The mechanics parameters of engineering rocks and soils usually are of the property of spatial and random variations due to the heterogeneity and should be considered as the spatial random fields. The researches are made on both the spatial variation analysis of the random fields and the estimations of rock mechanics parameters in elements of FEM by conditional simulation. The advantages of this estimation method are not only that the double characteristics of spatial variations of the random fields are considered，but also that the true dispersions of the random fields could be realized better in the value estimation of the rock mechanics parameters in elements compared with the Kriging method.

The digital image correlation technique is used to determine the deformation field of the rock material involving the microcracks. The light intensity pattern of the fine grain sandstone surface is taken from the scanning electron microscope，corresponding to different loading steps. Correlation computation is performed for a pair of light intensity images to evaluate the displacement components. The results show that the deformation varies in different areas separated by subcracks，which implies the effect of crack opening and closing in rock.

Oil production will change the stress field of reservoir and induce the strain of rocks. As a result，this will influence the fluid percolation. A math model of coupled fluid flow and geomechanics is set up. The following factors are considered in this model：constant temperature，two phases of oil and water，deformation of reservoir，changes of stress，porosity and permeability. There are seven variables in the governing equations to comprise the matrix of pore pressure，fluid saturation and displacement. The system of the nonlinear governing partial differential equations is discreted using the finite difference method. The finite difference equations are arranged as seven-point stencils. A fully implicit procedure is adopted for maximum numerical stability. Analyzed by an example，it is shown that the parameters of stress，strain，porosity and permeability change with time and space. This model can be used to solve many problems，such as simulating deformation of reservoir，calculating changes of stress and strain，analyzing changes of porosity and permeability in reservoir.

Based on the rock type of coal-bearing formation，the key factors to control rock mechanics properties，such as lithological characters，in-situ stresses, and moisture, are systematically analyzed. The mechanical characters of different rocks under different confining pressures and moistures are studied. The quantitative relationships between the rock mechanics properties and lithological characters，in-situ stresss and moistures are established，respectively. It is shown that the strength and stiffness of rocks are rapidly reduced with decrement of the grain diameter，namely from sandstone to mudstone. The stiffness and strength of different rocks increase with confining pressure. The behavior of the strain softening and failure mechanism of different rocks are transformed with the increment of confining pressure. Moisture influences the rock mechanics properties evidently. Under the dry condition or low moisture，rock reveals the attributes of brittle and shear fracture after peak strength. From the stress-strain curves，the strain softening characters are evidently shown. With the increment of moisture，the uniaxial compressive strength and elastic modulus of the rocks decrease remarkably，and plastic failure is the main evidence，but the properties of strain softening is not so remarkable.

Both of planar and axisymmetric methods for Rayleigh wave analysis are introduced. These methods are very useful for simulating testing signals and dispersion curves and studying higher Rayleigh wave modes. Rayleigh wave modes of the signals can be separated and the dispersions of various modes can be obtained by 2-D Fourier transformation or multiple filter/cross-correlation technique. The dispersion obtained by phase–unwrapped technique can be regarded as an average of weighted dispersion of various modes. The variation of dispersion is related to mechanic parameters of layered media，and the parameters can be obtained by forward or back analysis. Moreover，the application of Rayleigh wave into detecting of underground obstacles is described.

Based on dynamics of rock bolt and kinematics of stress wave in grouted bolt system，the vibration characteristics of grouted bolt system and energy attenuation of stress wave are studied. A method of quick inspection for anchoring state by using sonic-frequency stress wave is proposed. Also nondestructive determination of anchoring force by intersection of secant lines of the turning segment of a drawing curve is discussed. All results are confirmed by construction quality inspection for bolting in the first coal mine of Panji.

Due to uneven distribution of ground silty clay，the large settlement and structure crack are found in the 4-story building. Through scheme optimization，the static bolt-pile reinforcement is adopted，and favorable effect is obtained. The principle of static bolt-pile reinforcement is described and some problems that should be noticed in the course of design and construction are set forth.