Methods to Estimate the Rock Strength and Tooth Wear While Drilling With Roller-Bits—Part 1: Milled-Tooth Bits

2002 ◽  
Vol 124 (3) ◽  
pp. 125-132 ◽  
Author(s):  
H. Karasawa ◽  
T. Ohno ◽  
M. Kosugi ◽  
J. C. Rowley
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Rock Strength ◽  
Penetration Rate ◽  
Tooth Wear ◽  
Test Results ◽  
Study Methods ◽  
Hard Rocks ◽  
New Methods

This paper proposes new methods to estimate both the rock strength and tooth wear while drilling with roller-bits. Laboratory drilling tests were conducted to obtain the penetration rate, bit weight and torque using milled-tooth bits with different tooth wear (T0, T4, T7). Drilling media used for the tests were soft to medium-hard rocks whose uniaxial compressive strength ranged from 14 to 118 MPa. Based on the test results, a parameter, which presents the rock strength independent of the tooth wear, was first investigated. The investigation revealed that a parameter related to the axial energy and the rotary energy required to drill rock is effective to estimate the rock strength independent of the tooth wear. Second, methods to estimate the tooth wear were studied based on the same parameter that represents the rock strength. From the results of this study, methods to measure the tooth wear are proposed.

scholarly journals Analysis of The Rock Fracture on Uniaxial Compressive Strength Test

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Edward Dinoy ◽  
Yohanes Gilbert Tampaty ◽  
Imelda Srilestari Mabuat ◽  
Joseph Alexon Sutiray Dwene
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Poisson Ratio ◽  
Rock Fracture ◽  
Strength Test ◽  
Maximum Pressure ◽  
Test Results ◽  
Average Value ◽  
Compressive Strength Test ◽  
Uniaxial Compressive Strength Test

The compressive strength test is one of the technical properties or compressive strength tests that are commonly used in rock mechanics to determine the collapse point or the elasticity of rock against maximum pressure. The rock collapse point is a measure of the strength of the rock itself when the rock is no longer able to maintain its elastic properties. The purpose of this test is to find out how long the rock maintains its strength or elasticity properties when pressure is applied, and to find out the difference between the strength of compact rock and rock that has fractures when pressure is applied. Rocks that have fractures will break more easily or quickly when pressure is applied compared to compact rocks. This analysis is carried out by comparing the rock strength of each sample, both those that have fractures and compact rocks. To find out these differences, laboratory testing was carried out. The test results show the value (compressive strength test 57.76 MPa), (elastic modulus 5250.000MPa), (Poisson ratio 0.05) and the average value of rock mechanical properties test (axial 0.91), (lateral-0.279), and (volumetric 0.252) . Based on the test results above, it shows that rocks that have fractures will break more easily when pressure is applied, compared to compact rocks that have a long time in the uniaxial compressive strength test.

scholarly journals Strength and abrasive properties of andesite: relationships between strength parameters measured on cylindrical test specimens and micro-Deval values—a tool for durability assessment

2020 ◽  
Author(s):  
Balázs Czinder ◽  
Ákos Török
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Test Results ◽  
Strength Parameters ◽  
Data Set ◽  
Freeze Thaw ◽  
Laboratory Test Results ◽  
Significant Difference ◽  
Abrasive Properties ◽  
Water Saturated

Abstract Aggregates are necessary materials for the construction industry. Owing to their favourable properties, andesites are frequently used rock materials; hence, the investigation of their mechanical and aggregate properties has great significance. This paper introduces the analyses of 13 Hungarian andesite lithotypes. The samples were collected from six andesite quarries in Hungary. Cylindrical specimens and aggregate samples with 10.0/14.0-mm-sized grains were made from rock blocks. The specimens were tested in dry, water-saturated and freeze–thaw subjected conditions. Bulk density, uniaxial compressive strength, modulus of elasticity, indirect tensile strength and water absorption were measured. The abrasion resistance was tested by micro-Deval tests. The flakiness indexes of the samples were also measured. The data set of the laboratory test results provided input for further, one- and two-variable statistical analyses. According to the test results, there is no significant difference between the strength parameters measured in water-saturated and in freeze–thaw subjected conditions. The correlation and regression analyses revealed relationships between some rock mechanical parameters, as well as between micro-Deval coefficient and uniaxial compressive strength.

Methods to Estimate the Rock Strength and Tooth Wear While Drilling With Roller-Bits—Part 2: Insert Bits

2002 ◽  
Vol 124 (3) ◽  
pp. 133-140 ◽  
Author(s):  
H. Karasawa ◽  
T. Ohno ◽  
M. Kosugi ◽  
J. C. Rowley
Keyword(s):  
Rock Strength ◽  
Tooth Wear ◽  
New Approach ◽  
New Methods ◽  
Data Analyses ◽  
Tooth Type

New methods to estimate both the rock strength and tooth wear while drilling with roller-bits were developed and proposed in Part 1. These methods were derived from the results of drilling tests using milled-tooth type three-cone bits with different amounts of tooth wear. In this report, these methods were extended and applied to insert type three-cone bits. The validity of the test and data analyses techniques of Part 1 were confirmed for insert bits. The methods to estimate the tooth wear proposed in Part 1 were based on the drillability strength of rock. A new approach to determine the tooth wear is presented. This new approach could be more readily applied to evaluating tooth wear when compared to the previous methods based on the drillability strength of rock.

scholarly journals Korelasi Point Load Index dan Uniaxial Compressive Strength pada Satuan Batupasir dan Batulempung Formasi Latih untuk Penentuan Koefisien Kekuatan Batuan di Pit X Tambang Batubara PT Berau Coal, Kalimantan Timur

2021 ◽  
Vol 9 (1) ◽  
pp. 9-16
Author(s):  
Yan Adriansyah ◽  
Guruh Krisnantara ◽  
Kurniawan Setiadi
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Mining Industry ◽  
Point Load ◽  
Engineering Properties ◽  
Test Results ◽  
Rock Engineering ◽  
Point Load Index ◽  
Rock Samples ◽  
Laboratory Test Results

Physical and mechanical properties of rock for engineering purposes are indispensable for any civil/construction, mining and other engineering requirment. The results of the uniaxial compressive strength (UCS) test are very much needed in various geotechnical analyzes or engineering, in particular in the mining industry in relation to the calculation of the pit slope design and other mining infrastructure. Rock samples used in this study were obtained from the results of geotechnical drilling (full core drilling). The rock engineering properties test to obtain UCS and PLI values was carried out in the laboratory. Testing the rock hardness index using the point load index (PLI) can be done more quickly, cheaply, practically and can use rock samples with a variety of sample shapes.         The focus and object of the research are mudstone and sandstone units as part of the Lati Formation. These two types of layers are the most dominant rock types as a constituent of the pit slopes in the research area. To ensure that the correlation results are in accordance with the rules of scientific research, the distribution of UCS and PLI data from laboratory test results is verified using a statistical approach / testing. Correlation and analysis between the two rock engineering properties test results are very useful for geotechnical analysis data input. The coefficient or constant values obtained can be used to determine the rock strength values used in various geotechnical analyzes so that the analysis can be carried out more efficiently, effectively and quickly and can support geotechnical engineering work.

Study on Grain Size Characteristics and Strength Test of Gravel in Conglomerate Layer of a Coal Mine

2012 ◽  
Vol 170-173 ◽  
pp. 395-398
Author(s):  
Xiao Lei Wang ◽  
Shun Xi Yan ◽  
Shu Jiang Zhao
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Coal Seam ◽  
Uniaxial Compressive Strength ◽  
Coal Mine ◽  
Great Difficulty ◽  
Point Load ◽  
Test Results ◽  
Volume Percent ◽  
Very High

The direct roof of B132 coal seam is conglomerate layer in a coal mine, which is cemented with gravels and sandstones and has brought great difficulty for tunnel supporting. It is necessary to study the grain size and strength characteristics of gravel in conglomerate layer for the mining of B132 coal seam safely and efficiently. The statistics and analysis of grain-size characteristics of gravel was carried out in this paper, including of the quantity and volume percent of gravel. Uniaxial compressive strength of gravel was tested with point load method. The test results show that uniaxial compressive strength of gravel is very high, especially the black gravels, whose compressive strength is commonly above 200 MPa and the highest even can reach more than 300 MPa.

Degradation Phenomenon of Basic Mechanical Properties of Plain Reactive Powder Concrete with Time

2014 ◽  
Vol 1065-1069 ◽  
pp. 1871-1874
Author(s):  
Xiao Fei Wang ◽  
Yang Ping Wang ◽  
Li Cheng Wu
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Strength Test ◽  
Hot Water ◽  
Reactive Powder Concrete ◽  
Test Results ◽  
Compressive Strength Test ◽  
Water Curing ◽  
Uniaxial Compressive Strength Test ◽  
Reactive Powder

The same batch reactive powder concrete specimens were obtained with same raw materials and curing process, uniaxial compressive strength test had been done on the specimens after hot water curing placed in laboratory for seven days , three months and three years. The test results showed that seven-day strength and three-month strength of plain reactive powder concrete after hot water curing are almost equal. Strength of plain reactive powder concrete has not degradation within three months after hot water curing. While strength of plain reactive powder appears serious degradation phenomenon after placed in Laboratory for three years. Comparing uniaxial compressive strength test results of plain reactive powder concrete at three-month with three-year after hot water curing ,we find that strength of plain reactive concrete at three-year decrease about 27 percent than the strength of plain reactive powder concrete placed at laboratory for three months, and elasticity modulus increases about 71 percent, axial peak strain decrease about 62 percent respectively .With the passage of time, plain reactive powder concrete appears more Brittle Features and less toughness.

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