The soil can be considered as a collection of grains or aggregates with microstructures, aggregates are composed of particles with interparticle voids, and grains or particles are made of minerals with atomic structures. Thus, the origin of mechanical behaviours/properties of the soil can be investigated by downscaling, and the mechanical modelling of the soil can be conducted by upscaling.

Finite element or different method (FEM/FDM) based analysis is an effective way for geotechnical design and disaster protection. Our objectives are to develop advanced constitutive models (e.g. elastic viscoplastic model of clay, critical state based models of sand), to implement them into available FEM/FDM codes, to develop smoothed particle finite element method (PFEM) with model implementation for large strain analysis while keeping the accuracy of small strain analysis, and to develop macroelement model inspired from constitutive modelling and beyond FEM/FDM analysis.

We have extensively performed the application of AI in geotechnics due to the strong capacity of solving non-linear and high-dimensional problem of AI. For example, the optimization and Bayesian-based methods can bridge the gap between advanced constitutive theories and engineering practice; ML-based surrogate model can also be applied in engineering practice as the alternative to experimental and numerical methods, saving expenses for engineering design. Currently, we focuses on the following three topics.

We have developed various types of geotechnical tests: (1) scaled model testing, in which we aim to address the reclamation related geotechnical problems, such as sedimentation and consolidation of marine deposits, marine reclamation by super-fast consolidation methods, FRP pile behaviour filled with sand or cemented sand, and clay-FRP pile interaction under static and cyclic loadings; (2) advanced soil element testing, in which the soil element performance can be clarified by several advanced testing apparatuses, including multi-functional soil-structure interface testing apparatus, PolyU-patented true triaxial apparatus, dynamic hollow cylinder apparatus, and biaxial testing apparatus; and (3) soil microstructural testing, in which the soil microstructure can be well identified by X-ray computed micro-tomography, scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) test, with the relevant apparatus in PolyU and CEE.