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TEST METHOD FOR THE GRAIN-SIZE ANALYSIS OF TOPSOIL

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GEOTECHNICAL TEST METHOD

GTM-22

Revision #2

GEOTECHNICAL ENGINEERING BUREAU

APRIL 2007

GEOTECHNICAL TEST METHOD:

TEST METHOD FOR THE GRAIN-SIZE ANALYSIS OF TOPSOIL

GTM-22

Revision #2

STATE OF NEW YORK

DEPARTMENT OF TRANSPORTATION

GEOTECHNICAL ENGINEERING BUREAU

APRIL 2007

TABLE OF CONTENTS

1. SCOPE 3

2. EQUIPMENT 3

3. SIEVE ANALYSIS DATA SHEET 3

4. TEST PROCEDURE 3

4.1 Initial Separation of the Plus and Minus 1/4 in. (6.3 mm) Particles 3

4.2 The Plus 1/4 in. (6.3 mm) Portion of the Sample 4

4.3 The Minus 1/4 in. (6.3 mm) Portion of the Sample 4

4.4 The Moisture Content of the Minus 1/4 in. (6.3 mm) Material 4

4.5 The Wash of the Minus 1/4 in. (6.3 mm) Portion of the Sample 4

5. COMPUTATIONS 5

5.1 Rounding Numbers 5

5.2 Correct the Weight of Minus 1/4 in. (6.3 mm) Material for Moisture Content 6

5.2.1 Determine the Moisture Content 6

5.2.2 Compute the Dry Weight of the Minus 1/4 in. (6.3 mm) Material 6

5.3 Compute the Total Dry Weight of the Sample 6

5.4 Compute the Particle Size Distribution of the Plus 1/4 in. (6.3 mm) Material 6

5.4.1 Compute the Percent Retained 6

5.4.2 Compute the Percent of Total Sample Passing 6

5.5 Compute the Particle Size Distribution of Minus 1/4 in. (6.3 mm) Material 7

5.5.1 Compute the Percent Retained 7

5.5.2 Compute the Percent Passing Based on Minus 1/4 in. (6.3 mm) Material 7

5.5.3 Compute the Percent Passing Based on Total Weight 7

6. CHECKS AND BALANCES 7

6.1 Check the Computed Percent Retained 7

6.1.1 For the Plus 1/4 in. (6.3 mm) Material 7

6.1.2 For the Minus 1/4 in. (6.3 mm) Material 8

6.2 Check the Computed Percent Passing 8

6.2.1 For the Plus 1/4 in. (6.3 mm) Material 8

6.2.2 For the Minus 1/4 in. (6.3 mm) Material 8

APPENDIX 9

A. Sieve Analysis Data A-1

B. Requirements of Sieves B-1

1. SCOPE

This method describes the determination of particle size distribution for topsoil items stipulated in the Department Specifications. The method covers materials with particle sizes larger than No. 200 sieve (0.075 mm) and smaller than 4 in. (100 mm).

2. Equipment

The following equipment is required for this test:

Scale - Minimum capacity of 9 lbs. (4000 g). It shall be accurate to 0.1 percent and be readable to 0.1 g.

Sieves - A series of sieves which conform to the requirements of AASHTO M-92-91, pg. 87, Table No. 1 (excluding Column 7), See Appendix B.

Containers - Metal pan of sufficient size to contain the total sample for separation.

- Metal pan of sufficient size to contain at least ½ lb. (200 g) of material for moisture content determination and the wash test.

Oven - Capable of maintaining 230(9( F (110(5( C).

3. Sieve Analysis Data Sheet

Complete the heading of form SM 15b, "Geotechnical Engineering Bureau Sieve Analysis Data" (Appendix A), and be prepared to enter values from the test. The specification requirement column of the data sheet is optional.

NOTE 1: This data sheet was designed to be utilized with other types of material, as well. Therefore, some areas are not to be used with this method.

Form SM 15b uses US Customary Units (lbs.) for recording the larger weights (weight Plus ¼ in. (6.3 mm) material, etc.) and International System of Units (g) for recording the smaller weights (moisture content, weight Minus ¼ in. (6.3 mm) material, etc.).

4. Test Procedure

4.1 Initial Separation of the Plus and Minus ¼ in. (6.3 mm) Material.

The topsoil sample is separated on a ¼ in. (6.3 mm) sieve into plus and minus ¼ in. (6.3 mm) portions. If the sample is too wet, it shall be air dried until moist for easier separation on the ¼ in. (6.3 mm) sieve. (See Note 1).

4.2 The Plus ¼ in. (6.3 mm) Portion of the Sample.

The plus ¼ in. (6.3 mm) portion is oven dried, weighed to the nearest 0.1 g and recorded on Line C of the data sheet. This material is then sieved using the sieve size openings that comply with the particle size requirements for the topsoil item(s). After the sieving process, weigh the material retained on each sieve to the nearest 0.1 g and record the values accordingly in Column 1 of the data sheet. Sum the values in Column 1 and record this value at the bottom of that Column. Check for excessive loss of material during the test. The total dry weight of the plus ¼ in. (6.3 mm) material (Line C) should be within 0.4% of the sum of the weights retained by the sieves (Total of Column 1).

NOTE 1: During the initial separation, the plus ¼ in. (6.3 mm) material shall be cleaned in such a manner that the sieving operation will result in no minus ¼ in. (6.3 mm) material.

NOTE 2: Very often material will get stuck in the mesh of a sieve. Such material shall be removed from the mesh and weighed as being retained on that sieve. Do not force material through the sieves.

4.3 The Minus ¼ in. (6.3 mm) Portion of the Sample.

Weigh the minus ¼ in. (6.3 mm) portion of the sample to the nearest 0.1 g and record this value on Line D of the data sheet.

4.4 The Moisture Content of the Minus ¼ in. (6.3 mm) Material.

Immediately mix the minus ¼ in. (6.3 mm) portion of the sample thoroughly. Obtain a 150(5 g sample of this material and place it into a container of predetermined weight for a moisture content determination. The weight of container and the weight of the soil and container should be recorded on Lines J and H respectively to the nearest 0.1 g. After oven drying, allow the sample to cool and reweigh it to the nearest 0.1 g and record this value on Line I.

NOTE 1: For all oven drying, the sample shall be maintained at a temperature of 230(9( F (110(5( C) for a minimum of 12 hours or until it maintains a constant weight.

4.5 The Wash of the Minus 6.3 mm Portion of the Sample.

Thoroughly mix and weigh a 100 to 105 g portion from the dried moisture content sample (Note 1) and record this weight to the nearest 0.1 g on Line N of the data sheet. Wash this sample on a No. 200 (0.075 mm) sieve to remove all fines from the sample. It is suggested to wash the sieve sample over a white basin to make it easier to see when the wash water is clean. After the sample is thoroughly washed, carefully transfer the sample from the sieve to a container for oven drying. Weigh the dried sample to the nearest 0.1 g and record this value on Line O of the data sheet. This value is also used for the weight retained on the No. 200 (0.075 mm) sieve in Column 5 of the data sheet if no other sizes are required. If other sizes are required, then the material is sieved using the sieve size openings that comply with the particle size requirements for the topsoil item(s). After the sieving process, weigh the material retained on each sieve to the nearest 0.1 g and record the values in Column 5 of the data sheet. Sum the values in Column 5 and record this value at the bottom of that column. Check for excessive loss of material during the test. The weight of dry minus ¼ in. (6.3 mm) after wash (Line O) should be within 0.4% of the sum of the weights retained on the sieve (Total of Column 5).

NOTE 1: On soils with very high moisture contents, there may be insufficient material from the moisture content sample for the wash on the No. 200 (0.075 mm) sieve. Additional material from the original sample (oven dried) may be added with the moisture content material in order to achieve the required weight.

NOTE 2: Examine the No. 200 (0.075 mm) sieve prior to each washing to determine its condition. Replace the sieve if any holes or cracks are noticed in the solder or mesh, or if the sieve's mesh is stretched excessively. A new No. 200 (0.075 mm) sieve must be washed with soap and water prior to its initial use.

NOTE 3: The No. 200 (0.075 mm) sieves are delicate. Fingertips may be used to agitate the sample during washing, but do not apply pressure to the mesh itself.

NOTE 4: Do not allow water to overflow or splash out of the sieve. This may cause a loss of material and lead to inaccurate results. Tapping the side of the sieve will help break the surface tension as well as eliminate clogging.

NOTE 5: On soils with a high amount of silt and/or clay, it may be necessary to pre-soak the sample before the wash test. This will soften the silt and/or clay "balls" so proper washing can be achieved.

5. Computations

5.1 Rounding Numbers.

For all computed results, round the values in the following manner: Compute the values to one place beyond the required significant figure. If the extended value is less than 5, leave the last required digit unaltered. If it is greater than 5, round the last required digit up one unit. If the extended value equals 5, round the last required digit to the nearest even number.

5.2 Correct the Weight of Minus ¼ in. (6.3 mm) Material for Moisture Content.

5.2.1 Determine the moisture content.

Compute the weight of water by subtracting Line I from Line H and record this value on Line K. Compute the weight of dry material by subtracting Line J from Line I and record this value on Line L. Compute the moisture content by dividing the weight of water (Line K) by the weight of the dry material (Line L) and multiply this value by 100 and record to the nearest 0.1% on Line M.

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5.2.2 Compute the dry weight of the minus ¼ in. (6.3 mm) material. Divide the total weight of minus ¼ in. (6.3 mm) material (Line D) by the quantity 1.0 plus the moisture content (Line M) divided by 100 and record this value on Line E.

5.3 Compute the Total Dry Weight of the Sample.

Compute the total dry weight by adding the dry weight of the plus ¼ in. (6.3 mm) material (Line C) to the dry weight of the minus ¼ in. (6.3 mm) material (Line E) and record this value on Line F.

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5.4 Compute the Particle Size Distribution of Plus ¼ in. (6.3 mm) Material.

5.4.1 Compute the percent retained.

Divide the weight retained on each sieve (in Column 1) by the total dry weight of the sample (Line F). Multiply each value by 100 and record the results to the nearest 0.1% in Column 2 opposite the respective sieve. Sum the values in Column 2 and record this value at the bottom of the column.

5.4.2 Compute the percent of total sample passing.

The smallest sieve size in which all of the sample passes will have 100% total sample passing. For the rest of the sieve sizes, compute the percent total sample passing by subtracting the percent retained (in Column 2) from the percent of total sample passing computed for the previous sieve size. This makes it necessary to work from the top down. Record each of the values computed to the nearest 0.1% in Column 3 of the data sheet. For checking specification criteria, round the values in Column 3 to the nearest one percent and record these values in Column 4.

5.5 Compute the Particle Size Distribution of Minus ¼ in. (6.3 mm) Material.

5.5.1 Compute the percent retained.

Divide the weight retained on each sieve (in Column 5) by the weight of the minus ¼ in. (6.3 mm) sample prior to washing (Line N). Multiply each value by 100 and record the results to the nearest 0.1% in Column 6. Sum the values in Column 6 and record this value at the bottom of the Column.

5.5.2 Compute the percent passing based on minus ¼ in. (6.3 mm) material.

Subtract the percent retained on the largest sieve used on the minus ¼ in. (6.3 mm) material from 100% to determine the percent passing for that sieve. For the rest of the sieves, compute the percent sample passing by subtracting the percent retained from the percent sample passing computed for the previous sieve size. Record these values as percents to the nearest 0.1% in Column 7.

5.5.3 Compute the percent passing based on total weight.

Multiply the percents passing, computed in Section 5.5.2 (Column 7), by the percent of the total sample passing the ¼ in. (6.3 mm) sieve (last value in Column 3), for each sieve size. Divide each value by 100 to get the percent and record to the nearest 0.1% in Column 8. There is no check for the values in Column 8, so be sure the computations are correct. For checking specification criteria, round the values in Column 8 to the nearest one percent and record these values in Column 9.

6. Checks and Balances

6.1 Check the Computed Percent Retained.

6.1.1 For the plus ¼ in. (6.3 mm) material.

The total weight retained (Total of Column 1) divided by the total dry weight of the sample (Line F) and multiplied by 100 should be within 0.2% of the sum of the percents retained (Total of Column 2).

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6.1.2 For the minus ¼ in. (6.3 mm) material.

The total weight retained (Total of Column 5) divided by the weight of dry minus ¼ in. (6.3 mm) material before wash (Line N) and multiplied by 100 should be within 0.2% of the sum of the percents retained (Total of Column 6).

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6.2 Check the Computed Percent Passing.

6.2.1 For the plus ¼ in. (6.3 mm) material.

The sum of the percent retained (Total of Column 2) plus the percent of total sample passing the ¼ in. (6.3 mm) sieve (last value of Column 3) must equal 100%.

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6.2.2 For the minus ¼ in. (6.3 mm) material.

The sum of the percent retained (Total of Column 6) plus the percent passing the No. 200 (0.075 mm) sieve, based on minus ¼ in. (6.3 mm) (last value of Column 7), must equal 100%.

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APPENDIX A

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