Considering the energy consumption characteristic during the whole loading process of rock materials， a new rock burst proneness criterion was introduced based on the linear energy storage law and the residual elastic energy index. A series of uniaxial compression tests having one loading and unloading cycle were conducted on 14 kinds of rock materials(including six types of granite，two types of marble，four types of sandstone，a type of slate and a type of limestone) at different unloading levels. The values of total input energy density，elastic energy density and dissipation energy density of the rock specimens at different unloading levels were obtained with the graph integral method. The quantitative relationship between elastic energy density，dissipation energy density and total input energy density were investigated. A linear relationship between elastic energy density and total input energy density was found. The energy storage coefficient(the ratio of elastic energy density to total input energy density at different stress levels) is approximately a constant. Based on this linear energy storage law，a new method for calculating elastic energy density stored in rock before peak strength was thus proposed，and then the calculation method of energy impact index was modified firstly and a new rock burst proneness criterion based on the residual elastic energy index(the residual elastic energy index is defined as the difference between peak elastic energy density and failure energy density of post peak) was introduced. According to the failure characteristics of 14 kinds of rock materials，a classification standard of rock burst proneness in laboratory tests in terms of qualitative index and quantitative index was also put forward. The calculated results with the new rock burst criterion agreed with the actual rock burst proneness grade of rock materials.

The blasting in the holes detonated in the same delay in the process of tunnel drilling and blasting are regarded as the internal excitation load in a spherical cavity in infinite rock body and the natural frequency of a hollow sphere with an infinite external diameter is analyzed. The attenuation formula of the dominant frequency of blasting vibration in tunnel drilling and blasting excavation is deduced with the method of dimensional analysis， and is validated with the measured dominant frequency of blasting vibration in Pubugou hydropower station. According to the relationship between the charge weight and the radius of spherical cavity under the condition of spherical charge，another form of the proposed formula with the parameter of the radius of spherical cavity replaced with the charge weight has been used for comparison. It was found that the radius of spherical cavity was generally more desirable than charge weight for fitting analysis.

A one dimensional model for jointed rock is established and dimension analysis is carried out to investigate the effect of joints on stress wave propagation. For a single joint，the stress wave exhibited obvious time delay and amplitude attenuation，but there was no significant change in the main frequency. For multiple joints，the amplitudes of transmitted stress waves were reduced as the spacing and number of joints increased. The equivalent wave velocity in the jointed rock masses was reduced linearly as the number of joints increased. The influence of several joint parameters，such as the strength，stiffness，spacing and dip angle，on the blasting effect was discussed by using the Continuous-Discontinuous Element Method，which was then comprehensively evaluated in terms of several indexes such as the average fragmentation sizes，limit fragmentation sizes，percentage of massive blocks，system fragmentation degree and equivalent damage factor. The calculated results show that the blasting effect become worse gradually as the decreasing of strength(stiffness) of joint. When the strength(stiffness) of the joint is smaller than one thousandth of that of rock, the strength(stiffness) of joint has little influence on the blasting effect. When the strength(stiffness) of the joint is one thousandth of that of rock，the blasting effect is worse as the joints come closer，however，the dip angle of the joints has little influence on the blasting effect. Due to the fact that the blasting energy is trapped between the blast hole and adjacent joints during blasting in the jointed rock mass，the area near the blast hole is always over fragmented，whereas the area far away from the blast hole is under fragmented. A negative correlation is thus found between the development degree of the joints within the blasting area and the blasting effect.

The disorderly propagation of cracks formed by the traditional drilling blasting is liable to cause gas dynamic disasters when encountered with the tectonic coal and rock. Tunneling in structural coal and rock with directional concentrated energy blasting is studied in this paper. The mechanical model of rock fracturing under shaped energy blasting is established and the crack initiation and propagation under shaped energy blasting and ordinary blasting are compared and analyzed. The comminuted zone formed by shaped energy blasting and ordinary blasting and the multiple relations of peak stress are obtained. A blasting experimental platform for simulating ground stress and gas pressure was set up，the coal and rock blocks containing structural weak coal seam were constructed，and the modelling experiments under common blasting and shaped blasting were carried out. The experimental results show that the crushed area formed in the shaped energy direction is 0.838 times of that in the same direction under the ordinary blasting，the peak stress value is 1.58 times of that of the ordinary blasting. Compared with that of the ordinary blasting，the period of static action of the explosive gas was prolonged 300 μs in the direction of shaped energy，and was shortened 250 μs in the direction of non-shaped energy. The crack propagation range in the shaped energy direction is increased and the crack propagation range in the non-accumulative energy direction is reduced. The blasting efficiency was improved when the shaped blasting was applied to the tunneling in structural belt. The damage degree to supporting rock mass and structural coal was reduced，and the gas dynamic disaster accident induced by blasting excavation was restrained.

On August 31 to September 2，2014，affected by an extreme rainfall，deformation of a super large slope at Caijiaba in Yunyang County was found to increase rapidly. Hence，this paper employs the multi-source data，namely historical records，satellite remote sensing image，UAV aerial photography and field survey data，etc.，to determine the scope，characteristics and environment of the landslide. Afterwards，drilling，trenching，well exploration and geophysical exploration，indoor and field experiments were carried out to determine the landslide area formation，sliding zone and physical and mechanical properties. The failure mechanism of landslide was discussed and the slope stability was analyzed. The results show that Caijiaba slope is a large multi-stage flat sliding slope induced by rainfall. There are four slip surfaces(zone)，namely the soil sliding zone，shallow rock sliding zone，middle rock sliding zone and the deep rock sliding zone. The status quo of the sliding deformation is controlled by soil sliding zone，shallow rock sliding zone and middle rock sliding zone. Earlier stage of landslide accumulation and landslide slip surface(zone) provide the material basis for the status quo of deformation. The rear edge crack of front sliding zone provides the space for the rear sliding zone to move. Under heavy rainfall，a wide range of deformation and failure may be induced, and local sliding is likely to be caused. Stability analysis shows that the landslide is in a basically stable to steady state. However，the stability under heavy rainfall is significantly reduced. The stability of the slope has generally been declining to the unstable to basically stable state, and local sliding may occur.

The strength of rock deteriorates continuously during the progressive failure of slope and the strength reduction method to calculate the slope stability considering the tensile and shear progressive failure was therefore proposed employing the strain softening model instead of the ideal elasto-plastic model. The method was studied in terms of deterioration function，failure criterion，reduction factor，sliding surface display and reduction range. The ultimate plastic strain was used as the failure criterion for every point in the slope and all the points from the foot to the top of slope reaching the failure were taken as the failure criterion of whole slope. A quantitative index based on the initial stress method of elasto-plastic calculation was presented for displaying the complete sliding surface due to tension and shearing in the slope. The results showed that the plastic zone computed with the strain softening model is obviously smaller than that of ideal elastoplastic model，and the safety factor of slope considering tensile failure tend to be more dangerous. The tensile and shearing parts of the potential sliding surface of the slope can be displayed and distinguished at the same time by using the quantitative index.

In order to investigate the dynamic properties of limestone corroded in the chemical environment， three groups of chemical solutions with different pH values were firstly prepared to corrode limestone specimens for different time periods. Then，the porosity and magnetic resonance image of corroded specimens were obtained using the nuclear magnetic resonance(NMR) test. The impact dynamic properties of corroded specimens were finally tested with the split Hopkinson pressure bar(SHPB) system. The experimental results show that the damage degree of limestone is closely related to the pH value of chemical solutions. The specimens corroded in the acid solution are much more seriously damaged than those in the alkaline and neutral solutions. The damage degree of acid-corroded specimens varies from 1.38% to 2.02%. The porosity and the failure strain of limestone specimens increase with the corrosion time. Specifically，the porosity increases dramatically from 0.26%(in the natural state) to 3.20%(after 28 d acid corrosion). Consequently，the dynamic compressive strength and elastic modulus both decrease in two stages separated by a critical time(14 d)，and the maximal percentages of reduction are up to 36.6% and 59.3%，respectively. The damage degree and the fragment-distribution fractal dimension of limestone specimens both increase with the corrosion time，and there is a linear positive correlation between them in the acid and alkaline environments. However，this correlation between the damage degree and the fractal dimension is not obvious in neutral environment.

Brittle rocks have high strain energy under high in-situ stress. The quick release of strain energy during excavation often leads to fast unloading deformation and failure in the rock，which may induce the intense engineering hazards like rock burst. Based on the real conditions of Jinping Hydropower Station，a series of true tri-axial unloading tests were carried out under different stress paths together with acoustic emission monitoring and scanning electron microscopy(SEM) analysis. We investigate the strength characteristics of and the fracture evolution in the high strain energy rock induced by fast unloading process. The results indicate that the strength under true tri-axial condition is remarkable smaller than compressive rock strength，characterized by  – ，due to the unloading rate effect and the complexity of stress path. Acoustic emission(AE) system is used to monitor the failure process of rock tests. The characteristics of AE parameters were used to figure out the typical micro-fracture development of Jinping marble during the tests. The damage of rock initiates during the unloading cycle，with a number of tensile cracks generated in the specimen. The shear cracks are generated by the interconnection of tensile cracks to form the fracture，a large amount of elastic strain energy releases at the same time. The mechanism of the tensile-shear process is remarkably influenced by different stress paths and loading rates. This fracture pattern can be interpreted through a combination of modified Griffith′s strength theory，spalling limit and non-linear Mohr-Coulomb theory. All results can simulate well the different types of unloading failure process，such as rock burst in the large underground works.

In order to predict the potential failure mode and the entire process of progressive failure of dump slope，a non-contact measurement system developed for model testing is presented. The image acquisition subsystem collects the high resolution photographs during the test. The measurement and analysis subsystem obtains the surface displacement of model and the time curve of displacement at marked points with the speckle technique and tracking technology. With the non-contact measurement system，a series of model tests studying the bottom friction of slope dump on soft layer were performed. The test results show that the failure of slope dump on soft layer is progressive. The failure begins in the toe of the slope and expands gradually towards the deep part of the slope along the weak layer. A through sliding surface is finally formed in the rear part of the slope，then the entire slope slides. The failure cracks can be divided into two types：dislocation cracks with mainly the dislocation deformation and accompanied by horizontal separation，are mainly distributed in the interior of the slope；tension cracks with mainly horizontal separation and accompanied by the dislocation deformation，are mainly distributed in the rear part of slope.

Seepage discharge and exit water level in permeable layer cannot be computed with traditional seepage model in translational landslides，and both are assumed invariable as the water level in the slope cracks changes，which influences the accuracy of computation results in the range of artesian water. A new seepage model of translational landslide was thus established. Based on one-dimensional seepage theory of underground river channel，a new method was proposed to compute the action range of artesian water，seepage discharge and water level in seepage exit. Based on the geological data of Xiashan landslide，the safety factor was computed with different models and the outputs were discussed. Finally，the intrinsic relations and sensibility analysis of relative parameters including geological parameters，dimensional parameters and initial parameters of hydraulic condition were studied. Results showed that the range of artesian water，the seepage discharge and the water level in seepage exit were influenced significantly by the water level in the cracks of slope. The safety factor of slopes based on the new model is more reasonable and accurate. Any change in the model?s parameters made a difference in the range of artesian water，unit discharge and water level in seepage exit.

Normal materials are difficult to satisfy the requirements of filling and grouting the water rich karst for subsequent shield tunneling，an environmentally friendly controllable paste grout(TGM) is thus developed. The main performance parameters of TGM material and the behavior of grout in underwater Karst were tested through laboratory test on large samples. The TGM materials were successfully applied to grout the underwater karst in the project of the river cross shield tunnel of Metro Line 3 in Changsha. The TGM material solidifies fast，increases fast in strength，has high fluidity，low rate of water desorption，low rate in volume contraction and rapid onset of early strength，moderate late strength. When the clay pulp accounts for 1.30，the ratio of water to solid additives 1∶1，the content of additives a is 1%，and the content of additive b is 0.15%，the main performance of TGM is the best. Karst water flow rate is lower than 1 m/s，the retention rate is above 75%. The karst water cured grout after 12 h of solidification has the compressive strength of up to 2 MPa，90 d compressive strength 8 MPa，permeability coefficient 10－7 cm/s and has a stable microstructure. The on-site grouting application shows that TGM material can effectively fill the water karst，the permeability coefficient is approaching 4.7×10－5 cm/s，the shield tunnels successfully.

In order to study the stress distribution and mechanical failure characteristics of mining floor along the inclination of the working face above confined water，mechanical models of floor rock were constructed considering the combined action of supporting pressure and confined water along the inclination of the working face respectively. The stress distribution and failure form of floor were theoretically calculated considering the characteristics of initial and periodic pressure. The mechanical failure characteristics and stress distribution of mining floor based on numerical simulation of FLAC3D and in-situ testing technology were further discussed. The failure tendency of mining floor along the inclination of the working face has an“inverted saddle shape”. The corresponding shear stress is distributed in“reverse symmetry spiral”，which approximates a pair of positive and negative shear couple and is easy to produce shear failure along the boundary. This is in accordance with the failure zone and the stress distribution from numerical simulation. The maximal value of concentration level is located at the boundary of the elastic and plastic junction. The ratio of the supporting pressure coefficient under the initial and periodic pressure is approximately equal to that of the maximum vertical stress concentration coefficients. The simulation shows that the pore water is progressively promoted along the floor and easy to pour into the working face from the underneath part of its two ends，forming a water inrush phenomenon，which is in accordance with the actual water inrush position. The maximum failure depths from theoretical calculation，numerical simulation and field measurement are 12，12.875 and 13.75 m respectively，and the three results are quite close to each other. The results obtained from the mechanical model are in good agreement with one from the numerical simulation，and are consistent with the actual failure mode.

Shaking table tests were performed to model two landslides(micropiles reinforced landslide and unreinforced landslide). El Centro waves，Wenchuan waves，Kobe waves and sinusoidal waves with different frequencies were applied respectively. Acceleration response of landslides，dynamic earth pressure distribution in front and back of micropiles，the stress condition and failure mode of micropiles were monitored and analyzed respectively. The results indicate that micropiles have a good seismic performance for landslide，and it can suppress the seismic wave propagating through the landslide，especially at the toe of landslide，however，the suppression decreases with the height. For the dynamic earth pressure distribution in the back of micropiles，the pushing force of sliding mass and the resisting force of sliding bed is distributed triangularly(small at the upper part and large at the lower part). For the earth pressure distribution in front of micropiles，the resisting force of sliding mass and the pushing force of sliding bed is distributed triangularly(large at upper part and small at lower part). The peak bending moment of micropile shows an “M” shape. The maximum bending moment point is near the place 1.4 times of pile diameter above the sliding surface and 6.6 times of pile diameter below the sliding surface under earthquake，and the maximum bending moment point above the sliding surface moves up to the place 1.4 times of pile diameter with the increasing of loading amplitude. The failure characteristics of micropile after earthquake shows a reverse“S”shape，which is similar to that under static load conditions. The destruction area of micropile is distributed mainly in the place 1.4–4.0 times pile diameter above the sliding surface and 1.4–3.4 times pile diameter below the sliding surface.

When stabilizing piles are installed close to or far away from the piled bridge foundation in the slope，the shear deformation of soils around the bridge foundation may produce significant lateral loading and cause the deflection of bridge piles. A project on railway line from Chengdu to Lanzhou was investigated experimentally and numerically regarding the interactions between the bridge foundation and stabilizing piles. The results show that the maximum bending moment occurs close to the interface of the intercalated layer and bedrock. Because the rear stabilizing piles are installed so near the bridge foundation，the interaction between them is significant. The bearing mode of rear stabilizing pile installed directly behind the bridge foundation comes closer to the anchor anti-slide pile due to the resistance of the bridge foundation. A major part of the lateral load is concentrated in the pile cap correspondingly. Compared with the front stabilizing piles，the rear stabilizing piles have an obvious advantage to minimize the shear deformation of soils around the bridge foundation. The lateral displacement of the pile cap decreases firstly and then increases with the increasing distance of rear stabilizing piles. There is an optimal location for rear stabilizing piles which can decrease the lateral displacement of the bridge foundation effectively. To make the front stabilizing piles work at full capacity，the piles should be installed near the bridge foundation.

Based on the punching failure mode of the cavern roof， a functional equation of the failure surface of the punching body was established by using the upper bound method in limit analysis so that the functional expression of the ultimate bearing capacity of the three-dimensional cavern roof was derived. The breaking line equation of the punching body is obtained with variation method. The formula for the bottom diameter of the punching body and the ultimate bearing capacity of the three-dimensional cavern roof were obtained through the partial derivative. The rationality of the theoretical method was verified through comparison with the experimental results. The impact of GSI on the ultimate bearing capacity of cavern roof and the bottom diameter of the punching body were analyzed. The results indicated that when h is 1D to 4D，the ultimate bearing capacity of cavern roof increases approximately linearly with the increasing of h. When h is 5D，the ultimate bearing capacity of cavern roof is the same as the that of bedrock. When the ratio of thickness to diameter is constant，the ultimate bearing capacity of roof increases nonlinearly with the increasing of GSI. When h is 1D and GSI takes 44，the capacity coefficient of cavern roof is 0.73，and when GSI takes 100，the value is 1.42，which is about twice the former. Under the same thickness of cavern roof，the diameter of the bottom of the punching body decreases approximately linearly with the increasing of GSI. When GSI takes 44 and the thickness of the cavern roof is 1D，the diameter of the bottom of the punching body is 0.20 m，which is 1.25，1.54 and 1.70 times of that when the GSI is taken as 65，85 and 100，respectively. Similar relationships exist for other thickness of cavern roof.

Mechanical-biological treatment(MBT) has the advantage of significantly reducing the amount of municipal solid waste. Therefore，MBT waste has become a hot global research topic in geo-environmental engineering. In order to understand the basic geotechnical characteristics of waste more comprehensively，MBT waste samples were collected from Tianziling landfill in Hangzhou，and tests were conducted，including a composition analysis，sieve analysis，water content test，specific gravity test，natural density test，compression test，direct shear test，and permeability test. The main components of the MBT waste from this site were plastic，glass，and dust soils，which accounted for 57% of the total wet mass. The uniformity coefficient of the MBT waste was 21.4，and the curvature coefficient was 1.93. The relationship between the void ratio and the logarithmic pressure was fitted linearly，and the compression index was calculated to be 0.726，indicating the high compressibility of the MBT waste. The shear strength of the MBT waste conformed to Coulomb?s law. The cohesion was 10.8 kPa，and the internal friction angle was 44.5°. The permeability coefficient decreased with increasing vertical pressure. The relationship between the logarithmic permeability coefficient and vertical pressure was fitted linearly. The permeability coefficients of the MBT wastes were in the range of 10－2–10－6 cm/s. These conclusions can provide reference for prediction of reservoir capacity, stability analysis and design of seepage drainage system in an MBT landfill.

Q3 loess in Longdong has pronounced structural characteristics. Studying its mechanical deformation characteristics and deducing a suitable constitutive model are of theoretical and practical interest. A new constitutive model for Q3 loess from Longdong is presented based on the concept of disturbed state. The volumetric strain disturbance factor Dp and the shear strain disturbance factor Dq are proposed according to the experimental results. A function to describe the disturbed state is established according to the experimental results. The constitutive model proposed is relatively simple and it?s parameters can be obtained through triaxial isotropic compression test and triaxial shear test easily. Compared with the modified Cambridge model through the test curve and the calculated curve，it is proved that the constitutive model proposed can describe deformation characteristics of loess reasonably.

The theoretical formulas of soil deformation and pore water pressure caused by the additional thrust，shield shell friction and pressure of shield-tail grouting of the earth-pressure balance shield in the semi-infinite space of saturated soil were deduced. Numerical integration method was used to calculate the soil deformation and excess pore water pressure induced by shield excavation in soft area. The calculated results were compared with measured data, showing that the calculated results are close to the measured values. The proposed method is more practical than the Mindlin solution. In the whole process of shield tunneling，the pore water pressure increases when the shield workface is approaching and when the shield tail is departing this section. When the shield workface is approaching，the pore water pressure is mainly induced by the additional thrust and the friction of shield shell. The increasing of pore water pressure during the departure of shield tail is due to shield-tail grouting and shield shell friction.

In this study，an indoor simulation test is conducted to monitor the swelling process of joint area which is backfilled with bentonite powder. The basic mechanism of swell-sealing of joint between blocks is investigated with microstructure analysis. According to the swelling test，the swelling stress development in the joints of blocks is anisotropic. The growth rate of swelling stress at joint area is higher than that of axial direction. The swelling stress at top surface，which is far away from the wetting surface，lags behind that at the bottom surface due to the water migration and sidewall friction. With the increasing of saturation degree，the joint areas are squeezed and compacted under the radial and axial swelling stresses of blocks. The final dry density of blocks decrease and of joint area increases. According to the microstructure analysis，the number of micropores in the soil aggregates decreases and the number of macropores and connected pores increase gradually from the block center to the joint area. A certain width of transition zone is formed between blocks and joint areas.