Theories of elasticity，plasticity，thermoplasticity，thermoviscoplasticity，continuum damage are often used to develop constitutive models for engineering materials. A new and unified approach which possess a number of advantages compared to the foregoing and available models is introduced，namely the disturbed state concept (DSC). The DSC is based on the idea that a deformed material element can be treated as a mixture of two constituent parts in the relative intact (RI) and fully adjusted (FA) states，referred to as reference states. During external loading，the material experiences internal changes in its microstructure due to a process of self-adjustment. And as a consequence，the initial RI state transforms continuously to the FA state. The self-adjustment process may involve relative motions of material particles and lead to microcracking and damage or strengthening. The disturbances are caused in the observed response with respect to the responses under the two states. Then，the observed response is expressed in terms of the responses for the RI and FA states that are determined from laboratory tests on material specimens. The research results show that the DSC can develop unified constitutive models for engineering materials，which include，hierarchically，other previous continuum and damage models as special cases.

Based on direct shear tests，the development of localization during the failure of rock specimens is studied. Testing results show that ductile deformation appears with brittle deformation before the failure of rock. It is suggested that the main factor to induce macro fracture is the formation and accumulation of sub-shear band formed in the intensely deformed area of shear band. Subsequently，a preliminary analysis on those bifurcation behaviors is conducted according to symmetric groups bifurcation theory.

The uniaxial cyclical load experiment is conducted. The - hysteresis curve and elastic responses，such as Young′s modulus, Poisson’s ratio, attenuation，elastic wave velocity are obtained when load is below yield-point，and the visco-plastic responses are also gained when load is beyond yield-point.

The failure of rock is closely relative to energy change. The specimens of siltsand were pseudo-triaxially compressed in MTS servo-controlled testing machine，and the complete curves of stress and deformation in axial and circumference were measured to calculate the energy. The specimens failing in axial compression were absorbing energy continually to overcome the internal friction in rock. And the specimens failing in confining pressure reduction while keeping axial deformation constantly were releasing energy through its circumference expanding in hydraulic oil. However，the absorbed energy of specimens at crack point in the two loading paths has the same linear relation with confining pressure.

The deferent mechanical behaviors of rock failure are simulated by the two-dimensional physical cellular automata (PCA)，and the results show that the typical mechanical characters of rock failure，such as the relations between force and deformation，the evolution of acoustic emission，and so on，can be effectively simulated by PCA. PCA model can be used for valuable reference to studying the chaotic features and the self-organized characters of rockmass failure.

Based on the statistical and damage theory，the characteristics of elasto-plastic deformation and damage of rock are studied. The elasto-plastic statistical damage constitutive model of rock is developed. The effective stresses are totally expressed in the damage evolution function. The residual strength property of rock can be considered in the model. The presented model is verified as reasonable and practical with comparison to the experimental results.

Many kinds of rock materials bear random speckle pattern on their surface due to the componential reason. This speckle structure can be captured and saved as speckle images for DSCM method when doing deformation measurement. DSCM method based on the natural speckle pattern is studied. Some rock material experiments are completed and the results of experiments prove the feasibility and advantage of the method.

A special surface replica technique for microcrack observation of rocks is introduced. The replica，which is hard，thick and semi-transparent，is convenient to be used for observation and analysis under optical microscope and SEM (Scanning Electron Microscope). By using this technique，cracks wider than 0.2 m and the microstructural natures of minerals can be satisfactorily copied for the microscopical investigation. The noticeable characteristic of this replica attributes to its capacity of distinguishing the minerals on the rock surface. Application of this technique in the study on failure behavior of different minerals in granite shows that this is an effective and convenient method for the study of microcracking in rocks，especially for the study of cracking behaviors of different minerals and their relations with the failure of the rocks.

The characteristics of pulse X-ray and medical X-ray machines are introduced. A series of impact loading experiments in saturated sand are carried out. By using medical X-ray machine，the photos of the horizontal cracks，longitudinal drainage pathways and settlement in saturated sand under impact loading have been taken for several times. And then，the appearance law of the horizontal cracks and longitudinal drainage pathways are obtained. As a result，an experimental observation means is provided to study the structure failure and settlement mechanism after the saturated sand is liquefied.

The mechanism of the fracture coalescence between three flaws is studied using rock-like modelling material under confining pressure condition. The specimens contain three pre-existing flaws with different geometry distribution and different confining condition. Experimental and numerical results show that the mechanisms of crack coalescence is controlled by the geometric setting of the flaws and the confining pressure. Under the confining condition，there are four modes of coalescence between the rock bridge：tensile mode，shear mode，compression mode and mix mode(shear and tensile). The growth of tensile crack slows down with the increasing of confining pressure. Compressive crack is active when the flaws are overlapping and with a distance between two flaws 1＜b/c＜2. Under the confining pressure，the opening of flaws becomes more close，and leads to increase the friction between flaws. It also causes the growth of crack more close to the axial direction.

The complexity and variety of rockmass structure are the very important reasons to induce variety of macroscopic deformation character of jointed rockmass. To evaluate the variety of rockmass structure，a correlation model is set up between deformation parameters and fractal dimension. The dimension is made as a measureable guideline to describe the rockmass structure in this model. Based on this model，the deformation character of surrounding rockmass is studied for a large-scale hydroelectric underground powerhouse.

The fracture mechanics effects of chemical action of water-rock and their time-dependent and chemical environment-dependent behaviors in grey granite，green granite，grey sandstone and red sandstone are analyzed by test of KIc and COD for rock under different conditions. The fracture mechanics effect of chemical action of water-rock is evident and time-dependent. The big differences exist for the influence of different aqueous solution，different rocks，different immersion ways and different velocity of cycle flow on the fracture mechanics effects of rock. The mechanical effect of water-rock interaction on propagation of fracture is consistent with the mechanical effect on the peak strength of rock. The intensity of the fracture mechanics effect increases with the intensity of chemical action of water-rock. Iron and calcium ion-bearing mineral or cement in rock are some key ion or chemical composition，and especially iron ion-bearing mineral resulting in chemical action of water-rock is provided with both positive and negative mechanical effects on rock.

In the surrounding rocks of conveying water tunnel with inside higher water pressure at Guangzhou pump storage project, the erosion belts expanding intensely with water being are quite developed. But according to the results of hydraulic fracturing test and the minimum principal stress criterion，the steel liners of the high pressure conveying water tunnel and even at the branch section are all cancelled，and just supported by reinforced concrete liner with thickness of 60 cm. The power station has being operated smoothly for years，which shows that the designing of the project is quite reasonable.

On the basis of the study of principle fundamentals for geostress measurement by hydraulic fracturing technique，the direction of breaking fracture on the hole wall and the universally applied calculating formulas of data processing for 3-dimensional geostress measurement are studied profoundly with practical examples.

The interaction mechanism of landslide and several rows of passive piles is studied to stabilize landslide. A new method is presented to simulate the interaction between landslide and passive piles with combination of finite element method and limit equilibrium method. The flow charts calculating the safety factors and the stresses of passive piles are given. Finally，good results are obtained for practical projects by the developed software based upon the new method.

The behaviors of Daganping clays are obtained under the unloading stress-path by triaxial tests and the goal is to quantify the parameters for stability analysis on slope excavation. A non-linear finite element analysis for stability of slope excavation is established. The results provide a systematic description of the whole process，including deformation behaviors，extension of plastic zone，formation and evolution of slip surface, and failure in slope during excavation. The location of slip surface is determined by the results from the finite element analysis，and the Janbu slice method is used to calculate the safety factors of slope stability. The stability of slope excavation is estimated according to calculating results.

Based on the model testing results，the impact of length and prestress value of anchor cable in blocky rockmass on its reinforcement effect is emphatically analyzed and the impacted scope and characteristics are given. All this will provide scientific and essential basis for further analyses on the reinforcement mechanism and design method of prestress anchor cable.

Combined with the construction of anchor cable on the slope of TGP’s permanent shiplock，the rockmass properties near anchor is studied after being prestressed. The changes of sonic wave velocity，elastic moduli and deformation values of rockmass near anchor are discussed，and the general regularity of rockmass properties near anchor after being prestressed is brought to light. The proposed achievement is valuable for the further research on prestress reinforcement mechanism and engineering design of anchor technology.

The factors which control and affect the shear strength of rockmass are complicated and uncertain variables. As artificial neural network method can consider both quantitative and qualitative factors，it is suitable to solve the uncertain problems with artificial neural network method. The neural network model is establlished for prediction of shear strength of engineering rockmass and a lot of engineering data are collected to train and examine the model. Some valuable results are derived at last.

A reliability model of shear strength of rocks and soils from test data is proposed. The model possesses special advantage for limited test samples. The shear strength parameters， and c，generally are of two dimen- sional probability distribution with strong negative correlation. Using this reliability model，one single guaranteed factor can be used to determine uniquely the design values of and c.

From point of view of energy accumulation and energy dissipation during deformation and break of rock， it is pointed out that the ratio of uniaxial compressive strength to uniaxial tensile strength can show the accumulation performance of elastic deformation energy of rock with relatively complete texture and the ratio of total strain before peak strength to total strain after peak strength can show the relation between energy accumulation and energy dissipation. The rockburst proneness index is defined as the product of the two ratios. Testing study is made on the typical rocks at the deep deposit of Dongguashan Mine，Tongling Nonferrous Metal Corporation. Based on the testing results and the investigation of actual rock burst at the mine，the index is analyzed by contrast to existing rockburst proneness index and is verified to be able to show fairly well the rockburst proneness. Finally，a criterion of rockburst proneness is put forward.

Safe height(SH) is an important problem for rock mechanics when the stability of surrounding rocks of underground houses of a huge hydroelectricity power plant in Southwest is studied. The height between the discontinuity and the vault is defined as SH. The solution of this problem is of important significance for the design of support structure of surrounding rocks for underground houses economically and reasonably. The problem of SH is analyzed with catastrophic theory. On the basis of catastrophic theory，a catastrophic model with cusp point of SH is developed by using elastic mechanics theory，which is better to solve the problem in comparison with another solution developed from structural mechanics.

Taking the south tower piling-foundation scheme of Jiangyin Bridge as an example，a foundation scheme applied to high，heavy and large building in high slope is introduced. The 70 times of measured data for axial force of pile at 64 points show that this foundation scheme can ensure the vertical load of 1.2×106 kN transferred to foundation rockmass of 26 m under ground. Then, the stability of the shallow rock mass will not be influenced by the engineering load. The measured data still state that the pile of the tower is overloaded, and the overload is up to 35 percent. In addition，7 m below the surface of embedded-rock，the axial force of pile reduces 75 percent because the load taken by embedded-rock foundation dissipates fast to the surrounding rockmass.

The basic structure and the function of MTS digital program servo-controlling uniaxial mechanics test machine are introduced. Based on the uniaxial MTS test machine，the development idea of the measuring system for mechanics properties of rock under the convectional triaxial stress state and pore content of rock is elaborated. The complete-process deformation property of RCC under the convectional triaxial stress state and the porosity change of fine sandstone with confining pressure are tested using the developed test equipment. The results show that the developed equipment can meet the demand of rock mechanics testing study for scientific research and design of rock engineering.

The stress field of perfect elasto-plastic thick-wall tube is considered again. The re-research result shows that there are some questions in current solutions to this problem. Furthermore，a new accurate solution to the problem is presented.

Numerical manifold method of elastoplastic analysis is presented by using the parametric variation principle. This method can solve the elastoplastic problem including non-associate flow. It avoids iterations at every load step. It is suitable to the elastoplastic analysis of rockmass. An example testifies the validity of the proposed approach.

Based on the application of horizontal jet grouting reinforcement technique in Shahalamao railway tunnel，the technologic parameter，construction process and improvement effect of this technique are mainly introduced. The work efficiency and material consume are analyzed also. It is shown that the horizontal jet grouting reinforcement technique can be used to construct the tunnel in soft sandy soil.

A successful design scheme and informationalized construction method of the deep foundation pit are presented for the building of Guangdong Industrial and Commercial Bank Plaza. The experience is of some reference value to the designing scheme and construction of embosoming of deep foundation pit.

With the rapid development of expressway in China，the ground improvement is becoming more and more important. The decision of the ground improvement method often depends on the experience of engineer. A module of multi-layer fuzzy decision of the ground improvement method is set up for the expressway foundation construction. The values of the affected factors in rule layer and index layer are assigned. The character index matrix of project layer is set up and the total evaluation on projects is made. Combined with the project of ground improvement of the second cincture road in Wuhan，a case study is done and satisfying result is obtained.

Wuhan Labour Market Building is located at the west of Xinhua road，Hankou district，Wuhan. The geological conditions of the building foundation are very complicated and the pit is 8 meters deep. The design and construction process of the pit slope are introduced. It is pointed out that the keys of deep pit supported by shotcrete-bolt are construction according to the information，feasible design，and close cooperation between the excavation and the construction of shotcrete-bolt，and flexible management.

The design method and construction measure of soil nail in deep excavation of thick soft soil are introduced. From the foundation pit bracing system of Guoan Building in Shanghai，the monitoring and measurement results prove that good technical effects and economic benefits can be obtained when soil nail technique is applied in deep foundation pit of soft soil.