The effective dynamic viscosity of a soil-rock mixture (S-RM) serves as a essential parameter for simulating flowlike landslides in the context of fluid kinematics. Accurate measurement of this viscosity is significant for understanding the remote sustainability and rheological properties of landslide hazards. This study presents a method for determining dynamic viscosity, incorporating experimental measurements and numerical inversion. The experiment involves monitoring the movement of S-RMs with varying water content and rock block concentration, followed by the calculation of centroid displacements and velocities using digital image processing. The power-law model, combined with computational fluid dynamics, effectively captures the flow-like behavior of the S-RM. A grid search method is then employed to determine the optimal parameters by comparing the predicted centroid displacement with experimental results. A series of flume experiments were conducted, resulting in the observation of spatial mass distribution and centroid displacement variations over time during soil-rock movement. The dynamic viscosity model of the S-RM is derived from the experimental data. This dynamic viscosity model was then employed to simulate an additional flume experiment, with the results demonstrating excellent agreement between the simulated and experimental centroid displacements. Sensitivity analysis of the dynamic viscosity model indicates a dependence on shear rate and demonstrates a high sensitivity to water content and rock block concentration, following a parabolic trend within the measured range. This research contributes to the fields of geotechnical engineering and landslide risk assessment, offering a practical and effective method of measuring the dynamic viscosity of S-RM. Future research could explore additional factors influencing rheological behavior and extend the applicability of the proposed method to different geological environments.

A novel framework for nonlinear thermal elastic-viscoplastic (TEVP) constitutive relationships was proposed in this study, incorporating three distinct thermoplasticity mechanisms. These four TEVP formulations, combined with an existing TEVP constitutive equation presented in the companion paper, were integrated into a coupled consolidation and heat transfer (CHT) numerical model. The CHT model accounts for large strain, soil selfweight, creep strains, thermal-induced strains, the relative velocity of fluid and solid phases, varying hydraulic conductivity and compressibility during consolidation process, time-dependent loading, and heat transfer, including thermal conduction, thermo-mechanical dispersion, and advection. The performance of CHT model, incorporating different TEVP constitutive equations, was evaluated through comparing the simulation results with measurements from laboratory oedometer tests. Simulation results, including settlement, excess pore pressure and temperature profiles, showed good agreement with the experimental data. All four TEVP constitutive relationships produced identical results for the consolidation behavior of soil that in the oedometer tests. The TEVP constitutive equations may not have a significant effect on the heat transfer in soil layers because of the identical performance on simulating soil compression. The CHT model, incorporating the four TEVP constitutive equations, was then used to investigate the long-term consolidation and heat transfer behavior of a four layer soil stratum under seasonally cyclic thermal loading in a field test, with excellent agreement observed between simulated results and measured data.

The unclear impact of small-spacing construction between new road piles and railway piers in China's coastal soft soils can threaten the safety of operating high-speed railways. By field monitoring and numerical simulation tests, this study examines the deformation characteristics of railway piers and the surrounding stratum due to adjacent pile construction in soft soils. The stratum-lateral deformation (SLD) and the displacement of the bridge pier group with various pile-forming processes or pile construction schemes were measured in field monitoring. Furthermore, the intricate interplay between varying pile diameters and spacing was examined using comprehensive numerical methodology. On this basis, a comprehensive evaluation model for the Construction Deformation Comprehensive Index (CDCI) was established to compare the multi-stage combined effects of pile construction. The results indicate that the bored pile drilling and concreting procedures significantly affect the deformations of the stratum and pier. Specifically, a negative correlation is observed between stratum deformation and the bored pile's distance and depth. The most significant deformation is in the depth direction within the three-direction pier profile. The displacement amplitude caused by single-pile construction surpasses about 2-3 times that of non-construction. Additionally, the CDCI could provide valuable insights for evaluating the holistic impacts on stratum and pier deformation in similar pile construction projects.