Plastic Shear Deformation Research Articles

Experimental investigations on the blast response of reinforced NSC, FRC and UHPC I-shape girders under contact explosions

To investigate the blast response and evaluate the structural resilience of reinforced I-shape girders, seven reinforced normal strength concrete (NSC), fiber reinforced concrete (FRC), and ultra-high performance concrete (UHPC) specimens are subjected to multiple contact explosions in this study. With the test results, the concrete damage regions and plastic deformation of steel bars are used to recognize the damage mechanism of the test specimens. The experimental results show that the damage modes of I-shape girders are mainly dominated by vertical punctures and transverse shear failures. Due to fragile characteristics, nearly 35 % of the punching crater in concrete webs, the entire shear failure of top plates, and severe plastic deformation of steel bars are discovered in NSC specimens. Polyethylene fibers improve ductility, allowing for smaller steel bar deflection and a reduction in punching depth to 21.6 % in FPC specimens. However, due to the oversized impact energies and the insufficient material strength, the transverse shear failure cannot be significantly mitigated. By contrast, not only significantly reduced punching depth but also greatly mitigated transverse shear failures are observed in UHPC specimens. Under 50 g∼200 g contact explosions, the punching depth ratios are reduced to 3.3 %, 16.6 %, and 25.8 %, merely. Apart from that, after explosions, the transverse shear failure and plastic deformation of steel bars can be effectively reduced. Due to the remarkably decreased damage regions, the UHPC specimens exhibit better structural resilience after blast loadings.

Plowing mechanism of rapid flow-like loess landslides: Insights from MPM modeling

Plowing refers to the phenomenon by which a landslide displaces and pushes the path material forward. Despite its importance in shaping the dynamics of many rapid flow-like loess landslides, the mechanism of plowing is not fully understood. Therefore, this paper presents an improved numerical model based on the material point method (MPM). This model takes into account the interactions between the landslide mass and the path material. The reliability of this model was validated by simulating two granular column collapse experiments involving interaction with an erodible mass. The model was then applied to analyze the plowing dynamics of the Ximiaodian loess landslide in Jingyang County, Shaanxi Province, China. A series of well-designed simulations were conducted to investigate this specific landslide event, contributing to a deeper understanding of the plowing phenomenon in loess landslides. The simulation results show that our model can satisfactorily simulate the plowing process of the Ximiaodian landslide. The plowing process of a rapid-flow loess landslide is proposed to consist of four distinct stages: 1) the collision stage, when the landslide strikes the terrace, resulting in the bending of its strata; 2) the shear failure stage, characterized by significant plastic shear deformation within the bent strata, resulting in the formation of multiple shear failure planes; 3) the steady plowing stage, during which the deformation structure in the affected terrace stabilizes and plowing continues in a steady pattern; and 4) the stopping stage, when the propagation of the disturbed terrace gradually stops. Furthermore, the disturbed terrace zone exhibits three distinct deformation structures. In the rear part, a stable zone develops where the terrace layers are compressed. However, due to the compressive forces exerted by the overlying loess, no significant shear deformation is observed. The middle part is the shear failure zone, characterized by the formation of multiple shear failure planes. The front part is the upheaval zone, where the terrace layers are slightly bent and tilted.

Superlubricity of Silicon-Based Ceramics Sliding against Hydrogenated Amorphous Carbon in Ultrahigh Vacuum: Mechanisms of Transfer Film Formation.

Tribological interfaces between silicon-based ceramics, such as Si3N4 or SiC, are characterized by high friction and wear in unlubricated conditions. A solution to this problem is to use them in combination with a hydrogenated amorphous carbon (a-C:H) countersurface from which a passivating carbon film is transferred onto the ceramic surface. However, the mechanisms underlying a stable film transfer process and the conditions that favor it remain elusive. Here, we present friction experiments in ultrahigh vacuum in which friction coefficients lower than 0.01 are achieved by sliding Si3N4 against a-C:H with 36 at. % hydrogen but not against a-C:H with 20 at. % hydrogen. Chemical surface analyses confirm that the superlubric interface forms via the transfer of a hydrocarbon nanofilm onto the Si3N4 surface. Quantum-mechanical simulations reveal that a stable passivating a-C:H film can only be transferred if, after initial cold welding of the tribological interface, the plastic shear deformation is localized within the a-C:H coating. This occurs if the yield shear stress for plastic flow of a-C:H is lower than that of the ceramic and of the shear strength of the a-C:H-ceramic interface, i.e., if the a-C:H hydrogen content ranges between ∼30 and ∼50 at. %. While the importance of a relatively high hydrogen content to achieve an efficient passivation of a-C:H surfaces in a vacuum is well-documented, this work reveals how the hydrogen content is also crucial for obtaining a stable a-C:H transfer film. These results can be extended to glass, SiC, and steel, supporting the generality of the proposed mechanism.

Mechanisms of formation and accumulation of misorientations in deformable metals and alloys

The formation of misoriented substructures in plastically deformable metal materials has been theoretically studied. Expressions are obtained for the intensity of accumulation of low-angle and high-angle misorientation boundaries. Within the framework of a mathematical model of shear plastic deformation and hardening, numerical calculations of the dependences of the average characteristics of a defective medium on the degree of deformation under conditions of uniaxial compression with a constant strain rate at room temperature are performed. It is shown that the intensity of generation of low-angle tilt walls depends significantly on the scenario of changes in the density of jogs on the screw segments of dislocation loops emitted by dislocation sources. The main mechanism for the formation of low-angle walls is the rearrangement of clusters of edge segments of dislocation loops into tilt dislocation walls under the influence of flows of interstitial atoms generated by moving screw segments. It is assumed that low-angle walls merge into one until the total misorientation angle of the merged walls reaches a critical value of about 10°, after which the distance between dislocations in the wall decreases to the corresponding critical value and further penetration of individual dislocations into the wall becomes impossible. The expression for the intensity of the formation of high-angle boundaries was obtained as a consequence of the continuation of the work of dislocation sources and the formation of clusters of low-angle walls, the total energy of which is higher than the energy of an equilibrium high-angle boundary at the same misorientation.

Features of interaction bored pile with the soil base in the presence of structurally unstable soils

During the construction of pile foundations, the pile testing process is necessary and mandatory. Therefore, there is a need for a correct assessment of the interaction elements of the "foundation-pile" system with the provision of a reliable and effective design solution.
 If the soil parameters provided in the reports on engineering and geological searching are used without their prior refinement, this leads to a significant discrepancy in the results of numerical modeling of the interaction of piles with the base and data from field tests. In this regard, there is a need to identify the design parameters of the adopted soil model in order to match the modeling results with the results of experimental studies in a wide range of loads.
 The Hardening Soil Model was chosen to describe the interaction behavior of the elements of base-pile system in this study. The nature of the influence of the three modules identified in the above model was investigated: modulus deformation at 50% of the base strength ( ); compressive strain module ( ); strain module at unloading ( ). The influence of the effect of dilatancy of the sand base was also analyzed.
 At the initial stage of loading, the values of the and modules make a significant contribution to its performance. With further increased loads in the soil, significant plastic shear deformations occur, and accordingly, the parameters of soil strength (c, φ) are the leading parameters. Due to the fact that the upper part of the bored pile is located in structurally unstable soils (bulk soil and plastic sandy loam), and the lower part of the pile is located within sandy soil for a significant part of its length, it is also important to take into account the effect of soil dilatancy (ψ).
 It was found that an increase in the unloading module ( ) reduces not only the settlement along the unloading curve, but also along the load curve.
 The results of comparison of full-scale testing of a bored pile and its numerical modeling of interaction with structurally unstable and sandy soils are presented, and the design parameters of the soil environment model are identified in order to match the modeling results with experimental data at the corresponding specified loads.
 The obtained convergence is within 5% in a wide range along the curve of the load on the bored pile.

A low-cost strategy to enhance strength-ductility balance in AISI1045 steel

In the current research, the impact of cold single-roll drive rolling as a low-cost technique on the microstructural evolution and mechanical properties of the AISI1045 sheet was studied. The microstructure of the as-received sample was a lamellar structure consisting of soft domains (proeutectoid ferrite) and hard domains (pearlite). The average grain size of proeutectoid α decreased from 24.5 μm (for the initial steel) to 7.1 μm (for the 60 % rolled steel) due to the occurrence of continuous dynamic recrystallization (CDRX). With an increase in the rolling deformation, the homogeneity of the ferrite and pearlite distribution in the microstructure was improved. Fragmentation and bending of the θ lamellae and several shear bands were seen in the 60 % deformed steel. By increasing the strain, the rotation of ferrite grains towards the θ fiber (as shear texture) increased due to the introduction of severe shear plastic deformation caused by the single-roll drive rolling. By increasing the intensity of ⟨100⟩‖ND (caused by the rolling deformation increasing), the amount of hardness enhanced less in the RD-TD section compared to the RD-ND section. As the rolling reduction increased to 60 %, the yield and tensile strength significantly enhanced and reached a maximum of 993.1 MPa and 1017.8 MPa, respectively. This was due to work hardening, grain refinement strengthening of α, and fragmentation of θ. The decreasing trend of the work hardening of the 60 % rolled steel was not similar to the strain hardening behavior of homogeneous materials, indicating that the number of geometrically necessary dislocations accumulated at the hard domain/soft domain interfaces was large, which was beneficial to the increment of work hardening in the second stage. After the rolling reduction increased, the proportion of dimples reduced, the depth and number of dimples decreased, and the plasticity reduced, which had a large effect on the secondary cracks.

Effects of Thermal Cycling and Porosity on Phase Transformation of Porous Nanocrystalline NiTi Shape Memory Alloy: An Atomistic Simulation

Herein, the effects of thermal cycling and porosity on the martensitic phase transformation behavior of porous nanocrystalline (NC) NiTi shape memory alloys (SMAs) at the atomic scale are investigated by molecular dynamics simulation. The simulation results show that thermal cycling causes the NC NiTi SMAs to repeatedly undergo martensitic phase transformation and inverse phase transformation processes. The martensitic phase transformation capability is suppressed with increasing porosity and number of cycles, but the suppression effect of thermal cycling is weakened with increasing porosity. Moreover, the start temperature of martensitic transformation, residual martensitic phase, and the fraction of interstitial atoms increase with increasing porosity. Thermal cycling causes the disordered structures and shear plastic deformation to accumulate as cycling increases. Recoverable shear deformation is generated within the grain, but shear plastic deformation is mainly concentrated at both grain boundaries and pore surfaces. Residual martensitic phase increases after thermal cycling. These results provide important explanations and references for a deeper understanding of phase transformation behavior and pore effects caused by thermal cycling.

Methodology to assess damage mechanisms of rail steels based on small-scale experiments

A new methodology to distinguish between the damage mechanisms wear only and RCF crack initiation in combination with wear in rolling contacts is proposed in this work. The new methodology distinguishes between the damage mechanisms by comparing the experimental crack depth against a critical crack depth which is governed by the surface roughness and by the plastic shear deformation depth in the near-surface layer. The new methodology is used to assess the results of twin disc experiments that have been conducted with three pearlitic rail steels at different normal contact pressures and different longitudinal creep values. The observed experimental results show agreement with the criterion and the threshold of the new methodology.

Numerical simulation of interaction bored pile and soil mass with taking into account the dilatancy of the soil

Pile testing is a necessary and mandatory process of construction buildings and structures erected on pile foundations. There is a need for a correct assessment of the interaction of the elements of the "foundation-pile" system for the reliable and effective design of pile foundations.
 The use of soil parameters provided in reports on engineering and geological investigations, without their clarification, leads to a significant discrepancy in the results of numerical modeling of the interaction of piles with the foundation and data from real observations of their settlement as a result of loads. Therefore, there is a need to identify the calculated parameters of the adopted soil model in order to match the simulation results with the results of experimental studies in a wide range of loads.
 In this paper, a model of ideal elastic-plastic behavior of the soil environment using the Mohr-Coulomb strength criterion was chosen to describe the interaction behavior of the elements of the "foundation-pile" system. When using this model, it is necessary to take into account a number of its inherent shortcomings, for example, not taking into account the change of the young`s modulus depending the change of the stress-strain state. Additionally, this work examines the influence of the dilatancy effect of sandy soil.
 At the initial stage of loads up to 15% of the total settlement of the pile (displacement resulting from potential pile failure), the value of the young`s modulus (E) makes a significant contribution to its operation. At the later stages of loading, significant plastic shear deformations occur in the soil, and accordingly, the leading parameters are the soil strength parameters, in this case, the specific cohesion (c) and the friction angle(φ). Since in this work the drill pile passes through sandy soil for a considerable length, it is also important to take into account the effect of soil dilatation(ψ).
 The results of a comparison field test of the bored pile with large-diameter and their numerical simulation of interaction with sandy soils are presented, and the calculation parameters of the soil environment model are identified in order to match the simulation results with experimental data at the corresponding specified loads.
 A convergence of up to 5% was achieved in a wide range of loads on the bored pile.

Optimizing dry-wear performance of a Ti-based high entropy bulk metallic glass via isothermal annealing

The evolution of microstructure, thermal stability, mechanical response behavior and tribological properties of the Ti20Zr20Cu20Hf20Be20 high entropy bulk metallic glass (HE-BMG) before and after isothermal annealing were systematically studied. The results demonstrate that isothermal annealing affects the mechanical and tribological properties by modifying the microstructure and the consumption of free volume in the structure. Although the strength/hardness of HE-BMG can be improved after the isothermal annealing before crystallization, the deterioration of shear plastic deformation leads to serious brittle fracture, thus cancelling out the contribution of strength to wear resistance and resulting in negligible variation of wear rates. When the crystallization isothermal annealing is performed, the wear resistance can be dramatically enhanced and the wear mechanism changes to slight abrasive and oxidation wear, which can be mainly attributed to the good co-deformation between the amorphous matrix and precipitated crystalline phases.

Surface Integrity Analysis in Grinding of Dual-Phase High-Entropy Alloy

Abstract High-entropy alloys (HEAs) are highly anticipated because of their superb properties in strength, hardness, wear resistance, etc. However, compared with numerous studies on the design and properties of HEAs, the machinability research of HEAs is extremely rare, which limits the application of HEAs. In this work, grinding experiments of (FeCoNi)86Al7Ti7 dual-phase HEA workpieces were carried out, and the results are analyzed from a general machinability perspective (the machining parameters’ effect on grinding force and surface roughness) to a more in-depth perspective, including grinding-induced changes in morphology and microstructure on the ground surface and subsurface. With scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) information of subsurface, the deformation mechanisms have been studied, including the role of the second-phase (Ni2AlTi) in the grinding process, the material removal modes of the different phases, and the morphology of the nanoprecipitates in the matrix, based on the completely opposite properties of different phases in HEA. It is noticed that the hard and brittle property of the second phase brings support to the material, reduces the plastic deformation, and also makes its own removal brittle, while the plastic matrix experiences shear deformation in grinding, which makes the nanoprecipitates in it assume different morphologies. These detailed findings could be of help to understand the effect of grinding on material properties so as to improve the machining quality of this material.

Microvoid Formation of Ferrite-martensite Dual-phase Steel via Tensile Deformation after Severe Plastic Shear-deformation

Microvoid Formation of Ferrite-martensite Dual-phase Steel via Tensile Deformation after Severe Plastic Shear-deformation

Microvoid Formation of Ferrite-martensite Dual-phase Steel via Tensile Deformation after Severe Plastic Shear-deformation

One of the objectives for the development of high-strength dual-phase (DP) steel is improving the stretch-flangeability. Large-strained sheared edges are deformed and frequently cracked during stretch-flange formation. Considering shearing as the first deformation, the stretch-flange deformation may be regarded as a secondary deformation. To improve the stretch-flangeability of the DP steels, many researchers have analyzed the microvoid formation. However, in these analyses, the shearing process was not considered. With this background, ex-situ mini-bending tests combined with scanning electron microscopy (SEM) monitoring of microvoid formation were conducted during the secondary deformation. Prior to the secondary deformation, several microvoids were observed on the sheared surface and fine subgrains formed in the ferrite. During secondary deformation, the preliminary microvoids present at the ferrite-martensite interface propagated into the ferrite phase. In contrast, this behavior was not observed for the reamed surface deformation, which was formed without preliminary deformation. Furthermore, microvoids were initiated on ferrite grains that were not present at the ferrite-martensite interface, and martensite islands were not cracked during secondary deformation. This result is noteworthy because martensite cracking was the main factor involved in microvoid initiation, in the absence of shearing. Electron backscattering diffraction analysis revealed that the work hardening of ferrite, prior to the secondary deformation, caused a deviation in the strain concentration sites from those found in the reamed surface deformation. Therefore, this study elucidated microvoid formation on preliminary deformed surfaces via shearing and provided insights for material development considering deformations on the sheared surfaces of materials.

Finite Element Simulation and Experimental Investigation of Nanostructuring Burnishing AISI 52100 Steel Using an Inclined Flat Cylindrical Tool

This article is devoted to the development of a sliding burnishing scheme using a flat cylindrical indenter. The previously established patterns of nanostructured state formation in the AISI 52100 steel subsurface layer showed a need to create a special tool with a variable tilt angle of the indenter and with force regulation. A new tool with a cubic boron nitride indenter opens wide possibilities for nanostructuring burnishing of hardened bearing steel. Firstly, a flat cylindrical indenter has high durability due to repeated rotation around its axis. Secondly, the change of the tilt angle to the treated surface allows controlling the contact compression pressure and plastic shear deformation, which determines the formation of a nanostructured state of the material by the method of severe plastic deformation (SPD). The purpose of the work is to determine the optimal parameters of the process and tool in order to form a nanostructure and significantly increase surface layer microhardness. The goal was achieved by the methods of finite element modeling (FEM) and experimental studies of burnishing when the indenter tilt angle changes from 0.5° to 2.5° under dry processing conditions. Numerical simulation of the process made it possible to establish optimal values of the indenter tilt angle of 2° and the burnishing force 250 N according to the criteria of maximum contact pressure and cumulative deformation. The experimental studies of cumulative deformations and the coefficient of friction by the method of burnishing a split disc and dynamometry of the process confirmed the FEM results. The transmission microscopy, durometry, and 3D surface profilometry showed the sensitivity of nanocrystallite sizes, microhardness, and roughness to an indenter tilt angle and confirmed the optimality of the established tilt angle value.

Characterization of Plastic Deformation in CuZr Metallic Glasses Subjected to the Rolling Process

Using the rolling process, it is possible to induce multiple shear bands in the microstructure of metallic glasses (MGs) and improve the overall plasticity in the subsequent mechanical loadings. Hence, it is crucial to understand the mechanism of shear banding and plastic deformation under the rolling process. In this work, molecular dynamics (MD) simulation was applied to evaluate the formation and generation of shear bands in a CuZr MG under cold- and hot-rolling processes. Based on the results, it is found that the shear bands are formed with secondary branches in the cold rolling, while the shear events are scattered in the bulk of material in the hot rolling. Considering Voronoi analysis, it is revealed that the hot rolling is accompanied by the recovery of crystalline-like clusters provided that rolling process continues for subsequent passes. On the other hand, the cold-rolled sample shows a stable behavior in the evolution of crystalline-like clusters; however, the population of main icosahedral polyhedrons decreases in the system.

Synergistically toughened epoxy resin based on modified-POSS triggered interpenetrating network

The toughening of epoxy resin has always been one of the key topics in the researches about high-performance matrix used for advanced composites. Up to now, single-property enhancement is usually accompanied by some compromises of other properties. This work constructed a novel in-situ interpenetrating network (IPN) structure composed of epoxy resin and vinyl ester resin (VER), along with modified octavinyl polyhedral oligomeric silsesquioxane (EPOSS) as the toughening core. In the present resin system, the VER component was firstly introduced to form IPN structures without phase separation to bring the improvement of overall strength and plastic deformation capacity. Moreover, the EPOSS could realize nano-scale dispersion in the resin matrix through the chemical reactions, which acted as the trigger of plastic shear deformation toughening under particle debonding. The side chains' physical entanglement of EPOSS played the key role in maintaining a balance between toughness and mechanical strength. With only 2 wt% of EPOSS, the optimal increase in impact toughness reached 139.6%, in addition to the 17.9% improvement of tensile strength and 9.0% enhancement of Young's modulus.

A novel criterion for yield shear displacement of rock discontinuities based on renormalization group theory

Research on the plastic shear deformation of rock discontinuities is essential to the structural design of rock engineering, and the yield point is an important indicator for plastic shear deformation. In this paper, a conceptual model based on renormalization group theory is proposed to qualitatively explain the evolution mode of shear deformation. Then, considering the stress transfer mechanism, the mathematical description of the critical failure point is derived. Subsequently, the criterion for yield shear displacement is obtained by combining the renormalization group model with the shear constitutive model. Finally, experimental results based on the ratio of yield stress to shear strength for different rock types are provided to verify the proposed criterion. The theoretical and mathematical analysis indicates that the yield point is the phase transition point during the shear deformation of rock discontinuities, which is equivalent to the critical failure point in the renormalization group theory. The relationship between the failure probability of n-order blocks and the basic failure probability can be obtained according to the stress transfer mechanism and the conditional probability, so that a mathematical description of the critical failure point can be established. The verification by both laboratory and in-situ tests shows that the results of the proposed criterion are consistent with those of classical methods. In addition, the determination of the parameters has little influence on the criterion's performance, which means the proposed criterion could eliminate the subjectiveness in determining the yield shear displacement.

Impact design of die parameters on Severe plastic deformation during Equal channel angular pressing: An overview

Equal channel angular pressing causes less uniform deformation than simple shear, even though its not as obvious as with other metal forming procedures. Investigation is done into how internal and external factors affect the deformity inhomogeneity through Equal .channel angular pressing. Finite element analysis of plastic deformity are integrated with die corner angle and the strain harden ability of metallic workpiece. The material characteristics are significantly influenced by the type of plastic shear deformation that occurs through Equal channel angular pressing and this is primarily impacted by the die geometry, the properties of the material and the process factors. Segmenting the workpiece into a front transient zone, end transient zone, outer less sheared zone and the remaining shear deforming zone allowed researchers to examine the uneven strain distribution throughout the workpiece. The deformed geometry for the non-hardening and it was assumed that rate-insensitive materials would be largely homogeneous. In materials that are strain-rate sensitive, gaps between the upper and lower channels developed, whereas strain-hardening materials experienced the corner gap. The strain hardening and implications of strain-rate sensitivity exponent had a considerable impact on the deformation inhomogeneity. Metals having an ultrafine grain microstructure can be created by severe plastic deformation. The FE models were used to affect the process and they all took as inputs the material properties, load variation, Different velocity and boundary conditioned. For the purpose of evaluating the impact of the channel angle on the AA5083 sample, The FE analysis produced the value of strain distribution. When the channel angle was 1200, there was less strain overall, but there was also less concentrated stress in the channel corner area.

Anisotropy of elastic properties of SHS-synthesized porous titanium nickelide

Samples of porous NiTi were obtained by the method of self-propagating high-temperature synthesis. The mechanical characteristics of the porous ones were studied by quasi-static compression. When the samples of porous titanium nickelide were subject to quasi-static compression, the deformation was of an elastic-plastic nature. Three characteristic types of the fracture surface under quasi-static compression of the porous SHS – TiNi alloy were identified: 1) ductile fracture of the austenite phase in the form of a cup relief, 2) brittle fracture accompanied by the formation of cleavage steps, 3) large areas of plastic shear deformation, on which cups and cleavage facets were nucleated. To determine the anisotropy of the porous TiNi alloy properties, the volume of the porous sample was simulated, and estimated calculations were carried out. Based on the results of reconstructing 3D neutron high resolution tomography of the porous volume of titanium nickelide and the numerical parameters of the model porous medium, an algorithm was developed for obtaining a solid-state 3D model of the porous framework for using in finite element calculations. The studied porous titanium nickelide alloy, as well as spongy bone tissues, was shown to have orthotropic elastic properties conditioned by the geometric features of the porous framework. The effective moduli of elasticity and shear for the porous volume of the material were determined. The calculation results of the elastic moduli for the studied model of porous titanium nickelide numerically agree with the results obtained by compressing the samples of porous TiNi. The porous TiNi alloy under uniaxial compression was established to be destroyed under the action of tangential shear stresses at an angle of 45 degrees to the direction of uniaxial compression. The research was carried out with financial support of the Russian Science Foundation under the Grant No. 22-72-10037, https://rscf.ru/project/22-72-10037/.

Simulation analysis on seismic dynamic response of pile supported tunnels in deep backfill area of soil-rock mixture

To reveal the seismic dynamic response of the pile-supported tunnel group in the soil-rock mixture deep backfill region, a three-dimensional finite element model was established based on the engineering conditions of the subway section and three tunnels with close access lines. Subsequently, the seismic dynamic response of the tunnel lining structure was studied. The results show that: Under the action of seismic, the soil-rock mixture stratum presents nonlinear characteristics with shear failure and plastic deformation. In addition, the acceleration and earth pressure of the soil-rock mixture stratum is in a “saturated” state; The seismic dynamic response of the three tunnels influences each other. The bending moments in the X and Y directions of the tunnel lining cross-section are distributed in “X” and inverted “V” shapes, respectively. Meanwhile, the tensile stress and shear stress are distributed in an “X” shape; Under the action of seismic, the main failure form of tunnel lining is tension shear failure, and the most vulnerable position is the left and right arch foot, followed by the left and right arch shoulder; The bending moment of the pile body changes nonlinearly in the height direction. The most significant bending moment value appears at the top 1/5 of the pile length and the junction of different strata. Furthermore, the most significant horizontal displacement of the lining structure occurs at the tunnel vault.