An analytical drilling model of drag bits for evaluation of rock strength

Li, Zhantao; Itakura, Keiichi

doi:10.1016/j.sandf.2012.02.002

Cited by 49 publications

(18 citation statements)

References 16 publications

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“…The proposed model and equations showed the possibility of eliminating unused components of cutting forces when investigating the relation between mechanical data and physical properties of rocks. Li and Itakura (2012) proposed an in situ method for evaluating the UCS of rocks using specific energy, based on an analytical model of drilling processes. They showed that the laboratory experiments verified the analytical model.…”

Section: Ground Characterization By Instrumented Drillsmentioning

confidence: 99%

Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

2015

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In underground mining, many miners are injured or lose their lives because of roof/pillar instability each year, and this is a persistent safety risk. Characterization of overlying strata is important for the design of safe and cost-effective ground support systems. Entry roof characterization can be performed by geological backmapping of the ground using various methods such as geophysical logging, borescoping, rock mass rating, and intelligent roof bolt drilling systems. This paper offers a brief review of mine roof characterization methods, followed by an introduction to and discussion of roof characterization methods using instrumented roof bolters. A brief overview of the various instrumentation systems developed for roof bolt drills is presented. The results of the preliminary study and initial testing indicate that, despite recent improvements in the area of ground characterization by instrumented drills, there are still several issues that must be addressed to improve the efficiency and accuracy of existing systems. A summary of suggested improvements is provided.

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Section: Ground Characterization By Instrumented Drillsmentioning

confidence: 99%

Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

2015

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“…Parameters such as the weight on bits or thrust and accelerometer data related with drilling-measured on the drill head as well as on other parts of the machine-have been used to estimate the mechanical properties of rock mass [11]. Another contribution to the evaluation of rock mechanical parameters with MWD measurements was presented in [12], in which an analytical model of a process that could be useful to evaluate the uni-axial compressive strength was described. The authors broke the process down into the repetitive cycles of feeding and cutting, and based on the fact that only cutting and indentation are effective, while friction on the flank surface and idle running do not contribute to the effective drilling work, an effective specific energy parameter that is independent of the penetration rate was derived.…”

Section: Monitoring Of the Drilling Process-the State Of The Artmentioning

confidence: 99%

Process Monitoring in Heavy Duty Drilling Rigs—Data Acquisition System and Cycle Identification Algorithms

et al. 2020

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The monitoring of drilling processes is a well-known topic in the mining industry. It is widely used for rock mass characterization, bit wear monitoring and drilling process assessment. However on-board monitoring systems used for this purpose are installed only on a limited number of machines, and breakdowns are possible. There is a need for a data acquisition system that can be used on different drilling rigs and for an automatic data analysis procedure. In this paper, we focused on the automatic detection of drilling cycles, presenting a simple yet reliable system to be universally installed on drilling rigs. The proposed solution covers hardware and software. It is based on the measurement of electric current and acoustic signals. The signal processing methods include threshold-based segmentation, a short-time envelope spectrum and a spectrum for the representation of results. The results of the research have been verified on a real drilling rig within the testing site of its manufacturer by comparing the results with the data of the on-board monitoring system installed on the machine. Novel aspects of our approach include the detection of the pre-boring stage, which has an intermediate amplitude that masks the real drilling cycles, and the use of the percussion instantaneous frequency, which is estimated by acoustic recordings.

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“…Process. Based on the working process of the cutting bit on the soil [13,23], we constructed a cutting model, as shown in Figure 1. To analyze the stress distribution on the shear plane, we assumed the soil as a wedge with its top corner as angle 2α, and we simplified the uniform load as a point load P and an equivalent couple M (M � Ph cos φ/2 cos c) acting on the top corner of the wedge.…”

Section: Force Analysis On Soil During Shearingmentioning

confidence: 99%

Quantitative Detection of In‐Service Strength of Underground Space Strata considering Soil‐Water Interaction

Zhou

2020

Advances in Civil Engineering

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The in-service strength test of underground space strata is a hot issue in geotechnical engineering. In this study, we conducted mechanical analyses on the soil and the cutting bit involved in a rotary drilling process, which revealed the key factors influencing drilling. This allowed us to establish theoretical relationships among torque, propulsion, and soil strength parameters (i.e., unconfined compressive strength, shear strength, and cohesion). Moreover, with consideration of the effects of water content and geostatic stresses, we used an independently developed rotary drilling system with a 3D flexible boundary loading device to conduct 75 rotary drilling model indoor tests on silty clay in 15 groups. Based on the test results, we simplified the theoretical relationships and determined model parameters to obtain 15 quantitative relationships with 5 different water contents (4.8%, 9.7%, 14.8%, 19.6%, and 24.9%). Finally, through field application, we verified the quantitative relationships and we discussed their scope of application. The results showed it is feasible to predict the soil in-service strength based on rotary drilling parameters. Under the premise that water content is considered, the drilling parameters were found correlated linearly (correlation coefficients are all greater than 0.85) with strength parameters. In field application, absolute errors between the prediction and investigation results were less than 5%, satisfying engineering requirements.

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An analytical drilling model of drag bits for evaluation of rock strength

Cited by 49 publications

References 16 publications

Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

Process Monitoring in Heavy Duty Drilling Rigs—Data Acquisition System and Cycle Identification Algorithms

Quantitative Detection of In‐Service Strength of Underground Space Strata considering Soil‐Water Interaction

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