The shaking table model test was used to investigate the dynamic response mechanism of slopes with serrated structural planes under multiple seismic loads and degradation of rock mass. The research shows that the dynamic response of slopes has“altitude effect”and“surface effect”，and the PGA amplification factor of slopes decreases steadily under continuous seismic loads. The slope cumulative displacement，soil pressure and pore water pressure around the hydro-fluctuation belt increase，decline，and increase respectively. The progressive failure evolution of slopes is characterized by micro fracture initiation and development，macro fracture propagation and the formation of macro composite slip surface. Residual damage traces of serrated structural planes with low，medium and high undulation are different，which are climbing，gnawing off after climbing and gnawing off respectively. The opening degree of prefabricated joints continuously increases under water erosion and seismic loads，the deterioration depth and width of rock mass also continuously increase，and a few split cavities are formed locally in hydro-fluctuation belt. In addition，the natural frequency and damping ratio of the slope keep increasing and decreasing respectively. The nonlinear cumulative damage mathematical model of slope rock mass was established and the evolution process of slope damage degree in the stages of micro earthquake and strong earthquake was described by“S-type”function and“upside concave type”function respectively.

During the mining process of high gassy coal seam，the fracture and permeability evolution law of mining overburden rock has a control effect on the pressure relief gas migration and partition enrichment. Therefore，how to quantitatively and accurately describe the fracture development and permeability distribution characteristics of mining overburden rock is the key to improve the gas drainage efficiency of goaf and fracture zone. Based on the engineering background of Pingshu Coal Mine in the Yangquan Mining Area，this paper simulates the movement and deformation of overlying strata and the dynamic evolution law of fractures during the mining process of the working face. The fractal geometry theory is introduced to quantitatively describe the generation and development process of mining-induced overburden fractures，and then the fractal permeability model of fractured rock mass is derived. The fine characterization of the dominant channel of gas migration and the non-uniform distribution of permeability in overburden fractures is realized. The research shows that，with the continuous advancement of the working face，the overburden fissures develop forward and upward，and the overall development of the overlying fissures is a“double-peak”distribution pattern of high development on both sides of the goaf and compaction in the middle. The distinguishing dimension of vertical fractures on both sides of goaf reaches 1.143 and 1.151 respectively，which is obviously larger than that of other areas. It is the fully developed area of mining fracture and the dominant channel of pressure relief gas migration. According to the fractal permeability model of fractured rock mass，the permeability of the collapse zone is calculated to be 1×10－5–4×10－5 m2，and the permeability of the fracture zone is 8.9×10－9–9.8×10－7m2. The permeability distribution in the overlying fissure zone has an obvious zoning phenomenon，generally showing a“saddle-shaped”feature with high sides and low middle. The high permeability area is mainly concentrated in the goaf near the working face side(length 0–30 m along the strike) and the goaf near the incision side(length 110–150 m along the strike). The upper limit of the vertical high permeability area can reach 35 m above the coal seam. Based on this，the technical parameters of the high and low-level drainage tunnels in the experimental working face are put forward and applied，and good gas drainage effects of pressure relief in the goaf and fracture zone have been obtained. This research has important reference value to promote the application of the evolution law of overburden fissures and seepage from theory to practice.

Landslide tsunami generation ranks as the most important process during Landslide Generated tsunami(LGT) hazard chain，in which the mechanics of landslide/water interaction and the dynamic models play a key role for precise prediction of LGT. Based on the Lift Up(LU)，Push Ahead(PA) and Drag Along(DA) effects during wave generation proposed by the authors in earlier study，this paper established a coupling dynamic model of the three effects considering the landslide/water interactions. At the same time，the relationships between the three effects and 16 influence factors of initial wave heights were explained，and 8 direct influence factors(including sliding length，width，thickness，the rate of thickness change，magnitude and direction of impact velocity，water depth and landslide density) and three core influence factors(sliding volume，impact velocity and water depth) were specified. Furthermore，a series of physical experiments of LGT were carried out and the whole process was well reproduced by Tsunami Squares numerical simulation，which quantitatively verified the correction of the proposed coupling dynamic mode. This research revealed the dynamic mechanics of landslide tsunami generation，and the proposed coupling formulation can provide accurate models for LGT simulation. It has an important scientific significance and application value for LGT hazard prediction and mitigation.

Under the influence of Luohe Formation aquifers in Shaanxi Binchang and Yonglong mining areas，the drilling index is difficult to clearly reflect the stress state of coal mass，which leads to the failure of drilling method and affects effective monitoring and pre-warning of rock burst. Taking natural and water-containing coal mass as the research object，the coal drilling test under different stress levels was carried out by using the self-developed triaxial loading and drilling platform to explore the mechanical response，borehole effect，evolution law of stress and energy，and damage failure mode of the water-containing coal mass. The results show that：(1) With the increase of the moisture content，the damage failure mode changes from“point-like”friction damage between microstructures to interlayer slip，dislocation and friction with weak structural planes. The number of cracks in the horizontal and vertical directions increase. (2) The frequency of dynamic response is positively correlated with the moisture content. Compared with natural coal body，the elastic energy storage capacity of water-bearing coal body decreases. For dynamic event，the incubation process is shortened，the frequency is increased but the magnitude of single energy release is reduced. (3) the damage of boreholes of natural coal structure is divided into three stages as movement concentration，crack initiation and crack penetration. With the increase of the moisture content，the sample only shows the characteristics of the first two stages. (4) The damage range of borehole deformation is positively correlated with the moisture content. When the moisture content is 1.4%，2.3%，and 3.7%，respectively，the damage radius along the borehole center is 2.03，2.98，and 3.36 times the drilling radius. The test results can provide reference for the correction of drilling index and disaster control under rich water condition.

In order to explore the lagging water inrush mechanism of deep coal seam floor and to clarify the seepage and mechanical characteristics of floor strata during mining，the Rock Top multi-field coupling tester was used to carry out stress-seepage coupling experiment of sandstone under different confining pressures(20，30，40 MPa) and cyclic loading. The results show that：(1) The complete stress-strain curve of rock under cyclic loading can be divided into five stages，including primary micro-fracture compression closure stage，elastic compression stage，crack stable development stage，crack rapid development stage and post-peak deformation failure stage；(2) Under different confining pressures，the peak strength of rock under cyclic loading decreases slightly compared with that under conventional triaxial compression，but the stress-strain curve shows obvious hysteresis；(3) With the increase of the number of cyclic loads，the dissipation energy periodically decreases，and the elastic modulus gradually decreases with the increase of the axial stress difference during the first cycle；(4) Under the same hydrostatic pressure，the permeability of sandstone after failure increases significantly compared with that before failure，and with the increase of the unloading level，the permeability increment is consistent with the growth rate；(5) Under different confining pressures and cyclic loads，the pre-peak permeability changes periodically with the increase of the stress difference，and the post-peak permeability decreases obviously with the decrease of the stress difference；(6) Under different confining pressures and cyclic loads，sandstone mainly shows shear failure，and with the increase of the unloading level，the degree of damage increases. Under 20 MPa confining pressure，sandstone shows a single shear failure. Under the cyclic load of 30 MPa and 40 MPa confining pressure，there is a crack network dominated by through shear cracks and supplemented by secondary tension cracks.

Taking the east area of Jinshandian Iron Mine as the engineering research background，the occurrence mechanism of ground pressure in metal mines under the influence of geological discontinuities is studied using geological survey，displacement monitoring，numerical simulation and theoretical analysis methods. The research results show that with increasing the mining depth，the rock mass structure has a significant control effect on the range of the surrounding rock pressure around the goaf. Under the action of the dominant steeply inclined discontinuous plane，the surrounding rock on the upper wall forms an anti-dipping rock wall，and the surrounding rock of the footwall forms a dipping rock wall. The surface pressure of the hanging wall is much larger than that of the foot wall. The characteristics of ground pressure are obvious different in different regions. The roadway in the main control area of the structural plane is characterized by the overall deflection and deformation of the section，but the roadway controlled by the fault is mainly characterized by the vertical collapse of the roof，in which the incoming pressure is more serious. The spatial dislocation effect manifested by ground pressure is the result of the combined action of structural plane occurrence and local fault slip，which manifests that the roadway is stable in the mining stage，and the transportation roadway in the stage of mined and deep unmined body has a large area of continuous collapse and falling.

To solve the technical problem of water cutoff and slope reinforcement in water-rich sandy gravel aquifer in the Tenglong iron mine，aiming at the complex conditions of the slope with high water pressure and low strength，the technology of large-scale underground diaphragm wall was first introduced into the water-management field in an open-pit mine. An arc-shaped underground diaphragm wall preventing water curtain with a length of nearly 1 152 m and a maximum depth of 50 m was built along the 39 m platform on the south side of the pit. The influence laws of structural parameters of the underground diaphragm wall such as the concrete strength grade，the thickness and location of the wall，and the depth of wall embedded into the bedrock，on the lateral displacement，stress state and bending moment of diaphragm wall were analyzed by numerical experiment，and it was found that the bending moment was more sensitive to the variation of parameters. The test index“anti-bending safety”was proposed and the orthogonal experiment was designed to optimize the structural parameters of the underground diaphragm wall. The combination of optimal parameters was proposed，with the concrete strength grade of C25，the thickness of the wall of 800 mm，the depth of the wall embedded into bedrock of 2–3 m and the location of 10 m away from the outer edge of the platform. According to the numerical calculation and field monitoring results，after constructing the underground diaphragm wall，the anti-bending strength and anti-shear strength of the diaphragm wall can satisfy the specification requirements. The drainage volume of the mine has been reduced by 97%，the slope stability has been significantly improved. The diaphragm wall has the double functions of soil retaining and water cutoff. The research results have successfully solved the major technical problems of slope excavation in the open-pit mine in water-rich sandy cobble ground，and it can provide a useful reference for anti-seepage engineering in similar open-pit mines.

Flexible barriers have been widely used for the mitigation of nature hazards including rockfall and granular flow. In practice，the empirical coefficient method is usually used for designing the flexible barriers without the consideration of the structure characteristics. In this study，the effects of the number of the cable，the type of the main mesh，the installation of the auxiliary mesh and the installation of the energy dissipator on the impact characteristics of the granular flow against the flexible barrier were revealed using the physical flume tests and the Discrete Element Method(DEM). The results shows that the increase in the number of the horizontal cable has less effects on the decrease in the maximum tensile force of the cables if the lateral cables are installed. The geometry of the mesh grid is an important index for estimating the large deformation of the flexible barrier. The changes in the geometries of the mesh grids are the main cause of the large deformation of the flexible barrier，rather than the deformation of the mesh material. The installation of the auxiliary mesh has less effects on the maximum tensile force of the flexible barrier if the ratio of the particles passing through the mesh is less than 10%. The installation of the energy dissipators can not only decrease the maximum tensile load of the cables，but also change the load transmission between the cables.

In cold regions，cyclic freezing and thawing leads to rock damage and deterioration，which in turn affects the development of local strain and its loading failure characteristics. In order to evaluate the meso-damage，strain concentration and failure modes of intact/fractured rocks under different freeze-thaw(F-T) types，discontinuous jointed sandstones were prefabricated. Then the cyclic F-T and uniaxial compression tests of saturated intact，saturated fractured and ice-filled fractured specimens were carried out. The meso-images under different F-T cycles and stress states were obtained by CT technology，and the damage evolution characteristics were analyzed. Then，combined with the digital volume correlation method to quantify the three-dimensional strain distribution，the intrinsic relationship between the mesoscopic and macroscopic damage of frozen-thawed rocks was realized. The results show that：(1) The deterioration of intact rock and fractured rock mainly occurs in the periphery of the specimen and near the prefabricated fracture with low dip angle. With the increase of F-T cycle times，the heterogeneity coefficient and fracture ratio of saturated F-T rocks gradually increase，while the ice-filled F-T rock is relatively stable. (2) The statistical frequencies of von Mises equivalent strain( ) and normal strain( ， ， ) in rocks show lognormal distribution and normal distribution respectively. However，the local strain distribution of intact rock and fractured rock are different. The former forms a 75°shear band after loading，while the latter occurs strain concentration at the low dip prefabricated fracture and rock bridge area，and the range and standard deviation of are about twice that of . (3) F-T damage directly affects the strain concentration area of intact rock，and then guides the development of secondary fractures. But for fractured rocks，it can only be used as the inducement of wing crack development，and its failure mode is determined by the arrangement of prefabricated fractures. The conclusion of this paper can provide reference for exploring the mechanism of F-T damage and the method of failure prediction.

Fracture process zone(FPZ) is easily generated at the crack tip during the fracture process of rock. The geometry feature of FPZ determines the fracture properties and macro-mechanical behavior of rock. It significantly influences the safety and stability of the rock mass in practical engineering. Mode I three-point bending tests using notched semi-circular bend specimens were performed on MTS testing machine to study the nucleation characteristics and evolution process of the FPZ in granites. To understand the FPZ nucleation process at the tip of the mode I crack，the digital image correlation method(DIC) and the acoustic emission(AE) localization were employed. Micro and macro failure behaviors in rocks were obtained. According to the self-programmed acoustic emission signal identification and localization method，the spatial distribution density of AE events and AE energy were obtained. Then the zone and boundary of the micro-scale FPZ were determined. After which the critical strain value εFPZ of the FPZ was obtained in cooperation with the DIC method. The Irwin-Bazant model was utilized to determine the fully developed FPZ length of the sample，and the experimental value was compared with the theoretical one. Combining the wave velocity of the sample，the theoretical solution of the critical crack opening displacement(COD) at the crack end is obtained and compared with the experimental results. The results indicated that：(1) the critical strain value of FPZ of the rocks used in the experiment is about 1.8‰. (2) The theoretical value of the length of FPZ is in good agreement with the experimental value. For the rocks used in the experiment，the theoretical length of the FPZ is 5.2–8.7 mm，and the experimental result is 5–8 mm. (3) The boundary of FPZ can be regarded as the position where the AE energy suddenly changes from high to low along the crack propagation direction and remains at low energy.

The laboratory direct shear test and PFC2D microscopic simulation were used to investigate the shear deformation，strength characteristics and damage evolution law of fractured rocks. The research results show that：(1) The shear strength-deformation curve of fractured rocks can be divided into four stages：compaction stage，approximate linear elastic stage，unstable development stage and residual deformation stage. (2) The peak shear deformation of fractured rocks is negatively correlated with the number of fractures(N)，the normal stress( ) and the shear rate(ν). And the peak shear stress of fractured rocks is negatively correlated with N and ν，while positively correlated with . Besides，the greater N is，the more obvious the effect of ν on the peak shear deformation is，and the greater ν is，the more significant the effect of N on peak shear deformation is. (3) With increasing the shear deformation，the number of meso-damage cracks(shear cracks and tensile cracks) increases with the variation characteristics of slight (Ⅰ) →steep (Ⅱ) →slow (Ⅲ). The frictional dissipation energy gradually increases，the elastic strain energy first increases and then decreases. Especially，the elastic strain energy of rock mass only accounts for 1/5～2/5 of the total energy of mesoscopic damage. (4) At the tip of the preset cracks，the micro-meso cracks initiate，expand and then penetrate. In the end，the central rock bridge is mainly damaged by tensile，and the failure modes of two sides shows shear(tensile) failure- tensile-shear failure- shear failure. The peak shear stress (displacement) is X-type＞M2＞round-hole＞Z-type. The damage cracks appear at the tip of pre-existing flaw，and also the top or bottom left of the hole. The distribution of cracks is basically the same for the X-type and M2 fractured rocks.

The prediction of major natural and engineering disasters in the rock mass system such as earthquakes，landslides，rock burst and gas outburst is a major problem far from being solved by mankind. The short-term prediction of rock failure is its key scientific problem. The purpose of carrying out the short-term prediction competition of rock failure will not only stimulate the creation and innovation inspiration of scholars in multiple fields but also will promote the innovation and rapid development of instability destruction monitoring prediction theory，methods，technologies and instruments in rock and rock mass. In this paper，a detailed description of the first and second short-term competitions of rock failure is provided，including competition rules，scoring indexes consisting of prediction time，energy and location of damage，forecast theory，methods and test instruments used by each participating team，and final forecast results. At the same time，the latest theories and methods adopted by the participating teams regarding rock destruction prediction research，as well as the advantages and disadvantages of test instruments and the development direction of future research are comparatively analyzed. The results of the two competitions show that the theory，methods，and testing instruments of nonlinear rock mass mechanics- disaster rock mass mechanics，which are at the core of the destruction short clinical predictions，are still at an elementary level.

Thermally induced cracks play an important role in the failure process of grotto rock mass. The crack propagation caused by surface temperature change is key for studying thermal damage. However，no quantitative evaluation method is applied to such studies yet. In this paper，infrared thermography monitoring is used in parallel with normal inspection to analyze the temperature change characteristics of the rock mass surface of North Grottoes temple in Qingyang，Gansu Province. In doing so，the relationship between temperature change and thermally induced crack propagation in grottoes would be clarified. And，based on mineral distribution，an improved thermal crack evaluation method is established to quantitatively evaluate the damage characteristics of thermal crack propagation. Besides，the evaluation results are inversely verified by ground-based SAR monitoring. Three high thermal crack propagation areas in the North Grottoes temple are identified by infrared thermography，which highly coincides with significant deformation areas discovered by ground-based SAR. The innovative combination of infrared thermography and ground-based SAR can be applied to long-time sequence monitoring of the spatial-temporal characteristics of thermal crack damage in grottoes. This method may have practical implication for the protection of grottoes.

Manganese residue is a solid waste generated by the production of electrolytic manganese. And it contains soluble salts，which have a significant effect on its physical and mechanical properties. In this paper，the dynamic triaxial tests of two kinds of manganese residue，original and desalted states，were carried out. The effect of soluble salts in manganese residue on the dynamic characteristics was obtained，which provided a basis date for the earthquake response and seismic stability assessment of manganese residue pond. The results show that the hysteretic circle of desalted manganese residue decline faster than the original at the same conditions. Meanwhile，the hysteretic circle area and plastic deformation of original manganese residue are smaller than those of the desalted. The dynamic strength curves of the two kinds of manganese residue are both in the form of power function，but the desalted manganese residue is more easily damaged than the original. At the same condition，the maximum dynamic shear modulus and dynamic shear modulus of desalted manganese residue are both smaller than those of the original，but its damping is larger than original manganese residue. The Davidenkov model and Hardin model were used to fit the dynamic shear modulus ratio and damping ratio of manganese residue，respectively. And these two properties of desalted manganese residue are worse than those of the original. The dissolution of soluble salt would reduce the dynamic characteristics of manganese residue，thereby，affecting the seismic stability of manganese residue pond. Therefore，during the operation and management of manganese residue pond，special attention should be paid to the dissolution of soluble salts in manganese residue caused by rainfall infiltration.

The soft clay foundation formed by tideland reclamation is generally unconsolidated. To study the behavior of negative skin friction of a pile in unconsolidated soft clay foundation，4 single-pile model tests were performed，in which different initial water contents of soft clay and two working conditions including self-weight consolidation and surcharge were considered. The characteristics of relative displacement between pile and soil，axial force of pile，negative skin friction and neutral plane position were investigated based on the test results. In both self-weight consolidation and surcharge conditions，the increase of the initial water content leads to the increase of pile settlement，clay settlement，axial force of pile and negative skin friction，and the decrease of the initial water content induces the rise of neutral plane position. In the condition of surcharge，the increase of vertical load leads to the drop of neutral plane position，while in the condition of self-weight consolidation the consolidation time has little effects on the position of neutral plane. In engineering practice，the initial water content of clay foundation should be pained attention since it would cause the increase of negative skin friction and pile axial force.

The efficient disposal of sediment in river and lake environmental control engineering has become an important problem of environmental control. The grouting reinforcement method commonly used in geotechnical engineering needs a large number of grouting materials. Considering the difficult problem of sediment disposal and the demand for grouting materials in geotechnical engineering，this paper proposes to study geopolymer grouting materials with pure sediment as the basic material. Taking Wuhan South Lake to produce sediment dredging engineering as raw material，based on analyzing the basic properties of the sediment，this paper combines alkali excitation and thermal activation method of sediment base polymer preparation experiment. On this basis，the orthogonal experiment is carried out to explore the alkaline exciting agent module，alkali equivalent，water cement ratio，and other factors that influence on the strength of sediment mass base polymer. The strength of the prepared base polymer reaches 16.37 MPa in 28 days. X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR) reveal the formation process of geopolymer gel. The results show that under the combined action of alkali excitation and thermal activation，the preparation of sediment base polymer is feasible and can meet the engineering needs. This method can not only solve the problem of disposal of a large amount of sediment but also provide a low-carbon green cementitious material for engineering construction.

At present，triaxial tests of energy soils and their constitutive models are mostly based on coarse-grained reservoirs such as sandy soils. There are few tests and constitutive simulations of clayey-silty energy soils，and it is even rarer to have a constitutive model that can uniformly describe clayey and sandy energy soils. In this paper，triaxial tests of clayey-silty energy soils were firstly carried out，and the mechanical properties of energy soils were deeply summarized based on previous achievements. Then，under the framework of unified hardening model for clays and sands(CSUH)，considering the special mechanical characteristics of energy soils，the compressibility parameter related to hydrate saturation was constructed to describe the compression characteristics of energy soils. The cementation factor and dilatancy factor were introduced to reflect the cohesive strength and dilatancy effect respectively. The shear state of energy soils was reflected by state parameter，and an elastoplastic constitutive model which could describe clayey and sandy energy soils in a unified way was established by combining the non-associated flow rule. The verification program of the model was compiled，and the validity of the constitutive model was verified by several groups of triaxial tests of this paper and other scholars. The results show that the established elastic-plastic constitutive model can uniformly describe the shear characteristics of clayey fine-grained and sandy coarse-grained energy soils. It can effectively reflect the mechanical characteristics of energy soils such as strain hardening and softening，shear contraction and dilatation. It also has a good prediction effect on the influence of hydrate saturation and effective confining pressure.