Papers by Keyword: Rock Mass

Abstract: The article discusses the experience of drilling and blasting operations in the conditions of high water cut of the rock massif, it also presents practical experience in modeling and forecasting water inflows into workings. By the example of the Koashvinskoe deposit, the problems of work in conditions of high water cut of the rock mass leading to the collapse and silting of drilled boreholes are considered. The article presents calculations showing the effectiveness of the drainage systems for lowering the groundwater level of a prepared rock mass section. The paper provides a rationale for the optimal mass of bottom charges for the preparation of drains in the rock mass, depending on the water saturation of the mass and the grid of drilled boreholes.

Abstract: The paper contains comparative analysis of solutions for problems with the rock-mass stress-strain state in the vicinity of a spherical cavity for the case of stationary and non-stationary temperature conditions. Such a cavity was created by blasting and further was used as storage for products that tend to self-heating. So, both problems considered the process inhomogeneity of the rock mass soil and the inhomogeneity caused by an action of various high-temperature fields. The results obtained prove the significant impact of the inhomogeneity on the stress state of the rock mass for any types of temperature conditions. The development of methods for calculation of underground structures that would fully consider the conditions of their creation and operation as well as actual properties of materials is one of crucial areas in structural mechanics.

Abstract: Discontinuities have an important influence on deformation and failure of rock mass in practical engineering. It is one of the key issues in modern rock mechanics to investigate geometric characteristics of joints and fractures inside the rock mass such as shape, size, location and direction etc. Based on the deep analysis of the above geometric properties, it is proposed that the stochastic fractures in the rock mass can be simulated with the random numbers generated by the Monte Carlo method. The related algorithm is designed and implemented. The correctness and effectiveness of the algorithm is verified with an example of a project. This will lay a solid foundation to further study the cutting problems of discontinuous rock block systems.

Abstract: A new nonlinear discipline named Fractal theory which is a scientific theory and method studied the irregular of nature and complex phenomena has been used in civil engineering direction successfully in recent years. Take the Kuo changshan tunnel as an example, this paper will use the Range finder to measure the shape of surrounding rock along different longitudinal section contour line, then using the fractal theory to analyze it as follows: using section assumption, box counting method and higher dimensional method to calculate the fractal dimension, and to explore the relative relations between fractal dimension and stability of surrounding rock of the tunnel. The research results show that the more rough the tunnel longitudinal section contour line, the bigger the fractal dimension, the worse the corresponding stability of surrounding rock and the worse the lower the level of surrounding rock . Above all the tunnel longitudinal irregular section contour line has obvious fractal characteristics.

Abstract: Analyzing wave behavior on acoustic emission laboratory tests from relationship between stress and AE rate , the rock AE signal wave in laboratory is decomposed into high and low frequency elements. Analysis and compare with the details elements include, the approximation elements and original AE wave, the results show that rock AE wave characteristics are not same in the course of transform fracture on stages, found AE wave characteristics storehouse, it is a matter of great significance for utilizing monitoring and prediction regularity and development trend in the course of fracture transform. The error between the original signal and the signal of wave coefficient of the approximation elements reconstructed is minor to, wavelet analysis makes accuracy and reliability of rock AE wave characteristics monitoring and prediction improved, States that wavelet analysis is a great efficiency method.

Abstract: A finite element model of rock mass under linear conical shaped charge liner including explosive, metal liner, air and rock mass is built. The ALE algorithm is applied to simulate the penetration characteristic of rock mass and analyze the influencing factors such as the cone angle, the wall thickness of metal liner, and the standoff distance. Fluid-structure coupling condition is used between metal liner and air as well as between air and rock mass. The present results show that LS-DYNA can be well used to simulate the progress of jet formation and rock penetration with the transmission and focusing of shock stress wave. The different cone angles, wall thicknesses of the metal liner, and the standoff distances will influence the penetration effect.

Abstract: The Point Cloud Library (PCL) is a good tool for point cloud data processing. In this paper, a method of 3D reconstruction for rock mass based on PCL is introduced, where hardware choosing, parallel computing, PCL, and edge extraction are analyzed and used in order to realize a better reconstruction effect, including both precision and speed. The reconstruction results can be used in engineering calculation.

Abstract: Use FLAC3D, the interface command to define joint surface, set up rock mass models with 15 °, 30 °, 60 °, etc. different dip joint, and in accordance with the laboratory test data of rock and joint surface for a variety of strength and deformation parameters setting, carries on the numerical simulation of uniaxial compression. Got failure mode, plastic zone evolution and the stress strain curve of rock mass with different dip joint, and the result compared with the actual test has a higher similarity, to prove the feasibility of the numerical simulation method.

Abstract: Firstly, the stability of the slope need to determine mechanical parameters of slope rock mass such as deformation modulus, Poissons ratio, cohesion and internal friction angle, etc. For intact rocks, the mechanical parameters mentioned before are easy to determined. While the stability of slope rock mass is controlled by the deformation and intensity. Therefore, how to determine the mechanical parameters of the structure is the key to analyze the stability of slope rock mass. This paper intends to set the slope rock mass below some extra-large bridge as the research object and use numerical calculation to determine the mechanics parameters of rock mass structure plane on the basis of rock sample mechanics test results.

Abstract: Joint roughness coefficient (JRC) is an important factor in the evaluation of the shear strength and deformation parameters of rock joints. This paper presents a method for measuring JRC of rock fractures based on digital image progressing technique. Though preprocessing of the rock fracture image, the skeleton of the fracture was got, the rough degree were analyzed and quantized by geometric parameters of the skeleton. By establishing the relationship between JRC and the rough degree, JRC will be got though the rough degree. This method improves automation degree and accuracy comparing to the previous methods. Finally this method was used to get the JRC of rock fracture in Jijicao, Beishan, Gansu province, where may be the high-radiation nuclear waste repository.