In order to solve the control problem of dynamic impact phenomena in roadways with high stresses，and to clarify its occurrence law and the control mechanism of the surrounding rock，a physical simulation test system for dynamic impact phenomena in deep roadways of coal mines is developed. It includes balanced loading device，boundary energy storage device and multi-source monitoring platform，which can achieve high stress equilibrium loading of the model body and instantaneous compensation of boundary stress. Therefore，the stress environment before and after the occurrence of dynamic impact phenomena in deep roadways is effectively simulated by this system. On the basis，a series of physical simulation comparative tests on dynamic impact phenomena in deep roadways are carried out with a typical deep high stress mines as simulation object combined with the developed high-strength energy absorbing support material. It reproduces the entire occurring process of dynamic impact phenomena in models with different types of support parameters. The dynamic failure mode，stress-displacement evolution law of surrounding rock in different parts of the roadway are analyzed. Meanwhile，the interaction and impact response characteristics between different support materials and surrounding rock are clarified. The control advantages of energy absorption in the dynamic impact phenomenon of deep roadways by the new energy absorption support material are revealed. The average deformation of the surrounding rock decreases by 36.9% though the application of this support material as the dynamic impact phenomenon occurs. According to the test results，further research is conducted on the field application of energy absorption support，which effectively reduces the risk of dynamic impact phenomena in deep roadways and ensures the safety of surrounding rock throughout the roadway operation cycle.

The working face of the thick roof is subject to strong dynamic loading，often resulting in coal rib spalling and hydraulic support crushing. In order to enhance the ground control under the thick roofs，the deformation and stress characteristics of the roof，failure modes，dynamic loading effects and control methods were investigated by taking the 14030 working face of the Zhaogu Second Coal Mine as the background. Based on the results from theoretical analysis，numerical simulation，and field measurement，it is found that the maximum tensile stress and maximum shear stress are located at the midpoint of the coal wall side and the cutting eye side during the first weighting，and the roof undergoes tensile failure. During periodic weighting，shear stress concentration zones form at both ends on the coal wall side，with significant development of shear cracks，resulting in mixed tensile-shear failure of the roof. The impact characteristics of the working face advance distance and the roof thickness on tensile (shear) stress were determined. The influence of roof thickness on failure mode was analyzed. Numerical models of first and periodic weighting of the roof were established using PFC3D，determining the roof failure morphology，crack distribution characteristics and failure modes. Based on the intervention of the sand and thickness effect，the reasons for the occurrence of shear failure in the roof were explained，revealing the mechanism of dynamic loading on the roof. By utilizing the principle of momentum conservation，the dynamic impact force caused by different fracture positions of the roof was calculated. The working resistance of the hydraulic support under dynamic load impact was obtained，and methods for dynamic load control were proposed. The research results can provide theoretical basis for medium-thick roofs or roofs that do not meet the conditions of thin plates，and help guide the safe production of medium-thick roof working faces.

In order to explore the effects of rock bridge inclination angle and mineral structure on coal body damage and failure at a three-dimensional scale，uniaxial loading tests are carried out on double-crack samples prefabricated from raw coal with different rock bridge inclination angles，and phased scanning of the compression failure process is carried out with CT scanning equipment. Image processing techniques such as threshold segmentation，3D reconstruction and digital volume correlation methods were used to analyze the dynamic evolution of internal cracks and deformation and damage characteristics of coal samples，and the PFC3D simulation program was used to explore the internal stress distribution characteristics at different stages of the loading process. The results show that the macro-strength of coal samples decreases gradually with the increase of rock bridge angle. The evolution characteristics of the displacement fields in X，Y and Z directions are different due to the influence of prefabricated fractures on coal samples. The local high displacement area in X direction shifts from the rock bridge area to the end with the loading，while the local high displacement area always drifts around the rock bridge area and the prefabricated fracture in the whole loading process of Y direction，and the Z direction displacement field presents obvious stratification at each loading stage. The displacement is small and uniform. According to the crack propagation path and the stress characteristics of the failure surface，the failure mode of coal samples with rock bridge angles of 0° and 90° is tensile failure，and the failure mode of coal samples with rock bridge angles of 30° and 60° is tensile shear compound failure. The relationship between the growth of new crack and the occurrence state of mineral mainly includes three types：encapsulation propagation，around gravel propagation and through gravel propagation. Among them，through gravel propagation is the most frequent and wrapped propagation is the least. The simulation results show that the stress characteristics of coal samples with double cracks in each direction are different at the peak stage. When the slice position extends from the outside of the sample to the inside of the sample，the Y，Z and total stress values show a trend of gradual increase，while the X stress values show a phenomenon of first decreasing and then increasing.

The difficulty of quantitative early warning of water inrush disasters on the coal mine floor is the selection of the sensitivity index. At present，the early warning of water inrush based on microseismic often selects multi-source data，and lacks detailed analysis of indicators closer to the development of water-flowing fractures. According to the field monitoring methods of 16091 working face in Zhaogu No.1 Coal Mine，the correlation and sequence relationship between microseismic event frequency index，energy index and water level change are analyzed in this paper. Practice shows that microseismic and water level have a good spatial and temporal correlation. Based on this，a comprehensive early warning index of floor water inrush disasters based on microseismic-water level is established. The following results are obtained. (1) During the period of high frequency and high energy of microseismic，the water level began to decline，and the water inflow increased after a while. In the low frequency and low energy period of microseismic，the water level began to rise. The decline time and amplitude of the water level in the observation holes correspond to the spatial position of the distance from the working face. It shows that microseismic and water level have an obvious correlation in time and space. (2) Under the combined action of mining disturbance and floor water pressure，the frequency and energy of microseismic events on the coal seam floor increase，and the range continues to extend. Then the water channel is formed，and the water level of the observation hole declines. With the periodic pressure，the cracks gradually closed. At this time，microseismic events are low frequency and low energy. Under the supply of water source，the confined water level rises to a certain height and tends to be stable. (3) Based on the correlation effect between microseismic and water level，the daily cumulative frequency of floor microseismic，daily cumulative energy，and daily decline of water level in four observation holes are taken as the basic parameters，and the comprehensive early warning index of microseismic-water level is established utilizing basic index standardization，weight calculation. After calculation，the comprehensive early warning index threshold of water gushing(inrush) in 16091 working face is 0.30. (4) The field application results of the project show that when the comprehensive early warning index value exceeds the threshold value of the working face，there is a large underground water inflow after the alarm. It has a good effect on the early warning of water inrush from the coal seam floor，so the microseismic-water level can be used as a comprehensive early warning index of floor water inrush.

The evaluation of reservoir fracturability is an effective method to characterize the difficulty of reservoir effective reconstruction and to judge the“sweet spots”for fracturing. However，the current domestic and foreign evaluation methods for reservoir fracturability do not fully consider the multi-lithology combination stratification. This article takes the sand-shale interbedded reservoir of Qingshankou Formation in Daqingzi area of Songliao Basin as the research object，and carries out X-ray diffraction and mechanical experiments on sandstone and shale at different depths. A new brittleness evaluation method based on the energy evolution and different stages of brittleness sensitivity index in the stress-strain curve is established through fuzzy analytic hierarchy process. The brittleness index of composite rock is analyzed and quantitatively evaluated，and the brittleness index of composite rock is combined with mineral content and cohesive strength to establish a fracturability evaluation system for multi-lithology composite reservoir. Experimental evaluation results show that the uniaxial and triaxial compressive strength of composite rock samples decrease with the decrease of shale interbed thickness，but the brittleness index first decreases and then increases with the decrease of shale interbed thickness，and the fracturability index decreases with the increase of confining pressure. By conducting continuous coring，mechanical experiments and mineral content tests，the curve of fracturability index changing with burial depth is plotted，and the results of on-site microseismic monitoring are compared with the corresponding burial depth reservoir fracturability index，which validates the accuracy and feasibility of this fracturability evaluation method. The research results can provide reference for fracturing transformation of multi-lithology composite layered reservoirs.

In the process of uranium reservoir reconstruction，blasting is one of the effective means to improve the permeability of low permeability uranium reservoir，and the design optimization of blasting parameters is the key factor affecting the blasting effect. Therefore，a three-factor and five-level orthogonal numerical test is designed firstly. Based on the simulation results，the millisecond blasting parameters suitable for rock parameters in reservoir reconstruction are determined. The influence of different blasting methods on the formation effect of fracture network in reservoir reconstruction is studied，and the advantages and disadvantages of fracture network in reservoir reconstruction are comprehensively evaluated from multiple angles. Subsequently，different injection pressure simulation tests are carried out to quantify the variation of the flow rate of the solution in the reservoir with time. The results show that under the combination of blasting parameters with a millisecond time of 5 ms，a peak pressure of blasting load of 5 GPa，and a pressure rise time of 150 μs，the effect of reservoir seepage flow transformation is the best. This paper expands the understanding of uranium reservoir reconstruction and provides an important reference for future research.

In shallow buried hard rock tunnels，the ground arching effect has a significant impact on tunnel stability. It is of great significance to clarify the interaction mechanism between the ground arching effect and tunnel support for determining the tunnel support pressure. In this study，a mechanical model has been constructed that can be applied to the laminated arch transfer effect in shallow buried tunnels based on the ground arch transfer effect. By analyzing the principal stress deflection and lateral limiting force of single-layer arches，the method for calculating the stress transfer in laminated arches is derived，and combined with the distribution characteristics of the principal stresses on the differential rock strips in the loosening zone，the formula for calculating the support pressure of shallow buried hard rock tunnels in stable state is obtained by using the limit equilibrium analysis method. Modelling tests and field monitoring are carried out to verify the applicability of the calculation method in the Qingdao Metro Line 6 project. The results show that：(1) The parametric sensitivity analysis indicate that the support pressure gradually decreases with the angle of internal friction. When the tunnel depth does not exceed the thickness of the maximum load transfer zone(namely H≤2.4B)，the support pressure gradually increases with the tunnel depth，and the sensitivity of the support pressure decreases with the layers of laminated arches n. (2) The implementation of active support enhances the constrain effect of the surrounding rock，which further improves the critical instability load rating of the tunnel on the basis of significantly enhancing the mechanical properties of the tunnel's surrounding rock. Compared with passive support，the stress transfer effect of the enhanced laminated arch increases the load carrying capacity of the surrounding rock by 11.9%. (3) The average relative errors between the predicted and measured tunnel support pressure under different modes are within 20.9%，which indicates that the predicted tunnel support pressure is in good agreement with the measured value when considering the laminated arch transfer effect，thus verifying the accuracy and applicability of the support pressure calculation method. The results have a significant reference for the safety design and evaluation of shallow buried hard rock tunnel.

Coal burst seriously restricts the safe mining of deep coal resources. It is important to establish reasonable coal burst proneness indicators from the perspective of inherent material properties to assess the coal burst risk. Due to the significant influence of the bedding structure on the mechanical behavior of coal，uniaxial compression experiments and discrete element numerical simulations were carried out on coal samples with different bedding angles in this study. The effect of bedding angle on the mechanical properties and burst behavior of coal was then analyzed. The experimental and numerical simulation results show that：with the increasing bedding angle，the strength，deformation，and burst feature of the coals decreased firstly and then increased; the fine-scale fracture mode gradually evolved from shear-dominated to tensile-dominated. Coal burst is a dynamic fracture issue; and the kinetic energy generates when the energy release rate is higher than the energy demand of dynamic fracture. Accordingly，a new indicator，realistic energy release rate(RERR)，was proposed as a criterion for coal burst proneness based on the experimental results. It considers the contribution of post-peak energy to coal burst and the time effect of failure，reflecting the intensity of energy release during the dynamic fracture process. By combining the actual failure situation(sound，ejection) and the comparison with the traditional indicators(including the uniaxial compressive strength USC，elastic stain energy index WET，bursting energy index KE，and duration of dynamic fracture DT)，the burst proneness of coals with different bedding angles was comprehensively assessed. The RERR was found to be highly linearly correlated with traditional indicators，the reasonableness and validity of the RERR were verified. Finally，the standard for classifying the coal burst proneness grade based on the RERR was established.

The pore size of tight reservoir rock subjected to deep high stresses approximates the average free path of gas molecules，leading to occurrence of gas slippage. This phenomenon can exert a significant impact on the sustained and stable production of gas(or coalbed methane) over the long term. The helium injection experiments on coal and sandstone under deep high stresses were investigated. The results demonstrate that helium migration exhibits a significant slippage effect throughout the entire extraction cycle within a high-stress coal，even under reservoir pressures reaching up to 8 MPa. Under identical conditions，the seepage of sandstone typically remains unaffected by the slippage effect. When correcting the apparent permeability( ) of coal under deep high stresses，the double-slip Klinkenberg equation provides more accurate results compared to the linear Klinkenberg equation and the quadratic Klinkenberg correction equation. Furthermore，the linear relationship has been established between the inherent permeability( ) of coal and the effective average stress( )，which is caused by the weakened heterogeneity and the enhanced homogeneity within the internal structure of coal subjected to high stresses. The seepage behavior of homogeneous sandstone exhibits a linear mechanical response，validating the rationality of correcting the coal slippage effect. As the inherent permeability of deep coal   decreases linearly with  ，the stress-induced permeability exhibits a slight decline under stress loading，ultimately resulting in a decrease in the slippage effect as increases. Based on the principles of double Hooke?s law，a permeability model was established. The model comprehensively considered the linear law of coal fracture opening under high stress and the exponential attenuation law of slippage permeability，resulting in excellent fitting outcomes across diverse boundary conditions.

Mining-induced stress is one of the fundamental driving force of geological disasters in coal mining. In order to master the evolution law of mining-induced stress of surrounding rock during heading and mining period，hollow inclusion stress measurement technology was employed to obtain the full-cycle stress evolution data of the 122110 working face auxiliary roadway from the heading to the end of mining for the first time，in the Shaanxi Coal Caojiatan Mining Co.，Ltd. A method for calculating the full amount of stress based on continuous monitoring of hollow inclusion strain gauges was proposed，and the validity of the measured data was determined based on the M-C criterion. The dynamic change law of the mining-induced stress in the surrounding rock under the influence of heading and mining was revealed，and the failure mode of the roadway surrounding rock was discussed using the stress ratio K. The research results show that the influence range of advance mining-induced stress during heading period and mining period was 8 m and 110 m，respectively，and the difference between maximum and minimum principal stress increases 0.17 and 1.58 times，respectively. The increase value during mining period was 9.3 times of that during heading period. The failure mode of surrounding rock was mainly tensile failure of surface surrounding rock during heading period，and plastic failure occurred in a large range during mining period，in which the shallow surrounding rock is mainly tensile failure，the middle surrounding rock is tension-shear composite failure，and the deep area is generally less failure. The comprehensive field-measured data，drilling results，and in-situ failure characteristics indicate that the stress ratio K can better reflect the relationship between the stress state and the surrounding rock failure mode of the mining roadway.

The stability of the underground reservoir dam body under water pressure conditions is crucial for the long-term safe operation of abandoned mine water storage power stations. Therefore，in response to the actual groundwater pressure environment，an independently designed and developed servo-shaft-water pressure joint test device was created，and mechanical tests on dam bodies under different water pressures were conducted. The affecting ways of the environmental water were analysed，the evolution process of the joint action structure between the shaft and water pressures was clarified，and the theoretical strength trend of the dam body was determined. Furthermore，the effect law of the water pressure on the mechanical performance of dam body specimens was ascertained，and the characteristics of microscopic fracture surfaces and macroscopic failure modes were explored. The results indicate that the real water pressure environment affects the dam body specimens through both hydrochemical and hydrostatic pressure influences，encompassing seven aspects of reinforcement and weakening effects. The specimen water environment consists of three parts: external confining water，penetrating pore water，and enclosed pore water. During specimen saturation and loading processes，the interaction of water media and crack propagation mutually influences each other，with a greater water pressure leading to increased infiltration and impact effects. The real water pressure environment alters the specimen damage and effective porosity，thereby affecting lateral effective stress and specimen strength. As the water pressure in the actual environment increases，the stress-strain curve exhibits a significant yield fluctuation，where the strength decreases first and then increases，while the axial strain continues to decrease. The energy consumption by the testing machine on the specimen gradually decreases，but the proportion of dissipated energy increases rapidly. After the increase in water pressure，the number of crack nuclei at the fracture surface decreases，with the main fractures occurring sequentially as transgranular fracture，intergranular fracture，and shear failure. The number of fine cracks increases，and the specimen failure pattern undergoes a transition from tension to shear to shear-shear，becoming increasingly complex，accompanied by brittle collapse sounds. The research outcomes can enhance the accuracy of underground reservoir monitoring and assessment，providing theoretical and experimental foundations for the construction of abandoned mine water storage power stations.

In order to explore the dynamic instability mechanism of rocks，uniaxial acoustic emission tests on rocks with high rockburst proneness were carried out. The stress-strain，acoustic emission evolution，macro and meso failure characteristics were analyzed. The results indicate that the dynamic instability of rocks is a self-organizing behavior of their meso-structural systems gradually forming a certain shape of mechanical structure，and then the mechanical structure suddenly collapses，which has the properties of self-organized criticality，symmetry breaking and loss of plasticity. The dynamic instability process of rocks was divided into two stages：energy accumulation and energy explosion. Based on the self-catalysis self-inhibition mechanism of self-organizing systems，the nonlinear dynamic equations for energy accumulation and energy explosion considering symmetry breaking were established respectively，and the corresponding dissipative energy evolution equations were derived. The binary medium theory was introduced and the breakage of rocks was regarded as the transformation of elastic-brittle cementation elements to elastic-plastic friction elements. The friction elements follow the Mohr-Coulomb criterion. The breakage law was defined according to the dissipative energy evolution equation of the energy accumulation stage. A binary medium model for rocks was established. The damage law was defined according to the dissipative energy evolution equation of the energy explosion stage and a damage model for rocks was established. The mechanical models were embedded in the finite difference software and were verified as correct. Based on the self-organization theory and combined with the numerical simulation results，the dynamic instability mechanism of rocks was analyzed from the perspective of energy and meso-scopic level. The results show that the meso-structural systems of ideal homogeneous rocks can evolve intoa centrally symmetric mechanical structure in the shape of hourglass under the influence of potential energy gradients. At the critical state，the potential energy gradient surfaces are densely gathered toward the center of the mechanical structure and the energy can flow at high speed within the surface. The rock bridge located at the symmetrical center can be easily torn apart，which can break the potential energy gradient surfaces around it and trigger a intense release of the in-plane energy and rock burst. The mechanical structure and failure mode with symmetry breaking will occur during the instability process of real rocks. The research results can provide theoretical support and numerical simulation means for the dynamic instability analysis of rock pillars and tunnel surrounding rock.

Current early warning models for slope safety in hydropower engineering exhibit certain limitations，such as insufficient consideration of multi-point comprehensive analysis and neglect of stability differences across various slope regions. To address these issues，this study approaches from the perspectives of slope structural characteristics and overall stability. By employing multi-data fusion technology and integrating actual engineering practices，we develop early warning indicators. Firstly，the concept of“Safety Stability Rate”is introduced to quantify the impact of rock mass structural characteristics on slope stability. Secondly，a method for converting Safety Stability Rate to Hazard Weight is established，and a combined formula for Hazard Weight and Copula function is derived. Finally，an overall safety early warning indicator based on the Copula function for the operational period of slopes in hydropower engineering is proposed. Engineering case studies demonstrate that the early warning indicators can reflect the structural characteristics of rock slopes，indicate the overall trend of multi-point residuals，and ultimately reflect the overall stability of slopes in hydropower engineering. The early warning monitoring system provides theoretical support for evaluating the overall stability of slopes in hydropower engineering.

The occurrence of rockburst in deep tunnels is closely related to impact disturbances，and the tunnel cross-sectional shape further affects the process and characteristics of rockburst. Based on the world?s first biaxial split-Hopkinson pressure bar apparatus，the two-dimensional high-stress tunnel sidewall failure test function under impact loading conditions was developed. Rockburst tests were conducted on specimens with circular hole，D-shaped hole and rectangular hole，all subjected to same coupling of static stress and impact load，to explore the influence of cross-sectional shape on tunnel rockburst. The high-speed camera and DIC were used to unveil the rockburst process and strain field evolution of the specimens. The test results indicate that the rockburst process for specimens with different cross-sectional shapes can be summarized into four stages：the calm stage；crack initiation，propagation，penetration stage；spalling stage and rock fragment ejection stage. There are significant differences in the rockburst characteristics among specimens with different cross-sectional shapes. In circular hole specimens，the strain concentration zone is located at the centerline of the hole，and cracks transition from arc to “V” shape，resulting in the least severe rockburst and a tensile failure mode in the surrounding rock. D-shaped hole specimens have strain concentration zones in the straight wall area between the arch foot and shoulder，with cracks transitioning from arc to“V”shape，primarily demonstrating tensile and tensile-shear failure modes. Rectangular hole specimens experience the most severe rockburst，with a strain concentration zone spanning the entire sidewall，and cracks transitioning from straight line to“V”shape，also primarily demonstrating tensile and tensile-shear failure modes. Rectangular hole specimens show the highest overall deformation rate with a maximum strain value of 0.003 4，followed by D-shaped specimens with a maximum strain value of 0.002 9，and circular hole specimens show relatively lowest deformation rate with a maximum strain value of 0.002 2. Comparative results suggest that circular hole sections can optimize stress or strain distribution，improve the overall structural stability of tunnels，and result in lower severity of rockburst. D-shaped and rectangular hole sections may experience stress concentration due to their irregular shapes，making them relatively more susceptible to damage and resulting in a higher severity of rockburst.

In deep geothermal reservoirs，a multitude of sealed rock fractures are prevalent. Utilizing hydraulic stimulation to induce shear along these fractures can significantly enhance the permeability and convective heat transfer performance of geothermal reservoirs. To investigate this mechanism，a series of shear tests were conducted on granite fractures at different temperatures(25 ℃ to 300 ℃)，and the evolution of permeability and convective heat transfer coefficient during the shear were measured concurrently. Through quantitatively characterizing the changes in surface morphology and the damage to surface asperities caused by shear slip，the mechanism of high temperature and shear induced damage effects on the permeability and heat transfer characteristics of fractured granite was revealed. The results show that：(1) the permeability and convective heat transfer coefficient of granite during shear slip exhibit three stages，which are closely related to shear-induced changes such as shrinkage，dilatancy，asperity damage，and gouge production；(2) The permeability K1 in the stable stage exhibits minimal correlation with temperature. However，as the temperature increases from 25 ℃ to 300 ℃，the rate of permeability increase  during the growth stage gradually decreases from 159.75 to 30.58，and during the attenuation stage，it decreases from 148.68 to 3.03. (3) There is a positive correlation between the convective heat transfer coefficient and permeability. Higher temperatures in granite are associated with higher convective heat transfer coefficients. (4) Higer temperatures exacerbate shear damage to surface asperities. As the temperature increases from 25 ℃ to 300 ℃，the damage volume increases from 508.1 mm3 to 729.3 mm3. The production of smaller particles from shearing contributes to the enhanced attenuation effect of gouge blockage on permeability and convective heat transfer coefficients during shear slip. This research provides valuable insights for the efficient extraction of heat energy from dry hot rocks.

To investigate the disturbance effect of radial vibration excitation on saturated sand，the vibration test system with radial excitation capability and adjustable frequency was developed. Disturbance tests on saturated sand were conducted using this system under vibration frequencies ranging from 10 to 50 Hz. The spatiotemporal evolution and distribution characteristics of the disturbance effect induced by radial vibration excitation were analyzed. The results indicated that，within the scope of the test conditions，the pore water pressure at each measurement point initially increased，and after reaching its peak，gradually decreased and stabilized under vibration excitation. It was observed that as the vibration frequency increased，the degree of disturbance to the saturated sand became more severe，with a gradual increase in excess pore water pressure，excess pore pressure ratio，liquefaction duration，and vibration acceleration at each measurement point. At the vibration frequency of 30 Hz，some measurement points reached liquefaction state，while at 40 Hz and 50 Hz，all measurement points entered liquefaction state. Moreover，as the depth increased，the pore pressure at each measurement point during vibration was higher，the peak was reached earlier，and the liquefaction duration was shorter. The soil near the middle of the vibrator experienced the most severe disturbance，with measurement points in this location entering liquefaction state earliest，and the amplitude of pore pressure oscillation，relative oscillation amplitude，and peak excess pore pressure ratio were all higher at these measurement points compared to those at both ends of the soil. Additionally，the closer the measurement points were to the vibration center along the radial direction，the greater the vibration acceleration，the higher the maximum excess pore pressure ratio，the earlier the entry into liquefaction state，and the longer the duration of liquefaction. These findings provide guidance for selecting grouting timing，setting grouting outlet positions，and choosing vibration parameters，laying a foundation for further research on radial vibration grouting tests.

To accurately predict the influence of osmotic suction on the mechanical behavior of overconsolidated saturated saline clay，an elastoplastic model considering the effect of osmotic suction is established to provide a theoretical basis for predicting the chemo-mechanical coupling behavior of saturated saline clay. Based on the theoretical foundation of the unified hardening(UH) model，the model is established to consider simultaneously the osmotic suction，degree of consolidation and chemo-mechanical coupling effect by introducing the osmotic efficiency parameter and coupling stress，as well as obtaining the theoretical expressions for the overconsolidation ratio and osmotic suction. From verification results，the new model has the following properties. (1) The effects of deformation softening and strength hardening induced by osmotic suction can be described with the help of the concept of coupled stresses. (2) The chemo-mechanical coupling behavior of saturated saline clay can be accurately predicted for different stress histories，drainage and saline conditions with the addition of only two parameters. (3) The relationship between the overconsolidation ratio of saturated saline clay and osmotic suction can be revealed，as well as the interaction mechanism of their chemo-mechanical coupling behavior. In addition，the results provide a valuable theoretical basis for the chemo-mechanical coupled analysis and behavior prediction of clay under chemical environment.

Basalt fiber reinforced polymer(BFRP) anchors have the advantages of high tensile strength and good corrosion resistance，which can replace the traditional steel anchors to solve the durability problem of anti-floating anchors in corrosive environment. In this test，cyclic loading was used to study the load carrying performance of fully threaded BFRP anchors with different anchorage lengths and diameters. The results show that the load-displacement curves of anchor rod and anchor solid under cyclic loading present hysteresis. The anchor displacement rebound rate is high when unloading，and the elasticity of BFRP anti-floating anchors is obvious. Anchor rod is damaged by cyclic loading，and the strain of anchor rod with the same anchorage depth increases with the increase of cyclic times. For anchors with different anchorage depths，with the increase of cyclic loading times，the strain increase of the anchor rod body and the plastic deformation generated after unloading of each level of loading gradually increased，and the strain of the anchor rod body was transferred to the deeper part of the anchor body. The axial force of BFRP anti-floating anchors? rods attenuated from the mouth of the aperture from the top to the bottom，and the range of the rods? axial force was in the range of 2.5 m from the mouth of the aperture downward. The increase in the number of cyclic loadings resulted in an increase in the anchor rod axial force and a deeper transfer depth，but the attenuation value of the anchor rod axial force in the range of 0.5–1.0 m downward from the orifice gradually decreased with the increase in the number of cycles. The amount of change of axial stress of anchor rods is greatly affected by cyclic loading，and there is a peak value of change of axial stress of anchor rods under different cyclic loading.The shear stress of BFRP anti-floating anchors increases rapidly with the increase of anchorage depth，and reaches the peak value at the depth of 0.75 m below the mouth of the borehole，and then decreases gradually，and the peak value of the shear stress appears to be attenuated with the increase of the number of cycles.

In response to the serious problems of plate bending and blockage in the treatment of high water content engineering waste slurry using vacuum preloading with vertical drainage(PVDVP)，a coagulation grading horizontal drainage plate vacuum preloading method(F-G-PHDVP) is proposed by combining two anti-blockage technologies-flocculation and grading method. This method can further alleviate the clogging problem caused by fine particle migration. Indoor model tests were conducted on Wenzhou pile foundation waste mud to compare and analyze the reinforcement effect and blockage of traditional，flocculation，and flocculation-graded vacuum preloading methods. The test results showed that the grading flocculation method had the best reinforcement effect. Compared to the traditional group，the flocculation group can increase the vane shear strength by 83.5%. On the basis of flocculation，the flocculation graded drainage capacity is increased by 4.03% to 12.73%，the average vane shear strength is increased by 1.91% to 5.66%，and the average moisture content is reduced by 1.66% to 4.27%. The flocculation-graded vacuum preloading method not only increases the average particle size，but also effectively slows down the migration of fine particles，preventing the aggravation of clogging and further improving the reinforcement effect. Among them，the vacuum loading method of 30–80 kPa can further improve the reinforcement efficiency by 4.1%. To verify the feasibility of this method for on-site treatment of pile foundation waste mud，a 30–80 kPa scheme was selected for vacuum preloading field tests. The results confirmed that this scheme has a good reinforcement effect on high water content waste mud.