Compressibility of lime-treated dredged slurry with high water content.

Lime is widely used for soft ground treatment, rendering the compressibility of lime-treated soil a crucial factor in deformation analysis in engineering applications. This study investigated the compressibility of three remoulded lime-treated slurries with high water content in Southeast China. Sixty groups of oedometer tests were conducted on lime-treated soils with an initial water content of 1 to 3 times the liquid limit and lime contents between 1 and 3%. The oedometer test results were discussed to examine the remoulded yield stress σ y ' of lime-treated slurry. Considering the relationships between σ y ' , the void ratio, lime content, and initial water content were preliminarily discussed and quantitatively established. Research on the normalised compression curve of lime-treated soil revealed that for soil samples containing a lime content of 0-%, the normalised compression curve at σ p ' > σ y ' can be represented by a unique line. Furthermore, the log(1 + e) - log σ v ' compression curve of lime-treated slurry at pre-yield state is analysed, and a prediction method for the modified compression index is proposed.

3D numerical investigation of the interaction between interchange tunnels at different angles.

The development of subway and highway tunnels has led to the spatial intersection of tunnels, significantly impacting tunnel deformation, lining stress, and ground settlement during construction. To study the influence of critical parameters such as the cross angle and centre-to-centre distance on the tunnel performance, a series of numerical simulations were carried out. The influence range and magnitude of stress in the spatial cross tunnel under different cross angles were determined. The results indicated that as the crossing angle increased, the stress on the lining decreased, and the vault displacement increased. Meanwhile, the parallel tunnels showed opposite tendencies. Based on these results, the crossing angle of the cross tunnels was suggested to be greater than 45°. Parallel tunnels should be considered individually because the loading is symmetrically distributed. Considering the vault displacement and von Mises stress of the lining, it is recommended that the tunnel spacing be greater than 2D. The numerical model was validated against field data, and the findings of this study can be useful in designing cross tunnels.