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| Experimental investigation on prefabricated horizontal drain-based vacuum preloading-alkali-activated GGBS solidification combined method for #br#
treatment of high-water-content mud slurry |
| SONG Dingbao1，PU Hefu1，HU Hailan2，LI Zhanyi3，ZHANG Chunxue4 |
(1. School of Civil and Hydraulic Engineering，Huazhong University of Science and Technology，Wuhan，Hubei 430074，China；
2. China Civil Engineering Construction Corporation(CCECC)，Beijing 100038，China；3. China Railway Siyuan Survey and
Design Group Co.，Ltd.，Wuhan，Hubei 430074，China；4. China Engineering Science and Technology Co.，Ltd.，
Hefei，Anhui 230022，China) |
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Abstract Dredged mud slurry has the characteristics of high water content，low or negligible strength and low hydraulic conductivity. Rapid and efficient treatment and utilization of these slurry are of great significance. This paper conducted a series of experimental to study the rapid treatment of high water content slurry using the combined method of prefabricated horizontal drain vacuum preloading and chemical solidification(abbreviated as PHDVPS). The solidifying agents used in the experiment included magnesium oxide(MgO)-activated ground granulated blast furnace slag(GGBS) and Portland cement. The treatment effect and efficiency of the combined method were compared with those of pure vacuum preloading method. Variation of discharged water mass and slurry volume were monitored during the vacuum preloading stage of the model tests，after which the unconfined compressive strength (UCS) of soil samples at different curing ages was tested，and the microstructures of the treated soils were analyzed. The experiment results indicates that PHDVPS method has a significantly better volume reduction efficiency and a significantly better reinforcement effect than the pure vacuum preloading method. The solidifying agent produces flocculation effects，which improve the vacuum dewatering efficiency，leaving the subsequent solidification process occurring in a denser state of soil matrix and thus achieving much higher strength. Moreover，using GGBS-MgO as the solidifying agent in PHDVPS method has better volume reduction and strength improvement effects than using cement.
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2023, Vol. 42 
