In this paper，the author puts forward its own views and suggestions in view of the several current key problems in the development of rock mechanics. First，this paper involves the stability problem of soft surrounding rock and hard rock mass related to high ground stress. Second，it studies jointed and fractured rock masses，some nonlinear weak surrounding rock and support，which deals with the fracture mechanism of complex rock mass and the influence of construction process. Third，the role of model test method is discussed，and the model test should be mainly applied in the problems，where the numerical analysis effect is not good. Fourth，the problems existing in the numerical analysis method are discussed，giving respectively applicable conditions，the existence question and the possible solutions，especially the solving thoughts that the current discontinuous analysis method cannot solve large engineering problems. Also for complex constitutive relation of rock mass，the research idea in the future are proposed. Finally，the author puts forward his own idea and suggestions on several other hot and difficult problems，including the idea nondeterministic analysis method as the criterial rock stability and discontinuous analysis method of seepage problems for the true stress-water couple model of jointed engineering rock mass should be developed.

Based on the relationship of the local failure and impact energy factor on the high-speed impact，the theory of energy equivalence and its formulation for average vibration of deep rock mass disturbed by excavation or explosion are first proposed in this paper. The physical foundation of the non-dimensional energy condition that quasi-resonance and pendulum-type waves occurring is interpreted，and the condition is defined as the ground shock energy factor in this paper. The occurring conditions for engineering disasters such as rock burst and zonal disintegration are derived using this theory. Also，the safety depth of protective engineering is defined by the theory combined with propagation laws of underground blasting waves. The research shows that the ground shock energy factor reveals a new way for understanding the complex mechanism of the static and dynamic phenomenon for deep rock mass.

There are fuzzy mechanical concepts，irrational methods of design and construction for anchored structures in ground in China. Which frequently lead to diseases and accidents，such as anchor failure，instability and even collapse of these structures. According to the geotechnical investigation of typical engineering and engineering accidents，theoretical analysis and experimental studies，some mechanical conceptual problems are studied which is significantly affected the stability and healthy development of ground anchorage engineering，in order to improve the construction level of ground anchorage engineering and provide a basis for improving ground anchoring engineering safety and economy，The main researches are as follows：(1) The prestressed anchor has the advantages of providing active resistance and transferring tensile stress of structures to the deep stable strata，which can be widely used to resist dumping，vertical displacement，shear failure along foundation base and openings collapse. (2) The anchor tendons section requirements of Adapting to tension stress control，enough anchor free length and anchoring formations fully mobilizing the ground shear strength of surrounding anchor roots are the basic elements for high tensile bearing capacity of anchors. (3) pressure- dispersive anchor significantly improves the load transfer mechanism and anti-corrosion protection performance and has excellent mechanical and chemical stabilities. (4) The timing lag of constructing anchors can be effectively controlled and avoided after excavation in the slopes and openings by timely applying tensile anchors and developing prefabricated reinforced concrete blocks as the high bearing capacity transfer structures. (5) In order to improve the stability of large openings in high stress and low-strength rock，It is necessary to adopt low prestressed anchors as initial support，strictly control the timing lag of constructing anchors，improve the initial prestressed value and strengthen the surrounding rock deformation—anchorage resistance(stiffness) interaction process control efforts.

The beach calcarenite is a sedimentary rock deposited at tidal beaches of coral reefs in South China Sea. It is consisted of coral sands that predominantly cemented by the carbonite calcium materials under tropical or sub-tropical marine environments. The beach calcarenites are also deposited in some of the coastal areas in Southern China. The research on the geotechnical engineering properties of beach calcarenites has a significant theoretical and practical impact on the safeguarding of our marine sovereignty and the development of defense facilities in the area. This paper studies beach calcarenite samples that collected from different locations in the South China Sea and the coastal area by using both micro and marco structure study measures. The objective of these studies is to establish the major parameters that control the mechanical strength of the beach calcarenite as well as to provide necessary theoretical guidelines for the further researches. The results indicate that，the beach calcarenite is characterized by the low unit weight，high porosity，and large permeability. The degree of cementation of the beach calcarenite is in between weak and medium. The measured uniaxial compressive strength under the air-dry condition varies from 2.02 to 19.39 MPa. It is evident that the saturation of beach calcarenite samples will reduce its uniaxial compressive strength with a softening coefficient varying from 0.45 and 0.96. In general，a smaller softening coefficient in the beach calcarenite sample correlates with a weak cementation. The tested tensile strength of beach calcarenite samples under the air-dry condition is between 0.62 and 2.52 MPa with a ratio of compressive to tensile strength varying from 3.08 and 9.14. The range of compressive to tensile strength of beach calcarenite samples is lower than that of rock samples from land origin，which is between 8 and 12. The differences in the compressive to tensile strength ratio might reflect the differences in the sedimentary conditions of different rock samples. The correlation analyses of parameters indicate that the unit weight and the cementation are major parameters affecting the compressive strength of beach calcarenite samples. Stronger cementation in samples results in a higher strength. Both porosity and grain size in samples are secondary parameters with an insignificant effect on the compressive strength of the beach calcarenite.

Experiments on acoustic emission(AE) characteristics in two frequency channels of the full failure processes in granite specimens under the different confining pressures are carried out through the load test in laboratory. The granite mechanical properties and AE characteristics in low and high frequencies are obtained. The relationship of AE ringing counts，AE accumulative energy，stress and time are analyzed. The distributions of AE signal peak frequencies before the main fracture of the granite are study in detailed. The results show that the AE basic characteristics in low and high frequencies are develop similarly during the granite failure. And they well match with the mechanical properties. The main difference between the AE basic characteristics in low and high frequency channels is the numerical value. In AE spectrum signatures side，the feature of AE peak frequency just before the rock main crack is the number of main frequency ranges increase. It shows that the peak frequencies disperse from one or two frequency ranges(40–50 kHz and 150–170 kHz) to five different ranges(25–30 kHz、40–50 kHz、60–70 kHz、90–100 kHz and 150–160 kHz).

Research on rock materials during saturation process for the change regularities of velocity and electrical resistivity and the interrelation between them is significant in practical engineering，such as the judgment of rock physical properties，the comprehensive analysis and interpretation of geophysical data and so on. However，mineral composition，existing fissures and other factors of the rock sample often affect the experimental results. In order to prevent these influences，cement mortar is used to make 30 rock-like samples with different porosity. The changes of velocity and electrical resistivity for different samples were tested to reveal the change regularities of velocity and electrical resistivity with saturation and porosity. The theoretical formula among wave velocity，saturation，porosity is obtained by applying Gassmann equation based on the Wood theoretical assumption，but compared with the test results，it cannot describe the characteristic of wave velocity rapidly rising after the saturation reaches threshold value. A reasonable assumption considering the gravity effect to the distribution of pore water in the sample is made，the formula among wave velocity，saturation，porosity in the saturation process is modified，and it is nearly in accordance with the change characteristics of experiment data. Meanwhile Archie formula of unsaturated rock resistivity model is well used to fit the change rule of resistivity varying with saturation and porosity. On this basis，according to the problem that the past relationship between wave velocity and resistivity only consider porosity，the influence of porosity and saturated state is taken into account，and the relationship between wave velocity and resistivity is founded using porosity and saturated state as a bridge. It can provide a better fit to the real data，and the rationality is validated through experimentation with the protolith of limestone.

Physical information monitoring are significant for the prediction of dynamic disasters such as coal and gas outburst under the unloading process of coal rock. The gas permeability and charge induction experiment have been done under the confining pressure unloading of containing-gas coal rock by using the charge collection device independently developed. The results show that the gas permeability characteristics and charge induction regularity closely associate with the deformation damage in the process of the confining pressure unloading of containing-gas coal rock. With the increase of confining pressure unloading rate，a large number of micro crack propagation，the coal rock deformation damage has been promoted，the mutation probability from partial bound charge to free charge increases in the internal cracks of coal rock，the inductive charge has a significant increase produced in the main rupture process of coal rock. The confining pressure unloading weakens the hoop restrictions of coal rock. New gas channels are added inside coal rock and it makes the permeability of coal rock increase. Streaming current formed by the friction action between coal particles carried by gas and coal rock holes wall. It contributes additional amount to the coal rock charge signal and enhances the charge signal.

Rockburst is a dynamic geological disaster often encountered during the excavation of deep hard rock tunnels，and structural plane is found playing an important role in controlling the rockburst in deeply buried tunnels of Jinping II Hydropower Station. On the basis of summarizing the present research status and enumerating the typical cases of structure-type rockburst，controlling roles of different structural plane types，occurrence，and different production environment，construction methods and other conditions on rockburst are analyzed and a structure-type rockburst classification method is proposed based on different mechanisms. Analyses show that structure-type rockburst can be classified into slip burst，shear rupture burst and extensile spalling burst；extensile spalling burst can be easily induced by vertical occurrence structural plane in sidewall which makes surrounding rock suppress to tensile crack，while slip burst or shear rupture burst can be induced by structural plane of inclined occurrence；the intensity of shear rupture burst evoked by unexposed inclined structural plane may be higher than that of slip burst induced by exposed plane under the same condition；large scale slip burst mainly occurs in mining engineering，while small scale slip burst is more prone to take place in hydropower and traffic tunnels，and structural planes control the depth and boundary of the crater as well as dimension of ejecting blocks；for structure-type rockburst dominated by shear failure，energy released from the burst is partly determined by mechanical properties and strength characteristics of the structure plane，which affects the intensity of the burst. The research result will contribute to mechanism understanding and controlling method for structure-type rockburst in deep hard rock tunnels.

To improve efficiency of construction and reduce the risk of site construction personnel and equipment，the 1#，3# diversion tunnel of Jinping II hydropower station adopt large-section TBM for construction. The full-section TBM construction under large buried depth，when encounter strong grade rock burst，it still may bring some damage to TBM equipment. Therefore，through the real time microseismic monitoring and numerical analysis，study the influence of TBM excavation scheme、heading construction on the risk of rock burst. The results show that，lowering the rate of construction，can reduce the risk of rock burst；pilot excavation and TBM joint construction is advantageous to prevent strong grade rock burst. The research results can provide important reference value for the safe and rapid excavation of TBM，will also provide reference for other similar project，it has an important engineering value.

It presents the in-situ tests on excavation damaged zone(EDZ) evolution of high sidewall surrounding rock mass in Houziyan hydropower station using microseismic monitoring and conventional testing methods such as multiple position extensometers，acoustic wave test and borehole TV. Firstly，through analyzing a series of conventional testing and microseismic monitoring results，deformation and failure characteristics of surrounding rock mass are revealed，and the evolution processes of surrounding rock fractures such as initiation，coalescence and extension are obtained during excavation unloading processes of underground powerhouse. Afterwards，the relationship among EDZ of surrounding rock mass，cracks evolution and construction status are also analyzed，which makes it possible for the whole procedure of cracks formation，development and close to be obtained. Finally，the depth of EDZ is recognized；the relationship between fractures evolution and construction progress is given；And the formation and evolution mechanism of EDZ is discussed as well. It will not only provide the direct data for geological exploration but also contribute greatly to excavation and support design and analysis of deformation behaviors of underground powerhouse. Some references can be thus provided for design and construction of similar underground engineering.

The macro-crack distributed in the rock mass continuously worsened after excavation，which may resulting the crack connect to each other and form macroscopic fracture in some areas，and could make the slope become unstable. The slope excavation process of each step is equivalent to the process of applying a distributed load in the excavation face and gradually reduced to zero. During the process of equivalent excavating the slope，the crack near the slope free surface within a certain range will be in the state of tension-shear stress. Based on the continuum mechanics，and combining with the damage mechanics and the fracture mechanics，the constitutive model of damage evolution are solved under the tension-shear stress state. The macroscopic bulk modulus are used to reflect the damage degree of rock，and the destruction degree are defined to represent the destroyed characterization in the actual rock mass. Based on the principle above，The calculation of fractured rock unloading damage model is programmed by using the interface of the FLAC3D. The excavation simulation of Guangxi Fengshan limestone building material mine is studied by the new model. The results of the displacement values and the plastic area under two conditions which are using and do not using the new model are calculated and analyzed. The validity of the new model are proved and the real situation in the slope are more accurately reflected. Using the destruction degree to indicate the damage of the rock mass can be more intuitively and accurately determined the rock mass stable state are proved by comparative analyzing the damage degree and the destruction degree after excavating the rock slope.

Creep deformation and stress relaxation are the intrinsic time-dependent properties of rock mass， and are close to long term stability of rock project. The consistency of creep and stress relaxation is discussed within framework of Rice irreversible thermodynamics with internal state variable. The fundamental thermodynamic equations are developed by giving specific complementary energy function and kinetic laws of internal state variables. The creep constitutive equation and stress relaxation equation are constructed based on those fundamental thermodynamic equations with different constraint conditions. Some classical viscoelastic equations from component models are covered in proposed viscoelastic constitutive equation and hardening effect is considered in the viscoplasctic creep equation. Creep and stress relaxation characterize the same non-equilibrium evolution of microstructure within material and are consistency in essence. The creep and stress relaxation equations can be transformed each other and the parameters in those two equations are all the same. So the relaxation properties can be analyzed through creep constitutive equation and creep test. This point is validated by uniaxial creep and stress relaxation tests of analogue material used in geo-mechanical model test.

Based on the self-developed digital image analysis software and the digital image correlation method，the deformation and failure characteristics of rock-like materials with pre-existing single flaw is experimentally studied under uniaxial compression. The law of crack initiation and propagation and the evolution properties of rock damage are analyzed and summed up quantitatively on meso-level from the perspective of the global strain field on the surface of specimen. Besides，FRANC2D/L，a fructure analysis software，is applied to a numerical model corresponding to the experimental specimen to simulate the path of crack growth and the corresponding distribution of stress field at different stages in the whole process of loading. Combining the results of experiment and simulation，the inner link between microscopic mechanical mechanism and macroscopic mechanical response of flawed rock is discussed，which provides a deeper understanding to the disaster mechanism of jointed rock mass engineering.

Bedding has a great influence on the macroscopic and microscopic mechanical properties of coal. In order to explore damage evolution and AE characteristics of coal with different bedding plane direction during the deformation and failure，coal samples are prepared as two types，i.e. axis parallel to bedding plane direction and vertical to bedding plane direction. Experiments on acoustic emission characteristics of full-regime failure of samples under uniaxial compression，are carried out by the MTS815 rock mechanics and the PAC AE testing system in laboratory. Effect of bedding plane direction on characteristics of AE time parameters and energy release，AE location distribution and AE amplitude distribution are revealed. The results show that compared to the samples with axis vertical to bedding plane direction，AE ringdown count and energy release of samples with axis parallel to bedding plane direction are stronger during the whole loading process，while AE ringdown count and energy release in unit time are smoother. Coal samples with axis vertical to bedding plane direction present the fiercer energy release characteristics；A mount of AE events are produced at lower stress level in the samples with axis parallel to bedding plane direction，where AE location distribution are more homogenous，and there are no nuclear phenomena；For the samples with axis parallel to bedding plane direction，during the deformation and failure ，the variation of AE amplitude distribution is smaller，b value is greater and proportion of big AE events is smaller. To a certain extent，experimental results show bedding plane direction has an obvious effect on AE features of working face and overlying coal during process of mining，and also provide the references for monitoring the state of surrounding rock by AE technique in the field.

With a reflected caustics experiment，the dynamic fracture induced by impact loading of some specimens was studied. These specimens processed by mirror transplantation，were made of natural metamorphic rock including white marble，slate and griotte，and rock-like materials including man-made rock and harden cement paste. The results show that the caustics spot of rock-like specimens were recorded at the crack tip，wherever natural rock specimens were not. Then another test to these specimens，which were not processed by mirror transplantation，was carried out with a high-speed photography directly. It is shown that there is a“white banded crack”arising at the surface of natural metamorphic rock specimen，which is different from the rock-like specimen. By contrasting the crack initiation time and propagation velocity between the caustics and high-speed photography test，it is concluded that the micro-crack development and propagation of the natural metamorphic rock specimen processed by mirror transplantation could not be recorded by the reflected caustics，and the transplanted mirror conceals the phenomenon of micro-crack development and propagation，which means that the caustics study on natural metamorphic rock is very difficult.

Supercritical carbon dioxide(SC-CO2) jet breaking shale is a prominent shale gas drilling method. The shale sample of Longmaxi Formation was collected from southeast of Chongqing area. Based on the experiment platform of SC-CO2 jet breaking rock，the collected shale samples were impact by the SC-CO2 jets with varied jet pressures. The micro changes between original and eroded shale samples were studied utilizing CT，SEM/EDX，XRD and XRF methods. It’s indicated that the collected shale is characterized by low porosity，high clay mineral content and concordant bedding；impacted by SC-CO2 jet，the end face of shale core take on grid-like broken phenomenon，while it takes on large volumetric layered broken phenomenon on the whole；the erosion of shale mineral induced by SC-CO2 may caused the changes of micro-structure of shale，which may reduce mechanical strength of shale and is conducive to the rock breaking.

According to the theory that the mining stress is the extrinsic impetus for coal and gas outburst，the micro-seismic monitoring system has been constructed to respond to the activities on the coal roadway mining. The process and its main causes of coal caving were analyzed，the characteristics responded by micro-seismic activities on the coal and its roof ruptures were studied. The monitoring system which is combined by sensors with three different levels of sensitivity is aimed to acquaint entirely the change law of mining stress emergence and development. Based on the selection of Wavelet basic function，the total signals which number is 396 activated by mining effects within half an hour were decomposed and reconstructed on the method of Wavelet packet into 4 layers based on the frequency sequence. The micro-seismic signals activated by mining were divided into four categories such as blasting，coal caving，roof and coal wall ruptures signals according to mining sequence and frequency band，and the change tendency of roof and coal wall ruptures events was analyzed on the normalized frequency energy. Coal caving and roof ruptures are caused by blasts；the roof pressure can lead to coal wall ruptures as well. Roof ruptures as well as coal wall ruptures represent the mining stress definitely. Roof pressure in the early stage responds tempestuously，which causes five sections of coal caving within 1.6 seconds after blasting，reached the peak after 1.933 seconds and stabilizes 24.89 minutes later；roof ruptures events are mainly concentrated in the early 2 minutes and its corresponding events rate is 76.2%. Comparatively，coal wall ruptures react with delay of 5.8 seconds relatively to roof pressure，reach the peak after 3.71 minutes and stabilizes 29.217 minutes later；coal wall ruptures events are mainly concentrated on the early 5 minutes and its corresponding events rate is 45.9%. Roof and coal wall ruptures events and the change tendency of its own normalized energy on the dominant frequency band disclose the process of transformation and adjustment of mining stress，and the result that the coal body itself can get stable or not responded by the mining effect can be used to predict and early warn the coal and gas outburst，which needs further thorough research.

Based on four pull-out creep tests of full-length bonding thread GFRP anti-floating anchors under long-term load，the creep mechanics model of pulling anchor has been established，and the creep mechanics parameters of the model were derived and the correctness of the model was validated in this paper. In addition，the concepts of the time damage effect were developed; the long-term pull-out strength of GFRP anti-floating anchor has been obtained. The experimental results demonstrate that， in moderately weathered granite，creep behavior of GFRP anti-floating anchors occurred under the ultimate load of 40%，and the creep properties of GFRP anti-floating anchor are excellent under the low load level which meets the needs of projects. The Burgers model can well describe the creep law of GFRP anti-floating anchors，and the predicted results are consistent with the experimental results，and that the mechanical parameters in the Burgers model are reduced gradually with the increase of drawing load. It has better applicability that creep damage model is used to predict the long-term pull-out strength of GFRP anti-floating anchors.

This article is aimed to solve the similar-transformation problem in using freezing pipes as the heat sink in the freezing model test. Considering the heat exchange between the flowing brine and the freezing pipe is the convection boundary condition，the similarity criterion between the prototype and the model is derived according to the theory of similar simulation. Theoretical analysis shows that the similarity of freezing pipe between prototype and model could be satisfied only if the product of geometric scale ratio and convection heat transfer coefficient scale ratio is equal to thermal conductivity scale ratio of frozen soil. Coefficients of forced convection heat transfer formula for brine at －30 ℃(Reynolds number in 533～2 143) was obtained in the experiment. The results of similar model test show that it is necessary to set brine flow rate of the freezer model in model experiment based on heat sink similarity criterion of freezing pipe in addition to setting brine temperature，especially under laminar condition. Some error would occur in model temperature field if the actual brine flow rate is larger or smaller than the setting value.

The bearing mechanism of the large diameter monopile and the one with wings is studied through centrifuge tests. Based on the large diameter monopole which is widely used in the offshore wind turbine，the wings are added with the large diameter monopole in order to use the soil resistance of the shallow soil as far as possible. Nine centrifuge tests are conducted for the sake of studying the horizontal bearing capacity of the large diameter monopile with wings. The horizontal bearing capacity h changes as the dimension and the embedded depth of the wings and the loading direction are different. The study results show that the horizontal bearing capacity of the large diameter monopile with wings is much more than that without wings. The amplitude of the enhancement is in connection with the dimension and the embedded of the wings. The research results provide a reliable evidence for the design and construction of the large diameter monopile with wings for offshore wind turbine.

A small-scale 1-g physical modeling under unconfined condition，using transparent soil，was employed to observe the complete curves of buckling of fully embedded slender piles with different constraint types. Meanwhile，the soil deformations caused by buckling of slender pile were measured non-intrusively by combining particle image velocimetry(PIV) and close-range photogrammetry. The transparent soil was made of fused quartz and correspondingly refractive index matched blended oil. Transparent soil model was sliced using a laser light sheet，and digital images of soil deformations，caused by buckling of slender pile，were recorded. PIV was utilized to obtain the generated displacement fields. Analysis of test results shows that the relative buckling length increases with the increasing of pile strength and decreasing of slenderness ratio；the effect of end constraint types of pile on buckling curves is dependent on the variations of pile strength and slenderness ratio；the movements of soil elements agree well with the classic Rankine?s earth pressure theory.

Based on the large tonnage static load tests of 2 large-diameter and super-long bored piles in Guangdong soft soil area，bearing characteristics and transport mechanism of load are studied in this paper，and the measured results obtained from the tests provide precious data for theoretical research of large-diameter and super-long bored piles in Guangdong area. The results show that load-movement curves of the piles vary gradually. The test piles show the characteristics of friction piles because sharing ratios of pile tip bearing capacity are fewer than 15%. With the increase of pile top load，the increasing rate of relative displacement of piles and soil at certain pile body first increase and then decrease. The ultimate pile-soil relative displacements for completely mobilizing the shaft resistance are found to be about 17mm and 6mm separately in muddy silt clay and silt，22 to 27mm in sand，18mm to 23 in upside silty clay layers of pile. Shaft resistance of upside soil of pile is softened inordinately. The shaft resistance in downside silty clay layers of pile is about more than 87% of ultimate shaft resistance while pile-soil relative displacement is 40mm and increasing rate of the shaft resistance is gently as the relative displacement continues. With the increasing of pile-soil relative displacement，the shaft resistances of weathering sandstone is developing and not fully play finally. Pile side resistance increase as hardening type along with the increasing of pile tip settlement.

A new walking type static cone penetration which has strong penetration ability was invented. It can penetrate into the hard rock and soil layers such as strong weathered rock and reach the required exploration depth of end bearing pile and was called triple-bridge cone penetration which the total penetration force test was added on the basis of the double- bridge cone penetration test. A new accurate estimation method of piling pressure at the specified pile diameter and depth or embedded depth of pile at the specified piling pressure and pile diameter has been proposed after the comparative study between triple-bridge cone penetration test and pressure test of model pile，and The whole rock and soil are considered as a system. A new estimation method of ultimate bearing capacity of the end bearing pile in the pearl river delta region was summarized after the comparative study between triple-bridge cone penetration test and static loading test，and these methods fill the gaps in current code. The findings show that the triple-bridge cone penetration test which has strong penetration ability will provide very useful guidance to the design，construction and inspection of pile foundation.

In order to study the micropiles anti-slide mechanism by the step loading method on rectangular arranged intensive micropiles retaining system，a full scale lateral loading test and a numerical calculation on it were performed. On the basis of prototype test，a finite element model is established to analyze the lateral bearing capacity of the pile group by changing the design parameters like soil parameters，micropile elastic modulus，pile spacing and row spacing. According to the results，the front-row piles will not play the role in retaining until the landslide thrust force exceeds a certain value for a stratum of silty clay；the position of the earth pressure peaks in front of piles is deeper than the earth pressure peaks inside of piles；the lateral load bearing rate of the soil and the pile is 7∶3. Controlling the piles in optimal row spacing was more effective than optimizing other parameters in enhancing the lateral bearing capacity and reducing displacement of pile tip. The test result provides reference for further analysis on anti-slip system of intensive micropiles and optimization of engineering design.