EXPERIMENTAL INVESTIGATION ON CONSOLIDATION OF SOFT SOIL IN MUDFLAT OF OFFSHORE WIND FARM BASED ON MICP TECHNOLOGY

Zhu Chenjun; Wen Xiaodong; Wu Jiayu; Wen Wei; Li Chaoen; Sun Zhiwei

doi:10.19912/j.0254-0096.tynxb.2023-1148

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Acta Energiae Solaris Sinica ›› 2024, Vol. 45 ›› Issue (11) : 467-476. DOI: 10.19912/j.0254-0096.tynxb.2023-1148

EXPERIMENTAL INVESTIGATION ON CONSOLIDATION OF SOFT SOIL IN MUDFLAT OF OFFSHORE WIND FARM BASED ON MICP TECHNOLOGY

Zhu Chenjun¹, Wen Xiaodong¹, Wu Jiayu¹, Wen Wei², Li Chaoen¹, Sun Zhiwei¹

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Abstract

During the process of wind power infrastructure construction in coastal tidal flat areas, the problem of mud improvement and solidification as well as reuse in tidal flats is becoming increasingly prominent. Compared with traditional soil chemical reinforcement methods, soil reinforcement technology based on Microbially Induced Calcium Carbonate Precipitation （MICP） has advantages such as low pollution and low energy consumption. In this study, the changes in bacterial liquid concentration over time were investigated under different pH values and with or without calcium sources in a room temperature culture environment using spore-forming bacteria slurry. Taking Ningbo tidal flat mud as the research object and considering the characteristics of coastal soft soil and slope structures, Bacillus pasteurii was used to induce carbonate consolidation treatment on coastal soft soil. Through compression, permeability, rainwater erosion tests, combined with X-ray diffraction（XRD） and scanning electron microscopy（SEM） characterization results, the consolidation effect and erosion resistance were analyzed from macroscopic and microscopic perspectives. The results showed that under an environment with a pH value of 7.3, spore-forming bacteria grew fastest, reaching peak concentration at around 48 hours of cultivation; calcium ions inhibited bacterial growth but had a smaller impact during early growth stages compared to later stages; after curing for 7 days with a bacterial liquid concentration of 1/100th by weight ratio reshaping soil sample, its compression coefficient decreased by 19.58% while its permeability coefficient decreased by 87.34%; after rainwater erosion ended, the erosion rate was only 3.9 g/（m²·s）; spore-forming bacteria induced crystallization formed carbonated calcium crystal aggregates filling between soil particles which improved consolidation performance, impermeability performance, and slope surface erosion resistance.

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offshore wind farms / microbial induced carbonate precipitation （MICP） / soil reinforcement / microstructure / coastal soft soil

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Zhu Chenjun, Wen Xiaodong, Wu Jiayu, Wen Wei, Li Chaoen, Sun Zhiwei. EXPERIMENTAL INVESTIGATION ON CONSOLIDATION OF SOFT SOIL IN MUDFLAT OF OFFSHORE WIND FARM BASED ON MICP TECHNOLOGY[J]. Acta Energiae Solaris Sinica. 2024, 45(11): 467-476 https://doi.org/10.19912/j.0254-0096.tynxb.2023-1148

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