Rock Core Logging For Engineering Purposes

چند روز قبل یه بحثی با زمین شناس مشاور تهران سحاب در مورد مرجع لاگ گمانه ها و اصول لاگینگ داشتیم که سه تا استاندارد زیر را بهش معرفی کردم.

Paul Maconochie, GeoTek Solutions Pty Ltd

1 Requirements of a Borehole Log

“A borehole log should provide an accurate and comprehensive record of the geological conditions encountered together with an other relevant information obtained during drilling.”[1]. To which should be added that “the accurate and comprehensive record” should use clear terminology that is unambiguously defined. The purpose of these notes is to help you achieve that goal. Appropriate sources for such definitions include:

• Australian Standard Site Investigation Code AS1726-1993[2],

• Rock Characterization Testing and Monitoring – ISRM Suggested Methods 1981 [3] and

• Logging of Rock Cores for Engineering Purposes by the Geological Society[1].

Much of the information you will require is summarised in the AusIMM Field Geologists’ Manual [4]

The primary borehole log may consist of a traditional paper log, a computer coding sheet or a composite paper log with imported geophysical data. Some sample logs are attached at the end of these notes.

The information to be recorded can be summarized as:

1.1 Basic information

• Project name and geographical location

• Borehole location as coordinates - include the geographical datum

• Those responsible for the borehole e.g. principal, contractor, logger

• Relevant dates e.g. date started drilling, date finished drilling, date of water level reading.

1.2 Drilling Method and Progress

• Machine

• Core barrel and bit should be described

• Details of core sizes and changes, use of casing, use of drilling fluids

• Penetration rates

• Groundwater observations while the hole is being drilled including standing water levels and water losses

1.3 Description of Type and Condition of Material Encountered

• Rock type

• Strength

• Weathering

• Defects

• Structures

1.4 Pictorial Log

Using symbols/graphs is effective shorthand in drill core logs and helps with later correlation.

Geological map symbols should conform where possible to standards published by Geoscience Australia, or more conveniently, as presented in the Field Geologists Manual

در ادامه اصول استاندارد لاگینگ که همیشه موضوع بحثه را به صورت کامل اضافه میکنم.