. Geotext Geomembr 47(6):798–802 Zhou Y, Yang H, Wang P, Yang XT, Xu F (2022) Vacuum-induced lateral deformation around a vertical drain in dredged slurry. Geosynth Int. https://doi.org/10.1680/jgein.21.00006a Chai JC, Zhou Y (2018) Method for considering the effect of nonuniform consolidation. Int J Geomech 18(2):97–98 Chai JC, Fu HT, Wang J, Shen SL (2020) Behaviour of a PVD unit cell under vacuum pressure and a new method for consolidation analysis. Comput Geotech 120:103415 Liu SJ, Cai YQ, Sun HL, Shi L, Pan XD (2021) Consolidation considering clogging effect under uneven strain assumption. Int J Geomech 21(1):04020239 Liu SJ, Sun HL, Geng XY, Cai YQ, Shi L, Deng YF, Cheng K (2022) Consolidation considering increasing soil column radius for dredged slurries improved by vacuum preloading method. Geotext Geomembr 50(3):535–544 ASTM. 2010b. Standard practice for classification of soils for engineering purposes (Unified Soil Classification System). D2487 American society for testing and materials. Philadelphia. Gu RG, Fang YG (2009) Experimental research on ion effects of ultrafine granular clay seepage. Rock Soil Mech 30(6):1595–1598 Wu YJ, Tran QC, Zhang XD, Lu YT, Xu JL, Zhang HQ (2022) Experimental investigation on the treatment of different typical marine dredged sludge by focculant and vacuum preloading. Arab J Geosci 15:642 Indraratna B, Rujikiatkamjor C, Sathananthan L (2005) Analytical and numerical solutions for a single vertical drain including the effects of vacuum preloading. Can Geotech J 42(4):994–1014 Guo X, Xie KH, Deng YB (2014) Consolidation by prefabricated vertical drains with a threshold gradient. Math Probl Eng 9:410390 Tyler SW, Wheatcraft SW (1992) Fractal scaling of soil particle size distribution: analysis and limitations. Soil Sci Soc Am J 56:362–369 Yuan XQ, Wang Q, Sun T, Xia YB, Chen HE, Song J (2012) Pore distribution characteristics of dredger fill during hierarchical vacuum preloading. J Jilin Univ 42(1):169–176 Taylor DW (1948) Fundamental of soil mechanics. JohnWiley and Sons Inc., New York Ruth BF (1935) Studies in filtration, III derivation general filtration equations. Ind Eng Chem Res 27:708–723
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International Journal of Geosynthetics and Ground Engineering

Tập 8

1-11

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