Three-dimensional characterization and quantitative research of Malan loess microstructure under seismic loading

The deformation and failure of loess in areas high seismic intensity are closely related to the dynamic vulnerability, which is primarily controlled by microstructure. This study performed a series triaxial tests microstructure on intact track quantitatively characterize evolution three-dimensional during deformation. microstructural observations were using micro-CT samples after varying vibration times. parameters (including pore radius, elongation, orientation, coordination number, throat area, channel length) obtained reconstructed network model. results this demonstrated that subsidence originated from both compositional characteristics. had loose structure with porosity limited cementation. Upon cyclic loading, cementation contact breakdown led structure, followed particle rearrangement. With increasing times, spaced inter-aggregate pores became intra-aggregate pores, size tended decrease while number increase, connectivity weaken, shape be long flat. Pores >28 μm mainly provided spatial conditions for collapse under load. In addition, ultimate large-volume cracks occurred inside sample. findings provide further insights into perspective microstructures research basis analyzing stability relation construction projects combining finite discrete elements.