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EXPECTED SLIDE PATH METHOD FOR STABILITY ANALYSIS OF ROCK MASS BASED ON STATISTICS MODEL OF JOINTS AND STRESS FIELD
DEM ANALYSIS ON THE THIRD PERIOD LONGITUDINAL COFFERDAM OF THE THREE GORGES UNDER BLAST LOADING
CREEP CHARACTERISTIC AND LONG-TERM STABILITY OF ROCK MASS IN SHIP LOCK HIGH SLOPE OF THE THREE GORGES PROJECT
ADAPTIVE ELASTO-VISCO-PLASTIC FINITE ELEMENT ANALYSIS OF THE STABILITY OF DAYANTANG SLOPE
FRACTURE-DAMAGE MODEL OF JOINTED ROCKMASS AND ITS APPLICATION TO THE NUMERICAL PARAMETES PREDICTING OF THE DAM-BED-ROCK OF THE THREE GORGES PROJECT
MONITOR OF DISTURBED ZONE FOR ROCK SLOPE BY SLIDING DEFORMETER
STUDY ON THE FORMING MECHANISM OF DISPLACEMENT VECTOR ANGLE AND STABILITY EVOLUTION RELATION OF ACCUMULATIVE-FORMATION SLOPES
THEORETICAL AND EXPERIMENTAL STUDY ON TIME-TEMPERATURE EQUIVALENT PRINCIPLE FOR ROCK
STUDY ON DETERMINATION OF SHEAR FRACTURE TOUGHNESS(KIIc)
STUDY ON FRACTAL INTERFACE EFFECT AND DYNAMIC PROBLEM OF GRAVITY-TYPE FRACTURE SURFACE SLIDING
ELASTO-PLASTIC MODEL OF SOFT CLAY UNDER REVERSAL LOAD
EXPERIMENTAL AND THEORETICAL STUDY ON SIZE EFFECT ON STRAIN SOFTENING OF ROCK MATERIALS
STUDY ON THE CO-RELATION LAW OF FRACTAL DISTRIBUTION OF CRACK IN ROCK STRATUM
CALCULATION ON ENERGY RELIEF AND LOAD EFFECT CAUSED BY BRITTLE FAILURE OF PRESSED POST
3-DIMENSIONAL NON-LINEAR FINITE ELEMENT SIMULATION OF TUNNEL STRUCTURE FOR MOVING-FORWARD SHIELD
STUDY ON MECHANICAL BEHAVIOR OF JOINTED ROCK MASS AFFECTED BY TEMPERATURE AND SATURATED WATER
The mechanic function is theoretically described with the relationship between effective elastic moduli of saturated cracks of jointed rock mass and elastic moduli of rock,derived by O′Connell.According to the implication of the crack-density parameter in the relationship,the mathematical relationship is derived between the crack-density and the fracture tensor introduced by Oda under temperature effect.On the basis of the experiment results,under the effects of temperature and saturated water the regression expression of stress-strain and the compressive strength are obtained for the rock mass with single joint.The model is demonstrated by the results of test. The mechanical model can be used for THM coupling analysis on jointed rock mass.
SEEPAGE FIELD CHANGES OF SHIPLOCK SLOPE OF TGP UNDER RAINING AND PERCOLATION
NUMERICAL ANALYSIS ON REINFORCED CONCRETE LINING FOR OUTLET MANIFOLD OF YELLOW RIVER DIVERSION PROJECT
DESIGN METHOD OF RETAINING PILE WITH PRESTRESSED CABLE
MODEL TESTING RESEARCH ON THE VARIATION OF TENSION FORCE OF ANCHOR CABLE WITH TIME IN REINFORCEMENT OF SOFT ROCKS
STRESS ANALYSIS AND INSTALLATION PROCEDURES OF ROCK BOLT FOR PERMANENT SHIPLOCK OF TGP
STABILIZATION TECHNOLOGY ON THE HIGH-STEEP ROCK SLOPE IN THE THREE GORGES PROJECT SHIPLOCK
UTILIZATION AND STRENGTHENING OF ROCK MASS OF DIVISION PIER AT TGP PERMANENT SHIPLOCK
STUDY ON KEY TECHNOLOGY OF FULLY-MECHANIZED SUB-LEVEL CAVING MINING FOR SPECIAL THICK AND HARD COAL SEAM
After analyzing fully-mechanized sub-level caving technology in the case of special thick and hard coal seam,it is presented that the increment of cavability of hard roof coal and available control of gas are the main difficult technology problem to be faced. The structure and breaking characteristic of hard roof coal are analysed,and the main technology approach and measurements to increase cavability of hard roof coal are proposed. The technology has been successfully applied in Baijigou colliery,Ningxia,where the coal seam is thicker than 20 m,with hard coal,hard roof,intensive gas and shallow oveburden. The annual output of coal there is 1.5 million tons. The proposed technigue is a breakthrough to sub-level caving mining technique,and anticipative effect has been obtained.
MECHANISM ANALYSIS ON GEOLOGICAL HAZARDS TRIGGERED BY EXTERNAL DISTURBANCE
CAUSE ANALYSIS AND QUASI-QUANTITATIVE PREDICTION ON THE COLLAPSE OF KARST OVERBURDEN
RESEARCH ON RELATIONSHIP AMONG LONGITUDINAL AND TRANSVERSE WAVE VELOCITIES AND TEMPERATURE OF ARTIFICIALLY FROZEN CLAY
PURE SHEAR FRACTURE OF BRITTLE ROCK ——A THEORETICAL AND LABORATORY STUDY
The determination of pure shear (Mode Ⅱ) fracture toughness,KIIc,for brittle rock is studied. Three types of specimens,which are anti-symmetric four-point bending specimen,direct shearing specimen and shear-box specimen,are experimentally investigated. A new criterion is established for either Mode I (tensile) or Mode Ⅱ (shear) fracture of brittle rock,which clearly distinguishes the fracture mode from the loading mode. With guiding-grooves in both the anti-symmetric four-point bending and the direct shearing specimens,Mode Ⅱ fracture can be successfully created. Numerical calculations show that the guiding-grooves in the notch plane can depress the tensile stresses at the notch tips and enable the crack to propagate along the notch plane. The value of KIIc obtained in this case is 2~3 times as high as the magnitude of KIc,which is considered as the true Mode Ⅱ fracture toughness of rock. Mode Ⅱ fracture can be easily created in a shear-box loaded square specimen.The compressive stress in the two directions can completely depress the tensile stresses around the notch tips and makes it easy for the crack to initiate and propagate along the notch plane,leading to Mode Ⅱ fracture. The shear-box test is suggested as a method for determining the Mode Ⅱ fracture toughness of rock. Both theoretical and laboratory studies of shear-box test show that the apparent Mode Ⅱ fracture toughness ,i.e. Mode Ⅱ fracture toughness under the compressive stress,linearly increases with the compressive stress on the notch plane. The intercept of straight line of versus (i. e. = 0) is defined as the Mode II fracture toughness KIIc. In some cases,it is not KIIc but that needs to be known. For instance,the pre-existing cracks and discontinuities in rock and rock masses are subjected to compressive loading in most cases. What is useful in this case is the Model II fracture toughness under the in-situ compressive stress, ,instead of KIIc. The size effect on the determination of KIIc has been experimentally studied. The examined dimensions include the specimen thickness B,the dimensionless notch length a /W,and the notch inclination angle a. Test results show that KIIc decreases with the increment of the specimen thickness B and becomes a constant when B is equal to or larger than the specimen height W for both the single- and double-notched specimens. When the dimensionless notch length a /W increases,KIIc decreases and approaches a limit if a /W is in the interval of 0.5~0.6 for single-notched specimens and 0.3~0.35 for double-notched specimens. The notch inclination angle has a significant effect on the failure pattern of the specimen. Too small or too large a will lead to either local crushing or Model I fracture. The favorable range for a is 60°~75° for Model Ⅱ fracture. Finally,a new criterion is established based on the examination of the Mode Ⅰ and Model Ⅱ stress intensity factors,KI(q ) and KII(q ). The criterion can predict either Model I or Model Ⅱ fractures,no matter what kind of loading condition is applied. Model Ⅱ fracture occurs when the ratio of KIImax to KImax is larger than that of KIIc to KIc and KIImax reaches its critical value,KIIc.
RESEARCH ON THE LOADING TEST AND STRUCTURAL MODELS OF PREFABRICATED SEGMENT REINFORCED BY SECONDARY LINING