Welcome to the November Issue of Ground Improvement. It is my great pleasure to introduce this issue to you on behalf of the Editorial Panel. There are five papers in this issue related to granular piles, soil reinforcement, chemical stabilisation and electrical methods. A summary of these papers is given as follows.
In the first paper, Raghuram et al. (2022) propose a new technique using granular pile-anchors (GPAs) and geogrid-encased GPAs for reducing heave and improving bearing capacity and pull-out capacity in expansive clay beds. They conducted laboratory experiments to study and compare the effectiveness of plain GPAs and geogrid-encased GPAs. The results indicate that the clay beds reinforced with geogrid-encased GPAs show better heave and pull-out performance.
The second paper by Astaraki and Esmaeili (2022) investigates the stability of railway embankment slopes over soft subgrades stabilised by deep-mixed columns (DMCs). The small-scale laboratory physical modelling was first conducted to study the load–settlement response of embankments over unreinforced and DMC-reinforced subgrade. Then, numerical modelling was used to perform a comprehensive parametric study to evaluate the factor of safety of the embankment side slopes against sliding. The results indicate an increase of nearly 63% in the bearing capacity of DMC-supported embankments compared with the unreinforced one.
In the next paper, Estabragh et al. (2022) study the effects of calcium (Ca2+) and magnesium (Mg2+) ions on stabilisation of a clayey soil via electro-osmotic and electrokinetic methods. For the electro-osmotic method, the distilled water was used as pore fluid, while for the electrokinetic method, calcium chloride (CaCl2) and magnesium chloride (MgCl2) solutions were injected into the soil samples. An increase in soil strength was found for both methods. The calcium chloride solution was more effective in increasing the strength, discharge flow and electro-osmotic permeability than the magnesium chloride solution.
The two-component grout is often used to fill the annular gap behind the precast concrete segments of tunnels to reduce movement due to tunnel excavation in soil. The fourth paper by Rahmati et al. (2022) presents a series of laboratory tests to investigate properties of two-component grout, including flowability, bleeding, gelling time and uniaxial compressive strength. The influences of the grout ingredients and effective parameters such as bentonite and cement contents, water–cement ratio and dosage of accelerator were investigated.
In the fifth paper, Gupta and Sawant (2022) use the pseudo-dynamic approach to determine the seismic behaviour of a reinforced soil wall considering the propagation of primary, shear and Rayleigh waves. A mathematical derivation is proposed to obtain the required strength of reinforcements, the critical angle of the failure wedge and the factor of safety of the reinforced soil wall. The results emphasise the prominence of Rayleigh wave consideration in the analysis.
Last, I would like to thank all the authors, reviewers, Associate Editors, Chief Editor and ICE Publishing team for making this issue possible. I hope you find these papers very interesting and useful. I also would like to invite you to send comments and questions to implement discussion on these papers.
