During the construction of a shield tunnel, it will disturb the surrounding ground and affect the use and structural safety of buildings around the tunnel. The geometric parameters of the tunnel, the operating parameters of the shield machine, and the geological parameters will affect the degree of disturbance. However, the existing theories and models are difficult to comprehensively consider the interaction of these factors, and it is difficult to accurately predict the response of the formation to solve the above problems. The research is based on the machine learning algorithm to establish a prediction model of stratum settlement caused by shield tunneling, which provides a new idea for real time prediction of the ground response caused by shield tunneling and risk reduction. The main results of this research are as follows: (1) propose a novel quantification method for geological parameters that can comprehensively consider the physical and mechanical properties of the rock,soil layers, and the geometric characteristics of depth and thickness and (2) establish a more robust proxy model and use the k-fold cross-validation method to enhance its performance.

Consolidation and settlement of soft soil ground are the main problems encountered for geotechnical engineers, and drainage boundary conditions play a crucial role in consolidation analysis and settlement prediction. Despite some theoretical approaches that have been proposed incorporating some particular drainage boundary conditions, there remains a dearth of rigorous analytical solutions for multilayered soils that effectively capture various drainage boundary conditions. This study presents a novel approach where the spectral method is used to capture the impact that drainage boundary condition has on the consolidation of multilayered soil. The drainage boundary condition over time is considered, while the excess pore water pressure (EPWP) profile across different soil layers can be described as a single expression using matrix operations. This proposed method is then verified with field investigations where the varying drainage condition is captured and compared with other solutions. The results show that the consolidation behavior will be overestimated if the traditional boundary conditions are used and the proposed method can predict the consolidation of soil with greater accuracy and flexibility. EPWP and settlement at different depths can be estimated such that they agree better with the field data, and the study also indicates that there is a noticeable discrepancy in the predicted consolidation when the drainage boundary condition is not considered properly.

Energy shallow foundations represent an innovative technology that can simultaneously support structural loads and harvest geothermal energy. During geothermal operations, the underlying soils are subjected to structural loads and temperature fluctuations. Despite the potential, knowledge regarding the thermo-hydro-mechanical behavior of the multilayered soils beneath the energy foundations remains scarce. This study proposed an analytical approach to investigate the thermo-hydro-mechanical response of soft fine-grained soils beneath energy shallow foundations. The analysis focused on the evolutions of the temperature, pore water pressure, and vertical displacement of the underlying soils. The results indicate that the generation and development of the thermally induced excess pore pressure are controlled by thermal transfer processes and soil hydraulic properties. Furthermore, the mechanical load-induced ground settlement decreases upon heating and increases upon cooling, primarily due to the development of thermally induced pore pressure and the thermal volume changes of the soil skeleton. Under the considered conditions, ignoring the thermally induced mechanical effects could result in a settlement prediction error of nearly 120%. Therefore, the thermo-hydro-mechanical interactions within the soils should be appropriately considered in the analysis and prediction of the displacement behavior of the energy foundations.

The self-weight stress in multilayered soil varies with depth, and traditional consolidation research seldom takes into account the actual distribution of self-weight stress, resulting in inaccurate calculations of soil consolidation and settlement. This paper presents a semi-analytical solution for the one-dimensional nonlinear consolidation of multilayered soil, considering self-weight, time-dependent loading, and boundary time effect. The validity of the proposed solution is confirmed through comparison with existing analytical solutions and finite difference solution. Based on the proposed semi-analytical solution, this study investigates the influence of self-weight, interface parameter, soil properties, and nonlinear parameters on the consolidation characteristics of multilayered soil. The results indicate that factoring in the true distribution of self-weight leads to a faster dissipation rate of excess pore water pressure and larger settlement and settlement rate, compared to not considering self-weight. Both boundary drainage performance and soil nonlinearity have an impact on consolidation. If the boundary drainage capacity is inadequate, the influence of soil nonlinearity on consolidation diminishes.

A novel model is put forward to characterize the seismic response excited by vertical P-waves in a transversely isotropic and layered nonlocal poroelastic seabed. The proposed model integrates nonlocal parameter, anisotropy, and stratification to accurately examine wave propagation behavior. The fundamental equations for the underlying seabed are formulated using Biot's poroelastodynamic theory and Eringen's nonlocal theory. The wave equation for the overlying water is expressed in terms of the velocity potential. General solutions in both the poroelastic seabed and water layer are derived by solving the involved ordinary differential equations. Employing the newly devised and unconditionally stable propagator matrix scheme, semi-analytical solutions are derived for the time-harmonic response in a layered poroelastic seabed subjected to vertical P-wave excitation within the frequency domain. The validity of the proposed solutions is confirmed through rigorous comparison with the previously established analytical solutions. The influence of key material properties of seabed on the velocities of P-waves and free-field response in the poroelastic seabed is estimated in detail, along with the freefield response in a nonhomogeneous poroelastic seabed.

This study constructs a multilayered transversely isotropic saturated model under thermal and horizontally circular loads, and further investigates the model's thermo-hydro-mechanical coupling response. Firstly, the ordinary differential matrix equations of thermoelastic saturated media in the integral transformed domain are derived. Secondly, the solution for multilayered thermoelastic saturated media is developed using the extended precise integration method (EPIM), along with the boundary conditions at both ends of the foundation and the continuity conditions between adjacent layers. After that, the solution in the physical domain is further attained with the use of Laplace-Hankel integral transform inversion. Finally, the accuracy of the proposed theory is confirmed through numerical examples, and the influences of anisotropic parameters, the soil's stratification and porosity on the thermo-hydro-mechanical coupling response of the media are studied.

In this paper, the one-dimensional rheological consolidation characteristics of multilayered saturated soil foundations under time-dependent loading and heating are investigated by considering the semi-permeability and the interface thermal resistance. By introducing the fractional derivative model and the thermos-elastic theory, a thermo-mechanical coupling model is established to describe the rheological properties of saturated soils. Semi-analytical solutions for strain, temperature increment, pore water pressure and settlement were derived through the Laplace transform and its inverse. The accuracy of the solutions proposed in this paper has been verified by comparing with existing solutions. The effects of different thermal contact models of the interface on the rheological properties of saturated soils under semi-permeable boundary are discussed, and the effects of fractional derivative order, constitutive material parameters, and thermal conductivity of soil on the thermal consolidation process are investigated. The results show that: neglecting the thermal resistance effect can result in an overestimates of the impact of rheological properties on the thermal consolidation process of saturated soils under semi-permeable boundaries; As the thermal resistance coefficient increases, the influence of soil thermal conductivity on settlement decreases.

Based on the basic control equations of orthotropic anisotropic half-space under moving harmonic loads, the transfer matrix solution of a single-layer foundation is derived by introducing the moving coordinate system, Fourier integral transform, and Cayley-Hamilton theorem. The three-dimensional (3D) dynamic mechanical model of layered orthotropic anisotropic foundation under the rectangular coordinate system is established. The dynamic response of the layered foundation along the depth direction in the frequency domain is derived by using the transfer matrix method, combining boundary conditions, interlayer contact conditions, and continuity conditions. The analytical expressions of the displacements and stresses in the layered foundation are obtained by using Fourier inverse transformation. Based on the derived theoretical method, degradation verification, and corresponding calculation program are prepared for numerical calculation, and numerical example parameter analysis was carried out in combination with the finite element analysis software ABAQUS to study the influence law of the stratification characteristics, load moving speed, load vibration frequency and orthotropic anisotropic properties on the dynamic response of layered foundation. The 3D dynamic characteristics of layered orthotropic anisotropic foundations under the moving load are revealed. The results show that the stratification characteristics of the foundation have a significant effect on the vertical displacement of the surface, and the changes in elastic modulus and shear modulus parameters of the first layer of soil have a greater effect on the displacement dynamic response than that of the subsoil. Within a certain range, the vertical displacement of the foundation surface increases with the increase of load moving speed and decreases with the increase of load vibration frequency. Compared with isotropy, the orthogonal anisotropy of the surface foundation has an obvious influence on the vertical displacement of the foundation surface. In practical engineering, the orthogonal anisotropy of the foundation should be considered in order to obtain more accurate results.