Test Method for Logging In Situ Moisture Content and Density of Soil and Rock by the Nuclear Method in Horizontal, Slanted, and Vertical Access Tubes

LTRC is conducting a research project to determine the seasonal variation of subgrade resilient modulus (MR) in an effort to implement PavementME. One objective of that project, which is presented in this paper, was to locally calibrate the Enhanced Integrated Climate Model’s (EICM Fenv) curve for seasonal subgrade MR changes. Shelby tube sampling was conducted on six different roadways to a depth of approximately 7.92 m beneath the shoulder pavement’s base course. The AASHTO T-99 MR test method was used on all samples with an additional eight specimens being tested with NCHRP 1–28A MR test method. Four soils from Louisiana which were not from the six roadways were also tested and included in the analyses. Once the MR tests were completed and plotted, it was noticed that there was a rather large scatter (R2 = −0.266) around the EICM Fenv curve. The authors hypothesized that this occurred due to the density differences between in situ and remolded specimens. Further analyses confirmed this hypothesis. LTRC developed a new method based on the EICM Fenv method to determine the relationship between changes in subgrade MR as a function of changes in moisture content with the in situ moisture content and MR used as the control. This method differs from the EICM Fenv in that the EICM Fenv uses optimum moisture content as the controlling parameter. The LTRC method can be used for design purposes as well as level 2 inputs into the EICM.

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Test method recommendations of RILEM TC 177-MDT 'Masonry durability and on-site testing' - D.4: In-situ stress tests based on the flat jack

Materials and Structures ◽

10.1617/14119 ◽

2004 ◽

Vol 37 (271) ◽

pp. 491-496 ◽

Cited By ~ 6

Author(s):

Keyword(s):

In Situ Stress ◽

Test Method ◽

Stress Tests ◽

Site Testing

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Development of a rapid field testing method for metals in horizontal directional drilling residuals with XRF sensor

Scientific Reports ◽

10.1038/s41598-021-83584-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hailin Zhang ◽

João Antonangelo ◽

Chad Penn

Keyword(s):

Moisture Content ◽

Standard Method ◽

Field Testing ◽

Field Method ◽

Filter Press ◽

Directional Drilling ◽

Horizontal Directional Drilling ◽

Excess Water ◽

Spiked Soil

AbstractPortable X-ray fluorescence (pXRF) spectrometer allows fast in-situ elemental determination without wet digestion for soils or geological materials, but the use of XRF on wet materials is not well documented. Our objective was to develop a rapid field method using pXRF to measure metals in the residues from horizontal directional drilling (HDD) operations so that proper disposal decisions can be made in-situ. To establish the procedure, we spiked soil samples with 4 concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb up to 1000 mg kg−1, and then the metal concentrations were determined by wet chemical method after drying and acid digestion (standard method), and by pXRF, also at laboratory conditions, after drying and at two different moisture conditions. The measurements by pXRF and standard method after drying and after removal of excess water (AREW) were highly correlated with slopes ranging from 0.83 ± 0.01 to 1.08 ± 0.01 (P < 0.001) for all metals. The relationship was better AREW than the saturated paste without removal of excess water and the moisture content affected only the accuracy of As, Cd, and Pb. The procedure established was successfully used for HDD residues collected from 26 states of US with moisture content ranging from 14 to 83% AREW. The pXRF was proven to be a reliable tool for fast detection of common metals in dried soils and HDD residues, and samples containing < 30% moisture content without needing to correct for moisture. If the moisture is > 30%, excess water in samples need to be removed with a commercially available filter press to achieve high accuracy. The developed procedures reduce time of metal detection from days to about an hour which allows drilling operators to make quick decisions on soil or HDD disposal.

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Steel-shot method for measuring the density of soils

Canadian Geotechnical Journal ◽

10.1139/t10-034 ◽

2010 ◽

Vol 47 (11) ◽

pp. 1299-1304 ◽

Cited By ~ 1

Author(s):

Reed B. Freeman ◽

Chad A. Gartrell ◽

Lillian D. Wakeley ◽

Ernest S. Berney ◽

Julie R. Kelley

Keyword(s):

Moisture Content ◽

Rapid Determination ◽

Content Volume ◽

Test Method ◽

Unit Weight ◽

Soil Density ◽

Engineering Construction ◽

Steel Shot ◽

Time Requirements

The density of soil is crucial in engineering, construction, and research. Standard methods to determine density use procedures, equipment or expendable materials that limit their effectiveness in challenging field conditions. Some methods require burdensome logistics or have time requirements that limit their use or the number of tests that can be executed. A test method, similar to the sand-cone method, was developed that uses steel shot as the material to which a volume of soil is compared to calculate soil density. Steel shot is easily recovered and reused, eliminating the need for specialty sand and calibrated cones or containers, and allows rapid determination of the volume of displaced soil. Excavated soil also provides measurements of total mass and moisture content. Volume, mass, and moisture content are applied in simple calculations to determine wet and dry densities and unit weight of the soil. Proficiency in performing the test can be achieved with minimal training, and the required kit can be assembled for a reasonable cost. Field uses of the method in dry environments in a variety of soil types demonstrated that the method can produce repeatable results within 2% of the values of soil density determined by traditional methods, with advantages in logistics.

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