| The forecast of advanced level drilling parameters is a prediction technology of a short tunnel surrounding rock geology,and with the drilling parameters of drilling process and geological conditions of surrounding rock has certain correlation,which can be based on the analysis of drilling parameters with the advanced level of borehole drilling depth varies regularly to infer the geological conditions of drilling depth.However, the research on forecasting techniques of advanced level drilling parameters is still rare.In this paper, taking a total of nearly 60 m long tunnel surrounding rock of Xiaochuan tunnel and Chengzhou tunnel in Gansu province as the research objects.The experimental study on the forecast of advanced level drilling parameters, focuses on the analysis of the coupling of the drilling parameters of different lithology and tectonic response corresponding to different extent and relevance, and how to use the coupling of the drilling parameters to divide different lithology and the structure of the surrounding rock strata for futher research.Based on the theory of rock drillability and the principle of energy conservation, combined with drilling parameters: Torque, Rotational Speed, Thrust pressure, Drilling speed of four physical parameters.For the relationship of apply work that using the power head and pipe work to boost system and drilling speed.It proposed to reflect concepts and formulas of the degree of difficulty of breaking rock drilling power ratio,and compare with the main geological tunnel corresponding to proved the drilling power ratio and tunnel rock lithology and structure have a good response feature. Through division drilling ratio curve extraction and characteristic value in further, got different lithology(Limestone, Gray conglomerate, Mudstone, Glutenite)in different structure(Joint fracture,Calcite filling,Bedding,Basal conglomerate transition)and the surrounding rock water characteristics of the situation corresponding work speed ratio range value.Aim at the work ratio curve of advanced drilling can better reflect the characteristics of the geological conditions of surrounding rock, and based on the basic theory of wavelet transform and the edge detection method, the research of wavelet analysis of geological strata boundary on the power ratio curve.In the study, the characteristics of several kinds of wavelet bases are selected and compared. Put forward that mexh wavelet suit to used in analysis of the work ratio curve, and use the module average method optimization the optimal scale of the wavelet transform. Through The zero of the second derivative product function of wavelet basis function and Power ratio function determine the lithology changes mainly point of boundary, and divides the different lithology of mileage and same lithology of hardness on this basis. The results show that after wavelet transform power ratio curve can be more accurately identify Argillaceous conglomerate and gray conglomerate of the main dividing line of the rock strata in different tectonic conditions.In the end, after extracted different lithology 、 structure power ratio curve characteristics,using time domain analysis method to get the time domain index(Average, Peak, Margin, Kurtosis) and using wavelet packet energy analysis method to get the energy distribution characteristics, formating of the database. According to the article research train of thought, put forward a method which use the power ratio curve characteristics to inversion identification tunnel surrounding rock geology and tested in actual use. It provide reference and reference to the application and make advanced level forecast drilling technology can serving better. |
PDF Full Text Request