It means rock quality designation and representative cross sections of the core sample must reach, or exceed 90 100 mm in length for it to be considered excellent in. Pdf of presentation given at 2004 aeg national meeting, dearborn, mirock quality designation rqdthe rock quality designation rqd in practicetechnical description of rock cores for engineering purposesrock mass rating. In deeres words from 1989, rqd is an index of rock quality in that problematic rock that is highly weathered, soft, fractured, sheared, and jointed is counted against the rock mass. The engineering geologist is responsible for the determination of rqd. Pieces shorter than four inches which were determined to be broken by drilling or by handling were fitted. Rock mass characterization for underground hard rock mines d. Soil mechanics is a discipline of civil engineering involving the study of soil, its behaviour and application as an. Department of civil engineering and engineering mechanics, university of. Data management and geotechnical models ecf hamman et al. American society for testing and materials reprinted from the.
The rqd is an index of rock quality in which a modified core recovery per. This may be true based on the original definition of rqd, but is very misleading and gives the impression of competent rock. What is rqd rock quality designation and how to calculate it. Based on the subsurface findings, depths to bedrock vary from about 2. A frequently used parameter is the rock quality designation rqd index, developed by deere et al. The stability of the proposed shallow footing must also be examined. Rock quality designation rqd has several definitions. Milne university of saskatchewan, saskatoon, canada j. The rock mass rating rmr is a geomechanical classification system for rocks, developed by z. Cording and deere 1972, merritt 1972 and deere and deere 1988 attempted to relate rqd to terzaghis rock load factors and to rockbolt requirements in tunnels. The purpose of these services was to assess surficial and subsurface conditions at the site in order to provide geotechnical engineering recommendations and.
Download fulltext pdf download fulltext pdf download fulltext pdf rqd. A geotechnical database for tunnels article pdf available in geotechnical and geological engineering 3 june 2012 with 1,109 reads. Engineering judgment is necessary to allow decisions to account for unique. It was in the following year that the senior author developed the rqd concept to assist in the siting and the consultant, gainesville, fl 32608, and adjunct professor of civil engineering. Zhang journal of rock mechanics and geotechnical engineering 8 2016 389e397 391. Rock mass characterization for underground hard rock mines. In particular, we looked at the side resistance predicted in poor quality rock from the rock mass strength developed using rock quality designation rqd as well as the geological strength index gsi developed by hoek and brown. Rqd signifies the degree of jointing or fracture in a rock mass measured in percentage, where rqd of 75% or more shows good quality hard rock and less than 50% show low quality weathered rocks. The rqd is the sum of all core pieces longer than four inches divided by the total length of the cored interval. Response of rocks to applied loads earth materials rocks soils fluids.
Consistently finishes projects under budget and ahead of schedule. In rock classification systems for engineering purposes, ed. Rqd even though they possess the requisite 4 in, 100mm length. Rock quality designation rqd is a measure of quality of rock core taken from a borehole. Core recovery and rqd rock quality designation the easiest way to characterize the amount of material recovered during rock coring is to calculate core recovery as the amount i. Rqd may indicate the degree of jointing or fracture in a rock mass. The rock quality designation rqd index has been used for over 20 years as. Journal of rock mechanics and geotechnical engineering. Technical report documentation page transportation. Relationship between rqd and discontinuity frequency l after priest and hudson, 1976.
Geological and geotechnical mapping procedures in use in. Time to rest in peace article pdf available in canadian geotechnical journal 546 january 2017 with 1,682 reads. It expresses the quality of the rock mass in the socalled qvalue, on which are based design and support recommendations for underground excavations. Zhang l, determination and applications of rock quality designation rqd. Recently rmr14 has been proposed to improve the rmr performance by incorporating new experiences from tunnel practices. Determination and applications of rock quality designation rqd.
The rock quality designation rqd is a commonly used index for the description of rock mass fractured state. Odot office of geotechnical engineering oge foundations and retaining walls update june 18, 2019. Notes or rock core logging for engineering purposes. The prevalence of manual engineering methods in wiring harness manufacturing compounds these challenges, especially as harness complexity increases. Excavating and gradingnotes on concepts of mass grading.
Pieces shorter than four inches which were determined to be broken by drilling or by handling. Geotechnical engineer skilled in all phases of engineering operations. Canadian foundation engineering manual, 3rd edition. The rqd was initially introduced for civil engineering applications, and it has been quickly adopted in mining, engineering geology as well as geotechnical engineering. The qsystem for rock mass classification is developed by barton, lien, and lunde. In effect, the rqd is a measure of the spacing of the. Aashto specifications provide geotechnical engineering guidance for the necessary procedures and equations to conduct this analysis. Gopal mishra is a civil engineer from nit calicut and has more than 10 years of experience in civil engineering and construction.
The preengineering and environment division of indot performs environmental assessment reports on all state projects. Rock quality designation rqd, was introduced by don deere in the mid1960s as. Division geotechnical manual which is as described by. Consultant, gainesville, fl 32608, and adjunct professor of civil engineering. Variation of rqd with the length of sampling line l. This is a pdf file of an unedited manuscript that has been accepted for publication. Geological and geotechnical mapping procedures in use in the. Journal of rock mechanics and geotechnical engineering 2016, doi. The rqd in percent is obtained by dividing the sum of all the recovered pieces of core equal to or greater than 4 in.
Embraces modern principles and practices of civil engineering especially as they pertain to structural course work including steel design and concrete design. This report presents current geological and geotechnical mapping procedures for all the excavated areas in the onkalo, e. Gardner 1987 proposed the following relation for estimating e m from e r by using a reduction factor. Provide geotechnical recommendations for use in design of the proposed structures, as well as recommendations for related site work. Pdf hand book of geotechnical investigation and design. Rock quality designation rqd is a modified core recovery percentage in which the lengths of all sound. It was in the following year that the senior author developed the rqd concept to assist in the siting and the consultant, gainesville, fl 32608, and adjunct professor of civil engineering, university of florida, gainesville, fl 32601. Since in many cases rock quality designation rqd is the only rock mass classification index available, this paper outlines the key aspects on determination of rqd and evaluates the empirical methods based on rqd for determining the. The recording of rqd has since become virtually standard practice in drill core logging. Rqd was intended as more than an index of fracture spacing. Rqd geotechnical engineering general discussion engtips.
Geotechnical investigation and recommendations manual. Pakalnis the university of british columbia, vancouver, canada abstract. Pdf determination and applications of rock quality. Variation of estimated rqd % with scanline direction after choi and park, 2004. The rqd was initially introduced for civil engineering applications, and it has been quickly adopted in mining, engineering geology as well as geotechnical. Introduction to soil mechanics geotechnical engineering. Core recovery parameters ce 483 foundation engineering 2. The geotechnical engineering bureaus an engineering description of soils visualmanual procedure gtp2 presents a brief glossary of terms in gtp2, part 2. Fortunately, there are electrical systems and wiring harness engineering tools are available to help companies, large. Weber, pe continuing education and development, inc. Abstract characterization of rock masses and evaluation of their mechanical properties are important and challenging tasks in rock mechanics and rock engineering.
I mean its not for the tool lengths to determine the engineering quality for design. Geotechnical manual wisconsin department of transportation. Subsequently, it was incorporated into the rock mass rating rmr and q system classification methods that, worldwide, now play substantial roles in rock mechanics design, whether for tunnels. The rock quality designation rqd index in practice.
Rqd is an acronym for a technique that is used in geotechnical engineering principles in which that determines the quality of rock that was recovered when taking a core sample. Time to rest in peace university of toronto tspace. Since in many cases rqd is the only information available for describing rock discontinuities, this paper focuses on the determination of rqd and its utilization for evaluating the engineering properties mainly deformation modulus and unconfined compressive strength of rock masses. If the core run was in shale and then limestone, you could report the rqd of the shale separate from the rqd of the limestone. Rock quality designation rqd was introduced by don deere in the mid1960s as a means of using diamond core to classify rock for engineering purposes. Geotechnical engineering macarthur associated consultants, llc 2420 springer drive, suite 120 norman, ok 73069 attn. Rockquality designation rqd is a rough measure of the degree of jointing or fracture in a rock mass, measured as a percentage of the drill core in lengths of 10 cm or more. Palmstrom 1982 suggested that, when no core is available but discontinuity traces are visible in surface exposures or exploration adits, the rqd may be estimated from the number of discontinuities per unit volume. Since then it has undergone multiple modifications out of which, rmr89 is commonly used.
Rqd is defined as the percentage of intact drill core pieces longer than 10 cm recovered during a single core run abzalov, 2016, and the general equation is expressed as. Chapter 5 engineering properties of soil and rock 5. Rock quality designation an overview sciencedirect topics. Rock quality designation rqd is a standard technique in the mining industry for the qualitative and quantitative assessment of rock quality and degree of jointing, fracturing, and shearing in a rock mass. Title and subtitle geotechnical engineering circular no. To develop rational soil sampling devices and soil sampling methods. To collect and classify soils and their physical properties on the basis of fundamental knowledge of soil mechanics. Chapter 6 engineering properties of soil and rock nysdot geotechnical page 68 june 17, 20 design manual 6. Prediction of side resistance in poor quality rock.
Client executed on february 20, 2009 and modified on april 6, 2009. Rock mass classification 5 deeres rqd was widely used, particularly in north america, after its introduction. Procedure for measurement and calculation of rqd after deere, 1989. Pdf determination and applications of rock quality designation. Geotechnical engineer resume sample engineering resumes. In practice, a high rqd value does not always translate to high quality rock. Highquality rock has an rqd of more than 75%, low quality of less than 50%. Canadian geotechnical journal canadian science publishing. Engineering practice requires that professionals use a combination of technical skills and judgment in decision making. The rqd index is defined as the ratio of core that has competent core sticks 10 cm or 4 in. To develop suitable soil testing devices and soil testing methods.
Rock mass characterization is an integral part of rock engineering practice. We recommend all foundations derive support from the underlying clean, sound bedrock. Determination and applications of rock quality designation. Determining rock quality designation rqd of rock core1. Engineering manual preamble this manual provides guidance to administrative, engineering, and technical staff.
390 773 850 1379 757 431 93 1166 1162 379 378 536 1227 1194 1048 1342 1173 201 1282 525 731 866 1480 282 1051 943 719 796 123 433 1377 1029 252 364 651 1251