Intelligent Soil Compaction Systems (2010) / Chapter Skim
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c h a p t e r 2 2.1 Continuous Compaction Control and Intelligent Compaction Roller-integrated CCC has been used in Europe since the late 1970s, while IC technology has been available since the late 1990s. This section summarizes the history of CCC and IC as well as key results of previous research studies on CCC and IC in both Europe and the United States.
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a target roller MV is determined from the MV versus spot test regression equation. Acceptance is based on comparison of roller MV data collected in a production area to the target roller MV.
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to changes in soil stiffness and damping and were used to investigate compaction efficiency (e.g., maximizing transmitted force)
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Figure 2.2. Relative roller MVs depending on soil stiffness (from Adam & Kopf 2004)
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reported dozens of correlations between CMV and PLT moduli E V1 and E V2 as well as between CMV and density (or % compaction) for coarse-grained, mixed, and fine-grained soils.
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multiple linear regression analyses between MVs (CMV or MDP, both from a Caterpillar roller) , moisture content, and spot test measurements (density, DCP index, CIV, or E LWD )
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0 and 0.8, depending on the spot test being correlated (dry unit weight, E V1 , E LWD , CIV 4.5-kg , DCP index)
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Ping et al.
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Grabe concluded that there were no patterns in the roller MV data maps. Grabe found that CMV values at close distances were correlated, and he concluded that the data had an infinite correlation length (limited by the sample size of the data)
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2.2.1.2 Feedback Control The Ammann ACE Plus eccentric assembly (shown in Figure 2.8) is comprised of outer and inner masses.
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determined value of k s is reached, the ACE Plus system automatically decreases the eccentric mass moment to 0.5 F s(max) for the range chosen.
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Figure 2.9.
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26 relates z d , F s , drum length L, and radius R to Poisson's ratio ν and Young's modulus E of the half-space as shown in Equation 2.4: (2.4) where b is the contact width as given by: b R v E L F s = × ×( )
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1980. CMV is defined as the ratio of the second harmonic of the vertical drum acceleration frequency domain amplitude A 2Ω (operating frequency Ω)
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Figure 2.15. Method to determine CMV involves spectral analysis (b)
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Figure 2.16. Overview of Dynapac's Compaction Optimizer (DCO)
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0 particular machine (White et al.
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Figure 2.19. CD700 Caterpillar documentation system illustrating completed passes (left)
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(Adam 2007)
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performed, involves compaction with roller-integrated measurement until the mean roller MV increases by no more than 5%. Acceptance is then based on static PLT or LWD (dynamic PLT)
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four E LWD values at a minimum of nine locations is reported (hence 36 LWD tests are required)
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erable thickness of base and subbase layers used. The maximum percentage of particles less than 0.06 mm (0.002 in)
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2.3.4 minnesota doT pilot Specifications In 2007 the Minnesota Department of Transportation (Mn/DOT) developed pilot specifications for QC/QA of granular and nongranular embankment soil compaction using CCC and/or LWD.
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If a significant portion of the grade is more than 20% in excess of the selected corrected IC-TV, the engineer shall reevaluate the selection of the applicable control-strip-corrected IC-TV. If an applicable corrected IC-TV is not available, the contractor shall construct an additional control strip to reflect the potential changes in compaction characteristics.
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