Papers by Author: Hong Guang Ji

Abstract: In order to study the strength change of high strength concrete shaft lining structure in underground complex environment resisting composite salt damage erosion, C70 high strength concrete test specimens were made and composite salt disaster solutions of different concentrations were compounded. The test results show that the coefficient of compressive strength and flexural strength of high strength concrete increase in early corrosion and then decline. The strength of specimen declines more quickly in higher corrosion solution concentration in latter time. The change law of the flexural strength is more complex than the compressive strength. Composite salt disaster solutions have little effect for no damage high strength concrete.

Abstract: Existing numerical grid generation based on Surpac block model is inefficient when the grid quantity is large. This article obtains from the existing methods, summarizes the complete process, and adds the key details of it. By setting simpler nodes condensation algorithm, improving the problem of low conversion efficiency caused by the too large node number, achieving the fast effective conversion of Surpac block model to FLAC3D model by using C language programming. This new method has been used in building rock burst hazard analysis model of Ling-Long gold mine, which proves this modeling method is feasible and effective.

Abstract: Geo-stresses distribution of mining areas was analyzed by means of the partial least squares regression method (PLSRM). Based on the data measured in Wushaoling tunnel ridge section, numerical simulation of initial geo-stress field around the area had been done using the commercial software called ANSYS. PLSRM was achieved through actual measurement data and calculation results of geo-stress, then fitting data was ready. Compared with the traditional method of least squares, it is suggested that, due to the advantage of principal component analysis in applying PLSRM, present method can effectively reduce regression error caused by correlation between response variables. It can more effectively reflect the features of discontinuous geo-stress distribution in comparing to the method of traditional least-squares analysis. Therefore, it can provide effective data support for the establish of geo-stress field and it is applicable in back analysis on initial geo-stress field.

Abstract: Shuangliu mine is located in the middle of Hedong coalfield, Lvliang City , Shanxi Province. It is one of the typical NorthChinaType coalfields. The upper strata of the lower-group coal seams (8#, 9# seam) have several thin-layer limestones of the Taiyuan Formation, and the underlying strata of the lower-group coal seams have thick Ordovician limestone. Water inrush accident has ever happened in other mine in its vicinity. Therefore, whether the lower-group coal seams could be mined safely is related to the medium-and long-term program and sustainable development of Shuangliu Mine. Based on experimental study of physical and mechanical properties of main rocks of the roof and floor of the under-group coal seams, and the application of "Up Three Zone" Theory of coal seam roof (the caving zone, water flowing fractured zone and bending sinking zone), "Down Three Zone" Theory of coal seam floor (mining damage zone, water-resisting zone, water-conductive zone) and Water inrush coefficient Theory, we analyzed the water inrush risk and divided potential dangerous subareas of water inrush from coal seam floor while mining lower-group coal seams. The research findings can provide scientific basis for mining design and safe mining of lower-group coal seams in Shuangliu Coal Mine.

Abstract: In order to combine the advantages of Surpac in three-demensional modeling and ArcGIS Engine in three-demensional space analysis, the relation of data elements between Surpac and ArcGIS Engine is studied. In this study, the method of data conversion between two models is proposed. Take the model conversion of a large metal mine for example,showing the ability of the method,by adopting the software of Visual C++ to write a interface program of Surpac-ArcGIS Engine. The results show that the method of data conversion which is proposed in this study can switch Surpac and ArcGIS Engine.This switch function can extend the application space of ArcGIS Engine in Civil Engineering field.

Abstract: The research of slope failure, which is one of the main types of natural disasters, has become a hot topic. Effective landslide forecast can improve the early warning system of landslides and mitigate the landslide disasters. In this paper, a predictive model with the slopes displacement time sequence is established based on the phase space reconstruction theory, where the parameter of the predictive model is obtained by the minimum of prediction error method. The rationality of the evaluation index system is verified through the case studies.

Abstract: With the extensive use of concrete materials, concrete corrosion as an important hazardous factor of engineering safety and its impact on the engineering safety is receiving attention gradually. In order to study its impact on the safety of mining engineering, this paper summarized the corrosion factor of concrete shaft lining of mine and its research progress, and combined with the actual progress of the concrete corrosion. The author came to the conclusion that we should pay attention to the study of the corrosion of concrete shaft lining of mine, at the same time, analyzed the feasibility of the study. The authors believe that, at the present stage, studies of concrete corrosion are more comprehensive and thorough, and coupled with the comprehensive understanding of the underground environment. It is perfectly placed to study the problems of the corrosion of concrete shaft lining of mine deep and systematically.

Abstract: Rock bolting is one of the most common methods of rock reinforcement. To optimize bolt parameters for reasonably playing its properties under safe support condition, it’s a must to study the mechanical characteristics of roadway and bolt. This paper shows that anchor bolts at the top of the rise side has the maximum force, middle of the two sides minimal. Middle of two sides has the largest displacement, top and bottom smallest by using flac3d to simulate the force of special-shaped roadway under the support of anchor bolts, combined with field observance of anchor bolts force. Therefore, by optimizing anchor bolts supporting parameters, we can effectively control the deformation of surrounding rocks and improve the whole stability through strengthening support and changing partial anchor bolts supporting parameters.

Abstract: Concrete is a key support material of underground chamber, its stress state is important parameter that can characterize the stability of underground chambers. The changing rule of the electrical conductivity of C50 steel fiber concrete in relation to the changes of the current, voltage and pressure was studied experimentally. And resistivity-stress regression equations of the concrete was fitted with much high correlation coefficient. Research results show that: (1) within the framework of elastic deformation, the electrical conductivity of concrete increases with the strengthening pressure (i.e., the concrete resistivity decreases with increasing pressure); (2) there exists the good correlation between the resistivity and pressure of the concrete; (3) given the certain pressure, the conductivity of the concrete is to some extent unaffected by voltage and current.

Abstract: Settlement calculation of composite foundation is a hot field in geotechnical engineering research . In the paper with an engineering example, useing the equivalent natural settlement calculation methods and weighted modulus settlement calculation methods to calculate the settlement of composite foundations combined by CFG pile and concrete ramming enlarge pile, which compared with the practical measurement result . The results show that the errors of calculated value of the equivalent natural settlement calculation method were permitted and suitable for calculating composite foundation settlement.