Compared with the ground concrete structures, the tunnel lining structures are affected by the carbonated water environment, and its degradation mechanism is significantly different from the carbonization in the atmospheric environment. This study is to reveal the deterioration mechanism of tunnel lining structure under the action of the carbonated water. Experiments were conducted to study the accelerated erosion of cement mortar in the atmospheric and carbonated water environments, respectively. The results show that the carbonization depth of cement mortar in the carbonated water environment is obviously less than that in the atmospheric environment, and its carbonization coefficient is only 0.18 times that in the atmospheric environment. In the atmospheric environment, the volume of pores in cement mortar is reduced due to carbonization, whereas the uniaxial compressive strength and elastic modulus of cement mortar are sharply increased. However, in the carbonated water environment, the loss of Ca element is exacerbated, and the carbonization results in a lower content of Ca in the carbonized layer. As a result, the pore structure of the cement mortar is destroyed, leading to an increase in the pore volume of the cement mortar. Finally, both the uniaxial compressive strength and elastic modulus of the cement mortar are decreased in the carbonated water environment, especially the elastic modulus. The research results reveal that in the carbonated water environment, the loss of Ca is accelerated in the tunnel lining structure, resulting in an increase in the porosity and a decrease in the strength. Ultimately, the deterioration of the tunnel lining structure occurs, which affects the long-term safe operation of the tunnel lining structure.

Understanding rainfall infiltration process and rain-induced failure mechanism in unsaturated soils depends on experimental study with joint monitoring of multi-physical parameters. Based on the monitoring technology of soil response under a high-gravity environment, centrifuge modelling of rainfall infiltration in a unsaturated loess is carried out. Effects of high-gravity on micro-probe of time domain reflectometers (TDR) and tensiometer were evaluated. TDR probes, tensiometers, bender elements were jointly used to monitor the multi-physical response in the soil model. The experimental results showed that consistent waveforms were measured by the TDR probes for a given soil subjected to at different g levels. It indicated that the measurement by TDR was not influence by the high gravity, and the measurement error of gravimetric moisture content was within 2%. The value of matric suction measured by the tensiometer appeared to decline during centrifugal acceleration process. After the acceleration reached the stable value of 40g, the recorded suction was recovered to the initial suction measured under normal gravity within 10 minutes. During the process of rainfall infiltration, the TDR, tensiometer and bender element, which were buried at same depth, showed a concurrent response to the arrival of wetting front. Rainfall infiltration resulted in an increase in moisture content, a decline in matric suction, and a decrease in shear-wave velocity. The joint monitoring of muti-physical parameters will provide useful data for establishing the relationships among moisture content, matric suction and shear modulus.

Aphanitic basalt is one of the main types of surrounding rock widely observed in the cavern group of super large scale underground powerhouse of Baihetan hydropower station, which includes widely-seen hidden microfissures and unfolds special mechanical response characteristics during excavation. With the use of CT scan, high-speed camera, acoustic emission, scanning electron microscopy and other methods, the deformation and failure characteristics, crack propagation and AE evolution of aphanitic basalt were analyzed. Meanwhile, the microscopic failure mechanism was explored. The key outcomes are: The intact specimens with a smooth stress-strain curve instantaneously burst that caused AE signal abnormally concentrated when loaded to peak strength, which was mainly characterized by fragmented failure. The samples with hidden microfissures exhibited a stress-strain curve of “zig-zag” shape and multiple surface spalling and active AE signal during the whole compression process, of which the failure mode was primarily the splitting failure. The samples with macrofissures showed a stress-strain curve of double or multi-peak shape and the failure mode was primarily the shear failure that the preexisting fissures started to partially slip before the peak. After that, the macroscopic rupture surface formed at the first peak which led to AE signal concentrate at the moment when peak stress instantly dropped .The microscopic failure mechanism of aphanitic basalt was mainly characterized by intergranular fracture and transgranular fracture of mineral grains. The research results lay a solid foundation for accurately understanding and scientifically mastering the mechanical response and rupture evolution characteristics of the surrounding rock mass of underground powerhouse caverns of Baihetan hydropower station, and also provide reference and guidance for the understanding of high-stress failure and disaster control of brittle rock masses.

In this study, acoustic emission (AE) experiments were carried out on saturated granite under uniaxial compression. Fast Fourier transform (FFT) was used to extract the spectrum parameters of AE signals such as dominant-frequency and secondary dominant-frequency. Furthermore, the ratio of the dominant-frequency to secondary dominant-frequency (F) was proposed to characterize the spectral characteristics of the AE signal and study the characteristics of AE spectrum in rock fracture process. The results show that the numbers of the dominant-frequency and secondary dominant-frequency bands of AE increase first and then decrease in the rupture process of saturated granite. Compared with the characteristics of the dominant-frequency distribution, the proportion of the low-frequency interval of the secondary dominant-frequency reduces, and the proportion of the middle and high-frequency interval increases. In addition, the total average value of the secondary dominant-frequency is about 5 kHz higher than that of the dominant-frequency. The distribution range of the dominant-frequency ratio (F) reaches the maximum at the elastic stage: 0

It is of great practical significance to study the cumulative damage of slope under repeated seismic loads for long-term stability analysis of rock slope in reservoir area. In this paper, shaking table test and theoretical analysis were used to study the cumulative damage and failure mode of horizontal layered rock slope under repeated seismic loads. Results show that the fatigue crack propagation of concrete double K criterion explains the change tendency of the slope of the cumulative damage curve well. The complete cumulative damage evolution curve shows three stages, i.e., the initial damage stage, mesoscopic crack extension stage and macroscopic crack extension stage. The well fitted cubic polynomial and power exponent are adopted to establish the cumulative damage evolution model of slope rock mass under the action of micro-small earthquakes and strong earthquakes respectively. The cumulative damage curve of slope rock mass shows slight dip in the early stage, linear growth in the middle stage and moderate growth in the last stage under the action of micro-small earthquakes, which has the features of the positive "S" type. And the cumulative damage of slope rock mass under the action of strong earthquakes has a relatively rapid growth compared with that under the action of micro-small earthquakes, and the increase rate of which is accelerated before the slope failure. Under the action of frequent micro earthquake, stepped failure surfaces on the upper part of the horizontal layered rock slope are formed and exposed to the slope surface, while straight shear failure surface if formed on the lower part of the slope. The final failure surface of the slope is a stepped one.

Negative-pressure extraction is one of the most important factors affecting the seepage law of coal gas in the perforated hole. To study its influence, the gas flow in the hole was determined by designing a similar simulation test platform for gas seepage. Moreover, the numerical software was used to analyze the gas seepage in the coal around the hole. Combined with the above conclusions, the percolation characteristics of gas in the coal around the hole was studied. The results showed that the negative pressure was used to provide the power for gas seeping from the coal to the borehole. When the negative pressure was set in the range of 25~35 kPa, the Reynolds number was concentrated between 10 and 20. Thus, the low-speed turbulent flow is ensured, which was conducive to extracting the gas efficiently. With the increase of pumping time, the effect of negative pressure on the gas extraction gradually became weak, and the gas flow showed a negative exponential decay with time. The saturated value of coal seepage velocity was between 7.41×10?6 m/s and 1.30×10?5 m/s. The internal viscous resistance of the coal body inhibited the gas seepage. With increasing the negative-pressure extraction, the negative pressure of the borehole increased faster than that in the coal around the hole, which indicated the effect of the negative pressure on the borehole was more significant.

Based on microbial induced carbonate precipitation (MICP), soil modification technology has attracted widespread concern in geotechnical engineering. This technology can not only improve the soil strength, stiffness, the properties of anti-liquefaction, anti-erosion and anti-permeability but also maintain good soil permeability and water permeability and improve the growth environment of the plants simultaneously. As the microbial mineralisation involves a series of complex biochemical and ion chemical reactions in the curing process, soil modification through MICP curing can be affected by many factors. In this paper, the effects of influence factors on the performance of microbial improved geomaterials were summarised, such as bacterial species, bacterial concentration, temperature, pH, the ratio of cement solution and soil properties, and their optimisation methods and future research direction were discussed as well. The conclusions are as follows. The bacteria type, bacteria concentration, temperature, pH, and the nature of the cement can affect the crystal type, crystal appearance, and size of calcium carbonates microscopically, and further affect the cementing effect of geomaterials macroscopically. The optimized conditions for strengthening the geomaterials are under the high bacteria concentration, the temperature from 20℃ to 40℃, the pH from 7 to 9.5, and the concentration of the cementation solution within 1 mol/L. In the optimised range of those factors, the soil permeability is improved by relatively low temperature, high pH value, and low concentration of cementation solution, while the soil strength is enhanced by the relatively high temperature, low pH value and high concentration of cementation solution. The effective grain size ranges from 10 to 1 000 μm, and the relatively large size and good gradation can promote the consolidation effect. The methods of multi-phase grouting, multi-concentration grouting and electroosmosis grouting improve the uniformity of soil solidification. The grouting speed below 0.042 mol/L/h is beneficial to improve the utilization ratio of the cement solution. The grouting pressure of the sand specimen is generally between 10 kPa～30 kPa bar, the grouting pressure of the silt and clay specimen should not exceed 110 kPa, and the high grouting pressure destroys the structure of soil and reduces the curing effect.

In order to reasonably reflect the influence of particle breakage on the mechanical properties of the rockfill material, it is obtained by the analysis of the test results that the particle breakage characteristics of the rockfill material under the compression and shear. By introducing the related parameters in the compression breakage and shear breakage, some reasonable definitions of the existing constitutive models are used. Taking the advantages on the critical state theory and the boundary surface theory, a unified constitutive model is developed considering the particle breakage and state parameter, and the determination method of model parameters is described. The model can reflect not only the low pressure dilatancy, high pressure shear shrinkage, strain softening and hardening phenomenon of the rockfill material under the static loading, but also the stress-strain hysteresis characteristics and the cumulative effect of residual deformation under the cyclic loading. Finally, in order to verify the reasonability of the model, the static triaxial and cyclic triaxial tests of rockfill material are carried out. The results show that the model prediction is in good agreement with the experimental data, and the constitutive model can reasonably describe the impact of particle breakage on the static and dynamic deformation characteristics of the rockfill material.

Grain-size analysis is widely used to determine the particle size distribution (PSD) of materials in civil engineering, water conservancy and hydropower, and mining. However, there is limited information on the reasonable sample mass of super large-size fillers commonly used in engineering. Based on the theory of stratified sampling, a theoretical formula was established to obtain the sample capacity. A general method for determining the sample mass in the sieving test was proposed by considering the relationship between the average particle size of granular materials and its particle size distribution. Targeted tests were carried out to study the distributions of different gradations, and the reliability of the method was validated. The method was applied to determine the particle size distribution of the fillers used in Chongqing Jiangbei airport and Guizhou Longdongbao airport. Therefore, the proposed method provides references for the development and improvement of relevant engineering practices and specifications.

Basalt fiber-reinforced polymer (BFRP) anchor, which has much higher tensile strength, better corrosion resistance and lighter weight than steel bar, is a new kind high performance fiber-reinforced anchor. However, its application in slope engineering is still at preliminary stage. In this study, a series of pull out tests for BFRP anchors were performed at a loess slope site, based on which the performances of BFRP anchor systems with different bolt diameter and anchorage length were studied. The failure modes of BFRP anchor system were investigated by examining the excavated anchors at the slope site. The test results show that the failure modes of anchor system depend on the relative strength of interfaces. The anchors with 12 mm and 16 mm diameters tend to fail in shear at the interface between bar and grout (the 1st interface), and 25 mm fail in shear at the interface between grout and surrounding soil (the 2nd interface). Under certain anchorage conditions, the increase in the bolt diameter can significantly improve the ultimate pullout load of the anchor system. With the increase of the anchorage length, the ultimate pullout force does not always increase linearly but with the increasing trend decreases gradually, showing the existence of a critical value in the anchorage length. The average bond strength of the interface between 1st and 2nd decreases with the increase of the anchor length. The recommended values for average bond strength of interfaces are also presented for practical engineering design. The axial force of the anchors gradually attenuates along the depth with its distribution pattern related to the magnitude of the tensile load, the diameter of the bolt and the length of the anchorage. The shear stress distribution, which increases first and then decreases with the anchorage depth, obeys the single peak shape with the peak value located within the range of 0.5 m at the front of the anchorage, also influencing by the length and diameter of the anchorage. It is suggested that the performance of shear resistance, the design of surface morphology design and fabrication process of BFRP anchor should be further improved in the future.

In this paper, a new type of support form-shear bond supporting system, which is composed of vertical and oblique piles, is put forward for deep and large foundation pit construction. Through model test, the horizontal displacement of pile top and internal force of pile body are measured at different excavation depths for shear bond group and single row cantilever pile group, respectively. Finite element numerical simulation is carried out at the same time. The results show that the maximum horizontal displacement of the pile top in shear bond group is about 1/10 of that in cantilever group, and the maximum bending moment of the pile in shear bond group is about half of that in cantilever group. Shear bond supporting system has greater stiffness, and it can effectively reduce the displacement of pile top and the maximum bending moment of pile body. It consumes less material, is able to support deeper excavation, and occupies less space, which will not hinder the construction of the main basement. Therefore, it can save time and cost, and provide a new idea for deep foundation pit supporting.

Soil seismic response analysis is of great meaning to the seismic response and seismic safety evaluation of structures. In this study, the non-linear seismic response law of soil in free field under uniform and non-uniform excitation and its influencing factors are studied by means of large-scale shaking table model test, which can provide support for analyzing the seismic failure mechanism of structures. By analyzing the dynamic characteristics of soil, acceleration peak magnification coefficient, shear stress-shear strain curve and soil settlement, the ground motion response characteristics and variation of free-field soil under different earthquake motions and different seismic intensities are studied. The results show that the non-linear development degree of soil is not only related to the record of ground motion, but also to the input mode and loading level of ground motion. In the case of large earthquake or longitudinal non-uniform excitation, inconsistent movement of free-field soil leads to stronger soil structural change, decrease of frequency, increase of damping ratio, weakening of soil stiffness and relatively faster nonlinear development of soil. The variation law of soil shear stress-shear strain curve and settlement curve also reflected the plasticity development of soil. The conclusions obtained are consistent with the observed macroscopic phenomena of the free-field seismic response, which mutually corroborated the rationality of the results.

To examine the influence of strengthening effect of skin resistance on the bearing mechanism of laterally loaded pile, this study firstly established τ-s curve models with consideration of strengthening effect under horizontal loading. Then its numerical solution for resisting moment per unit length caused by vertical shaft resistance was obtained. This work performed the analysis on normalized curves with form of Ms,ini /Msu,ini-θ/θref,ini under the influence factors including pile diameter, critical displacement and limit shaft resistance. Accordingly, based on the theory of strengthening effect of skin resistance, this paper deduced simplified theoretical solutions of resisting moment for τ-s curves with linear elastoplastic type, hyperbolic type, clay and sand type of API Code, respectively. Moreover, combined with the principle of transfer matrix method, this work obtained the semi-analytical solutions for laterally loaded pile considering resisting moment effect. The results from proposed calculation models compare well with validation cases, which verify the reliability of simplified solution of side friction caused resisting moment and of proposed pile responses considering resisting moment effect. The comparisons also indicate that the influence of strengthening effect of skin resistance on bearing capacity of laterally loaded pile is non-negligible. Finally, the results reveal that in case of no test data for reference, the recommend values of rigidity indexes for interfaces of sand-pile and clay-pile could be 0.725 and 0.600, respectively. This resisting moment effect will increase as pile diameter, ultimate shaft resistance increases or increase as critical displacement decreases, while pile diameter has more notable influence.

In cold region tunnels, the moisture migration during the frost heave always aggravates freeze-thaw induced damage of the surrounding rock. Therefore, it is of great importance to consider the moisture migration effect on the collapse and landslide mechanisms of rocks due to freezing and thawing weathering. In this paper, the moisture migration was introduced into Helmholtz free energy as an intrinsic variable based on internal state variables theory. A general thermo-hydro-mechanical coupled constitutive model was proposed under the thermodynamic framework. The effects of temperature and moisture migration on the damage threshold, isotropic hardening saturation and isotropic hardening rate of the rock after freezing and thawing were described. The degradation of mechanical properties of rock after freezing and thawing was simulated. This model was given as an incremental form, which was convenient for the numerical modelling under complex stress loading conditions. The parameters used in the constitutive model had clear physical meanings. Finally, the simulation stress-strain curves of the constitutive model were compared with the results of triaxial compression test of the rock specimens after freeze-thaw cycles. It was proved that the proposed constitutive model could well describe the mechanical behaviors of rock after freeze-thaw cycles.

The microstructure and section characteristics of three kinds of Wudang group schist with obvious foliation were studied by polarizing microscope and scanning electron microscope. Multiple indicators including area percentage, size and perimeter area fractal dimension and directional distribution coefficient were proposed to quantitatively analyze the content, morphology and distribution characteristics of mineral system and pore (micro fissure) system by professional image processing software. The roughness of fracture surface was quantitatively evaluated based on the digital image processing technology of MATLAB. Polarizing microscope shows that the schist has typical characteristics of mineral orientated alignment and intergranular distribution of granular and lamellar minerals. The microscopic quantitative analysis of the mineral system shows that the content of the muscovite of Wudang group schist is 11%~30%. The perimeter-area fractal dimension of muscovite calculated by island method is 1.31~1.39. The directional distribution coefficient is 0.61 to 0.85. Since micro fissure is attached to the edge of muscovite, there is a strong correlation between microscopic indicators of micro fissure and those of mineral. The section of the schist along foliation mainly presents the characteristics of intergranular failure, so the fracture surface is relatively flat. The box dimension of the grayscale signal wave curve based on the profile map is 1.48~1.60. In contrast, the fractured schist section is mainly transgranular failure, with the signs of alternate transgranular and intergranular failure, which lead to rough fracture surface. The box dimension of the signal wave curve is 1.65 to 1.69. The roughness anisotropy of the fractured schist section is about 1.03 to 1.14.

The composite rock strata is highly detrimental to the cutters of tunnel boring machines (TBMs) during the tunneling construction. To improve the tunneling efficiency and reduce the construction cost, it is necessary to study the efficiency of composite rock fragmentation by TBM cutters. In this study, the rock breakage experiments were carried out on the specimens of the sandstone and granite composite (composite ratio of 4:6). A series of rotary synchronous cutting tests was conducted on three cutters with three penetration depths at five cutter spacings. During the experiments, the total normal force and total torque of the rock fragmentation were monitored, and slags of two rock types were separately collected for screening and weighing. The relationships between normal force, torque, and specific energy under different cutter spacings and penetration depths were analyzed. The results showed that the average normal force and the average torque increased with the increase of the penetration depth under different cutter spacings. However, their increase trends were different, which meant that with the increase of the penetration depth, the average normal force increased almost linearly, while the average torque increased slowly. In addition, the optimal cutter spacing varied at different penetration depths. It was found that the efficiency of rock fragmentation was the highest when the ratio of cutter spacing to penetration depth was about 14, and the cutting length ratio of the sandstone to granite was 4:6.

Large-scale hydraulic fracturing is the most effective way to construct the artificial reservoir in the development of hot dry rock geothermal energy. The key issue is to reveal the hydraulic fracture mechanism of rock under high temperature and pressure. The high-temperature-vapour-driven failure experiments were carried out on granite under uniaxial stress, and the preliminary results on the failure mechanism were obtained under thermo-mechanical coupling. Results indicate that high temperature can greatly cause the failure of granite by weakening the strength and reducing the breakdown pressure. Compared with the breakdown pressure of hydraulic fracturing at room temperature, they were decreased by at least 58% at the high injection rates of 430℃ and 350℃ vapours, while they were reduced by 75% at the low injection rates of 400℃ and 450℃ vapours in the vapour driven failure experiments. The process of high-temperature-vapour-driven failure can be divided into two stages, namely, thermal fracture damage and macrocrack propagation. In the thermal cracking stage, the thermal stress resulted in thermal cracks randomly around the borehole. With the increase of vapour injection time, the thermal cracking range gradually extended, and the microcracking density enhanced, which facilitated the fracture propagation. In the second stage, the fractures were primarily generated on both sides of the borehole and then propagated along the final trace of macrocracks until the failure of the specimen. Compared with hydraulic fracturing at room temperature, the failure induced by vapour at a low injection rate was a slow ductile tensile failure. The fracture extended asymmetrically along the borehole, and the width was smaller than that of hydraulic fracturing at room temperature.

Rock damage is considered as a state of instability phenomenon under the driving of energy, the law of energy evolution in the process of deformation and failure can reflect the essential characteristics of rock mass deformation and failure. The loading and unloading tests were carried out on coal samples to explore the laws of energy evolution under different unloading confining pressure rates. The experimental results show that before the peak stress, the coal sample mainly experiences the energy storage and dissipation, whereas it mainly experiences the energy release and dissipation after the peak stress. It is found that when the unloading confining pressure rate is high, the duration of unloading confining pressure is short, the internal cracks of coal sample extend and circumferentially deform insufficiently, and the powers for energy dissipation and overcoming confining pressures are small. Moreover, most of the energy release when the coal sample ruptures, which make the coal sample damage seriously. Meanwhile, when the unloading confining pressure rate is larger, the damage rate of the coal sample increases faster before and after the rupture, which results in the sharp increase of the damage curve. Therefore, when the high-stress coal is excavated with a high construction speed, it is easy to cause a sudden release of a large amount of accumulated energy, causing serious disasters.

Gas-hydrate-bearing soil is a special soil with hydrates filling in the pores of the soil. Its mechanical properties are not only related to hydrate saturation but also to the occurrence habits of hydrate. The mechanical characteristics of hydrate hosting structures with different habits are different. Considering the failure of structure in gas-hydrate soil under loading, the stress and strain model of hydrate bearing soil is established based on the disturbed state concept to describe the whole process of loading failure of cemented structures. At the same time, the disturbed function expressed by the effective saturation of hydrates is used to describe the development of the internal structure of the hydrated soil under the loading condition. According to the mechanical behavior of hydrate bearing soil, two reference states are described by the ideal elastoplastic model and the Mohr-Coulomb model. The form of this model is relatively simple, and the parameters are easy to be determined. Finally, the three triaxial compression tests are used to verify the model. The results show that the model can reasonably simulate the deformation characteristics of hydrate bearing soil in the process of disturbance.

The main study of this paper focus on the problems that the absolute breakage amount of particles in a certain size range can not be acquired and the hidden breakage amount can not be considered in the particle breakage rate in a sample. Three kinds of calcareous sands, rich in coarse, medium and fine sands respectively, are subjected to the confined compression test. Particles with different sizes are dyed in different colors, and pictures contain the breakage information of particle in all certain particle size range are taken. Then, the Image J software is employed to segment and binarize these pictures and records the area of particles with different colors, which is used to calculated the content of the particles with different colors after failure. Finally, an accumulated particle breakage Ba, which considers the absolute breakage amount of particles in a certain size range, is proposed. Test results show that with the increase of pressure or the concentration of particle distribution, overlapping breakage of samples increases. Among these calcareous sand samples consisting of particles in different sizes, the sand in intermediate particle sizes (0.25-1 mm) is breakable, and edge and corner breakages are the dominant break pattern in the particles with different sizes. The accumulated particle breakage Ba is larger than the relative breakage Br, and has a linear relationship with the logarithmic value of vertical pressure. The study of this paper provides a new method for the research on particle breakage.

The conventional triaxial tests were carried out on sandstone to study the stress-strain relationship of rock during the loading-unloading process. The nonlinear characteristics of rock in the post-peak unloading process were analyzed, and the damage variable of rock was defined. Meanwhile, the elastic modulus model was established to describe the stress-strain relationship in the post-peak unloading process. The Poisson's ratio model under unloading was obtained by analyzing the relationship between the axial strain and radial strain in the loading-unloading process. The D-P plasticity model was introduced to modify the hardening function according to the plastic-hardening characteristics of sandstone, and a damage model associated with the equivalent plastic strain was established. At last, the established model was matrixed and numerically calculated. In this study, the following conclusions are obtained. During the loading process, the porous rock exhibits obviously nonlinear characteristics, and the elastic modulus of the rock increases with the increase of the body stress. During the post-peak unloading process, when the axial stress is greater than the confining pressure, the stress-strain can be described by the elastic modulus in the pre-peak elastic phase multiplying by the continuity factor. With the increase of equivalent plastic strain, Poisson's ratio increases first and then decreases until reaching a stable value. During the unloading process, the equivalent plastic strain maintains stable, and Poisson's ratio remains constant. The numerical calculation is conducted by the proposed constitutive model. Compared the numerical results with the experimental results, the proposed model can reflect the stress-strain relationship of rock in the post-peak unloading process.

In the traditional model test, the pile deformation subjected to soil movement is measurable, while the soil displacement around the pile is difficult to obtain. Therefore, a model test system was designed based on the transparent soil (mixed by fused quartz and a pore fluid with a matching refractive index), particle image velocimetry (PIV) and optical measurement system. A series of model tests were carried out to measure the soil deformation in a non-intrusive way. By analyzing the images of multiple horizontal and vertical slices, a three-dimensional displacement field was obtained. The results show that transparent soil material is technically feasible for studying the displacement field of soils around passive piles. The results also indicate that the shielding effect, i.e. displacement difference between the back and side of the pile, increases with the embedment depth of the pile at the same lateral displacement. Furthermore, a finite element model was calibrated by experiment results, and parametric studies were conducted on the effects of movement profiles and pile diameter. Numerical results indicate that the influence degrees of the soil lateral displacement profile on the soil shielding are classified into rectangular, paraboloid and triangle, respectively. In addition, this shielding effect is positively proportioned to the pile diameter.

To ensure the dynamic stability of seabed site is the prerequisite for the safe operation of offshore engineering. However, limited test data on the dynamic properties of saturated silt subjected to cyclic loading with complex stress path in marine environment are available. Using the GDS hollow cylinder apparatus, a series of undrained tests is performed on the remolded saturated silt under combined axial-torsional cyclic loading for simulating changes in the amplitude of the wave and the depth of seabed. To take the generalized shear strain ?g = 5% as the liquefaction triggering criteria, the influences of cyclic stress paths (cyclic stress ratio CSR and cyclic loading amplitude ratio ? ) on the undrained behavior of saturated silt under isotropic consolidation conditions are studied. The test results show that the effects of CSR and ? on the development patterns of excess pore pressure and deformation of saturated silt are significant. The saturated silt under the cyclic loading with circular stress path (? = 1) is the most susceptible to liquefaction. The liquefaction of saturated silt is not triggered when CSR≤ 0.050, but when CSR≥ 0.065 and ? = 1, the liquefaction of saturated silt can be triggered, and the saturated silt is more susceptible to liquefaction when CSR > 0.150. The correlation between ?g and excess pore pressure ratio (ru) is less influenced by CSR and ?, and the ?g can be characterized by the tangent function of ru. When the equivalent cyclic stress ratio ESR is uesd as the index of the amplitude of cyclic stress with complex stress paths, the liquefaction number of cycles (NL) required to cause ?g = 5% may be uniquely correlated to the applied ESR, and the ESR decreases with the increase of NL.

The mechanical properties of the regenerated rock mass are intrinsically changed due to the reorganisation of the structure and components in the coal mine. In this study, the fractured rock mass was repeatedly compressed during the compaction and diagenesis process of the regenerated rock mass. Then the fractional compaction test under confined conditions was carried out using the broken surrounding rock of the regenerated roof of the Zhoujing coal mine in Guangxi. The results show that the process of fractional compression can be divided into three stages: compaction crushing, compaction stress memory and compaction consolidation. At the first compression, the compacting characteristic curve changes linearly, and the subsequent compaction curve gradually changes to an exponential form, while the stage of compaction stress memory shows a polynomial change. Under the confined compression condition, the criterion of minimum potential energy is used to determine the crushing fracture of irregular rock samples. The compression characteristics of fractured rock samples are influenced by the number of compaction and the height of rock mass. When the times of compaction are larger, the cumulative compression strain is greater, and the stress increment in the subsequent compression is higher. As the loading height is higher, the cumulative total strain is greater at the same compressive stress. When the compaction stress reaches a certain degree, the grain-size distribution of the broken rock samples with different coarse-grained sizes tends to be consistent. Therefore, the correlation between the size distribution of broken rock samples and the compaction degree of the regenerated rock mass is established.

In this paper, an improved scaled boundary finite element method (SBFEM) is used to solve the dynamic response of rigid buried pipe in multi-layered soil combined with finite element method. A new coordinate transformation relation is introduced into the improved SBFEM, with a similar line instead of the similar center in traditional SBFEM. Then the dynamic stiffness matrix equation can be obtained by using weighted residual method for multi-layered soil. Finally, the dynamic stiffness matrix is coupled with finite element method at the boundary between the near field and far field to solve the dynamic response for rigid buried pipe in multi-layered soil. The comparison with an existing solution validates the accuracy of the proposed method. And the influence of heterogeneity characteristic of layered soil, Poisson’s ratio and buried depth on the dynamic response of the buried pipe is further investigated through a parametric analysis which provides the necessary numerical basis for the engineering practice. As the results show, the heterogeneity characteristic of layered soil and Poisson’s ratio have significant influence on the dynamic response of the buried pipeline. With the increase of the buried depth, the dynamic response of the pipeline under the same load decreases.

Determining the unified representative element volume (REV) is the primary issue to be solved when studying the meso-scale pore structure of soils. We use the synchrotron radiation μ-CT, in 6.5 μm voxel resolution, to scan a Nanjing silty-fine sand specimen. Five groups of cubic pore REV with the same dimension are chosen from the three-dimensional reconstruction model, at different heights, of the specimen. The maximal ball algorithm is used to analyze each pore REV. The pore network model of each REV is developed to extract eight pore structure parameters, namely porosity, pore number per unit volume, mean volume of pore, minimum pore volume, maximal pore radius, minimal pore radius, mean radius of pore and average shape factor of pore area. Subsequently, the correlations between the eight pore structure parameters and the REV size are established respectively. The results show that all the pore structure parameters tend to converge when the REV size increases. The T test and F test are performed with different REV edge lengths for the eight pore structure parameters in sequence. The REV edge length of each pore structure parameters is determined and the maximal value of them is selected. Finally, unified REV edge length is determined at 400 voxels, namely 2.60 mm, for all the pore structure parameters. This determination method can be used for the meso-scale pore structure analysis of grain soils such as sand soil and silty soil.

A new method of fundamental solution based on complete spherical wave potential (SWP-MFS) is proposed to solve 3-D elastic-wave scattering and dynamic stress concentration. The method established the boundary integral equation according to the boundary condition. The solution was solved by placing the spherical wave sources of compressional wave and shear wave on a virtual boundary based on the single layer potential theory. Through comparing with other available results, the excellent numerical accuracy and stability of the SWP-MFS are validated. The method was demonstrated in an example of the 3-D scattering of P or SV waves around an inclusion and a cavity in elastic full-space. Several important conclusions about scattering of 3-D elastic waves around an inclusion were obtained. As the modulus ratio decreases (the inclusion becomes softer), the displacement amplitude spectrums oscillate more rapidly with large amplitude. For horizontal incident P waves, it seems that the dynamic stress concentration effect is more pronounced near the top and bottom of the spherical cavity, while it is more obvious near the two 45-degree angles of the longitudinal section for horizontal incident SV waves. Compared with employing the Green’s functions of concentrated force, the fundamental solution of SWP-MFS is more concise and easy to use, and provides a new meshless boundary-type method for elastic waves analysis.

A simulation method for multi-point spatially correlated earthquake ground motions in sedimentary valleys, which considers the scattering effect of seismic waves, is proposed. Based on elastic wave propagation theory, a reasonable power spectrum, coherence function and transfer function model were used to obtain multi-point spatially correlated earthquake ground motions in sedimentary valleys using the prototype spectral representation method and then the feasibility of the method was verified. The transfer function obtained by the dynamic boundary element method can fine model the waveform conversion and focusing effect of sedimentary valleys in a very wide frequency band. The simulations for common V-shaped valleys were performed and the results show that the valley topography and loose sediments have a significant impact on the seismic wave propagation. The spatial variability of the earthquake ground motions in the valley surface is very significant. One-dimensional models can hardly consider the scattering and focusing effects of seismic waves. As a result, the peak acceleration of the ground motion within the interior of the sedimentary region will be significantly underestimated. Seismic design of large-span structures in sedimentary valleys should adopt multi-point spatially correlated earthquake ground motions input which considers the scattering effect of seismic waves.

Uncertainty in geotechnical engineering greatly results in engineering risk. In this study, the first large-scale uncertainty experiment on the in-situ shear-wave velocity (Vs) was carried out on 20 typical sites in 7 major regions of China. A total of 11 kinds of common engineering instruments were completed by using single hole method in 47 units, and 600 groups of Vs were obtained finally. According to this in-situ database, the corresponding formula between Coefficient of variation (COV) of time-average shear-wave velocity (Vs, z) and the calculated depth (Z) was fitted. We revealed the impact of in-situ Vs uncertainty on the judgement of site stiffness and pointed out the possible potential misjudging area of site classification in China. At the current level of in-situ Vs test in China, COV of Vs, z is negatively correlated with depth, which indicates that it reaches the max value of 15% near the site surface and then decreases significantly with the increasing of the depth. In the depth range from 0 m to 10 m, the COV of Vs, z decreases rapidly; in the depth range of 10-20 m, the COV of Vs, z decreases slowly; after the depth of 20 m, the COV of Vs, z is less than 5% and basically unchanged; the COV of equivalent shear wave velocity (Vse) used for site classification of Class III and IV sites in China is basically the same as that of the field classification index Vs, 30 used in Europe and America. Based on China building code GB50011-2010, Class I and Class II sites with the soil thickness less than 5 m or Vse close to 500 m/s should consider the potential impact of Vs uncertainty, while other types of Class II and Class III and Class IV sites could ignore the uncertainty.

In this study, the parameter characteristics of the database including 473 shear wave velocity test results from all over the world were analyzed. After that, the Logistic model was selected to build a new formula to evaluate the probability of liquefaction, considering four conventional parameters: PGA, shear wave velocity, water table and the depth of liquefiable layer. At last, the applicability of the formula under different probabilistic levels was studied and compared with the existing methods. This study shows that the ground vibration intensity is the primary parameter to influence liquefaction estimation. The shear wave velocity of liquefaction layer does not differentiate from the shear wave velocity of the non-liquefaction layer, so it is difficult to meet the basic requirements by using a semplice formula. The methods developed by Andrus and Shi Zhaoji misjudge many obvious non-liquefied points. Those misjudgments breach the existing knowledge and need improvements. The formula developed by this paper conforms to equal distribution of liquefaction points and non-liquefaction points when PL=50%, and the accuracy can reach about 70% in different intensity levels. In summary, this formula provides a reasonable and easy-to-use shear wave velocity liquefaction evaluation method.

The construction of new subway stations under the existing subway tunnels has high risks and strict requirements for settlement control. The ceiling of Satellite Square station, which belongs to Changchun metro line No.1, contacts tunnel baseplate of light rail line No.3 directly. There is no soil layer between the upper tunnel and lower station, under such circumstances it is described as dual-layer formation. The engineering approach is introduced in this paper. Soil was reinforced firstly by grouting before any excavation, then ten hydraulic jacks were arranged in pilot tunnels No.1 & No.4 right beneath baseplate of upper tunnel to mitigate adverse settlement. Then two groups of concrete-filled tubes, together with longitudinal beams, were forged in pilot tunnels No.3 & No.5 and pilot tunnels No.2 & No.4 as permanent supporting. As soon as these tubes were operative, hydraulic jacks and preliminary supports of pilot tunnels were removed orderly while ceiling of station was cast piece by piece, and the rest of station was cast conventionally at last. In the second part, bearing capacity and settlement of upper tunnel are discussed by numerical simulation. It shows that the maximum bending moment on the baseplate of upper tunnel is allowable, and the settlement on central of baseplate is variable from w-shaped to v-shaped. Analysis of filed monitoring about this case is introduced in the third part, the settlement curves fall into two distinctive categories and highly depend on physical positions of monitoring points. The observed settlements on central of baseplate are consistent to numerical results both in maximum value and overall profile. Due to effective control of hydraulic jacks, the differential settlements on movement joints are also manageable.

Incomplete wells have been widely used in practice. For those wells whose filter screen ends are at the middle of the aquifer, they cannot be calculated simply by conventional methods. A simplified calculation method is to divide the flow field near the filter screen into layers based on the horizontal stream line. However, it is very difficult to determine the position of the layering line. Therefore, in this paper, several simplified layering methods of seepage field were proposed, including the modified equal seepage path method which assumes that the upper and lower seepage fields have equal seepage path, the modified equal ratio method which assumes that the ratios of well filter length to aquifer thickness in the upper and lower seepage fields are equal, and the equivalent resistance method developed from the equal ratio method. Based on the above results, an approximate calculation method for incomplete wells with filter screen ends away from the confined aquifer level that was developed to improve Sha’s formula which is superior for its simple-calculation and high-precision. Compared with the finite element analysis, this method is more accurate and more applicable.

Combined with the spatial data processing capabilities of GIS, a calculation method for reservoir bank landslide speed based on grid column elements was proposed. The Pan Jiazheng method was extended from two-dimensional to three-dimensional. A three-dimensional (3D) landslide speed calculation model based on grid column elements was first established, and the spatial computational expression of each parameter in GIS was clearly specified. Secondly, based on the Newton's law of motion, the dynamic equilibrium equations were established along and perpendicular to the sliding direction to derive the three-dimensional landslide speed. Finally, an expanded module of 3D landslide speed calculation was embedded in GIS platform, and the result of a case study was compared with that obtained from the Pan Jiazheng method. The results showed that compared to results from the Pan Jiazheng method, the maximum speed calculated by the method in this paper is 15.2 % higher and the acceleration is 32.8 % higher, and 1 s shorter for reaching the maximum speed.

The thickness of karst cave roof at the bottom of socketed pile is a significant influence factor on the vertical bearing capacity of the pile. In practice, related engineering standardizations in China request that the thickness of karst cave roof should not be less than 3 times of the pile diameter. Obviously, this method determining the thickness of karst cave roof based on engineering standardizations is empirical and non-specific without consideration of rock-mass quality and karst cave’s size. In this paper, based on punch failure mode of rock mass around the tip of the pile, we develop an approach to determine the critical thickness-diameter ratio of karst cave roof ( , the ratio of karst cave roof’s thickness to pile’s diameter) through generalized Hoek-Brown failure criterion and limit analysis method. In addition, the suggested values of critical thickness-diameter ratio for different classifies quality of engineering rock mass are also supplied. The results show that the ultimate tip resistance, hardness degree of rock and rock-mass quality have significant influence on the critical thickness-diameter ratio. The smaller the ultimate resistance, the better the rockmass quality and the harder the rock, the smaller critical thickness-diameter ratio. Besides, this paper suggests that the critical thickness-diameter ratio for the rock-mass with I~IV quality levels are: for I level, for II level, for III level and for IV level.

When calculating slope stability under anchorage force by limit equilibrium method, anchorage force is usually treated as a concentrated force, and the distribution curves of normal stress on slip surface and inter-slice forces are very unreasonable. In addition, if the effect of anchorage force is treated by conventional method and the stability of anchored slope is analyzed by critical sliding field method, the sliding surface searched will change abruptly. In order to overcome the above inherent defects, the elastic solution of semi-infinite body subjected to normal force is approximated as the equivalent model of additional stress generated by anchoring force in slope body. On this basis, the calculation method of critical sliding field of slope under anchoring force is established. The analysis of examples shows that the approximate equivalent treatment method of concentrated force is reasonable, which further enriches the stability analysis method of anchored slope. The method has also successfully applied to evaluate the stability of a practical complex slope engineering. The results show that the anchorage force can change the location of the potential slip surface. The proposed approach can search the real potential slip surface with reasonable distribution of normal stresses and inter-slice forces under the action of anchorage force and the corresponding safety factor is more reliable. Meanwhile, the method can comprehensively evaluate the overall and local stability of the slope, and provide the spatial distribution of the unstable region for the actual slope engineering, so as to effectively control it.

Groundwater is an important factor affecting landslide deformation and instability. At present, the research on water transport process of natural slope mostly relies on sensor monitoring or numerical simulation, which can not fully meet the requirements of non-disturbance and fast measurement. In this study, a natural slope is tested using high-density electrical resistivity tomography (ERT) method and time-domain reflectometry (TDR) to obtain the water content in the slope, and the relationship between electrical resistivity of soil and water content is revealed. Furthermore, the distribution and migration characteristics of underground water in slope are inverted and analyzed. Sequentially, the capability of ERT in capturing moisture migration and distribution is verified. Results of in-situ tests show that: water content of soil has obvious logarithmic relation with soil’s resistivity. Moreover, the effective infiltration or evaporation depth of this slope is 2 m, and water content gradually decreases when the depth is greater than 2 m. The main reason for the sharp increase of water content between 1.3m-2m depth under moderate rainfall intensity is the preferential flow through a crack at the back edge of slope. It is also found that the transition zone between highest water content (lowest resistance zone) and lowest water content (highest resistance zone) is highly consistent with the position of sliding zone in subsequent failure of slope.

Based on the ground temperature and deformation of the embankment with thawed interlayer at the monitoring sections of P32 and P33 along Qinghai-Tibet railway from 2005 to 2015, artificial permafrost table, maximum seasonal frozen depth, thickness of thawed interlayer and annual process of the ground temperature nearby artificial permafrost table are analyzed. Meantime, annual process of the total settlement of left and right shoulder at P32 and P33 sections, the effect of ground temperature at the left shoulder on deformation at P32 section and the effect of ground temperature difference at the left and right shoulder on its difference of settlement at P33 section are investigated. The results indicate that: at P32 and P33 sections, artificial permafrost table of left shoulder descended annually, maximum seasonal frozen depth remained nearly constant, thickness of the thawed interlayer thickened and the ground temperature nearby artificial permafrost table increased annually; during the monitoring period, the left and right shoulder deformation all performed mainly settlement and its magnitude at P32 section was smaller than at P33 section. Moreover, at P32 section, left shoulder settled during warm season and frost heave occurred slightly during cold season. The occurrence of settlement and frost heave lagged the variation of the ground temperature. The temperature difference can lead to differential settlement under left and right shoulder at the monitoring section of P33, and its value increased annually.

In order to comprehensively explore the ultimate bearing capacity of uplift piles in combined soil and rock masses, combined with engineering geotechnical parameters and experimental data, the Flac3D numerical analysis software is adopted to carry out numerical simulation analysis to obtain the ultimate bearing capacity of uplift piles in the composite rock mass. The Kotter limit equilibrium passive equation is employed to solve the pull-out force provided by the soil layer. And based on the rock strength, the strength of the rock mass embedded in the rock pile can be determined by the Hoek-Brown failure criterion. In turn, the pull-out force of the rock mass embedded in the rock can also be obtained. In addtion, based on the principle of force balance, the ultimate bearing capacity of rock in lay uplift piles in the combined rock mass can be obtained by superimposing the pull-out resistance provided by failure rock layer and the rock mass on the gravity of failure cone. The theoretical calculation value obtained from the analytical formula is close to the numerical simulation analysis value in the case of small rock-socketed depth. However, with the increase of the rock-socketed depth, the theoretical calculation value fluctuates within a certain range around the experimental value. Therefore, combining with the numerical results, the theoretical formula of the ultimate bearing capacity is modified. Finally, by taking the consideration of the effect of rock wathering, rock-sockering depth, soil thickness and pile length, the improved ultimate bearing capacity analytical formula is obtained. The modified analytical formula is used to predict the ultimate bearing capacity of different uplift piles under different geological conditions. The predicted results show that the numerical simulation results are consistent with the theoretical calculation results, which means the analytical method of the ultimate bearing capacity of uplift piles in this paper is feasible. Based on a part of test result, the ultimate bearing capacity of different rock-socked piles with different rock-socked depths in similar projects can be determined by this method.

The pile-soil shear modes have significant influences on the displacement of pile-soil shear and the development of pile side resistance. Field experiments and long-term monitoring were carried out to study shear properties of six bored piles under three modes: bearing pile type, uplift pile type and negative friction pile type. The curve of side resistance versus displacement was established by systematically analyzing the pile strain, displacement of the top pile, and pile-soil layered subsidence of different pile types. The established curve was further used to determine the displacement of pile-soil shear in different modes and the ultimate lateral resistance at different depths. According to the characteristics of the ultimate lateral resistance in different modes, its five influence factors were analyzed, including the relative motion direction of pile-soil, shearing boundary constraint, shear displacement, loading rate and shear duration. Meanwhile, we discussed the feasibility of using the in situ testing results of uplift pile to predict the ultimate lateral resistance of negative friction pile in the increasing stage. This study provides useful references for similar projects.

The Bayu tunnel is a controlled project in Nyingchi-Lhasa section of the Sichuan-Tibet railway. Rockbursts happen frequently, and rockburst locations are different in adjacent areas during the construction process. By using the microseismic monitoring system, the evolution laws of rock mass fracture were observed in situ during the process of rockburst location deflection. In addition, the reasons for the deflection of the rockburst locations were discussed. The results showed that the microseismic information was distributed unevenly on both sides of rockburst location deflection. Meanwhile, all the microseismic activities (the number of events, energy and apparent volume) deflected with the deflection of rockburst location, which indicates that they have an obvious spatial correlation. The evolution laws of apparent stress and excavation damaged zones of rock mass in the deflection location reveal that the deflection of rockburst location is related to the change of local stress concentration area, and the rockburst more easily occurs in the area with larger stress concentration. The results provide significant references for the warning and prevention of the deflection of the rockburst locations.

Based on the geographic information system (GIS) and numerical simulation software, a scheme was proposed to achieve the strong applicability and smooth operation of three-dimensional slope modelling and simulation. This scheme can make full use of the historical data of complex slopes and truly realize the entire process of slope simulation, including processing survey data, establishing slope model, stability analysis and result feedback. The modelling theory and method of surface and soil layers are analyzed in depth to establish a model that meets the accuracy requirements. The three-dimensional modelling of the slope is completed by GRASS, and detailed error analysis is discussed on the established model. The coupling of GIS and numerical simulation software is realized in the Python language. The data transfer and format conversion between different platforms can be completed through self-compiled programs and data interfaces, which can avoid the loss or distortion of the data in the transmission process. Python can also deeply mine the model data. Finally, this scheme is verified by Hangkouling tunnel project. The analysis results show that the three-dimensional slope model established by this scheme has characteristics of high speed and high precision and can accurately reflect the actual slope condition and search for the most dangerous area of the slope.

Landslides have characteristics such as regionality, multipleness, and seriousness. The traditional area landslide spatial prediction method, under massive data condition, has poor real-time performance and strong subjectivity, and the evaluation performance is poor under multiple factors. A distributed regional landslide prediction method based on BP neural network is proposed in this paper. The algorithm is designed as a parallel computing environment of big data processing platform Spark, and the cost function of BP network is designed as two items of mean square error and L2 regularization, which improves generalization ability. Through statistics of the quantitative indicators of landslide factors and the definition of hazard index of monitoring profile, the influencing factors are selected. This approach is applied to massive data mining of 9 landslides in 11 years in Zhongxian area of Three Gorges Reservoir area, which achieves the combination of qualitative analysis and quantitative analysis. All the landslide monitoring sections in the study area were monthly evaluated to determine the risk level, and the spatial prediction of the monthly landslide risk degree was achieved. Experiments show that the fitting accuracy and efficiency obtained by the method are better than gradient-based decision trees and random forest algorithms, and the prediction area landslide risk assessment accuracy is good. This method can be used as a new approach for regional landslide spatial prediction.

Hydraulic fracturing technology is widely applied in shale gas extraction engineering. In this study, the state-based peridynamic theory was introduced into the modeling and analysis of hydraulic fracture in horizontal shale wells. The mechanism of the multi-fracture propagation and the formation of complex fracture networks were analyzed as well. An equivalent hydraulic pressure term was embedded in the constitutive function, which describes the interactive forces between material points, to track the applied hydraulic pressure on the new crack surfaces. Thus, a simplified state-based peridynamic model was established to describe the hydraulic fracturing. Through the proposed model, the hydraulic fracturing process of shale reservoirs was simulated to investigate the complex crack propagation paths, the formation process of crack networks, as well as the effects of natural stratification, cracks, and perforation spacing on the hydraulic crack propagation. Numerical results indicate that when the perforation spacing is sufficiently small, the cracking process is disturbed and the crack propagation along the central perforation is inhibited. Under certain fracturing pressure, a proper increase of perforation distance can significantly accelerate the hydraulic fracture process. During the hydraulic fracturing process, horizontal cracks may be formed in the horizontal stratification, and complex vertical cracks may be formed by the induction of natural cracks. The proposed model and numerical methods provide alternative and promising ways for the profound investigation into shale hydraulic fracturing and engineering applications.

In this study, the anchored rock slope with weak intercalated layers was investigated by using the FLAC3D software. The modified cable element modeling and improved shear stress extraction method were used to analyze the shear between two anchorage interfaces of the anchored rock slope and its evolution law, respectively. The results showed that the shear stress at the mortar-rock interface was much smaller than that at the anchor-mortar interface, while these two shear stresses extended in opposite directions from the neutral point on the anchor rod. In addition, the shear stress distributed unevenly and mutated near the neutral point. With the increase of the seismic response of the slope, the anchorage interface in the unstable rock was first debonded, and then the anchorage interface in the bedrock was also debonded. Meanwhile, the debonding propagated toward the anchor head and the anchor root, respectively, until the pull-out section or the anchorage section was completely debonded and destroyed. We obtained the shear stress, the distribution of shear stress, and the debonding failure process at two anchorage interfaces of the slope under earthquake. The shearing interaction and anchorage failure mechanism at the anchorage interface were revealed and verified by experiments. The research results provide important references for the design and construction of the anchorage slope.