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2004, 23 (01): -0 doi:
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2004年第1期目录

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ANALYSES ON STRAIN LOCALIZATION AND COMPLETE STRESS-STRAIN RELATION OF MESOSCOPIC HETEROGENOUS ROCK UNDER UNIAXIAL TENSION

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2004, 23 (01): -1 doi:
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Stress redistribution induced by excavation results in the tensile zone in parts of the surrounding rock mass. A micromechanics-based model is proposed for brittle rock undergoing irreversible changes of microscopics structures due to microcrack growth. The influences of all microcracks with different sizes and orientations are introduced into the overall compliance tensor by using the statistical average method. Overall compliances of damaged brittle rock are nonsymmetric and anisotropic. Micromechanical kinetic equations for microcrack growth characterizing the ‘process domains’of active microcracks are introduced. These ‘process domains’together with ‘open microcrack domains’domcom pletely define the integration domains of ensemble averaged constitutive equations relating macro-strain and macro-stress. Special attention is paid to the transition from structural rearrangements on the microscale to the macroscopic inelastic strain. Analyses are made on the localization of strain and damage. Results show that the onset of localization is very sensitive to the details of a constitutive law. The complete stress-strain relation including linear elasticity，non-linear hardening，rapid stress drop and strain softening is established. The behaviour of rapid stress drop and strain softening are due to localization of strain and damage. The constitutive model to analyse the localization of strain and damage is distinct from the conventional model. An illustrative example is worked out to show the capability of the presented model to predict experimentally observed reponse of brittle rock. It is emphasized that no fitted phenomenological material parameter is employed in the proposed damage model.

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INFLUENCE OF RATIO OF MESOSCOPIC COMPRESSIVE STRENGTH
TO MESOSCOPIC TENSILE STRENGTH ON PROGRESSIVE
FAILURE OF ROCK

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2004, 23 (01): -7 doi:
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Numerical simulation software RFPA2D is used to analysis the progressive failure process of rock with different ，the ratio of mesoscopic compressive strength to mesoscopic tensile strength. Ten rock samples are divided into five sets with 1，3，5，7 and 9，and they are subjected to uniaxial compressive loading. In order to investigate the influence of on the fracture process and failure mode of rock，the rock samples in different sets are of the same mechanical parameters except . The results show that is an important parameter of rock. With the increase of ，the macroscopic peak strength and residual strength decrease and the failure mode changes from shear failure mode to tensile failure mode. However, when decreases to a certain value, it has little influence on rock deformation and failure mode.

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ELASTIC AND ELASTOPLASTIC ANALYSIS METHODS OF DISCONTINUOUS DEFORMATION FOR MULTI-BODY SYSTEM(I)
—— FUNDAMENTALS

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2004, 23 (01): -12 doi:
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Discontinuous deformation is a fundamental character of multi-body system. For the general plane problem，divisional parameter principle of minimum potential energy is employed to establish the computational model for discontinuous deformation analysis of multi-body system in this paper. Mathematical formulations of global controlling equations of elastic and elastoplastic analysis of discontinuous deformation of multi-body system are presented and the numerical solution approach is developed. The mothod can not only perform both static and dynamic coupling analysis，but also conduct step-by-step simulation and prediction of deformations and stresses of multi-body system together with complex nonlinear process such as contact stress and relative movement along contact interfaces. The theoretical basis is established for numerical model of discontinuous deformation computational mechanics.

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ELASTIC AND ELASTOPLASTIC ANALYSIS METHODS OF DISCONTINUOUS DEFORMATION FOR MULTI-BODY SYSTEM (II)
——NUMERICAL EXAMPLES

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2004, 23 (01): -17 doi:
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Several specific numerical examples and analysis are made for complex multi-body system composed of rigid bodies，elastic bodies and elastoplastic bodies with applications of elastic and elastoplastic analysis methods of discontinuous deformation of multi-body system from different aspects. The effects of mechanics parameters of contact interfaces and strength parameters of materials on deformations，stresses and contact stresses，and plastic zone of these systems are studied. Very interesting results and comparatively reasonable conclusions are obtained. From examples it is showed that discontinuous deformation computational mechanics model is a new and powerful method of numerical analysis and simulation，and may process numerical analysis and simulation of static，dynamic and coupled nonlinearities of contact and materials for general complex multi-body system composed of rigid bodies，elastic bodies and elastoplastic bodies，with wide-range application foreground.

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REMOTE SENSING-ROCK MECHANICS ( I )————
LAWS OF THERMAL INFRARED RADIATION FROM FRACTURING
OF DISCONTINOUS JOINTED FAULTS AND ITS MEANINGS FOR TECTONIC EARTHQUAKE OMENS

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2004, 23 (01): -24 doi:
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The fracturing of discontinuous jointed faults is a mechanism of tectonic earthquake. By use of biaxial loading system and thermal infrared imaging system，the thermal infrared radiation features of two kinds of discontinuous jointed faults，en echelon faults and collinear disconnected faults，were experimentally studied in the process of loading and fracturing. It is revealed that the thermal infrared radiation of the surface of loaded samples is related to the load stress，and the variation stage can be classified into five stages including initial，elastic，stress blocking，stress deblocking and fracturing stage. From elastic stage to stress deblocking one，the dynamic curve of average infrared radiation temperature (AIRT) vs time is of the features of rising to dropping，and to rising again. During the stage of stress deblocking，positive infrared abnormity strip emerges in the discontinuous locations of en echelon faults and disconnected faults，and the positive infrared abnormity strip of disconnected faults is of the features of enhancing to weakening (or silence)，and to enhancing again. Its important meanings for earthquake omens include that (1) the rise of AIRT curve of satellite infrared remote sensing for the seismic active region can be taken as the index for the middle-term forecast of structural earthquake，(2) the location of local positive infrared abnormity strip can be used to predict the location of hypocenter and (3) the dropping of AIRT curve together with the weakening (silence) of local positive infrared abnormity strip can be taken as the short-term prediction omen.

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ANALYSIS ON INCLINATION ANGLE OF SHEAR
BAND UNDER LOW CONFINING PRESSURE
BASED ON GRADIENT-DEPENDENT PLASTICITY

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2004, 23 (01): -31 doi:
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The inclination angle of shear band is analyzed considering heterogeneity of rock material when a single shear band is formed in the center of specimen under triaxial compression. The analytical solution of post-peak axial stress-axial strain curve is deduced using the assumption that the total post-peak deformation is composed of entire uniform elastic deformation and localized shear plastic deformation dependent on the thickness of shear band. The obtained solution shows that the post-peak stiffness is related to the inclination angle of shear band，confining pressure，thickness of shear band and elastic modulus，etc. Using the solution，the expression for the inclination angle of shear band can be presented easily and it is dependent on constitutive parameters of rock material and geometry parameters of rock specimen. Larger dilation angle or loading rate leads to increment of the inclination angle. In addition，the inclination angle increases with the thickness of the shear band，which cannot be explained or forecasted by other existing solutions，such as Coulomb inclination，Roscoe inclination and Arthur inclination，etc. The presented analytical results are compared with earlier experimental investigations and the agreement is good.

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APPLICATION OF CATASTROPHE THEORY TO SAND LIQUEFACTION ANALYSIS

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2004, 23 (01): -35 doi:
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In this paper the liquefaction of sand is discussed based on catastrophe theory，which reflects the discontinuous changes during some physical progress. A catastrophe model on the liquefaction of saturated sand is set up with the analysis method of liquefaction safety factor of sand，and a series of cases for the liquefaction of sand are estimated by the measured data. The results calculated by catastrophe theory model are in agreement with practical facts. The application of catastrophe theory to the liquefaction analysis of saturated sands is efficient and feasible.

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LONG-TERM PERFORMANCE AND LOAD PREDICTION MODEL
OF PRESTRESSED CABLES

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2004, 23 (01): -39 doi:
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The long-term performance of prestressed rock cables constitutes an important aspect of stability of the reinforced slopes. Based on analyzing the factors affecting the load variation in long-term，the variation law of prestress load is obtained，and prediction model is also developed. Monitoring data show that the load variations with time can be described as three phases. Phase I，lasting about 3～6 months，includes instantaneous losses of load during the lock-off operation. Phase II may take several years，in which load fluctuates. In phase III，the load is losed with uniform rate in long time. The main factors affecting the long-term performance of prestress rock cables are rock deformation，steel fiber relaxation and temperature change. The presented prediction model has been applied to practical engineering and good agreement is obtained with field monitoring data.

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STUDY ON DEFORMATION AND INTERNAL FORCE OF SURROUNDING ROCKS AND INITIAL SUPPORT IN DAFENGYAKOU ROCK ROAD TUNNEL

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2004, 23 (01): -44 doi:
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The long rock road tunnel named Dafengyakou in Yunnan province, a one-way and double lane tunnel with disjunctive up and down lines，is constructed by NATM. The tunnel is about 3 300 m long. After analyzing the monitoring data，such as the convergence, crown displacement，internal displacement，internal force of the initial support, the laws for the changes of the internal force and deformation of the surrounding rocks and initial support including the creep of rock with time and excavation are studied. The creep deformation of sandstone in this tunnel is found to be agreement with the formula put forward by Evans. In the excavation of top and bottom bench，there is a simple linear relationship between the internal displacement of surrounding rocks and the radial distance to the inside of tunnel. During the excavation of top bench，there is also a linear relationship between the displacement rate and the logarithmic value of the distance between the face of top bench and the measured section. It is also shown that the disturbance of excavation of top bench on surrounding rocks is larger than that of bottom bench. The measured contact pressure between the initial lining and surrounding rocks at the crown is smaller than the calculated data by Chinese road tunnel code. The relationship between the internal force after the excavation of top bench and the reciprocal value of the distance between the face and section satisfies the exponential rule. All the obtained conclusions can guide the construction of the rock road tunnel.

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NEW METHOD FOR ESTIMATING TRACE LENGTH OF DISCONTINUITIES AND ITS ENGINEERING APPLICATION

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2004, 23 (01): -53 doi:
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According to geometrical relationship between discontinuities and measuring window and referring to H-H method for trace length estimation，a new expression is proposed to express probability relationship between trace length of discontinuity and its orientation. Base on Laslett method for trace length estimation，the generalized H-H method for trace length estimation is put forwad，which overcomes some disadvantages of H-H method and extends its area of applications. Using this method，an application example of rock engineering is analyzed.

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APPLICATION OF HIERARCHICAL BLOCK ELEMENT METHOD TO DEFORMATION AND STABILITY ANALYSIS OF GRAVITY DAM ON COMPLICATED ROCK FOUNDATION

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2004, 23 (01): -58 doi:
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The application of hierarchical block element method to the deformation and stability analysis of gravity dam is briefly introduced. By using elasto-viscoplastic hierarchical block element method，the deformation and stability of gravity dam located on complicated rock foundation are analyzed and the calculation results are in favorable agreement with those obtained from physical model tests. The distribution rules of displacement，stress and local safety factor of dam and foundation system are revealed. The comparisons of the results between model tests and numerical calculations show the correctness and validity of elasto-viscoplastic hierarchical block element method illustrated in this paper. Additionally，some practical problems，such as simulations of embedded penstock and seam between dam body and power plant，and evaluation of dam safety，are tentatively explored.

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NUMERICAL ANALYSIS ON SPATIAL EFFECT OF MECHANICAL PARAMETER OF SURROUNDING ROCKS IN JINCHUAN DEPOSIT Ⅱ

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2004, 23 (01): -64 doi:
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FEM back-analysis of displacement is used to explore the spatial effect of deformation modulus of surrounding rocks in Jinchuan deposit II. After analysis，it is found that the deformation modulus is changed greatly as a result of excavation and unloading of surrounding rocks which is situated in the environment of high stress field and bad engineering geology conditions. At the same time，the spatial distribution of deformation modulus is obtained.

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STUDY ON MECHANICAL PRINCIPLE AND CONTROL TECHNIQUE OF FLOOR HEAVE IN ROADWAY DRIVEN ALONG NEXT GOAF

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2004, 23 (01): -69 doi:
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The mechanical situation of the roadway is different from that of average gateway. On one side of the roadway is the relative integrated coal seam and on the other side is the narrow pillar in which plastic deformation has occurred. The high abutment pressure zone on the integrated coal beside the roadway will occur due to superposition of the advancing abutment pressure in front of working face and the concentration stress of the goaf side in the course of extraction. The stress on the integrated coal is much greater than that on any side of the average gateway. The stress distribution in surrounding rocks and floor heave process of roadway driven along next goaf is analyzed by numerical simulation. It is supposed that when the roadway is near the next goaf，the floor is not affected by the horizontal stress，and the floor heave is formed because the floor rock moves into the interior of the roadway along next goaf under high stress on coal mass side. The narrow coal pillar may control elevation of the floor. The control technique of floor heave is introduced and applied to engineering practice.

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SAFETY ANALYSIS OF SECONDARY LINING OF A FREEWAY TUNNEL

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2004, 23 (01): -75 doi:
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Safety of secondary lining is of utmost importance to tunnel engineering quality as the main bearing structure and the last water-prevent line for rock types I，II，III. In this paper，firstly the rock stress on secondary lining of a freeway tunnel is obtained to provide a comparable criteria for its measured data，according to design specification of highway tunnel and P′s theory. Then the secondary lining strength in maximal measured-stress face is checked on the basis of numerical results of internal stress obtained by using GeoFBA code of Tongji University and design specification of highway tunnel. Finally，the reasons of the induced microcracks are listed after consideration of design parameters，given engineering case，and construction speed.

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REINFORCEMENT STUDY OF ROCK WALL ISOLATED BY COMPLEX TUNEELS IN SOFT-FRACTURED ROCK MASS

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2004, 23 (01): -79 doi:
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Abstract The failure background of an isolated rock wall in soft fractured rock mass of a mine shaft bottom is introduced. The in-situ rock stress near the shaft bottom is measured by using the over coring technique of hollow inclusion gauge. Four core boreholes are drilled from the surface of shaft field，and two core boreholes are drilled from the underground opening，which go into the isolated rock wall. Many core rock samples are obtained from the boreholes. The clay minerals of the rock samples are analyzed qualitatively and quantitatively，and the physico-mechanical parameters of the samples are tested. Using Hoek-Brown rock mass strength criterion，the strength parameters of the isolated rock wall are determined. The deformation parameters and Poisson’s ratio of the rock mass are also determined by W. Dershowits’ experience method. By using engineering geological classification-supporting method for surrounding rock stability of underground tunnel，the suitable support pattern and system are determined. The stability of the surrounding rocks and support system of the tunnels in the mine shaft bottom is analyzed according to the calculated and simulated results of 3D FEM. The reason of unsuccessful support in the past is analyzed，and a new type of reinforcement support for the isolated rock wall is proposed，which uses prestressed cable and grouting and makes successful application to practice.

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STUDY ON DYNAMIC NUMERICAL SIMULATION OF MINING-INDUCED SUBSIDENCE

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2004, 23 (01): -86 doi:
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In this paper，a dynamic analysis model of mining-induced subsidence is established，based on the analysis on the laws of movement and deformation inside overburden rock mass. Rock mass movement is under control of four essential factors，that is，face movement，overburden structure evolution，rock mass creep and waster compacting. The special program is developed for FEM analysis of plane problem. The presented model is applicable to prediction of mining-induced subsidence，analysis of the movement state，and especially control of mining-induced subsidence.

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ANALYTICAL CALCULATION ON STABILITY OF SLOPE WITH PLANAR
FAILURE SURFACE

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2004, 23 (01): -91 doi:
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The most critical slip surface and the minimum safety factor of slope are obtained by taking minimization value of a function. Planar failure surface whose shape is broken line or bench，tensile crack，water pressure and earthquake effects are considered. Limiting equilibrium principle is the basis of analytical calculation in this paper.

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NUMERICAL SIMULATION OF VIBRATION COMPACTING PROCESS ON LOOSE MEDIA BY DISTINCT ELEMENT METHOD

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2004, 23 (01): -95 doi:
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The breakwater is constructed in deep silt by blasting method and the construction of it will be affected by blasting vibration. Successful numerical simulation is presented of the vibration compacting process on the breakwater made of loose media by distinct element method，and the result of numerical simulation is analyzed. The location and motion state of loose media are successfully simulated by distinct element method. The result of simulation is consistent with fact.

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TIME-FREQUENCY CHARACTERISTIC ANALYSIS OF BLASTING VIBRATION BASED ON WAVELET TRANSFORM

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2004, 23 (01): -101 doi:
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The time-frequency process of blasting vibration is a nonstationary random one with short duration，and analysis is made on the process by means of wavelet transform technique. According to the multiresolution decomposition of discrete wavelet transform，the time history signal of blasting vibration may be expressed by different level reconstructed signals of wavelet decomposition. By using these signals，the relative energy distributions of blasting vibration in different frequency bands and the regularity of vibration strength varying with time can be obtained. Blasting vibration measurement shows that the time-frequency characteristic analysis based on wavelet transform yields more accurate information details of blasting vibration，compared with the frequency spectra analysis on the conventional Fourier transform. The suggested method provides a new approach for analyzing the structural safety under blasting vibration conditions.

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STUDY ON DETECTION OF COMPLEX ROCK STRUCTURE BY CT TECHNIQUE OF SEISMIC WAVE

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2004, 23 (01): -107 doi:
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The CT technique of seismic wave and in-situ measurement method are discussed. By all azimuth observation of CT technique of seismic wave，large scale rock structure distribution in the permanent ship lock slope of the Three Gorges Project is obtained，and the velocity distribution parameters in that area are presented in the form of fine units. The‘body’data of mechanical parameters are provided for generalized geologic model analysis，slope stability analysis and distortion calculation.

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LOOKING FOR RELICS OF JUN KILN OF SONG DYNASTY WITH GEORADAR

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2004, 23 (01): -112 doi:
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The georadar technique is experimentally used in detecting ancient Jun kiln of Song dynasty located in Shenhou town，Henan province. The clear image of cultural layer and immature layer can be obtained with georadar prospecting. The bed of ancient china kiln，china slice heap，china container and pool of material of clay are clearly displayed in the image of georadar well. On the background of strong reflections of cultural layer，the repeatedly scorched bed of ancient china kiln is represented with high frequency and weak reflection abnormality. The hyperbola arch-like abnormal character is caused by the sagger，and the abnormal character of china slice heap is represented with slightly high frequency and low strength reflection. The event is divided into two parts at some pools of material of clay. The first part is upward，the second part is downward，and finally they compose the georadar image with the same phase axis direction. The interference of confused stone heap is also discussed in this paper.

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GPR INSPECTION FOR SHANGHAI—NANJING RAILWAY TRACKBED

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2004, 23 (01): -116 doi:
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A new method is developed for interpreting GPR data to describe trackbed substructure layers and evaluate mud pumping along railway. This new method uses GPR image patterns to identify the substructure layers and types of mud pumping，and includes a new inspection concept called as mud pumping passage. Specifiecations of this new inspection method are outlined in this paper and its application is described for evaluating the railway from Shanghai to Nanjing. Details of the mud pumping results are given along with available repair recommendations.

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STUDIES ON CHARACTERS AND FORMING MECHANISM OF KARSTIC COLLAPSE COLUMNS AT MINE AREA OF NORTH CHINA

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2004, 23 (01): -120 doi:
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Karstic collapse columns are a kind of vertical structures typically formed at Carboniferous-permian coal fields of north China and widely distributed at 45 coal mines of 20 coal fields. Through characteristics analysis of interior rock masses and exterior shape of karstic collapse columns in the coal mine areas of north China，it is concluded that there are several influence factors and dynamic geological actions on forming process of karstic collapse columns，among which karst and geological structure are the basic factors of their formation. The forming of karstic collapse columns results from repeated processes of collapse，intermission，dissolve erode，convey，subsidence，fall and so on under the dynamical action of rock mass gravity，geo-stress concentration，negative vacuum pressure and other actions on karstic cavity and groundwater violence flow. The bottom of rocks at syncline axis is tensioned and inverse cuneiform-like rock masses are formed. By contraries，cuneiform-like rock masses are formed at anticline axis under compression. So，it is propitious for whole rock mass to move down under gravity at syncline axis and karstic collapse columns are formed. The basic rule is explained in the light of mechanics，following which karstic collapse columns are more likely formed at syncline axis than at anticline axis in north China.

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BASIC GEOLOGICAL VIEWPOINTS AND PRINCIPLES ON UNDERGROUND ENGINEERING STUDY

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2004, 23 (01): -124 doi:
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Geology is of significance on stability analysis of underground engineering，because underground engineering is typical geological engineering. The basic geological viewpoints and principles on underground engineering are explained and summarized. The basic geological factors affecting underground engineering stability，preferred plane analysis principles，quantitative evaluation methods and geo-engineering control principles are discussed.

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HOMOTOPY METHOD FOR INVERSING PARAMETERS OF WAVE EQUATION IN POROUS MEDIA

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2004, 23 (01): -129 doi:
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According to the principle that the computed response and measured response should be fitted，the parameter inversion problem is reduced to a problem of solving nonlinear equations’ zero. Then the homotopy method can be used and it is widely convergent to solve nonlinear equations. At last，this method is used to solve a 1-D model in porous media which has an analytical solution given by Simon in 1984. The numerical results confirm that homotopy algorithms are feasible and robust.

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CONFINING PRESSURE EFFECT ON ENGINEERING PROPERTIES OF WEAK LAYERS IN DAM SITES

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2004, 23 (01): -137 doi:
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The problems existing in the present sampling method for weak layers in exploratory adits are discussed. At present，the confining pressure effect on engineering properties of weak layers is often neglected，but the argillizational effect under ground water is emphasized. Ordinarily，samples of weak layers are obtained in exploratory adits. But the weak layers are easily affected by the stress relaxation after the excavation of exploratory adits. So the engineering properties of weak layers，based on laboratory or in-situ tests，are very poor. Obviously，the test results of samples from exploratory adits cannot reflect their engineering properties under natural ground stresses. To avoid the effect of stress relaxation on weak layers，a special sampling method in exploratory adits is adopted，which reveals that weak layers are of good engineering properties under confining pressure. Taking the weak intercalations at a giant hydroelectric station on Jinshajiang River as an example，the correlations between physical and mechanical indices and confining pressure indicate that confining pressure is the most important environmental factor to control the engineering properties of weak layers.

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3D FEM ANALYSIS OF BRIDGE
APPROACH SETTLEMENT

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2004, 23 (01): -144 doi:
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FEM simulation is conducted for the foundation settlement of backfill slope of high bridge approach. On the basis of all kinds of stress contour sketches and data obtained from the site，a simple mechanical model is put forward to explain the reason of the settlement occurring after construction of bridge approach backfill slope.

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PRELIMINARY STUDY ON INFLUENCE OF SOIL POROSITY ON GROUNDWATER PRESSURE APPLIED ON UNDERGROUND STRUCTURE

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2004, 23 (01): -149 doi:
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Ground water is different from surface water，therefore the groundwater pressure applied on underground structure is decided by soil structure. The influence of soil porosity n，one of the important parameters concerning soil structure，on groundwater pressure is studied by computations and in-situ measurements in the paper.

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INFLUENCE OF PILE DRIVING ON PROPERTIES OF SOILS AROUND PILE AND PORE WATER PRESSURE

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2004, 23 (01): -153 doi:
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The process of pile driving in saturated clay is modeled by the theory of expansion of cylindrical and spherical cavities in an infinite medium. The soil is assumed as a homogenous，isotropic and ideal elasto-plastic material. Solutions are presented for the stress distribution of the soil around pile surface during pile driving. Changes of soil properties around pile surface and its effects on the soil stress due to pile-driving are analyzed. Using the theory of hydraulic fracture，radial and vertical distributions of excess pore water pressure are subsequently studied along the pile surface during and after pile driving. A comparison of predicted and observed values shows good agreement.

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DEFORMATION ANALYSIS OF DEEP BURIED ANCHOR PLATE
UNDER HORIZONTAL LOAD

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2004, 23 (01): -159 doi:
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Based on Mindlin stress solution，the stress state of deep buried rectangular anchor plate under horizontal load is studied. A new theory using the modified layer-summation is proposed to predict the deformation of anchor plate. The effect of 3-D stress and nonlinear characteristic of soil on anchor deformation can been considered. Through a case study，it is shown that the new theory can successfully predict the anchor deformation.

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CHARACTERISTICS OF ENVIRONMENTAL GEOLOGY AND GEOLOGICAL DISASTERS OF ANHUI PROVINCE

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2004, 23 (01): -164 doi:
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Anhui province is the transitional zone from subtropical region to temperate zone，where the transitional climate characteristics are pronounced. Anhui province is situated on the third step of east China，where the terrain is complex and the geomorphic type is parti-colored. In mountainous area，the bedrock is broken，and the cutting of terrain is intense，the trenches and vales are serried，which forms the geomorphic landscape of ravines and klints. In plain，the buttes，slopes and depressions terrain are salient. The Huaihe River and Changjiang River have many branches and lakes on their water-fronts. The pluralistic natural，geomorphic and geological conditions result in all kinds of exogenic geological disasters，as karst cave and karstic earth cave collapse，toppling，landslide，land subsidence，continual descent of groundwater level，water resources pollution，soil erosion，endemic diseases，washoutting of banks of rivers and lakes，and toppling of banks，etc. The development and distribution of disaster are conditioned by the regional environmental geological conditions，and effected by hydrology，human being’s engineering activities and economic activities. The carriers of disaster are rock，soil and water. These disasters damage the geological ecological environment which human being lies on，and seriously restrict the sustainable development of economy，society and environment. Based on the research on the characteristics of regional environmental geology and the composition and engineering property of rock and soil mass，beginning with the crossfeed action among human being’s economy，engineering activities and geological environment，the article approaches the action regularity of regional environmental geology，forecasts the generation and development trend of geological disaster. These are of important significance to retain geological ecological environment，reappear human being’s living environment in accord of human being and terra，and insure the sustainable development of the regional economy，society and environment.

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SPLIT TEST OF FLATTENED ROCK DISK AND RELATED THEORY

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2004, 23 (01): -170 doi:
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The tensile strength can be determined from the split test of a disk specimen，or Brazil test. However，yield and fracture will occur in the rock near the loading points under high stresses，which is different from its testing principle. Two flats are induced to the Brazilian disk as loading sufaces for improving the stress states. The flats have the uniform deformation，but not the uniform stress，under the compression of testing machine. The modification coefficients for calibrating the tensile strength and Young¢s modulus are calculated based on the results of finite element analysis. In a given force compressed on the flats，the tensile stress in the center of disk decreases with the central angle of flats，and the ratio of compressive stress to tensile stress increases as well. So it is better to choose the smaller central angle for getting the true tensile strength. On the other hand，it is better to choose the greater central angle for the convenience of the flat milling and the facilitation of compression. So 30°is suggested for the available central angle of the flats. It is difficult to determine the fracture toughness KIc of rock from the Brazilian test with the flattened disk specimen，for the disk does not crack along the symmetric line and the loading method of testing machine is controlled by compression deformation.

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REPLY TO THE PAPER‘SPLIT TEST OF FLATTENED ROCK DISC AND RELATED THEORY’

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2004, 23 (01): -175 doi:
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The test method of the flattened Brazilian disc specimen is reviewed more comprehensively. This method can be used to determine three mechanical parameters，that is，elastic modulus，tensile strength and fracture toughness，in one test simultaneously. The loading manner of the test machine and the contact condition between the machine plate and flatten surface of the specimen can affect the test results. Such effect is taken into consideration and appropriate adjustment of the coefficient in the formulas is made for calculating the three parameters. The actual loading manner and contact situation in laboratory test may not be known exactly，in other words，the test condition is not in exact conformity with that for the numerical analysis. This setback should not frustrate our efforts to approach nearer to the reality in the analysis. In this paper，four extreme loading conditions are chosen for the renewed finite element analysis：(1) uniform pressure loading and zero shear stress，(2) uniform pressure loading and zero lateral displacement，(3) uniform normal displacement loading and zero shear stress and (4) uniform normal displacement loading and zero lateral displacement. They are applied to the finite element program as input boundary condition，respectively. Definitely more detailed results are obtained. However，it is considered that a suitable average value for the extreme values of the coefficient is more appropriate，so that the average values are given to update the formulas. Finally，an independent test record done by our collaborators in Sweden is given to show the applicability of the proposed test method.

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王永岩博士论文摘要

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2004, 23 (01): -178 doi:
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王永岩博士论文摘要

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ANTI-SLIDING BOUNDARIES ANLYSIS OF XILUODU HIGH DAM SHOULDERS AND THEIR ENGINEERING SUITABILITY

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2004, 23 (01): -179 doi:
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