Abstract: Low field proton nuclear magnetic resonance(NMR) technology is used to measure the distribution of transverse relaxation time T₂ of solidified dredging silt soil to study the content and distribution law of pore water in solidified soil. Results show that there is only one main peak in the distribution of relaxation time of solidified soil samples of different cement dosages; the peak area decreases gradually with the growth of curing age and the increase of cement dosage. Pore water content decreases gradually, and the decrease first starts from big pores. The main effect of curing age is reducing the moisture content in the big pores, whereas cement is not only beneficial for reducing the moisture content in the big pores, but also the moisture in the small pores. With the growth of curing age and the increase of cement dosage, the scope of T₂ distribution of solidified soil narrows and the distribution tends to short relaxation time, and pore water is distributed in smaller pores gradually. The weighted average relaxation time T₂ declines rapidly with the growth of curing age first, and the decline rate decreases gradually after 7 days. Solidified soil’s total nuclear magnetic signal amplitude of T₂ shows an overall trend of decrease with the curing age growth, and the speed slows down after 7 days; this is because the water is consumed or converted into mineral water due to internal chemical reaction in solidified soil. Nuclear magnetic resonance(NMR) technology can well present the content and distribution law of pore water in the process of solidification.

Key words: dredging silt, solidified soil, nuclear magnetic resonance, T₂ distribution, pore water, relaxation time