Time evolution of the height of dredged mud in a containment facility: a comparison between monitoring data and numerical predictions

An efficient and sustainable way to handle dredged sediments is to re-use them to fill coastal containment facilities and then reclaim their areas. When large volumes of fine-grained soils are involved, the dredging is usually carried out hydraulically. Adopting this technology, the soil is transported as a slurry and deposited in containment facilities, where it initially sediments at high void ratios before experiencing great deformations during consolidation. The paper presents a numerical model able to simulate the distinctive features of this class of boundary value problems. The soil behaviour was modelled adopting the Modified Cam-clay model, in conjunction with a strongly non-linear void ratio:permeability law. The gradual filling of the containment facility was modelled by generating the whole soil column and then progressively applying gravity to each element. The model was tested simulating a challenging and well-documented case study. The comparison between numerical results and monitoring data confirms the effectiveness of the developed model and remarks its usefulness both at the design stage and during works.