Abstract：The combined prefabricated horizontal drains(PHDs) with vacuum preloading is an effective method to treat the dredged clayey soils and shows significant advantages in shallow licensed storage dumps especially. This paper investigated the consolidation/dewatering characteristics of dredged high-water-content clay slurry using prefabricated vertical drains(PVDs) and prefabricated horizontal drains assisted by vacuum preloading. The dewatering capacity，surface settlement，bending of drains and water content after consolidation were recorded and analyzed. Compared with PVDs，the PHDs effectively avoided bending and thus resulted in a very uniform deformation within the model ground. The thickness of soil domain above and below the PHD decreased with time which accelerated the vacuum consolidation indicated by the dewatering rate from tests. The PHD showed a better treatment than PVD，and the water content of model soil decreased from an initial value of 360% to 150% in PHD consolidation which is 30%–40% lower than PVD consolidation. The possible differences between model tests and field cases due to size effect were discussed finally.
王 军，蔡袁强，符洪涛，等. 新型防淤堵真空预压法室内与现场试验研究[J]. 岩石力学与工程学报，2014，33(6)：1 257–1 268. (WANG Jun，CAI Yuanqiang，FU Hongtao，et al. Indoor and field experiment on vacuum preloading with new anti-clogging measures[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(6)： 1 257–1 268.(in Chinese))
[3]
CHAI J C，CARTER J P，HAYASHI S. Ground deformation induced by vacuum consolidation[J]. Journal of Geotechnical and Geoenvironmental Engineering，2005，131(12)：1 552–1 561.
[6]
WATARI Y，HIGUCHI Y，SHINSHA H. An improvement method on extremery soft clayey ground using horizontal board drains[J]. Society of International Geosynthetic，1991，8：101–110.(in Japanese)
[8]
SHINSHA H，KUMAGAI T，MIYAMOTO K，et al. Execution for the volume reduction of dredged soil using the vacuum consolidation method with horizontal pre-fabricated drains[J]. Geotechnical Engineering Journal Japan Geotechnical Society，2013，8(1)：97–108.(in Japanese)
[11]
ZHOU Y，CHAI J C. Equivalent“smear”effect due to non-uniform consolidation surrounding a PVD[J]. Geotechnique，2017，67(5)：410–419.
[13]
应 舒，陈平山. 真空预压法中塑料排水板弯曲对固结的影响[J]. 岩石力学与工程学报，2011，30(增2)：3 633–3 640.(YING Shu，CHEN Pingshan. Effects of bended plastic drainage plates on consolidation caused by vacuum preloading[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(Supp.2)：3 633–3 640.(in Chinese))
[4]
CHIBA T，SHINSHA H，TANI Y. Development of a vacuum- consolidation method employing horizontal drains[R]. Tokyo：[s. n.]，1992.
[2]
梅国雄，徐 锴，宰金珉，殷宗泽. 真空预压加固软土地基变形机理的探讨[J]. 岩土工程学报，2006，28(9)：1 168–1 172.(MEI Guoxiong，XU Kai，ZAI Jinmin，et al. Deformation mechanism of soft foundation under vacuum preloading[J]. Chinese Journal of Geotechnical Engineering，2006，28(9)：1 168–1 172.(in Chinese))
[5]
SHINSHA H，WATARI Y，KURUMADA Y. Improvement of very soft ground by vacuum consolidation using horizontal drains[C]// Proceedings of International Conference on Geotechnical Engineering for Coastal Development. Yokohama：GEO-COAST，1991：3–6.
[7]
SHINSHA H，KUMAGAI T. Bulk compression of dredged soils by vacuum consolidation method using horizontal drains[J]. Geotechnical Engineering，2014，45(3)：78–85.
[9]
张文彬，王贤奔，谢锦波，等. 水平排水板真空预压法处理吹填流泥试验研究[J]. 水运工程，2016，(7)：122–127.(ZHANG Wenbin，WANG Xianben，XIE Jinbo，et al. Experimental study on dredger fill flow mud improved by vacuum preloading method employing horizontal drains[J]. Port and Waterway Engineering，2016，(7)：122–127.(in Chinese))
[10]
罗玉龙，彭 华，何金平. 水平塑料排水带固结流态吹填土可行性研究[J]. 武汉理工大学学报，2008，30(6)：74–78.(LUO Yulong，PENG Hua，HE Jinping. Research on the feasibility of consolidating flowed dredger fill by horizontal plastic drainage strip method[J]. Journal of Wuhan University of Technology，2008，30(6)：74–78.(in Chinese))
[12]
CAI Y，QIAO H，WANG J，et al. Experimental tests on effect of deformed prefabricated vertical drains in dredged soil on consolidation via vacuum preloading[J]. Engineering Geology，2017，222：10–19.
2019, Vol. 38 
