Abstract

In geotechnical engineering and geological survey, the stratum structure and its corresponding physical and mechanical properties are the most concerned. The stratum structure not only affects the safety of the project but also plays a decisive role in the construction method and construction sequence. In this paper, a new type of stratum geological interface recognition system is adopted, and an R-20 rotary drilling rig is used to conduct on-site drilling experiments for a granite site with no ventilation. The research results show that the system can monitor and record the main parameters (axial pressure, drilling rate, rotation speed, flushing fluid pressure, and torque) of the drilling rig during the drilling process. The comparative analysis of monitoring data and on-site survey results shows that different drilling parameters have different sensitivities to changes in the formation structure. According to the prediction accuracy, the ranking from high to low is drilling rate, axial pressure, torque, rotation speed, and flushing fluid pressure. In drilling engineering, by observing the change law of drilling rig parameters, not only can the position of the special rock mass interlayer be predicted, but also the stratum structure and strength can be identified, and the prediction formula is also given. Based on the established drilling specific energy formula, the energy analysis method is used to predict the formation structure and compressive strength, and the corresponding prediction formula is given. The research results show that, compared with the single drilling parameter prediction method, the rock-soil structure and strength identification method based on energy theory has higher prediction accuracy and can meet engineering needs.

Highlights

  • In geotechnical engineering, to ensure the rationality, safety, and efficiency of the project, it is usually necessary to carry out a geological survey before the start of the project, to determine the stratum structure and the corresponding physical and mechanical parameters of rock and soil. ere are three kinds of common geotechnical engineering survey methods: 1. in situ testing technology: through various penetration tests or drillability tests on the rock and soil mass in the engineering site and comparing the test results with the empirical values to determine the geotechnical parameters

  • Compared with in situ testing and geophysical exploration, the coring test method is separated from the original environment of the rock and soil body, and it is difficult to restore the original environment of the rock and soil body in the laboratory test process, so the laboratory will be a certain difference between the result of the test and the value under the undisturbed state

  • KadkhodaieIlkhchi et al [31] used three methods: boosting algorithm, neural network algorithm, and fuzzy algorithm to analyze shale and iron ore according to the drilling parameters such as bit pressure, torque, and drilling speed measured by the measurement while drilling system. e lithology and strength of the rock are identified, and the results show that the drilling parameters can reflect the lithology and strength information of the drilled formation and the boosting algorithm is better than the other two algorithms

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Summary

Introduction

To ensure the rationality, safety, and efficiency of the project, it is usually necessary to carry out a geological survey before the start of the project, to determine the stratum structure and the corresponding physical and mechanical parameters of rock and soil. ere are three kinds of common geotechnical engineering survey methods: 1. in situ testing technology: through various penetration tests or drillability tests on the rock and soil mass in the engineering site and comparing the test results with the empirical values to determine the geotechnical parameters. It can be seen from the above analysis that there have been many studies on the division of stratum structure, the identification of special structures, and the prediction of mechanical parameters of rock and soil based on drilling parameters, and related scholars have developed monitoring systems suitable for different geological environments Most of these systems currently collect data according to the drilling depth, but, since the actual drilling process involves a large amount of auxiliary work such as drilling preparations and drill tool adjustments, these nondrilling processes will be recorded in the data collection, resulting in a large amount of invalid data; how to identify the pure drilling process still needs a lot of work [27]. 1 0 0 1 e status of each working parameter of the drill pipe drilling process

Test Engineering Background and Typical Rig Parameters
Main process Drilling
Statistics of Field Test Results
Discussion
Conclusions

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