Chapter 1 General Principles

Chapter 1 General Principles 1 Scope The purpose of this guildeline (draft) is to accurately prepare a borehole log and to ... the borehole number is ...

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Chapter 1 General Principles 1 Scope The purpose of this guildeline (draft) is to accurately prepare a borehole log and to correctly handle and store drilled cores.

2 Types of borehole logs The types of borehole logs stipulated by this guildeline (draft) are a borehole log in rock mass, a borehole log in soil (for core drilling), a borehole log in soil (for standard penetration test), a borehole log in a landslide (for core drilling) and a borehole log in a landslide (for standard penetration test ).

3 Scope of application The guildeline (draft) applies to preparing borehole logs including drilling in rock mass, drilling in soil (for core drilling), drilling in soil (for standard penetration test ), drilling in a landslide (for core drilling) and drilling in a landslide (for standard penetration test), drilled core photographs, and handling and storing drilled cores.

4 Constitution This guildeline (draft) consists of a title section, a log of boreholes in rockmass log, a log of boreholes in soil (for core drilling), a log of boreholes in soil (for standard penetration test ), a log of boreholes in a landslide (for core drilling) and a log of boreholes in a landslide (for standard penetration test), drilled core photographs, and handling and storing drilled cores and reference documents.

5 Electronic delivery Electronic delivery of borehole logs and drilled core photos etc. prepared according to this guideline (draft), are done according to “Guideline for Electric Delivery of Geological and Soil Investigation Results (draft) ”.

6 Terms and definitions The following are definitions of major terms used in this guideline (draft). (1) Drilling Drilling a bore hole in ground using a machine. (2) Drilling in rock mass Drilling a borehole in rock mass consisting of consolidated rock. (3) Drilling in soil

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Drilling a borehole in unconsolidated sedimentary deposits of various kinds. (4) Drilling in a landslide Drilling a borehole in a landslide. (5) Core drilling Drilling to obtain a full-length drilled core. (6) Borehole log A figure that shows geological classification based on engineering properties clarified by a drilling investigation, tests, or geophysical logging arranged in sequence by depth (based on JIS A 02061)). (7) Drilled core Cylindrical sample obtained by drilling. (8) Name of geological classification based on engineering properties Rock name combining a rock name categorized based on geological systems with engineering geological information with regard to bedrock formed by consolidated rock. (9) Site soil name Soil name decided based on visual observation of unconsolidated sedimentary deposits of various kinds. (10) Drilled core photograph Images photographed with a digital camera of drilled cores stored in individual boxes. (11)Connected drilled core photograph Result of connecting images of drilled cores photographed in individual boxes on a computer to link the full length from the top to bottom of a borehole or a specified section of a borehole.

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Chapter 2 General Section 1 General section Figure 2-1 shows the standard general section, and the following are rules for entering information. Investigation title Title of project or construction Purpose and object of investigation Borehole No.

Drilling period

Contractor Elevation of borehole top Total depth of drilling

Latitude

Borehole location

Client

m Inclination from m vertical

Project engineer

Site coordinator

Direction of non-vertical borehole

Inclination of ground

Longitude Core appraiser

Drilling supervisor

Drilling rig

Pump

Engine

Figure 2-1 General section

2 Investigation title In the investigation title box, the title of the ordered investigation is entered.

3 Title of project or construction In the title of project or construction box, the title of project or construction is entered.

4 Purpose and object of investigation In the purpose and object of investigation box, the purpose and object of the investigation are entered.

5 Borehole number In the borehole number box, the borehole number is entered systematically according to the serial number of the investigation location etc.

6 Borehole location In the borehole location box, the place-name of the location of the top of the borehole is entered including prefecture, subprefecture, municipality, district, and block. In the case of drilling in a landslide, the landslide block name is entered in parentheses.

7 Latitude and longitude In the latitude and longitude box, the latitude and longitude of the top of the borehole are entered.

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8 Client In the client box, the name of the client ordering the investigation is entered.

9 Drilling period In the drilling period box, the dates that the drilling begins and ends are entered.

10 Contractor and persons performing the drilling etc. In the contractor and persons performing the drilling box, as the contractor and persons performing the drilling, from among the project engineer, site coordinator, core appraiser, and drilling supervisor, people who actually performed the drilling work are entered.

11 Elevation of borehole top In the elevation of borehole top box, the elevation of borehole top is entered in units of 1/100m based on surveying results.

12 Total depth of drilling In the total depth of drilling box, the total depth of the drilling done is entered in 1/100m units.

13 Inclination from vertical In the inclination from vertical box, the angle formed by a vertical line and the vertical component in the borehole direction is entered.

14 Direction of non-vertical borehole In the direction of non-vertical borehole box, if the drilling is inclined, the horizontal component in the borehole direction is entered based on the 360°orientation method moving right from true north.

15 Inclination of ground In the inclination of ground box, the average inclination for about 5 m on the slope above and below the center of the borehole top is entered.

16 Drilling equipment In the machines used box, the names of the manufacturers of, model numbers of, and capabilities of the drill rig, engine, and pump are entered.

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Chapter 3 Log of Borehole in Rock Mass 1 Borehole log Figure 3-1 shows the standard log form used for drilling in rock mass, and the following are rules for entering information. Conditions of drilling

Returned water rate (L/min)

Drilling fluids and flow rate (L/min)

Injected water pressure (MPa)

Revolution speed (rpm)

Supply pressure (MPa)

Sample tube and drill bit

Borehole diameter (mm) and borehole wall stabilizing

Drilling rate (cm/h)

Drilling date

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Testing (3)

RQD(%)

Testing (2)

Max. length of core pieces (cm)

Testing (1)

Description

Ground water level/Measurement date

Rock classification

State of discontinuity

Discontinuity spacing

Hardness

Degree of hydrothermal alternation

Degree of weathering

Color tones

Geological classification based on engineering properties

Geological classification based on engineering properties (graphic symbols)

Depth (m)

Elevation (m)

Scale mark (m)

0

Core recovery (%)

100

1

2

3

4

5

Figure 3-1 Form of a log of borehole in rock mass

2 Scale mark The scale mark is entered starting from the borehole top in 1 m units. The borehole deepening work is also done with the borehole top as the starting point. The scale of the scale mark on the borehole log is, in principle, 1/100.

3 Elevation In the elevation box, the elevation of each boundary of geological classification based on engineering properties names etc. is entered. The elevation is also calculated and entered for inclined boring.

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4 Depth In the depth box, the depth of each boundary of geological classification based on engineering properties names etc. is entered based on distance from the borehole top.

5 Geological classification based on engineering properties (graphic symbols) In the geological classification based on engineering properties (graphic symbols) box, rock type etc. are entered based on graphic symbols.

6 Geological classification based on engineering properties In the geological classification based on engineering properties box, rock type etc. are entered.

7 Color tones In the color tones box, the color of the core observed in wet condition in bright natural light is entered.

8 Degree of weathering In the degree of weathering box, the degree of weathering is categorized based on the state of alteration or oxidization of the constituent minerals of the rock and the code is entered.

9 Degree of hydrothermal alternation In the degree of hydrothermal alternation box, the degree of hydrothermal alteration is categorized based on the state of alteration of the constituent minerals of the rock and the code is entered.

10 Hardness In the hardness box, the hardness of drilled core is categorized by hammering it and the code is entered.

11 Discontinuity spacing In the discontinuity spacing box, mainly the discontinuity spacing is categorized and the code is entered.

12 State of discontinuity In the state of discontinuity box, the degree of weathering and alteration along the discontinuity and the discontinuity aperture etc. are categorized and the codes are entered.

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13 Rock classification In the rock classification box, the rock classification is appraised and entered based on hardness,

discontinuity

spacing,

state

of

discontinuity,

weathering,

hydrothermal

alternation, core recovery, maximum core length, RQD and other rock mass properties.

14 Core recovery, maximum length of core pieces or RQD In the core recovery, maximum length of core pieces or RQD box, the values of core recovery per sampler lift (for drilling length of each run), maximum length of core pieces in 1 m sections or RQD are plotted and entered along with numerical values.

15 Remarks In the remarks box, any other noteworthy items are entered.

16 Description In the description box, any matters which could not be entered among any matters stipulated until now are entered.

17 Ground water level In the ground water level box, the water levels inside the borehole at the start of drilling each day are entered accompanied by the dates of measurement.

18 Testing (1) In the testing (1) box, the name of the test using the borehole and drilled core is entered and the diagram after analyzing and calculated values for these tests are also entered.

19 Testing (2) In the testing (2) box, the test section depth and test name etc. for tests other than those in “18 Testing (1)” are entered.

20 Testing (3) In the testing (3) box, the test section depth and test name etc. for tests other than those in “18 Testing (1)” and “19 Testing (2)” are entered.

21 Drilling date In the drilling date box, the depth of section drilled each day and dates are entered.

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22 Drilling rate In the drilling rate box, drilling rate is calculated by the drilled section length and time required for each drilling and entered.

23 Borehole diameter and borehole wall stabilizing In the borehole diameter and borehole wall stabilizing box, the borehole diameter, and in the case where the borehole wall was protected, the method and section depth are entered.

24 Sample tube and drill bit In the sample tube and drill bit box, the types of sample tube and core bit used for the drilling along with the drilled section depth are entered.

25 Supply pressure In the supply pressure box, the supply pressure during drilling is entered.

26 Revolution speed In the revolution speed box, the revolution speed during drilling is entered.

27 Injected water pressure In the injected water pressure box, the injected water pressure during drilling is entered.

28 Drilling fluids and flow rate In the drilling fluids and flow rate box, the type of drilling fluids, depth of each drilled section used, and flow rate of water during drilling are entered.

29 Returned water rate In the returned water rate box, the rate of returned water during drilling is entered.

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Chapter 4 Log of Borehole in Soil (For Core Drilling) 1 Boring log Figure 4-1 is the standard log used for soil drilling for core drilling and the following are the instructions for entering information.

Conditions of drilling

Returned water rate (L/min)

Drilling fluid and flow rate (L/min)

Injected water pressure (Mpa)

Revolution speeed (rpm)

Supply pressure (Mpa)

Sample tube and drill bit

Borehole diameter (mm) and borehole wall stabilizing

Drilling rate (cm/h)

Drilling date

Testing (3)

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Testing (2)

Max. length of core pieces (cm)

Testing (1)

Description

Ground water level/Measurement date

Relative consistency

Color ones

Classification of geomaterials (symbols)

Classification of geomaterials

Site soil name

Site soil name (graphic symbols)

Depth (m)

Elevation (m)

Scale mark (m)

0

Core recovery (%)

100

1

2

3

4

5

Figure 4-1 Soil borehole log format (for core drilling)

2 Scale mark The scale mark is entered starting from the borehole top in 1 m units. The borehole deepening work is also done with the borehole top as the starting point. The scale of the scale mark on the borehole log is, in principle, 1/100.

3 Elevation In the elevation box, the elevation of each boundary of site soil names etc. is entered. The elevation is also calculated and entered for inclined boring.

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4 Depth In the depth box, the depth of each boundary of site soil names etc. is entered based on distance from the borehole top.

5 Site soil name (graphic symbols) In the site soil name (graphic symbols) box, the site soil name etc. is entered by graphic symbols.

6 Site soil name In the site soil name box, the site soil name is categorized and entered based on visual observation.

7 Classification of geomaterials In the classification of geomaterials box, the drilled core is entered categorized based on the technical standard by the Japanese Geotechnical Society (JGS 00513).

8 Color tones In the color tones box, the color of the core observed in wet condition in bright natural light is entered.

9 Relative consistency In the relative consistency box, the relative consistency is judged on site and entered.

10 Core recovery, maximum length of core piaces In the core recovery and maximum length of core pieces box, the core recovery for each sampler lift (drilled length for each run), and maximum length of core pieces for each 1 m section are plotted and entered by numerical values.

11 Remarks In the remarks box, any other noteworthy items are entered.

12 Description In the description box, any matters which could not be entered among any matters stipulated until now are entered.

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13 Ground water level In the ground water level box, the water levels inside the borehole at the start of drilling each day are entered accompanied by the dates of measurement.

14 Testing (1) In the testing (1) box, the depth of testing sections of the testing done using the borehole and drilled core, or sampling depths, sample numbers, sampling method, test name and test number are entered. And if they can be entered, the test results are entered.

15 Testing (2) In the testing (2) box, the test section depth and test name etc. for tests other than those in “14 Testing (1)” are entered.

16 Testing (3) In the testing (3) box, the test section depth and test name etc. for tests other than those in “14 Testing (1)” and “15 Testing (2)” are entered.

17 Drilling date In the drilling date box, the depth of section drilled each day and dates are entered.

18 Drilling rate In the drilling rate box, drilling rate is calculated by the drilled section length and time required for each drilling and entered.

19 Borehole diameter and borehole wall stabilizing In the borehole diameter and borehole wall stabilizing box, the borehole diameter, and in the case where the borehole wall was protected, the method and section depth are entered.

20 Sample tube and drill bit In the sample tube and drill bit box, the types of sample tube and core bit used for the drilling along with the drilled section depth are entered.

21 Supply pressure In the supply pressure box, the supply pressure during drilling is entered.

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22 Revolution speed In the revolution speed box, the revolution speed during drilling is entered.

23 Injected water pressure In the injected water pressure box, the injected water pressure during drilling is entered.

24 Drilling fluids and flow rate In the drilling fluids and flow rate box, the type of drilling fluids, depth of each drilled section used, and flow rate of water during drilling are entered.

25 Returned water rate In the returned water rate box, the rate of returned water during drilling is entered.

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Chapter 5 Log of Borehole in Soil (For Standard Penetration Test) 1 Borehole log Figure 5-1 is the standard log used for drilling in soil for the standard penetration test and the following are the instructions for entering information.

Drilling date

Testing (3)

Testing (2)

Penetration when SPT sampler was settled

Testing (1)

Penetration at 50 (100) times blows

Penetration for each blow

Depth -N -value

Number of blows for each 100 mm

N-value

0

Standard penetration test

Depth (m)

Ground water level/Measurment date

Relative consistency

Relative density

Color ones

Classification of geomaterials (symbols)

Classification of geomaterials

Site soil name

Site soil name (graphic symbols)

Depth (m)

Elevation (m)

Scale mark (m)

description

50

1

2

3

4

5

Figure 5-1 Form of a log of borehole in soil (for standard penetration test)

2 Scale mark The scale mark is entered starting from the borehole top in 1 m units. The borehole deepening work is also done with the borehole top as the starting point. The scale of the scale mark on the borehole log is, in principle, 1/100.

3 Elevation In the elevation box, the elevation of each boundary of site soil names etc. is entered.

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4 Depth In the depth box, the depth of each boundary of site soil names etc. is entered based on distance from the borehole top.

5 Site soil name (graphic symbols) In the site soil name (graphic symbols) box, the site soil name etc. is entered by graphic symbols.

6 Site soil name In the site soil name box, the site soil name is categorized and entered based on visual observation.

7 Classification of geomaterials In the classification of geomaterials box, the drilled core is entered categorized based on the technical standard by the Japanese Geotechnical Society (JGS 00513).

8 Color tones In the color tones box, the color of the core observed in wet condition in bright natural light is entered.

9 Relative density, relative consistency In the relative density box, the relative density is assessed based on the N-value for a case where a standard penetration test was performed, and a code is entered. In the relative consistency box, the relative consistency is assessed on site and a code is entered.

10 Remarks In the remarks box, any other noteworthy items are entered.

11 Description In the description box, any matters which could not be entered among any matters stipulated until now are entered.

12 Ground water level In the ground water level box, the water levels inside the borehole at the start of drilling each day are entered accompanied by the dates of measurement.

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13 Standard penetration test In the standard penetration test box, for each 100mm of test depth, the number of blows and the number of percussions/penetration are entered. The N-value is represented by the line graph and entered along with a numerical value.

14 Testing (1) In the testing (1) box, the depth of testing sections of the testing done using the borehole and drilled core, or sampling depths, sample numbers, sampling method, test name and test number are entered. And if they can be entered, the test results are entered.

15 Testing (2) In the testing (2) box, the test section depth and test name etc. for tests other than those in “14 Testing (1)” are entered.

16 Testing (3) In the testing (3) box, the test section depth and test name etc. for tests other than those in “14 Testing (1)” and “15 Testing (2)” are entered.

17 Drilling date In the drilling date box, the depth of section drilled each day and dates are entered.

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Chapter 6 Log of Borehole in Landslide (For Core Driliing) 1 Borehole log Figure 6-1 is the standard log used for drilling in a landslide for core drilling and the following are the instructions for entering information.

Borehole wall stabilizing

Conditions of drilling

Returned water rate (L/min)

Drilling fluid and flow rtae (L/min)

Injected water pressure (MPa)

Depth - resistivity

Revolution speed (rpm)

Supply pressure (MPa)

Sample tube and drill bit

Drilling rate (cm/h)

Reason

Method

Borehole diameter (mm)

Depth of casing bottom

Detected sectoin

Ground water level

)

Drlling dtae

Method (

Ground water level for each drilling date

Screen pipe

Groundwater Prospecting

Testing (2)

Testing (1)

Core weight (kg)

Core recovery (%)

Hardness and relative consistency

Degree of crushing

Degree of hydrothermal alternation

Degree of weathering

Color tones

Geological classification based on engineering properties

Geological classification based on engineering properties (graphic symbols)

Depth (m)

Elevation (m)

Scale mark (m)

Description

1

2

3

4

5

Figure 6-1 Form of a log of borehole in a landslide (for all core boring)

2 Scale mark The scale mark is entered starting from the borehole top in 1 m units. The borehole deepening work is also done with the borehole top as the starting point. The scale of the scale mark on the borehole log is, in principle, 1/100.

3 Elevation In the elevation box, the elevation of each boundary of geological classification based on engineering properties names or site soil names etc. is entered. The elevation is also calculated and entered for inclined boring.

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4 Depth In the depth box, the depth of each boundary of geological classification based on engineering properties names or site soil names etc. is entered based on distance from the borehole top.

5 Geological classification based on engineering properties name (graphic symbols) or site soil name (graphic symbols) In the geological classification based on engineering properties name (graphic symbols)/site soil name (graphic symbols) box, the rock type or site soil name etc. are entered by graphic symbols.

6 Geological classification based on engineering properties name or site soil name In the geological classification based on engineering properties name box, the rock type is entered. In the site soil name box, the site soil name is categorized and entered based on visual observation.

7 Color tones In the color tones box, the color of the core observed in wet condition in bright natural light is entered.

8 Degree of weathering In the degree of weathering box, the degree of weathering is categorized based on the state of alteration or oxidization of the constituent minerals of the rock and the code is entered.

9 Degree of hydrothermal alternation In the degree of hydrothermal alternation box, the degree of hydrothermal alteration is categorized based on the state of alteration of the constituent minerals of the rock and the code is entered.

10 Degree of crushing In the degree of crushing box, the degree of crushing due to landslide movement etc. is categorized and entered.

11 Hardness and relative consistency In the hardness box, the hardness of a rock fragment is categorized by hammering and the code is entered. In the relative consistency box, the relative consistency is assessed on site and the code is entered.

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12 Core recovery In the core recovery box, the values of core recovery per sampler lift (for drilling length of each run) are entered along with numerical values.

13 Description In the description box, any matters which could not be entered among any matters stipulated until now are entered.

14 Core weight In the core weight box, the depth of the section where the core was weighed and its weight are entered.

15 Groundwater prospecting When groundwater prospecting was done, the prospecting method performed and its results are entered in the groundwater prospecting box. Resistivity is plotted and detected sections are also entered.

16 Testing (1) In the testing (1) box, the test section depth and test name etc. for tests other than those in “15 Groundwater prospecting” are entered.

17 Testing (2) In the testing (2) box, the test section depth and test name etc. for tests other than those in “15 Groundwater prospecting ” and “16 Testing (1)” are entered.

18 Drilling date In the drilling date box, the depth of section drilled each day and dates are entered.

19 Depth of casing bottom In the depth of casing bottom box, the depth when the work is completed on the drilling date is entered.

20 Ground water depth In the ground water depth box, the water levels in the borehole before and after the work of drilling on the drilling date and the stable water level after the completion of all work are entered.

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21 Borehole diameter In the borehole diameter box, the borehole diameter is entered.

22 Method In the method box, the method of borehole wall stabilizing used is entered by a code.

23 Reason In the reason box, the reason for executing borehole wall stabilizing is entered.

24 Screen pipe In the screen pipe box, if a screen pipe was installed after completion of drilling, its specifications are entered.

25 Drilling rate In the drilling rate box, drilling rate is calculated by the drilled section length and time required for each drilling and entered.

26 Sample tube and drill bit In the sample tube and drill bit box, the types of sample tube and core bit used for the drilling along with the drilled section depth are entered.

27 Supply pressure In the supply pressure box, the supply pressure during drilling is entered.

28 Revolution speed In the revolution speed box, the revolution speed during drilling is entered.

29 Injected water pressure In the injected water pressure box, the injected water pressure during drilling is entered.

30 Drilling fluids and flow rate In the drilling fluids and flow rate box, the type of drilling fluids, depth of each drilled section used, and flow rate of water during drilling are entered.

31 Returned water rate In the returned water rate box, the rate of returned water during drilling is entered.

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Chapter 7 Log of Borehole in Landslide (For Standard Penetration Test) 1 Borehole log Figure 7-1 is the standard log used for drilling in a landslide for standard penetration test and the following are the instructions for entering information.

Conditions of drilling

Returned water rate (L/min)

Drilling fluid and flow rtae (L/min)

Sample tube and drill bit

Reason

Method

Borehole diameter (mm)

Depth of casing bottom

Ground water level

Screen pipe

Borehole wall stabilizing

Groundwater prospecting (method:

Ground water level for each drillin date

Drlling dtae

Testing (3)

Testing (2)

Penetration when SPT sampler was settled

Penetration at 50 (100) times blows

Penetration for each blow

Number of blows for each 100 mm

N-value Depth -N -value

Testing (1)

Standard penetration test

Depth (m)

Relative density

Hardness and relative consistency

Degree of crushing

Degree of hydrothermal alternation

Degree of weathering

Color tones

)

Geological classification based on engineering properties

Geological classification based on engineering properties (graphic symbols)

Depth (m)

Elevation (m)

Scale mark (m)

Description

0

50

1

2

3

4

5

Figure 7-1 Form of a log of borehole in landslide (for standard penetration test)

2 Scale mark The scale mark is entered starting from the borehole top in 1 m units. The borehole deepening work is also done with the borehole top as the starting point. The scale of the scale mark on the borehole log is, in principle, 1/100.

3 Elevation In the elevation box, the elevation of each boundary of geological classification based on engineering properties names or site soil names etc. is entered. The elevation is also calculated and entered for inclined boring.

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4 Depth In the depth box, the depth of each boundary of geological classification based on engineering properties names or site soil names etc. is entered based on distance from the borehole top.

5 Geological classification based on engineering properties name (graphic symbols) or site soil name (graphic symbols) In the geological classification based on engineering properties name (graphic symbols)/site soil name (graphic symbols) box, the rock type or site soil name etc. are entered by graphic symbols.

6 Geological classification based on engineering properties name or site soil name In the geological classification based on engineering properties name box, the rock type is entered. In the site soil name box, the site soil name is categorized and entered based on visual observation.

7 Color tones In the color tones box, the color of the core observed in wet condition in bright natural light is entered.

8 Degree of weathering In the degree of weathering box, the degree of weathering is categorized based on the state of alteration or oxidization of the constituent minerals of the rock and the code is entered.

9 Degree of hydrothermal alternation In the degree of hydrothermal alternation box, the degree of hydrothermal alteration is categorized based on the state of alteration of the constituent minerals of the rock and the code is entered.

10 Degree of crushing In the degree of crushing box, the degree of crushing due to landslide movement etc. is categorized and entered.

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11 Hardness and relative consistency In the hardness box, the hardness of a rock fragment is categorized by hammering and the code is entered. In the relative consistency box, the relative consistency is assessed on site and the code is entered.

12 Relative density In the relative density box, the relative density is assessed based on the N-value for a case where a standard penetration test was performed, and a code is entered.

13 Description In the description box, any matters which could not be entered among any matters stipulated until now are entered.

14 Standard penetration test In the standard penetration test box, for each 100 mm of test depth, the number of blows and the number of blows/penetration are entered. The numerical value of the N-value is entered.

15 Testing (1) In the testing (1) box, the test section depth and test name etc. are entered.

16 Testing (2) In the testing (2) box, the test section depth and test name etc. for tests other than those in “15 Testing (1)” are entered.

17 Testing (3) In the testing (3) box, the test section depth and test name etc. for tests other than those in “15 Testing (1)” and “16 Testing (2)” are entered.

18 Drilling date In the drilling date box, the depth of section drilled each day and dates are entered.

19 Depth of casing bottom In the depth of casing bottom box, the depth when the work is completed on the drilling date is entered.

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20 Ground water depth In the ground water depth box, the water levels in the borehole before and after the work of drilling on the drilling date and the stable water level after the completion of all work are entered.

21 Borehole diameter In the borehole diameter box, the borehole diameter is entered.

22 Method In the method box, the method of borehole wall stabilizing used is entered by a code.

23 Reason In the reason box, the reason for executing borehole wall stabilizing is entered.

24 Groundwater prospecting When groundwater prospecting was done, the prospecting method performed and its results are entered in the groundwater prospecting box.

25 Screen pipe In the screen pipe box, if a screen pipe was installed after completion of drilling, its specifications are entered.

26 Sample tube and drill bit In the sample tube and drill bit box, the types of sample tube and core bit used for the drilling along with the drilled section depth are entered.

27 Drilling fluids and flow rate In the drilling fluids and flow rate box, the type of drilling fluids, depth of each drilled section used, and flow rate of water during drilling are entered.

28 Returned water rate In the returned water rate box, the rate of returned water during drilling is entered.

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Chapter 8 Drilled Core Photographs 1 Scope of application This chapter applies to taking photographs of drilled cores.

2 Drilled core photographs 2-1 Drilled core photographs Drilled core photographs are taken with a digital camera to ensure picture quality with resolution of at least 1 mm or better.

2-2 Test photographing and photographing method of drilled core photographs When taking drilled core photographs, a test photograph is always taken first to clarify photographic conditions capable of achieving resolution of about 1 mm or better, then information about a color sample and the drilled core are simultaneously photographed, with careful attention paid to the weather during photography, shadows during photography and the moisture content of each drilled core.

2-3 File format and specifications of drilled core photographs The file format of drilled core photographs is basically JPEG format, and the number of recording pixels and compression ratio are such that picture quality does not decline. Corrections such as color calibration of the photographs taken must not be done.

3 Connected drilled core photographs 3-1 Specifications of connected drilled core photographs Connected drilled core photographs are prepared by connecting drilled core photographs taken of each box of cores on a computer.

3-2 File specifications of connected drilled core photographs The file format of connected drilled core photographs is optional.

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Chapter 9 Smplified Log 1 Configuration of simplified log A simplified log consists of parts showing attributes of boreholes and parts showing a simplified log.

2 Attributes of boreholes Attributes of boreholes always shown are boring number, borehole top elevation, and total borehole depth; while latitude and longitude, inclination from vertical, and direction of non-vertical borehole are shown as necessary.

3 Simplified log in the narrow sense A simplified log in the narrow sense always shows the scale mark, geological classification based on engineering properties (graphic symbols), and site soil name (graphic symbols), while necessary information from the logs specified from Chapter 3 through Chapter 7 is shown.

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Chapter 10 Methods of Handling and Storing Drilled Cores 1 Scope of application This Chapter presents general standards for handling and storage methods of drilled cores, and does not apply to cases where, because of the purpose of the investigation etc., it is difficult to comply with this Chapter.

2 Core box 2-1 External shape and dimensions A core box has rectangular external shape, and the internal dimensions are length of 103 cm, so that the number of 100 cm long drilled cores it can hold are 5 pieces that are about 50 mm in diameter, 3 pieces that are about 70 mm in diameter, and 2 pieces that are about 100 mm in diameter.

2-2 Markings The following are marked on core boxes in waterproof ink, paint etc. [1] Outside of lid The investigation title, borehole number, core box number, depth interval, drilling period, and contractor are marked. [2] Sides of the boxes Boring number, core box number and depth interval are marked.

2-3 Rim plates On each side, a scale in 10cm units is marked from the left of the core box. The borehole number, core box number, section depth, and depth are marked.

2-4 Partition On the partition, a scale in 10 cm units is marked from the left side of the core box.

2-5 Lid The lid of a core box is in principle, removable.

2-6 Material The material of a core box is, in principle, wood, and it is adequately strong including hardware.

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3 Handling drilled cores 3-1 Extracting a drilled core from inner tube When extracting a drilled core from inner tube, the drilled core is setted on a holder and carefully arranged. When a drilled core is extracted, great care is taken to avoid damaging the drilled core by tapping the inner tube or breaking the drilled core.

3-2 Cutting a drilled core A drilled core too long to be stored in a core box is cut with an electric cutter, and then stored in the core box.

3-3 Storing a drilled core in a core box A drilled core that has been extracted from an inner tube and arranged in the core holder is stored in the specified core box for each 1m of depth.

3-4 Inserting spacer plates A spacer plate is inserted for drilled length of each run. A spacer plate is marked with the borehole depth for each run. And so it will be used for a rock testing, when the drilled core has been pulled out, the spacer plate is inserted, and the depth above and below the section where it was pulled out and the sample number are marked on it.

3-5 Cleaning the surface of drilled cores The drilled core surfaces are cleaned by the following procedure. [1] The sleeve around the drilled core that has been taken out of the inner tube is peeled off. [2] Mud cake adhering to the surface of the drilled core after the sleeve has been peeled off is carefully washed off.

3-6 Photographing drilled cores The drilled cores are photographed immediately after the drilled cores that should be stored in the same core box have all be stored.

3-7 Treatment of soft rock etc. When drilled cores made of soft rock or unconsolidated sediment that will deteriorate quickly after they are taken out of the inner tubes must be provided for laboratory testing, they must be inserted in PVC or acrylic tubes or sealed inside vinyl bags.

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3-8 Indicating man-made cracks When a drilled core is cracked by hammering for example, a seal is attached indicating that the crack at the location was man-made.

3-9 Handling core boxes during transport When transporting core boxes containing drilled cores, great care is taken to prevent any damage to the drilled cores.

4 Storing drilled cores To prevent the deterioration of drilled cores, they are stored by appropriately managing the temperature and humidity of the core boxes.

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