scholarly journals Recent Development and Future Perspectives of Quality Control and Assurance for the Deep Mixing Method

2021 ◽  
Vol 11 (19) ◽  
pp. 9155
Author(s):  
Masaki Kitazume
Keyword(s):  
Quality Control ◽  
Soil Stabilization ◽  
Mechanical Mixing ◽  
Deep Mixing ◽  
Recent Developments ◽  
Stabilized Soil ◽  
Mixing Method ◽  
Stabilization Technique

The deep mixing method (DMM), an in situ soil stabilization technique, was developed in Japan and Nordic countries in the 1970s and has gained increased popularity in many countries. The quality of stabilized soil depends upon many factors, including its type and condition, the type and amount of binder, and the production process. Quality control and quality assurance (QC/QA) practices focus on stabilized soil, and comprises laboratory mix tests, field trial tests, monitoring and controlling construction parameters, and verification. QC/QA is one of the major concerns for clients and engineers who have less experience with the relevant technologies. In this manuscript, the importance of QC/QA-related activities along the workflow of deep mixing projects is emphasized based on the Japanese experience/results with mechanical mixing technology by vertical shaft mixing tools with horizontal rotating circular mixing blade. The current and recent developments of QC/QA are also presented.

scholarly journals Delayed-Mode Quality Control of Oxygen, Nitrate, and pH Data on SOCCOM Biogeochemical Profiling Floats

2021 ◽  
Vol 8 ◽  
Author(s):  
Tanya L. Maurer ◽  
Joshua N. Plant ◽  
Kenneth S. Johnson
Keyword(s):  
Quality Control ◽  
Southern Ocean ◽  
Chemical Sensors ◽  
Visual Inspection ◽  
Stages Of Development ◽  
Crucial Step ◽  
Ocean Carbon ◽  
Automated Processes

The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project has deployed 194 profiling floats equipped with biogeochemical (BGC) sensors, making it one of the largest contributors to global BGC-Argo. Post-deployment quality control (QC) of float-based oxygen, nitrate, and pH data is a crucial step in the processing and dissemination of such data, as in situ chemical sensors remain in early stages of development. In situ calibration of chemical sensors on profiling floats using atmospheric reanalysis and empirical algorithms can bring accuracy to within 3 μmol O2 kg–1, 0.5 μmol NO3– kg–1, and 0.007 pH units. Routine QC efforts utilizing these methods can be conducted manually through visual inspection of data to assess sensor drifts and offsets, but more automated processes are preferred to support the growing number of BGC floats and reduce subjectivity among delayed-mode operators. Here we present a methodology and accompanying software designed to easily visualize float data against select reference datasets and assess QC adjustments within a quantitative framework. The software is intended for global use and has been used successfully in the post-deployment calibration and QC of over 250 BGC floats, including all floats within the SOCCOM array. Results from validation of the proposed methodology are also presented which help to verify the quality of the data adjustments through time.

scholarly journals Statistically Quantifying the Uncertainty in Strength of Marine Clay Stabilized by a Type of Portland-Fly Ash Cement

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Zhi-Ren Zhu ◽  
Qiang-Qiang Cheng ◽  
Yang-Yang Chen ◽  
Elton J. Chen ◽  
Yuan Su
Keyword(s):  
Monte Carlo Simulation ◽  
Quality Control ◽  
Fly Ash ◽  
Soil Stabilization ◽  
Simulation Method ◽  
Monte Carlo Simulation Method ◽  
Marine Clay ◽  
Operational Parameter ◽  
Binder Concentration

This study deals with the variation in strength of clays stabilized by a special binder—the CEM II/B-V type of Portland-fly ash cement. Two sources of uncertainties were examined, that is, the uncertainty in cement fraction in the binder, and the nonuniformity in binder concentration resulted from the process of mixing binder slurry with in situ clays. These two uncertainties were quantitatively described as two random variables, and the analyses were conducted through the Monte Carlo simulation method. Results indicate that the strength is insensitive to the cement fraction in the binder but is sensitive to the binder concentration; the variation of the latter even results in an amplified variation of strength. The variation of binder concentration is proposed to be linked up with the variation of strength through the operational parameter of blade rotation number. By doing so, the results could benefit designers in quality control prior to the construction of soil stabilization.

scholarly journals Evaluation of Discharging Surplus Soils for Relative Stirred Deep Mixing Methods by MPS-CAE Analysis

2021 ◽  
Vol 14 (1) ◽  
pp. 58
Author(s):  
Koki Nakao ◽  
Shinya Inazumi ◽  
Toshiaki Takaue ◽  
Shigeaki Tanaka ◽  
Takayuki Shinoi
Keyword(s):  
Simulation Analysis ◽  
Ground Improvement ◽  
Normal Type ◽  
Deep Mixing ◽  
Improvement Measures ◽  
Improvement Method ◽  
Mixing Method ◽  
Cae Analysis ◽  
Great Damage

Most of the ground in Japan is soft, leading to great damage in the event of liquefaction. Various ground-improvement measures are being taken to suppress such damage. However, it is difficult to carry out ground-improvement work while checking the internal conditions of the ground during the construction. Therefore, a visible and measurable evaluation of the performance of the ground-improvement work was conducted in this study. The authors performed a simulation analysis of the relative stirred deep mixing method (RS-DMM), a kind of ground-improvement method, using a computer-aided engineering (CAE) analysis based on particle-based methods (PBMs). In the RS-DMM, the “displacement reduction type (DRT)” suppresses displacement during construction. Both the DRT and the normal type (NT) were simulated, and a visible and measurable evaluation was performed on the internal conditions during each construction, the quality of the improved body, and the displacement reduction performance. As an example of these results, it was possible to visually evaluate the discharge of surplus soil by the spiral rod attached to the stirring wing of the DRT. In addition, the authors succeeded in quantitatively showing that more surplus soil was discharged when the stirring wing of the DRT was used than when the stirring wing of the NT was used.

scholarly journals A compilation of global bio-optical in situ data for ocean-colour satellite applications – version two

2019 ◽  
Author(s):  
André Valente ◽  
Shubha Sathyendranath ◽  
Vanda Brotas ◽  
Steve Groom ◽  
Michael Grant ◽  
...  
Keyword(s):  
Quality Control ◽  
Original Data ◽  
Ocean Colour ◽  
Attenuation Coefficients ◽  
Standard Format ◽  
Inherent Optical Properties ◽  
In Situ Data ◽  
Satellite Applications

Abstract. A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&CO) and span the period from 1997 to 2018. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll-a, spectral inherent optical properties, spectral diffuse attenuation coefficients and total suspended matter. The data were from multi-project archives acquired via open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were propagated throughout the work and made available in the final table. By making the metadata available, provenance is better documented, and it is also possible to analyse each set of data separately. This paper also describes the changes that were made to the compilation in relation to the previous version (Valente et al., 2016). The compiled data are available at https://doi.org/10.1594/PANGAEA.898188.

scholarly journals The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements

Ocean Science ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 1-18 ◽  
Author(s):  
C. Cabanes ◽  
A. Grouazel ◽  
K. von Schuckmann ◽  
M. Hamon ◽  
V. Turpin ◽  
...  
Keyword(s):  
Quality Control ◽  
Global Ocean ◽  
Diagnostic Tools ◽  
Data Types ◽  
Ocean Reanalysis ◽  
Service Desk ◽  
Background Check ◽  
Potential Applications

Abstract. The French program Coriolis, as part of the French operational oceanographic system, produces the COriolis dataset for Re-Analysis (CORA) on a yearly basis. This dataset contains in-situ temperature and salinity profiles from different data types. The latest release CORA3 covers the period 1990 to 2010. Several tests have been developed to ensure a homogeneous quality control of the dataset and to meet the requirements of the physical ocean reanalysis activities (assimilation and validation). Improved tests include some simple tests based on comparison with climatology and a model background check based on a global ocean reanalysis. Visual quality control is performed on all suspicious temperature and salinity profiles identified by the tests, and quality flags are modified in the dataset if necessary. In addition, improved diagnostic tools have been developed – including global ocean indicators – which give information on the quality of the CORA3 dataset and its potential applications. CORA3 is available on request through the MyOcean Service Desk (http://www.myocean.eu/).

scholarly journals Applicability of molding procedures in laboratory mix tests for quality control and assurance of the deep mixing method

2015 ◽  
Vol 55 (4) ◽  
pp. 761-777 ◽  
Author(s):  
Masaki Kitazume ◽  
Massimo Grisolia ◽  
Enrico Leder ◽  
Ignazio Paolo Marzano ◽  
Antonio Alberto S. Correia ◽  
...  
Keyword(s):  
Quality Control ◽  
Deep Mixing ◽  
Mixing Method

scholarly journals A SYSTEM TO EVALUATE THE QUALITY OF SOIL-CEMENT COLUMN BY DEEP MIXING METHOD

2001 ◽  
Vol 66 (550) ◽  
pp. 79-86
Author(s):  
Masahito TAMURA ◽  
Yoshio INOUE ◽  
Ryuji KOBORI ◽  
Kazuhiro WATANABE ◽  
Mamoru FUJII ◽  
...  
Keyword(s):  
Deep Mixing ◽  
Soil Cement ◽  
Mixing Method

scholarly journals A compilation of global bio-optical in situ data for ocean-colour satellite applications

2016 ◽  
Author(s):  
A. Valente ◽  
S. Sathyendranath ◽  
V. Brotas ◽  
S. Groom ◽  
M. Grant ◽  
...  
Keyword(s):  
Quality Control ◽  
Original Data ◽  
Ocean Colour ◽  
Attenuation Coefficients ◽  
Standard Format ◽  
Inherent Optical Properties ◽  
In Situ Data ◽  
Satellite Applications

Abstract. A compiled set of in situ data is important to evaluate the quality of ocean-olour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GEPCO), spans between 1997 and 2012, and have a global distribution. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll-a, spectral inherent optical properties and spectral diffuse attenuation coefficients. The data were from multi-project archives acquired via the open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were propagated throughout the work and made available in the final table. Using all the data in a validation exercise increases the number of matchups and enhances the representativeness of different marine regimes. By making available the metadata, it is also possible to analyse each set of data separately. The compiled data are available at doi:10.1594/PANGAEA.854832.

scholarly journals A compilation of global bio-optical in situ data for ocean-colour satellite applications – version two

2019 ◽  
Vol 11 (3) ◽  
pp. 1037-1068 ◽  
Author(s):  
André Valente ◽  
Shubha Sathyendranath ◽  
Vanda Brotas ◽  
Steve Groom ◽  
Michael Grant ◽  
...  
Keyword(s):  
Quality Control ◽  
Original Data ◽  
Ocean Colour ◽  
Attenuation Coefficients ◽  
Standard Format ◽  
Inherent Optical Properties ◽  
In Situ Data ◽  
Satellite Applications

Abstract. A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT and GeP&CO) and span the period from 1997 to 2018. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties, spectral diffuse attenuation coefficients and total suspended matter. The data were from multi-project archives acquired via open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenization, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) was propagated throughout the work and made available in the final table. By making the metadata available, provenance is better documented, and it is also possible to analyse each set of data separately. This paper also describes the changes that were made to the compilation in relation to the previous version (Valente et al., 2016). The compiled data are available at https://doi.org/10.1594/PANGAEA.898188 (Valente et al., 2019).

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