In view of the characteristics of the large goaf of jianlin hill, Daye iron mine (with horizontal exposed area of the roof being 6434m2 , and the height being 45m) , are conducted the geological investigation, vibration measurement, geomechanical tests, 3-dimensional BEM analysis, photoelastical tests and dynamics model tests. The comprehensive studies gave the conclusion that the goaf is basically stable and can undergo mining under the condition of monitoring and restriction of blasting jobs. At the present the mining in No.1 ore body has been finished and the large goaf still remains basically stable with it length of 200m, width of 78m and height of 73m, and the maximum horizontal exposed area of 9850m2. The conclusion proved to be correct and had led to an apparent economical affects. It is a typical example of the application of rock dynamics in the engineering and have significance for appraisal of the stability of the large goaf in similar mines.

In this paper, through analyzing the subcritical crack growth, a new formula is presented which can be used to calculate the crack fracture initiation stress at low and middle stress rates. By way of integration of the stress intensity factortime relation of crack under impact load, is attained a formnla from which the crack fracture initiation stress at middle and high stress rates cen be calculated. Combination of the two formulae leads to a general expression for caloulating the crack fracture initiation stress at all stress rate, low or high. The critical unstable fracture of material which contains many cracks is also analyzed in this paper, and a new viewpoint is put forward that the σfi-σ curve of material at high stress rate is an envelop of all σfi-σ curves of crack in the material, which leads to a conclusion that crack fracture initiation stress is proportional to the cube root of loading rate.

In this paper, the relation is studied between the geologic structnre feature and rock strength by means of the theories and methods of rock mechanics with geomechanics combined. According to geologic structure feature of red rocks in Gezhouba has been obtained the strength performance and constitute mechanism. In this paper, a concept and method which would play an important part in rock engineering and theories of rock mechanics are proposed.

In this paper, according to in situ experimental data of sonic, seismic, hole television, acceleration, velocity and visual investigaton after explosion, we consulted laboratory experimental results. Study in soil and rock blasr destroy effect and zone. By comparing with blast destroy zone of rock mass, vartical tunnel, parallal tunnel.

A boundary element method formulation in the real time domain in the transient elastodynamic problems is presented. The equation motion of the linear isotropic elastiic bodare transformed into the elliptic partial differential eqnations by means of the differential formulations of the Wilson-θ method. By utilizing the particular solution corresponding to a dynamic point force in an infinite medium and the Betti’s theorem the bundary integral equations may be obtain. As this approach formulates and solves the problem in real time domain in conjunction with a time-stepping algorithm, it does not require a nimerical inversion.Which transformes the results from the Laplace or Fourier ransformed domain to the time domain. A numerical example was shown in order to demonstrate the applicability of the present method to the practical problems.

According to experience of the work during the recent years, an ideas was presented that in order to better use SEM for the study of soil microstructure, basic requirements that should be satisfied are as follow:l (1) Sample prepiration must reflect actually the original features of the Soil (2) Observation results must be thoroughly analysed; (3) In application the observation results should be combined with the macroscopic features.

The damping characteristics of the bedrock in a nuclear power station are studied experimentally by free vibration system with one degree of freedom. On the basis of a numeridal analysis of the results, we come to the conclusion that the damping coefitciemt C of the bedrock is not constant, but a function of the frequence. This conclusion indicates that the subject we studied has non-linear behaviour. This point of view seems to be useful especially for the further study of dynamic constiutive equations of the rock mass.Also the damping coeficient C reported in this paper is of referential value to the engineering design.

The necessary knowledge about the error theory and the data processing sich as precision, accurary, system error, random error, is briefly introduced and the systematical error analysis on tape extensometers is presented.

This paper describes the design priciple , the features and the performance of type ment CBS-3 digital displacement (presure) measurement instrument and the messure system.

In this paper the phase difference of lateral system for dynamic are soil triaxial testing system is discussed and variant measurement meth-ods are compared, according to testing requirement “zero crossing triggering digital phase meter ” was designed, which can measure the phase difference of variant waveforms. In addition, the opration principle, the designing, and the noteworthy prlobems are presented.

Taking model TRS-1 system for measurements of rock and soil mechanical parameters and data processing as an example, in this paper, the principle and the method of choosing the transducers, the secondary instruments and the microcomputers are descrbied. The compsions , functions and main technical indes of the system are presented. The block diagram of the system are also described.

In this paper a brief description is given on the main content and application of endochronic theory proposed by Valanis, K. C. . Some opinions on the further development of endochronic theory in the problems, such as the formulation of the in trinsic time scale Z and the relationship between Z and strength of solid materials, are presented for the purpose of applications.

The models of specific electrical conductivity were studied which can be used for saturated anisotropic clay, Based on the assumptions, T=TS or T≠TS , two kinds of models were obtained separately. The methods and procedures for determining the parameters in those models were defined, and the rules of variation of some parameters with change of direction were studied. Some experimental examples were given.

The rock deformation and failure tests are performed along various stress paths under true triaxial stress state. The experimental results have shown that the change of three principal stresses (the increase of the maximum principal stress, the decrease of the minimum principal stress, the decrease of the confining pressure and the increase or decrease of the intermediate principal stress ) can lead to deformation and failure in rocks. The strength, the deformability and the failure precursors of rocks are related with stress paths. Based on the results of the study, the problems of the stress path in rock engineering are discussed.

The paper deals with the ultrasonic wave-spectra parameters including velocities of compression and shear waves, dynamic young’s meduli and Poisson’s ratio, density function and average frequency ration of amplitude spectra, waveforms, etc.. And also, presented are the change law of these parameter of variously-weathered granite in the course of uniaxial compressive loading and its relationship with the mechanical characters.

Results form both SPT in situ and triaxial dynamic test in laboratory are discussed. A simplified analysis is made for liquefaction potential of sand deposit under ground and the suitability of SPT in the region of river beach is checked, too.

Results of in situ deformation and creep testing were verified by FEM analysis in this paper. According to the extended Kelvin Body, a in situ creep equation has been derived. Some correspondent parameters were determined. This equation fits the testing rather well.

Based on considerations of theological and dynamical behavior of rocks and soils, the mechanism of xintan Beach Landslide is discussed in this paper, From the status of the slope as it is now, the sequences of landslide are pointed out and some concepts for controlling the potential landslide are presented.

In this paper, the principle of Lagrangian electromagnetic particle velocity gauge and measuring system are described. By means of the measuring technique, the particle velocities in three materials (plexglass, gypsum and marble) are obtained in the loading of explosion. The results from gauge records are satisfactory.

The design idea, principle of measurement, structural feature and some results obtained from the field measurements in hard intact and cracked soft rock masses are introduced in this paper.