In order to know about the rheological properties of rock in a long range of the time scale, method of increasing temperature was brought forward to accelerate the rheological process of rock, which could extend the time scale of experimental test data. Firstly, based on the generalized linear viscoelastic constitutive equation with temperature variable, the creep behavior of rock was divided into three types according to the different strain dependences of the time, that is, Hookean deformation, Newtonian flow, and retarded elasticity. Then the general equivalence relationship between time parameter and temperature parameter was derived for each type of strain. Finally, the relation between time parameter and temperature parameter in the whole creep was considered and the general theory of time-temperature equivalence effect (TTEE) of rock was established. This research reveals: ①The temperature effect on the instantaneous strain could be modified through vertical shift. ②The key point of the TTEE of Newtonian flow depends on whether in the study of linear viscoelastic behavior of rock change of temperature is completely equivalent to a shift of the logarithmic time scale or not. ③By plotting the results of a creep experiment performed at different temperatures and comparing the curves obtained, one can decide whether the rock considered have TTEE. ④The TTEE of the whole creep should satisfy that the horizontal shift function of Newtonian flow and retarded elasticity is consentaneous.

Aiming at the limitations and deficiencies of the current rock damage models, firstly, the rock under stress is divided into three parts abstractly: voids, damaged and undamaged material. The voids ratio is employed to describe rock’s change of the volume and the voids; and the damage variable or damage coefficient is used to reflect the conversion degree of mechanical property and state of rock. Then, a new damage model for rock is proposed according to analysis of microcosmic stress and discussion on the relationship between rock’s macrocosmic stresses and strains. Secondly, starting with the discussion on the reasonable method to measure the rock microcosmic elemental strength, a statistical damage evolution model for rock to reflect the effect of the damage threshold value is presented by working in statistical damage theory; moreover, a statistical damage constitutive model to simulate the rock full deformation process and its parameters determination method is developed. This model can reflect the properties of not only strain softening or hardening but the volume compression in initial as well as expansion in later. Finally, the analysis and discussion with practical example indicates the rationality and feasibility.

A series of direct shear tests were performed using self-developed large-scale interface shear apparatus to investigate the shearing resistance properties of sand-geogrid interface and compare the experimental results under normal cyclic load with those under static load. The test results demonstrate that the development trend of shear stress-displacement curves under cyclic load are similar to those under static load; but the shear curves under cyclic load show cyclic development characteristics; the relationships between the maximal shear stress of peak value and normal stress, and the maximal shear stress of trough value and normal stress both conform basically to Mohr-Coulomb rule; the maximal shear strength under cyclic load decreases with the increasing of frequency, but increases with amplitude increasing; the shear strength under cyclic load fluctuates with shear displacement, but is always in between the upper and lower boundaries defined by the shear stress under corresponding static normal stresses; the specific quantitative relationship among these related physical variables needs further researches.

Aiming at the softening problem of red-layer soft rock, the quantified study of softening mechanism has been carried out from the point of microstructure evolution, based on data from the saturated softening test of sandy mudstone. Firstly, a structure component describing the granular characteristic is proposed to combine with the microstructure model of clay mineral proposed by M. Tuller, D. Or, and the combination components of microstructure for soft rocks are obtained. Then considering the basic types and features of soft rock microstructure, two typical microstructure units to represent the granular structure and dense stripy structure are established. On this basis, renormalization group method is adopted to build the renormalization model and analyze the critical criterion for microstructure evolution of soft rocks in softening process. So the quantified relationship between microstructure and mechanical properties is obtained. Finally, according to comparing the results of the mechanical properties test of saturated soft rocks, the rationality of proposed models is verified.

Mechanical properties and acoustic emission characteristics of briquette samples are studied under fixed gas pressure and confining pressure. The results show: mechanical properties discreteness of coal containing gas is decreased because of gas existing; triaxial strength is decreased and Young’s modulus is increased compared with coal; acoustic emission events are comparatively well distributed in process of triaxial compression of coal containing gas; the concentrated regions only appear at near damage regions; the distribution of AE events amplitude shows three peaks mode, energy of AE events is increased as deformation increasing; AE events parameters lag behind triaxial compression curve.

In order to investigate the deformation characteristics of saturated clays due to long-term groundwater withdrawal, several oedometer tests were conducted on the clay samples acquired from the second aquitard unit in the Suzhou-Wuxi-Changzhou area. The creep deformation of the samples under complex loading was studied. The test results have shown that the saturated clay behaves as a creep material obviously under the initial loading; and the relationship between creep deformation and time is approximately linear in a double logarithmic space. The slope of the fitting straight line decreases with the increasing loading; but it shows little changing when the loading is great enough. Saturated clay also exhibits creep deformation when rebounding under initial unloading. The higher the unloading level is, the more remarkable the rebound creep is. The creep deformation can be expressed as a power function of stress and time when rebounding. The test results have also revealed that, under repeating loading, the time when the deformation of samples satisfies the steady requirement decreases with increasing number of cycle. If the maximum loading is smaller than the preconsolidation pressure, the sample becomes elasticity after two cycles; while the sample becomes elasticity after five cycles if the maximum loading equals to the preconsolidation pressure.

By means of 20 MN servo control rock mass triaxial testing machine with high temperature and high pressure, the experiment of feldspar fine sandstone permeability was carried out. Under the condition of constant triaxial pressure and room temperature up to 600 ℃, the change characteristic of sandstone permeability were researched. It is observed that the permeability of feldspar fine sandstone appears five stage characteristics with temperature rising: ① Low temperature stage, its permeability declines with temperature rising. ② Fore-stage of temperature threshold, its permeability acutely rises, the value increased 65 times as much as that in room temperature. ③ Back-stage of temperature threshold, its permeability declines with temperature continuously rising. ④ Stabilizing stage, its permeability is stabilized at a high level upon to valley value, which is 8 times as much as the permeability value in room temperature. ⑤ High temperature stage, its permeability rises again. After the comprehensive analysis of micro configuration, and AE events of feldspar fine sandstone, it is considered that the stage characteristic law of feldspar fine sandstone permeability is correlated with the opening and closing of micro cracks induced by partial thermal stress centralizing in rock minerals granule edge and interior, and the second acutely increased phenomena of feldspar fine sandstone permeability is mainly affected by some minerals crystal granule fusing and recrystallizing in high temperature environment.

GMZ001 bentonite is chosen as the main buffer material in high level radioactive waste (HLW) geological disposal. Laboratory swelling test was conducted on compacted mixture of GMZ001 bentonite and quartz sand in different addition of 0, 10%, 20%, 30%, 40% and 50%.Test results show that the swelling strain of the mixture is exponentially increased with lapse of time. The maximal swelling strain shows a linear increase with initial dry density; while it increases with sand addition presents a parabola. By the use of the concept bentonite filled density, an optimum model has been established to describe the relationship between maximal swelling strain with sand addition percentage and initial dry density, which provides a useful tool for predicting and controlling the swelling behavior of bentonite-sand mixture in HLW geology disposal.

The advantages and disadvantages were pointed out by comparing the apparatus including direct shear apparatus, simple shear apparatus and ring shear apparatus, which are commonly used to study the deformation and strength behaviour of the interface. The deformation and strength behavior of the interfaces between a soil and concrete are investigated by using simple shear test. The interfaces include two types, i.e. interface between soil and concrete, and that of soil-mudcake-concrete. The existing results of ring shear tests from references are employed to compare with those from simple shear tests in this paper; and the differences between them are investigated. The results show that the shear strength measured in simple shear test is smaller about 30%-40% than that found in ring shear test. It is pointed out that the ring shear test is more suitable for studying the strength behavior of interface; and the simple shear test, however, is better for investigating the behavior of stress and strain under lower stress level. The strength of interface decreases about 30% due to the existence of mudcake between soil and concrete.

Anchor pullout is a complicated anchor-soil interactive process. The deformation mechanism of soil around an uplifting anchor is essentially important for reliable prediction of pullout force. In order to quantatively analyze the deformation mechanism of soil when anchor uplifting, a new data acquisition system, which can acquire force, displacement and images simultaneously, is coded based on a graphical programming environment LabVIEW. A test set-up which consists of a load cell, a linear variable differential transformer (LVDT), a camera, a loading frame, a Plexiglas mould, and a computer is developed to perform tests. The deformation fields are measured during the anchor uplifting based on particle image velocity (PIV). The displacement fields, the shear strain fields and volume strain fields of soil around an uplifting anchor are quantatively analyzed. The results show that an inverted trapezoidal is shaped in displacement fields during anchor uplifting. The symmetric shear zones tangent with the anchor side and inclining upward to the surface are shaped after local shear band forming and expanding. Dilatancy is also observed in shear zones. After peak the inward inclined shear zone tends to incline outward. The flow softening phenomenon is observed near the anchor sides. These results will benefit for developing prediction model for anchor pullout and design.

Triaxial compression tests have been made to investigate the stress-strain behaviors and strength characteristics of composite soil with different kinds and different components of polypropylene fiber. The test results show that it is single tied polypropylene fiber dispersed well rather than mesh polypropylene fiber was chosen by reinforced clayey soil. The best mass percentages of polypropylene fiber content was tested to be 0.2%. The single tied polypropylene fiber of 6mm+10mm+15mm+19mm in length was proved to be the ideal patterns of four components for the composite soil. The stability in microstructure, anti-cracking and shear strength are dramatically enhanced with the addition of fiber composite soil.

A laboratory test program was conducted in a self-made test tank to investigate one-dimensional electroosmotic drainage at different supply voltages. By monitoring drainage, voltage profile, water content and current intensity every one hour during the entire test period, results below were acquired: higher voltage would lead larger energy consumption per unit volume drainage; the combination of higher voltage and shorter electroosmosis time would cause the abnormal moisture distribution that the highest was in the middle of electrodes and the lowest was near anode; the gradually decreasing of drainage was because of the increasing electrode contact resistances and the decreasing electroosmotic permeability coefficient; the contact resistance existing on the interface of soil and electrode made the voltage used for electroosmotic drainage lower than the supply voltage; and the higher voltage lead the larger anode contact resistance, but the condition in cathode was different that slow increasing occurred at higher voltage and fast increasing at lower. They related to electroosmotic drainage rate which determined mainly by supply voltage.

This paper presents a study of the uniaxial unconfined compressive deformation properties of cement stabilized/solidified lead contaminated soils. The contaminated soils are prepared in the laboratory with different lead contents and cement contents. The control samples (cement treated soils without heavy metal) are also prepared for comparison purpose. The test results show that the presence of lead in soil interferes with the cement hydration process, which is directly reflected by the stress-strain curve, failure strain, and deformation modulus of cemented soil. For specimens with 0.01% and 0.1% lead concentration, the strain at failure decrease with the increase of strength and curing time, and are larger than that of control sample. Toughness Index is used to evaluate the toughness of cemented soils. The deformation modulus of cement treated lead contaminated soils changes with the variation of lead content, cement content and curing time. There is a linear relationship between the deformation modulus and unconfined compressive strength.

In order to study the load-displacement curves, the ultimate uplift capacity and the residual uplift capacity of piles in sand, a testing program for different L/d model piles pullout tests is conducted. The model piles have three different roughness interfaces, and the shearing behavior of interfaces are tested. The load-displacement curves are similar for the piles with same interface when L/d is different. The uplift load of smooth pile reaches a steady value after the ultimate uplift capacity. The uplift load of rough pile becomes smaller after the ultimate uplift capacity; then it reaches the residual uplift capacity. When the piles are at failure, the lateral earth pressure coefficient K are affected by the roughness of pile; the rougher the pile is, the bigger the K is. The residual uplift capacity, expressed as a percentage of the ultimate uplift capacity is smaller for rougher piles; and the ratio is about the same for different L/d piles. The residual uplift capacity are smaller than the ultimate uplift capacity for rough piles; this is attribute to two reasons, one is the reduction of interface friction angle, the other is the reduction of lateral earth pressure.

Cyclic triaxial-torsional coupling shear tests were performed on saturated silt by hollow cylinder apparatus under different relative densities, deviator stress ratios and vibration frequencies to study the development of pore water pressure of the saturated silt under wave loading. It is found that the normalized relationship between vibration cycles and pore water pressure can be fitted by arcsin function. The fitting parameter θ linearly decreases with increasing of deviator stress ratio and linearly increases with decreasing of relative density. Vibration frequencies have minimal impact on θ .

Since tire have characteristics of extremely high strength and high durability, using the waste tires to adopt as the reinforced element in the reinforced structure will be a good application to treat the waste tires. Pullout resistant behavior is the major topic to be evaluated in this reinforcement application. Since the 3D geometry of tire is different from traditional planar geosynthetics (such as geotextiles and geogrids), the boundary condition and interface interaction are also be different from current theoretical models. To evaluate the performance of waste tire as reinforcing element, the large size of pullout test system is therefore to be need in this study. Tires with and without one side wall cut are tested and compared in this study for their performances. Flexible materials were also used in this study to eliminate the extrusion of filled sands caused by front wall effects. After the front wall effects has been successful studied and controlled, the test results showed the cut-tire provide better compaction performance of filled sands and increase the area subjected to normal stress. It exhibits the significantly better pullout resistance than the reinforced soil mass with the tire without cut. When the cut-tire to reduce the side of bead wire, it results the larger deformation than tire without cut. To evaluate the reinforcing effect of two connected tires, the tensile elongation from the inter-zone of two tires is the major influence. Needs to restrain the tire deformation by lower elongation materials and rigid clips for connection. The findings provide some better knowledge to adopt the waste tires in reinforced earth application. In addition, from the results observation, significant settlement may be occurred during reinforcement construction process. This will be also a important consideration for the design approach.

Indoor model tests in which the slenderness ratio of uplift piles and compression piles were above 40 were carried out to research the distribution differences of carrying capacity, axial force and lateral friction when a single pile is under the situation of uplifting and compression. Through setting resistance strain gage in the piles, strain of the piles in different depth under each load level was gotten. Through the analysis, the displacement and its rising rate of uplift piles are far more than that of compression piles. As a result, the displacement of pile block should be taken into consideration to determine the uplift capacity in the process of design. The axial force distribution of uplift pile is similar to that of compression pile; the reduction factor of uplift piles' total lateral friction is λ=0.56 according to the test. The lateral friction of both uplift and compression piles first functions on the top and transfers from the top down. With the increase of load, the lateral friction on the upside rarely changes while the lower part grows rapidly. The tip of the uplift pile shows the weakening effect and the compression pile shows the strengthening effect.

Vertical and lateral dynamic soil pressure characteristics were studied by site tests under different impact rolling times, lines and velocities. It is found that the impact rolling load has a transient shocking effect on the embankment and the dynamic soil pressure near the load increases accumulatively. The dynamic soil pressure is closely related to impact rolling times, lines and velocities. Along with the impact roller coming from the near to the distant, the dynamic soil pressure increase firstly, then decrease. The impact roller can affect the embankment in a distance of 30m to the test location and effect significantly in a distance of 15m. Under different impact rolling times, the dynamic soil pressure increases firstly, then decreases. Resulted from the diffusion of load effected by Portland cement-concrete pavement (PCCP) and the base, the dynamic soil pressure is just only one-tenth of that impact directly on embankment. The research shows that the actual influence depth of embankment using impact roller is greater than the result of FEM; and the horizontal influence distance is about 10 m.

Anti-shear (cut) parameters of concrete-dam bedrock is concerned with dam design and running safely. Based on specificity of rubber power that can increase particle friction and disperse energy in concrete, anti-shear(cut) performance of dam bedrock-ordinary concrete is compared with that of bedrock-rubber powder modified concrete by the test on the spot of Tangshui reservoir . The results show that the anti-shear(cut) performance of bedrock-rubberized concrete is better than that of bedrock-ordinary concrete. Anti-cut friction coefficient of rubberized concrete-bedrock with 1.344 is increased by 70.1%, compared with that of ordinary concrete-bedrock with 0.790; and cohesion of rubberized concrete-bedrock is almost equal to that of ordinary-concrete. As far as anti-shear parameters is concerned, anti-shear friction coefficient of rubberized concrete-bedrock with 1.108 is increased by 62.2% compared with that of ordinary concrete-bedrock with 0.683. Cohesion of rubberized concrete -bedrock with 0.138 MPa is as almost two times as that of ordinary-concrete-bedrock with 0.061 MPa, And mechanism that rubber powder can improve anti-shear(cut) performance of dam bedrock- concrete is analyzed. So an effective technical measures that increases anti-shear(cut) parameter of dam bedrock- concrete is provided.

Based on the dynamic similarity criteria of dynamic model tests, a new type of dynamic test model materials of high concrete dams named DMM has been developed through a series of tests of proportion of mixture and mechanical properties as well as the ultrasonic detection. The fluvial sand being used as the coarse aggregate in the dynamic similarity material of concrete dams has been presented for first time. It has been found that by the way of regulating its mixture proportion the dynamic elastic modulus and density of the model material can be controlled and adjusted efficiently. So it’s significantly better than the quartz sand and so forth. The results of a large number of experiments show that DMM material has advantages of not only the high density, low dynamic elastic modulus, but also stable and apparent linear elastic stage involved in its stress-strain relation, with a stable and significant linear elasticity, conforming to the basic requirements of dynamic model test of high concrete dam and similarity criteria. It is green and non-toxic, cheap and its making is shorter. It’s expected to be a excellent dynamic similarity material.

In order to obtain the safety factor of unlined loess tunnel wall rock structure under earthquake, general finite element software ANSYS is adopted. Firstly, modal analysis is done by adopting the dynamic analysis model under the horizontal seismic action; and the coefficient of quality damping and stiffness damping is obtained. Secondly, the dynamic time-history analysis is made by inputting seismic wave; and the maximum horizontal displacement of model “vertices” is gotten. Finally, by adopting static analysis model, and considering gravity and lateral border node horizontal displacement when the horizontal displacement of model “vertices” being largest on the border of right or left, and shear strength parameters, cohesion c and internal friction angle , of wall rock soil is continuously discounted until the calculation is not convergent so far; and so the safety factor of unlined loess tunnel wall rock structure under earthquake is obtained. Numerical example shows that the method proposed is feasible; and that earthquake action may make the safety factor of wall rock structure lower; and thus in the future a theoretical basis is provided for the safety factor calculation and engineering application of loess tunnel wall rock structure under earthquake.

The theory of analysis of the vibration of pile group proposed by Dobry and Gazetas only for single phase soil, it is needed to verify the theory is suitable for the pile group in saturated soil or not. Based on the theory of porous media, the horizontal dynamic impedance of saturated soil and the attenuation function of horizontal displacement of free field were obtained with Novak layer method and potential functions by regarding soil as two-phase medium. The pile-pile dynamic interaction factor is obtained by initial parameter method; and the horizontal vibration of pile group in saturated soil is investigated by superposition principle which based on dynamic interaction factor; and analyzing the influence of main parameters on the dynamic impedance of pile group with an example of 3×3 pile group. A new method for studying the pile-pile dynamic interaction and the horizontal dynamic impedance of pile group in saturated soil is provided.

Based on wave function expansion method, an analytical solution for dynamic stress concentration of circular tunnel with double-layer-liner in infinite media under incident plane P waves is deduced. According to the solution, parameters sensitivity analysis of dynamic stress concentration is carried out in combination with the tunnel #3of the first phase project along the Western Route Project of South-to-North Water Transfer Project. The calculation results show that the elasticity modulus of surrounding rock and inner concrete liner have a greater effect on dynamic stress concentration factor; and the effect of rock Poisson’s ratio on the factor almost can be neglected. The layer between surrounding rock and inner concrete liner exhibited role in seismic isolation under the prerequisite conditions of its elasticity modulus is less than 1/20 of one of the surrounding rock; otherwise, the effect on seismic isolation is not obvious.

The rock shed is the most effective protective structures against rock-fall in mountainous areas; generally, a slab covered with sand-gravel cushion in the zone exposed to falling blocks, which acts as a shock absorber. To determine the impact force is key problem in design of rock shed; however, there is no reasonable calculation formula which result in great waste in project and restrict its application. Meanwhile, as large impact energy, short impact time, involving large deformation and complex energy conversion, the study of dynamic response is also difficult to carry out. This paper takes the rock shed as prototype, using the dynamic finite element method to investigate the impact response of rock shed to rock-fall. The results can provide theoretical base for rock shed design.

The bamboo-steel cable composite anchor (BSCC anchor) is a new anchor with phyllostachys heterocyclavar as pipe material, and was applied to reinforce earthen ruins bequeathed on the ancient silk road in Northwest China, which can get high anchorage strength due to its big cross-section. Field test illustrated that the failure of BSCC anchor was characterized by pulling-out of steel strand from inner binder .In order to understand the working mechanism between inner binder and steel strand, laboratory tests were conducted on four species of specimens, to investigate the bond-slip property between them. The test results indicate that there are three stages for the bond-slip process between inner binder and steel strand which are exponential-enhancing stage, softening-declining stage and residual stress stage. Moreover, the length of softening-declining stage is short, and the bond-slip process can be described by a simplified model and an exact model. It is found that the shear stress is not uniform distributing between the interface of inner binder and steel strand; and it approaches a peak near the loading end; and the peak stress increases and shifts far further from the loading end when pulling load is increased. The average shear stress between inner binder and steel strand, submits exponential decay regularity, and decreases along with the anchor length during the bond-slip process. It acquires the differential equation of bond-slip through theory analysis ,and the variation rules of the axial force of steel strand and relative displacement between the interface of inner binder and steel strand. From results, it is found that the axial force of steel strand and relative displacement decrease along with the anchor length; and the results can be used for anchor design and application.

Rayleigh damping coefficients can influence the result to a great extent for seismic response analysis of earth-rock dam. The method is improved for calculating Royleigh damping coefficients. A series of dynamic analyses are performed in time domain by using different methods for caculating damping respectively and compared with dynamic analyses in frequency domain. The results show that, with the height of earth-rock dam over 100m, the damping coefficient calculated by the first frequency of the structure overestimated the damping in all frequency regions and resulting in underestimation of response; the improved method for caculating damping can reasonably reflect the damping properties of the dam. The dynamic response of Shuangjiangkou dam is analyzed by different methods, for caculating damping to validate the rationality of the improved method.

A continuous version of St. Venant model, named continuous Masing-Iwan model which includes an internal variable, is adopted to simulate the nonlinear behaviors of soils in confined disturbed zone around pile-soil interface. Based on this model two different nonlinear load transfer functions are developed for single piles. By adopting the assumption that the pile-soil-pile interaction effect is elastic and the principle of superposition, two new kinds of load transfer models are obtained for piles in group. Furthermore, by comparing with elastic governing equation, a procedure of perturbation analysis is developed to solve the nonlinear governing equation for both single pile and piles in pile group in an approximate analytical way. The theoretical solution can be asymptotic to the elastic solution rigorously under lower loading and reflects the nonlinearity of load-displacement distribution up to the failure. Finally, the predictions of load settlement distribution from the proposed method are compared with a well-documented full scale field pile group test data, which shows the effectiveness and applicability of these proposed methods.

Squeezed process of compaction pile is considered as a series of constant along the length of the spherical cavity expansion point forming process; the stress distribution due to the spheric cavity expansion is divided into three zones: flow damage zone, plastic deformation zone and elastic deformation zone. The analytical expressions for distribution of the stress and displacement could be deduced on the basis of the cavity expansion theory combining with the Modified Cam-clay model. The results show that the radius of plastic zone is 2.92 times that of radius of pile, verified the feasibility of the method of analysis. The results will provide a new idea for compaction effect research.

As an important part of load transfer behavior and settlement, the research for pile penetration into cushion would improve and perfect the theory of composite ground. There are only few studies of penetration. We analyze the shortcomings of existent calculating methods for penetration, and obtain the more rational method. Finally, this method is compared with the existent methods and model experimental results; it is shown that this method is reasonable and feasible .

Topography affect greatly propagation of vibration wave under condition of variety of terrains. Through analyzing the physical quantity of blasting vibration, a blasting vibration formula of reflecting amplification effect on elevation is established by means of dimensional analysis. Based on the field test of monitoring blasting vibration, when the site topography changes greatly, the velocity error is large by conventional Sodev’s empirical formula, and the average is 42%-59%. The average error of velocity of blasting vibration is respectively 24%-49%, 40%-58%, 58%-59% and 31%-39% with other four practical formulas. The velocity error is small with author’s formula of dimensional analysis; and the average error is only 10%-14%. It is shown that the formula of blasting vibration which is established by means of dimensional analysis can accurately predict amplification effect on positive elevation.

The existing problem of load transmission path of traditional prestressed anchor piles is discussed; and a mechanical calculation model is first proposed based on three-dimensional soil arching effect by its mechanics property; and the correctness of the model is verified. Then the soil arch shape and arch rise are analyzed; and further the mathematical expression of the model is presented. Meanwhile, three-dimensional soil arch formation conditions are demonstrated; static equilibrium and the strength of the conditions are established. On this basis, anchorhead spacing control equation is deduced and the influences of shear strength parameters c and ? and soil pressure q on anchorhead spacing are analyzed. Finally, a project example is given so as to verify saving project cost.

In view of the deficiencies of current ways to calculate weights of indexes when evaluating debris flow risk, modified analytic hierarchy process (AHP) and entropy method are used to calculate the weights of factors of debris flow in the Jinsha River. On this basis, a new combination rule is proposed to determine the weight which can exclude the interference of human factors and unstable data. The fundamental idea is to make the difference between weights same as the difference between distribution coefficients which determine the importance of different types of weights in the evaluation. This way can help us to get a relatively objective and accurate result. Typical debris flows in the Jinsha River are taken for example. After the acquisition of field data, the above-mentioned method is used to calculate the weights of factors. Then they are taken to classical risk analysis model which is totally accepted by the academia. The result coincides with the local conditions which improves the rationality of this method.

In-stitu tests can not be broadly used due to time and funds restrictions, so the strength assessment of jointed rock mass is the problem what engineers concern in practical engineering, Because of its complexity at present there is not yet any rock mass failure criterion can meet practical requirements. For the jointed rock mass, the authors refer research results at home and abroad, Combined with large amount of collected-data and amended the empirical formula based on joint density, a relationship between rock elastic wave velocity and rock mass strength is presented; collect number of empirical formulas based on joint density, rock mass classification, elastic wave velocity, the authors apply their three methods to Jiubao and find that the results fit the practical rock mass strength.

The construction time of secondary lining of tunnel is a very controversial issue in tunneling engineering. Associating with the large-section loess tunnel construction of Zhengzhou—Xi′an high-speed passenger railway, the determinant indexes about the construction time of secondary lining are put forward, which are basic stability deformation rate and basic stability time and distance. The solving method for basic stability deformation rate was carried out with regression analysis and numerical analysis. In this case, we take the Hejiazhuang tunnel as our experimental section, the construction time of secondary lining of large section loess tunnel is studied. The study results indicate: the value of vertical deformation rate of tunnel crown less than 0.55mm/d and the value of horizontal absolute convergence rate of tunnel sidewall less than 0.17mm/d; we can construct the secondary lining. In conclusion, these results are instructive for the design and construction on similar tunneling engineering.

In rock burst forecast tangential stress ?θ is a dynamic index closely related to initial in-situ stress field. According to the results of three-dimensional in-situ stress measurement and occurrence features of multilayer rockmass in Kaiyang Phosphate Mine, some problems of surrounding rock property, space tunnel, inclined bedding, etc. influenced tangential stress ?θ are analyzed. Its initial in-situ stress field shows that the measurement values in sand stone is about 3 times larger than that of red shale though red shale is buried deeper than sandstone. Considering the lithology of measuring points, the viewpoint of region application of initial in-situ stress field is accordingly proposed; similarly, the space decomposition method of in-situ stress is correspondingly put forward to adapt to the spatiality of laneway axial direction. According to above-mentioned methods, numerical simulation indicates that when inclined bedding is taken into account rock burst location is mainly side foot which almost accords with the rock burst in field. Rock burst forecast by region application and space decomposition method is closer to actual case than by linear fitting regression method.

Analyzing the geological condition of the diversion tunnel, and according to the layout features of the tunnel and field construction situation, the scheme of fixed measuring points was adopted to monitor the tunnel excavation By analyzing the test data, we found that the particles vibration velocities have obvious directional effect; and the vibration velocities of the particles those faces towards free face are much greater than those of the particles in other direction. If measuring points and explosion points are not in the same elevation, and when the ratio between elevation difference and blast center distance is relatively large, the difference of the peak vibration velocities in different directions caused by elevation effect is obvious; and when the ratio is relatively small, the elevation effect weakens obviously. For the relation between elevation difference and the blasting vibration attenuation, previous studies put forward some amended formulas; however, these formulas took the elevation difference as an independent variable to consider, and the physical meaning was not clear. According to the previous data analysis, considering the practical meaning of elevation effect and combining dimensionless analysis, we take the ratio between elevation difference and blast center distance as the impact factor of elevation effect, and modify the traditional empirical formulas of blasting vibration attenuation. Through contrasting and analyzing, the modified empirical formula is relatively precise. In the meantime, the condition that vibration velocities exceeded the standard is analyzed and blasting parameters are adjusted in time, which control the damage effect of blasting vibration effectively. This research plays an important role in guiding the excavation blasting construction in tunnel projects and assuring the safety of dam body and dam curtain, which ensures the successful completion of blasting construction.

Compared with Mohr-Coulomb strength criterion, Hoek-Brown strength criterion considers more influential factors such as the rock structure, rock mass strength, rock mass stress state,and so on. It reflects the nonlinear failure characteristics more accurately and consists with practical rock engineering much better. The estimated mechanical parameters of rock masses based on Hoek-Brown strength criterion could provide important reference for ultimate determination mechanical parameters of rock masses. A quantitative geological strength index (GSI)rock mass classification system based on volumetric joint count Jv and joint condition factor JC and Hoek-Brown strength criterion can estimate mechanical parameters of rock masses, and connected with the practical engineering to verify its application effect. The results will provide important guiding significance to engineering design and construction.

Infrared imaging system is used for earthen architecture protection in Ruins of Jiaohe for the first time, solving the problem of earthen architecture temperature measurement. The law of surface temperature changing with time and space for the wall of rammed earth architecture is obtained by field monitoring. It’s come to a conclusion that solar radiation, orientation of wall and the degree of wall surface weathering are significant factors which have an influence on surface temperature of earthen architecture. The maximum daily temperature difference of the wall reaches 35?C during the monitoring. It can be supposed that the temperature difference will higher at extremes of heat and cold. The acute change of surface temperature weakens soil strength and exacerbates soil mass deterioration. The prediction model of the surface temperature for rammed earthen architecture, by which the daily temperature difference can be calculated, is established on the basis of above analysis, which provides data support to the researches on migration of hydrothermal and salt.

Through massive examples of multilayer slopes with different intensities, slopes and thicknesses of soil layer, the factors of safety and the locations of critical failure surfaces obtained by the strength reduction method and limit equilibrium method are compared. The differences between two methods are investigated. Failure mechanism of multilayer slopes is studied. The result of numerical simulation shows: ①If the shear strength of the lower layer is larger than the upper one, when difference in shear strength between two layers increases to a certain degree, soil in the upper breaks. Meanwhile, the relative difference of strength reduction method (SRM) and limit equilibrium method (LEM) is in maximum, about 5%-7%. When thickness of upper soil layer increases, the factor of safety gradually decreases; when the upper layer locates below surface, critical failure surface throughs the toe of slope; the factor of safety remains unchanged. ②If the shear strength of the upper layer is larger than the lower, when difference in shear strength between two layers increases to a certain degree, the factors of safety obtained by SRM tend to be stable. As to LEM, the factors of safety maintains increase, the relative difference of is 12% in maximum. When thickness of upper soil layer is increased, the factor of safety increases correspondingly. When thickness of upper soil layer is in the range of 9-12 m, failure mode is deep layer slide, while h=12 m, critical failure surface obtained by LEM just throughs the toe of slope; but with a very small difference in the factor of safety. When thickness of upper soil layer is in the range of 3-5 m, the relative difference of two method is in maximum, about 6%-10%. The distribution of failure zone indicates that multilayer slope is caused by tension and shear failure. As to the slope which the shear strength of the upper layer is larger, this composite failure mechanism is obvious. In comparison with single shear failure, the relative difference is about 10% in maximum.

A three-dimensional numerical manifold method for seepage problems with free surfaces is proposed. The hydraulic potential functions for arbitrarily shaped manifold element are constructed and the element conductivity matrix is derived in detail. The global governing equations for unconfined seepage analysis are established by minimizing the flow dissipation energy. The proposed method employs the tetrahedral mathematical meshes to cover the whole material volume. In the process of iterative solving for locating the free surface, the numerical manifold method can strictly realize the seepage analysis of the saturated domain on the condition of mathematical meshes keeping unchanged. Furthermore, the seepage force acting on the transitional elements cut by the free surface can be accurately calculated by the manifold method. Therefore, the proposed method is featured in high accuracy, fast convergence rate and simple programming, especially applicable to simulate the unconfined seepage problem with free surface.

Rock burst is a serious problem during the excavation process of the ventilation shaft No.2 of Qinling highway tunnel according to the analysis of in-situ engineering geological condition. Rock burst mechanism is a physical process related to the rock microstructure including particle diameter, particle cement and particle void, etc. The microscopic parameters of mixed gneiss are calibrated based on the theory of particle flow and basic macroscopic mechanic properties of mixed gneiss. The analysis of similarity criteria about particle flow simulation is conducted because particle diameters are not free parameters and then the rock burst mechanism is simulated using particle mechanics approach and strength reduction method. The results show that the rock burst mechanism is a progressive failure process including crack initiation, crack propagation, crack coalescence and formation of macroscopic fracture. The failure type is compression–induced tensile-shear failure; and it is dominantly tensile cracking. The results provide preliminarily references for stability analysis of rock burst of ventilation shaft.

For general stability analysis of slopes, a new method that can search for random sliding surface is found by using a series of random angles. In this process, simplified Janbu method is used to calculate the safety of factor. The process of this new method creating random sliding surface is as follows: firstly the intersection point of upper edge and lower edge of slope and sliding surface have been identified; then in the case of some initial direction, every angle direction randomly generated with intersection of the lower edge as base point is made to intersect with corresponding vertical line of divided slices of sliding body until random angle direction arrived connection direction of intersection point of upper edge and lower edge of slope; at the end, a random curve, or called random sliding surface, is obtained by connecting these intersections successively. Through simulating curves randomly, it is found that random angles have a clear physical meaning and two unique advantages as follows. First, it has only one random condition, so random factors are easily controlled; and computer programming is also convenient. Second, if random angles are appropriately optimized, it can ensure that the random curve is a smooth curve; and we can also get all shape curves when there are enough slices. At the same time, as non-high accuracy of random search in the past, this article takes improved method that approximate curves replace random curves, and generation of approximate curves is also simplified. Through comparison and analysis of a series of examples of slopes, it is concluded that factor of safety calculated by this method is quite close with research results; and the critical sliding surface derived from this method is identical with real situation; so it is shown that this method can be used in the general stability analysis of slopes.

Based on the elastic foundation beam theory, the finite element method in which step excavation and support in stage is considered, is adopted to simulate the actual situation of excavation construction; and the displacement back analysis of m value of soils is carried out, according to field monitoring data, to provide reliable guarantee for predicting the deformations in succession construction stages. Firstly, support system FEM model is established by using APDL language embedded in ANSYS software. Then, the modified simplex optimization program is programmed by Matlab software, with calling the ANSYS FEM model circularly through original interface program in order to implement optimization inversion step by step. Through the calculation of deep foundation pit of Wuhan Yangtze River tunnel in Wuchang open excavation section, it is proved that the jointed programming technology based on modified simplex method can be easily and efficiently applied to the displacement back analysis and forecasting of retaining structure. Finally, an extended displacement back analysis and forecast model is established which can forecast the retaining structure displacement for the next working condition or adjacent sections based on the current condition. And the predicted results and measured results represent a high degree of fitting in the calculation example.

Apparent particle size grading is the most important characteristic of super-high dumping site, which is different from soil slope. On the basis of the development of the HHC-CA model and on-site survey of granular size distribution, the slope model of current situation，considering the features of particle size grading, was established according to Xiyuanlin 413 step dumping site．FLAC3D was used to analyze the slope stability of current situation and various piling up patterns slope based on the slope model．The results indicated that the upper displacement vector, whose displacement direction maintained the same direction of the current situation slope of Xiyuanlin 413 step dumping site，performanced for subsidence．The middle displacement vectors showed shear and the displacement vector of bottom had slightly the trend of anti-lift．The slope failure model of current situation expressed in crack at the top platform and shearing out with a arc in the middle．This status of current situation slope was temporary steady stage．To adopt full overlay dump of multi-step, the displacement vector of dumping site slope showed subsidence at the top and transited to the horizontal direction at the bottom．The slope failure mode expressed in crack at the top platform and shearing out with a arc at the bottom. When considering the influence of strength characteristics of granular pile on the slope stability only, the particle size grading of super-high dumping site is helpful to slope stability．

Triangular elements with constant strain rate and linearization of Mohr-Coulomb criterion are regularly used for finite element upper bound solution to form a linear programming model. However, a calculating and storage difficulty has been brought out by numerous variables, which are required to be introduced in the linear program, to seek for precision requirement. Calculating program using Matlab for finite element upper bound solution is compiled based on linear programming model. And it takes full advantage of the highly sparseness of equality constraint matrix. By saving the matrix as sparsematrix, the calculating and storage problem can be solved. Finally, stability problems of large-scale geotechnical engineering can also be solved. A calculating example of the bearing capacity of strip footing is given to show the validity of the compiled program and the effect of precise results on the number of elements; and plastic multiplier rate has been discussed.

Based on three-dimensional mathematical model of groundwater flow to horizontal well，the finite layer equations and the formula of sources and sinks is presented by using the principles of semi-analytical numerical analysis in layered anisotropic confined aquifer. A computer program is developed for solving the finite layer equations. Numerical examples are given and compared with analytical solution and finite difference solution to verify the validity of the presented method and the program. The comparative analysis of finite layer method(FLM) and finite difference method(FDM) shows that the FLM is suitable for modeling the three-dimensional groundwater flow to horizontal well in anisotropic layered confined aquifer; and it has high computational efficiency.

In this paper, by taking the landslide as the research object which may be formed at Huashiban tension crack zone in the Tiger Leaping Gorge of the Jinsha River, according to the results of Huashiban slope stability analysis, the volume of landslide is obtained; on the basis of analyzing the landslide hazard characteristics of natural river in deep-cut gorge, the hazards to the plants site area of Liangjiaren hydropower station may be caused by Huashiban landslide are analyzed, which based on predicting the landslide swell height, simulating the water level rising process and evaluating the maximum size of block stone carried by dam breaking flow, the conclusions which according to above analysis will be treated as the basis for feasibility study on decision making of Liangjiaren powerhouse sites selection. A new method of simulating the water level rising process due to the weir dam blocking up a river is proposed on the basis of hydrodynamic numerical simulation which using Delft3D software, as well as the method of estimating the maximum size of block stone carried by dam breaking flow is given, which based on applying the theory of riprap grain size for closure by vertical blockade in the field of water conservancy and hydropower project; these methods can be used as a reference to hazard prevention measures and disaster effects analysis of the natural river landslide in deep-cut gorge.

The process of rock breaking under abrasive water jet(AWJ) is concerned with lots of factors; and it is a complicated and nonlinear dynamic coupling problem between multiphase flow and structure. Based on the arbitrary Lagrangian Eulerian(ALE) fluid-solid coupling penalty function method, a model of rock breaking under AWJ is established with continuum damage mechanics and micro damage mechanics.The results show that the body of rock damage and breakage is mainly attributed to impact; the local effect is the main feature; and the evolvement of rock damage shows a funnel trend. The results show that the internal process of breaking rock experienced three stages within 50 microseconds. On the whole, numerical results agree with relevant results; and the numerical simulation is the important aspect for developing and applying abrasive water jet breaking rock technology.

All naturally formed rocks belong to multicrystal material; and abundant mesascopic experimental studies reveal that the rock failure is mainly caused by intercrystalline fracture which occurs along the boundaries of crystalline grains of the rocks. The extension of the cracks along the kink grain boundaries constitutes the form of winged crack extension among different materials. At present, there are many methods to calculate the winged cracks; and most results are obtained based on equivalent method under the condition of homogeneous medium. This paper establishes the computational process by using ANSYS Parametric Design Language and obtains winged crack tip stress intensity factor at the interface of the intercrystalline fracture via using the numerical extrapolation method for the nodes displacement.Then a comparison is made with the HN approximate calculation model brought forward by H.Horri and S.Nemat-Nasser; the similarities and differences of crack extension between the heterogeneous brittle material and the homogeneous material are analyzed; and also, the influence exerted by the geometrical characteristics of the crystalline grain and the heterogeneity degree (Dundurs parameter) of the material on the crack extension are studied. The result takes the multicrystallinity and heterogeneity of the rocks into consideration and reveals the changing process of the stress intensity factor when the intercrystalline crack extends in the rock.

The centrifugal modeling system has been established relying on Tsinghua University 50g-t geotechnical centrifuge. The system is composed of six segments which are model box system, data collecting system, data storage system, communication system, analytical system and detonation system. It can avoid the high-level centrifugal effect and collect high quality data. This system can collect such parameters as stress, strain and acceleration simultanously. Level ground experiment has been done; the results prove that the system has the capability of testing parameters under the condition of blasting; and it provides favorable condition for more complicated blasting experiments.

Collecting the digital images of geological drilling holes and interpreting the underground geological structure is a new method of geological prospecting. The interpretation of structural planes on drilling holes images is usually done by hand; and results of interpretation may be quite different for different people. Automatic identification system of structural plane (AISSP) can process the digital images of drilling holes to get structural plane parameters automatically. First of all, the images conversion from RGB color space to HSV color space should be done to highlight the structural plane region. Secondly, the S component images are filtered and enhanced for the next processing step. After the image segmentation, the binary image edge will be extracted and thinned by image morphology method; and edges of the structural plane are effectively extracted. Finally, structure plane altitude and thickness parameters are obtained by the Hough transform of sine curve and identified edge points. As example, a real digital drilling hole picture is analyzed by AISSP and the space parameters of the 4 structural planes appearing in the picture are calculated. Compared with the results interpreted by people, the results from AISSP are more precise and unique.