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.