The evolution characteristics and laws of surrounding rock disturbance stresses in deep tunnels are the most important factors for engineering stability and disaster analysis. At present，the research on the disturbance stress characteristics of hard surrounding rock is limited to analytical and numerical simulation，and there is a lack of reliable in-situ testing technology and equipment. In view of the complex geological environment of deep hard rock tunnel engineering，the disturbance stress comprehensive sensing technology based on fiber bragg grating and hollow inclusion was developed on the basis of the systematic analysis of the measurement principle and theory of the disturbance stress，and a multi-point three-dimensional disturbance stress testing system was developed. The seal oil pressure calibration device was designed to carry out the overall calibration of the sensor，and the indoor concrete model test was designed to verify the accuracy and reliability of the stress testing system. Based on the China Jinping Underground Laboratory phase II project，the in-situ test of the corresponding disturbance stress was carried out. The three-dimensional disturbance stress distribution and evolution characteristics during the excavation of deep hard rock tunnels were obtained for the first time，the evolution characteristics and laws of the magnitude and direction of the disturbance stress and their relationships with construction activities were systematically analyzed，and the applicability and reliability of the fiber bragg grating hollow inclusion stress testing system were further verified. The research provides a scientific method and technical support for deep hard rock engineering disturbance stress test and evolution characteristics research.

Tunnel engineering faces complex geological conditions in the construction process，and the surrounding rock large deformation disasters cause many economic losses and personnel safety threats. Given the challenging issue of controlling the large deformation disaster of tunnel surrounding rock under complex geological conditions，firstly，based on the excavation compensation method，it is presented that the active support method with high support force effectively controls the large deformation of surrounding rock by the rock mechanics method. Secondly，in response to the demand for high support force active support methods for high-performance new materials，multi-generation NPR(negative Poisson?s ratio) materials with high constant resistance and large deformation characteristics developed by our team are introduced. Finally，the active support method with NPR new material as the core is introduced in engineering applications to control large deformation disasters of tunnel surrounding rock under complex geological conditions. The results indicate that：(1) Large deformation in the tunnel surrounding rock is mainly caused by the redistribution of stress resulting from tunnel excavation，and active support can provide support force to restore or approach the initial stress state. (2) Unlike traditional materials，the NPR new material developed by our team can provide high support force for deep surrounding rock to restore the original stress state. (3) Based on the analysis of engineering cases，the NPR active support technology has demonstrated effective control of large deformations in soft rock tunnels，fault-fracture zone tunnels，and rock burst tunnels，providing a reference and practical basis for dealing with large deformations in complex geological conditions.

Size effect of shear strength of rock joints has become the consensus of academic and engineering circles，but the existing theoretical and numerical studies show that the shear strength of rock joints may have positive size effect，negative size effect or no size effect. Due to the difficulty，high cost and long period of size effect test of shear strength of rock joints，there are few direct shear tests of joints with series size，especially for full-coverage direct shear test of rock joints with fluctuation morphology in a series of sizes(100–600 mm). In this paper，based on Barton's typical morphology curves，16 sets of multi-scale joint samples were made by multi-scale joint integration mold. The direct shear test of a series of multi-scale joints with full coverage of fluctuation morphology was carried out through the self-developed shear strength size effect test system of rock joints，and non-contact dynamic deformation measurement of the whole test process was carried out by DIC. The results show that：(1) Upper asymptote of peak shear strength of rock joint exhibits a negative size effect law，and lower asymptote exhibits a positive size effect law. The specific pattern of size effect is related to the sampling position and fluctuation morphology characteristics. (2) Different shear failure modes such as shear，climbing and coupling will occur in the same morphology of rock joints with different sizes. The shear failure modes of joints with different morphology characteristics of the same size samples are also different，and the larger the fluctuation degree of surface morphology，the faster the strain growth. (3) The larger the size，the more obvious the peak characteristics of shear stress and shear displacement curves of rock joint with large fluctuation morphology；the smaller the size，the larger the discreteness of peak shear strength of rock joint with large fluctuation morphology. (4) Based on the equal weight coefficient method，peak shear strength evaluation of large-scale rock joint is carried out. The weighted evaluation value of peak shear strength calculated by Grasselli formula has a large error compared with the measured value.

In shale gas extraction，shear fractures in the reservoir serve as critical seepage channels and show different inflow characteristics depending on the direction of shale stratification. To investigate the influence of laminations on the conductive properties of shale shear fractures，shear fractures with parallel and perpendicular laminations were created in the Longmaxi Formation shale in the Fuling area of Chongqing，China. The surface of the fractures was characterized using a three-dimensional morphology scanner to analyze their initial morphology and mechanical openness. Gas conduction experiments were conducted under different effective stresses using a three-axis rheological experimental system to analyze the conductive properties of the fractures. The results show that vertical shear fractures have a rougher surface，a larger standard deviation of the opening distribution，and more small opening fractures(＜200  ). When the effective stress is lower(＜8 MPa)，the equivalent hydraulic openings of vertical shear fractures(17–100  ) are higher than those of parallel shear fractures(22–66  )，indicating that vertical shear fractures have a stronger flow-conducting ability. As the effective stress increases，parallel shear fractures exhibit higher flow-conducting ability than vertical shear fractures. The parallel shear fracture also demonstrates stronger flow conductivity with increasing effective stress. The critical Reynolds number of the vertical shear fracture(3.1–15.6) is larger than that of the parallel shear fracture(4.2–8.5)，making it less likely to occur under the same conditions of nonlinear flow. Gas flow analysis reveals that vertical shear fractures exhibit laminar，transitional，and turbulent flows，while parallel shear fractures only exhibit transitional and turbulent flows.

A dynamic assessment method for rockburst risk in tunnels is proposed in response to the complex construction conditions of high ground stress tunnels，which make it difficult to assess rockburst risk. Fault tree analysis method is adopted to identify rockburst risk sources and to screen risk assessment indicators. Based on the risk matrix method，the values of probability level and severity level are expanded from discrete points to a range，refining the classification criteria and constructing a risk level assessment regional map. The dynamic assessment model for rockburst risk is established by introducing the concept of dynamic weight based on the static risk indicator system，thus achieving a finer classification of rockburst probability levels. Taking the Taoziping tunnel as an example，the implementation process of the dynamic assessment method for rockburst risk is discussed. After evaluation，the results are consistent with the actual construction situation. The research can provide theoretical and practical guidance for the risk management of actual tunnel engineering construction and have good application prospects.

The stress distribution characteristics ahead of the hydraulic fracture under in-situ stresses will affect the fracture propagation and stimulation effect. In this paper，the mechanical behaviors and the tension-compression stress distribution ahead of the Mode-I fracture under in-situ stresses were studied using a self-designed visual fracturing experimental device. Based on the digital image correlation，a method to identify the boundary of the tension-compression zones ahead of the Mode-I fracture tip was proposed，from which the positive linear correlation was found between the tension zone length and the fracture tip opening displacement. Before fracture initiation，the range and length of the tension zone will increase with the stress intensity factor. During the fracture propagation，the range and length of the tension zone remain constant. With the increase of in-situ stress，the length of the tension zone will decrease，and the influence of in-situ stress on the tension zone will decrease. The boundary of fracture process zone and elastic zone in tension zone was investigated，and the position of fracture process zone and the tension zone was described. The concept of process zone index in the tension zone was proposed，which was found increase with in-situ stress，indicating that nonlinear fracture is dominant in the tension zone under high in-situ stress.

In order to overcome the“ten world-class technical problems”faced by the Central Yunnan Water Diversion Project and to solve the choking problem that affects the safe and efficient construction of underground projects，this paper discusses the disaster causing mechanism and summarizes research progress from the key issues of passing through the active fracture zone，water(mud) inrush disaster，TBM ultra long distance tunneling，and large deformation of soft rock，and further presents the theoretical guidance rules and breakthroughs in on-site construction technology. It is found that the treatment of relevant underground engineering problems needs to focus on the study of disaster geological discrimination and fine regulation，such as the advanced geological prediction technology system that has been applied in the Central Yunnan Water Diversion Project，the observation mode of“source pilot sensing＋wave field measurement in the tunnel”，and the auxiliary software for on-site rapid discrimination of TBM tunnel surrounding rock types. The key breakthrough lies in revealing the mechanism of disaster incubation and forming an efficient excavation virtuous cycle，such as the development of a 3D stress induced fault creep and dislocation simulation test device，optimization of main excavation parameters during TBM rock breaking process，and exploration of synchronous lining related technologies. Focus on mastering research on disaster control and related disaster warning，such as the applicability of support structures for red bed soft rock tunnels in central Yunnan，and the construction of a comprehensive stress-strain monitoring and warning platform for active fault tunnels in central Yunnan. In addition，the challenges faced by various difficulties are summarized and prospected to provide reference for the future research difficulties and development direction of Central Yunnan Water Diversion Project.

To address the long-term stability of water-related slope projects such as water conservancy and hydropower after excavation and unloading，the CDT1305–2 microcomputer-controlled electronic pressure test system and the YAW–3000A electro-hydraulic pressure test system were used to carry out the uniaxial compression and graded load creep tests of yellow sandstone after different pre-peak unloading and cyclic water intrusion. Taking the undamaged state of the rock as the base state，the damage mechanics theory and the principle of strain equivalence after promotion are applied to construct the ，the macroscopic and microscopic coupled damage variable of the rock. The creep properties of the rock reloading under the action of different influencing factors are investigated，and the elastic-visco-plasticity theory is introduced to establish a new type of nonlinear creep damage model. The results show that：(1) After and pre-peak unloading，the internal vertical pores of the rock are gradually expanded and the transverse pores are compacted，resulting in the improvement of axial homogeneity，but after and pre-peak unloading，the internal vertical and transverse pores are further developed and widened，making the whole inhomogeneity of the rock more significant. (2) The rock creep damage angle α and the cracks gradually increase with the pre-peak unloading point，while the creep deformation shows a tendency to first decrease and then increase，and the level of creep stress increases with the number of cyclic water intrusion. (3) According to the deformation modulus evolution law in the rock creep process，the variables of global damage and local time-varying damage are defined to reveal the rock damage evolution mechanism，then the rock macroscopic and microscopic coupled damage variable are analysed and constructed，taking into account the effects of pre-peak unloading，cyclic water intrusion and creep loading. (4) A nonlinear creep damage constitutive model is established by combining the nonlinear components and damage processing，and the model identification and validation are carried out based on the experimental data，which can not only satisfy the whole creep process damage evolution law，but also accurately describe the nonlinear deformation law in the stage of accelerated creep. The results are of great significance for the prevention and control of creep-type landslide disaster following the excavation and unloading of wading and high steep rocky slopes.

In order to study the influence of confining pressure on the strength characteristics and failure characteristics of rock mass with cross cracks，considering the influence of crack penetration ratio，initial static load and strain rate，a biaxial dynamic and static combined loading test was carried out by using the biaxial Hopkinson pressure bar(BHPB) test system. The deformation process of the sample was analyzed with the help of digital image correlation(DIC) technology，and the strength characteristics，energy dissipation and fracture properties of cross-jointed rock mass were studied. The research results show that the dynamic strength and peak strain in the direction of the maximum principal stress decrease with the increase of the maximum principal stress or stress difference，but increase with the increase of the intermediate principal stress or strain rate，while the dynamic stress and peak strain in the direction of the intermediate principal stress show the opposite trend. With the increase of the differential stress，the energy loss per unit volume increases. With the increase of the crack penetration ratio，the dynamic strength of the sample decreases，and the energy loss rate increases significantly. The primary and secondary crack penetration ratio determines the final failure mode of the sample，when the penetration ratio of the cracks is small，the crack initiation-expansion of the cross-jointed specimen is mainly controlled by the main cracks. When the penetration ratio is greater than 0.67，the interaction between the primary and secondary cracks is obvious，and the formation of the sample is composed of primary and secondary multiple fracture surfaces composed of anti-wing cracks and coplanar cracks. Under the action of bidirectional constant pressure，the anti-wing cracks penetrate at the tip of the primary and secondary cracks of the sample，and finally show shear failure. Under the two-way unequal confining pressure，the test sample presents delamination，peeling and block failure approximately perpendicular to the direction of the minimum principal stress，and the overall performance is compressive shear failure.

Injecting low-temperature water into high-temperature reservoirs during geothermal exploitation of deep hot dry rocks will change the permeability of reservoir rocks，which will directly affect the heat recovery efficiency of the enhanced geothermal system(EGS). To explore the variation characteristics and evolution mechanism of the permeability of hot dry granite after water cooling，permeability tests were conducted on hot dry granites under different cooling rates through a fully automatic gas permeability test system，based on which the influence of confining pressure and loading path on the permeability of granite was analyzed. The microstructures of hot dry granite were observed by polarization microscope and computed tomography(CT)，so that the two-dimensional and three-dimensional microstructure change characteristics can be discussed，and the permeability evolution mechanism can be revealed. The experimental results show that：(1) The permeability and seepage flow rate of hot granite gradually increase with the increase of temperature under different cooling rates，and the permeability and seepage flow rate of granite under the condition of water cooling are always greater than those under the condition of air cooling，while the minimum seepage pressure showing the opposite trend；(2) The two-dimensional microcrack density，average width，and three-dimensional porosity of granite under different cooling rates continuously increase with temperature，and the values of microcrack density，average width，and porosity under water-cooling conditions are always greater than those under nature cooling conditions；(3) The changes of granite permeability under different cooling rates are mainly related to the evolution of microcracks inside the rocks，which are mainly caused by the non-uniform mineral expansion and internal physical and chemical reactions. Water cooling further promotes the increase of permeability of hot dry granite；(4) As the confining pressure increases，the permeability of hot dry granite under different cooling rates shows a negative exponential decrease trend，and the permeabilities of granite under unloading conditions are much lower than those under loading conditions. The experimental results are expected to reveal the permeability evolution mechanism in the process of deep hot dry rock geothermal exploitation and provide reliable parameters for EGS thermal recovery simulation.

In deep hole blasting，the initiation position plays a decisive role in determining the propagation direction of the shock wave，subsequently influencing the distribution of the explosive stress field and rock fractures. Leveraging the superposition principle proposed by Starfield，the propagation and superposition rules of the explosive stress field generated by chain-like spherical charges are derived. This forms the basis for constructing an equivalent cylindrical explosive model. By introducing a delayed loading method for the chain-like spherical explosives，numerical simulation of stress fields is carried out through the superposition of cylindrical explosives using the discrete element method. The focus is on investigating the directional effects on the distribution pattern of rock fractures under different propagation directions. The findings indicate that due to the phase delay of explosive stress waves，a significant directional effect is present in the superposition of stress waves from cylindrical explosives and in the distribution of fractures. The superposition of stress waves is stronger along the propagation direction，with the growth rate of superimposed stress amplitudes increasing initially and then diminishing. The range of fracture distribution also gradually expands along the propagation direction. For different propagation directions，when blasting occurs from the bottom or top sides individually，fractures generally exhibit a“funnel-shaped”distribution along the propagation direction. When blasting occurs simultaneously from both ends towards the center，fractures are most developed near the center of the borehole，exhibiting an overall“spindle-shaped”distribution. When blasting initiates from the center towards both ends，fractures are slightly broader near the ends of the borehole，indicating a relatively uniform overall distribution. The fracture distribution patterns aptly mirror the distribution laws of superimposed stress fields under different blast propagation directions. The superposition effects of the equivalent cylindrical explosives under different propagation directions provide a rational explanation for the development and evolution of fractures within rock formations，thus revealing the underlying mechanisms of the directional effects.

Stability of rock slope with weak interlayers is controlled by weak interlayers and rock mass. There are obvious differences in geological model，failure mode and stability analysis method between rock slope with multiple and single weak interlayers. With the employment of associated flow rule for the upper interlayer and non-associated flow rule for the rest，the upper bound method is used to construct sliding mechanism of rock slope with double weak interlayers based on traditional plastic theory and the generalized plastic theory and，thus the calculation method of stability coefficient is proposed in this paper. The minimum value of stability coefficient is solved and corresponding failure mechanism of the slope in the limit equilibrium state is drawn based on the sequential quadratic optimization algorithm through an example from an engineering. Calculation is compared with the results of 3DEC discrete element numerical analysis. The results show that the larger the inclination angle of double weak interlayers is，the closer the sliding surface is to the top of the slope，and the more unstable the slope is. The theoretical method presented in this paper is in good agreement with the numerical results to verify accuracy of proposed method.

Rock masses consist of nesting rock blocks with various scales separated by weak structural layers，and their complex hierarchical structures play a significant role in dynamic deformation and stress wave propagation. In this paper，based on the Cosserat theory，a dynamic model of pendulum-type and rotational waves in blocky rock mass with complex hierarchical structures is established to determine the influence of hierarchical structures on dynamic deformation. Then，aiming at low-frequency and low-velocity characteristics of pendulum-type waves，dispersion equations of waves are determined and solved in different hierarchical structures based on the Bloch theorem，and furthermore，the dispersion relation and velocity characteristics of waves are investigated. Finally，mechanism of low-frequency characteristics of pendulum-type waves is revealed on the basis of solid energy band theory，and the possibility of pendulum-type and rotational waves inducing rock bursts is discussed based on the research results. It is indicated that ignoring higher-order hierarchical structures of rock masses may underestimate displacement and overall deformation of rock masses，resulting in unsafe numerical results. Under the action of long wave disturbance，for the first mode pendulum-type waves(the acoustic branches)，the dispersion is not significant and propagation velocity decreases，and higher-order hierarchical structures inside rock masses hinder the wave propagation. However，the dispersion of other waves(the optical branches) is significant so that they hardly exist and propagate independently. The low-frequency pendulum-type waves are dominant，which have slower attenuation and longer propagation distance than the high-order mode waves and traditional P and S-waves.

Studies show that the stability of gangue side surrounding rock in gob side entry retaining by roof cutting affects the formation effectiveness and reusability of roadways. In this regard，various methods such as on-site investigations，theoretical analysis，and engineering experiments are widely employed to study the pressure bearing and deformation of the gangue side surrounding rock and support body. According to on-site investigations on the test section，the load formed on the gangue side support during the process of gangue collapse can be divided into dynamic load caused by the initial gangue collapse，analogous static load caused by slow compaction of gangue in the middle stage during the formation of roadway，and quasi static load originating from the stability in the later stage during the formation of roadway. A model was established to calculate the lateral pressure of the gangue side. The obtained results revealed that the lateral pressure of the gangue side increases from the roof to the floor. Then a correlation between the lateral pressure of the gangue side with the overlying rock pressure，internal friction angle of the gangue，gangue broken bulk coefficient，roof cutting height，and roof cutting angle was developed. A mechanical model was established to simulate interaction between the roof and floor of the roadway，the gangue side support，and the surrounding rock of the gangue side. The present study focuses on the influencing factors on the deformation of gangue side support and demonstrates that the lateral pressure on gangue side support was the internal cause of instability. Based on the obtained results，the construction of gangue side support was optimized and the linkage coupling support effect of single hydraulic prop and composite U-shaped steel was enhanced. The theoretical results were verified through on-site monitoring. The performance of the gangue side control demonstrated that the proposed optimized scheme effectively controls the surrounding rock deformation.

To explore the asymmetric failure characteristics of layered soft rock tunnels in complex and difficult mountainous areas，and to propose reasonable construction deformation control technologies for layered soft rock tunnels under different large deformation grades，by taking a typical layered soft rock tunnel of Jiuzhaigou—Mianyang expressway，a large deformation grade classification standard for layered soft rock tunnels in complex and difficult mountainous areas was established as the engineering background. Then a series of studies were conducted on the influence of construction methods and support patterns on the mechanical behavior of layered soft rock tunnels under different large deformation grades through model tests and numerical simulations. The research results indicate that the most unfavorable position for the spatial asymmetric distribution of stress and deformation in layered soft rock tunnels is located in the normal or tangential position of the bedding plane due to the coupling effect of stress field and soft bedding direction，and the asymmetric mechanical characteristics of the tunnel become more obvious with the increase of large deformation grade(slight，medium and strong). Additionally，there are differences in the improvement effects of construction methods and support patterns on the deformation and stress of layered soft rock tunnels under different large deformation grades. Therefore，for three types of layered soft rock tunnels with large deformation grades，the recommended construction deformation control technologies for two-step construction＋single-layer primary support＋short rock bolt support，three-step construction＋single-layer primary support＋long and short rock bolt support，and three-step reserved core soil construction＋double-layer primary support＋long and short rock bolt support were proposed separately.

The analysis of uplift failure mechanism for underground lined rock caverns is of significant importance for improving the storage capacity and safety of hydrogen. In this paper，the functions of the uplift failure lines in layered rock formations and the expressions of critical uplift pressure( ) are derived based on the Hoek-Brown strength criterion and the upper bound method of limit analysis. Subsequently，the analytical solutions are compared with numerical simulations. On this basis，the influence laws of shape and layout parameters of the caverns on the  and uplift failure lines are investigated. The results show that the error range of between the theoretical and numerical solutions are within the range of 1.57%–2.20%，and the ranges of uplift failure are essentially the same.  is directly proportional to the additional loads and cavern spacing，while inversely proportional to the cavern radius. Besides， exhibits the highest sensitivity to the additional loads，followed by the cavern radius，while the lowest sensitivity to the cavern spacing. The horizontal distances between the uplift failure lines at the layered interface are directly proportional to the thickness of the rock layers. Similarly，the gaps between the horizontal uplift failure ranges at the surface are also directly proportional to the thickness of the rock layers. In the selection of the storage sites of lined rock cavers，the cohesion and internal friction of soil can be considered as the safety reserve. Additionally，the influence of the cavern radius on and the capacity for hydrogen storage should also be comprehensively considered. Furthermore，sites with geological tectonic defects should be avoided based on the range of uplift failure lines. The research results hold significant guidance for the selection of hydrogen energy storage sites and the design of cavern shapes in layered rock formations within lined rock caverns.

The Jiangpinghe concrete faced rockfill dam is a tall dam of 200 m height located in a karst valley. During construction and reservoir impoundment，cracking of concrete face slabs occurred and an abnormal pressure rise was observed in the dam foundation downstream of the grout curtains，leading to an urgent need to reevaluate the safety of the seepage control system. Inspection borehole packer tests，inverse modelling and cross-correlation analysis were used to investigate the seepage characteristics through the dam and its foundation. On this basis，the performance of the concrete face slabs and the grout curtains was systematically assessed，and the mechanisms causing the local pressure rise in the dam foundation were clarified. The results show that the face slabs，though having a permeability 3.6 times higher than the design value after cracking and seepage treatment，perform well for long-term safety operation. The quality of the seepage control treatment at the karst foundation satisfies the design requirements，which limits the amount of leakage at a sufficiently low level. The local pressure rise in the dam foundation can be attributed to the hydraulic connection through a fault(at the left bank) and depositional contact zones(at the right bank)，both of which have enhanced permeability due to groundwater erosion and provide channels for quickly transmitting the reservoir pressure towards downstream across the grout curtains. Although the grout curtains effectively reduce the leakage through the dam foundation，they are not able to completely inhibit the pressure transmission，hence making the abnormal pressure rise occur around the eroded channels. The results are of great significance for completion acceptance and safety evaluation of the Jiangpinghe Hydropower Project.

In order to research the mechanical properties and damage characteristics of low-temperature soft rock under unloading，triaxial loading and unloading tests of frozen sandstone(temperature －5 ℃，－10 ℃ and －15 ℃) at different initial confining pressures and unloading rates were carried out by using GCTS low-temperature rock triaxial machine，which was compared with conventional loading tests. By obtaining the stress-strain curve during the whole experimental process，the mechanical properties and deformation characteristics of unloaded frozen sandstone were analyzed. The failure characteristics of sandstone were studied. The results show that：(1) The failure mode of unloaded frozen sandstone is a combination of shear failure and splitting failure，and the main failure mode is splitting failure. At high initial confining pressure and high unloading rate，the brittle characteristics of the rock sample are obvious，and the failure is more severe. (2) The peak strength of unloaded sandstone is generally lower(about 1/4 times) than that of conventional sandstone，but the residual strength is exactly the opposite，and both strength values are linearly positive correlated with the initial confining pressure. The elastic modulus of unloaded sandstone is about 1.5 times that of conventional sandstone，while the Poisson?s ratio is 2–4 times. (3) The deformation and dilatation of frozen sandstone are obviously increased by unloading. The pre-peak stress strengthening effect and post-peak stress weakening effect of stress-strain curve are weakened，and the post-peak stress appears horizontal section. (4) Unloading affects the mechanical strength of frozen sandstone mainly by reducing cohesion and increasing internal friction angle. With the increase of unloading rate and the decrease of temperature，the peak strength and elastic modulus of frozen sandstone increase，while the deformation，Poisson?s ratio and residual strength decrease. Based on the equal strain hypothesis of damage mechanics and Weibull distribution，the unloading damage constitutive model suitable for frozen sandstone is established，which can effectively reflect the lateral unloading mechanical characteristics. The research results can provide important reference for the study of mechanical properties of low temperature soft rock and its engineering application.

To solve the problem of anti-floating stability of shallow buried underground utility tunnel structures in liquefiable soil，a support and anti-floating device designed to control the displacement of underground utility corridors is introduced. Through multiple sets of shaking table model tests，the operational performance of the LS-type support and anti-floating device under liquefied soil conditions is validated. Additionally，the impact of the spacing between steel sheet piles and the inclination angle of diagonal bracing plates on the performance of the support and anti-floating device is investigated. Furthermore，the anti-floating mechanism of the support and anti-floating device under liquefied soil conditions is elucidated. The results indicate that during the process of soil liquefaction in the foundation，the soil pressure on the bottom of the corridor gradually increases，while the soil pressure on the top of the corridor rapidly decreases，leading to the instability and uplift of the corridor. The LS-type underground utility corridor support and anti-floating device effectively mitigates the uplift problem caused by soil liquefaction in the foundation and reduces the strain response of the corridor. When using a spacing L = 150 mm between Larson steel sheet piles and an inclination angle of diagonal bracing plates of = 45°，the structural forces and deformations of the utility corridor are relatively small. The conclusion can provide reference basis for the anti-floating stability of underground utility tunnel.