<p><p><strong>Reference(s):</strong></p><p><em>Broms (2003)<br>Bruce (2001)<br>CDIT (2002)<br>Elias et al. (2006a)<br>EuroSoilStab (2002)<br>Usui (2005)<br>Werle et al. (2000)</em></p><p><strong>Method Summary</strong></p><p>Installation control and monitoring is the primary quality control measure in the deep mixing QC/QA process. Deep mixing equipment should include data acquisition systems and proper instrumentation to monitor and record real-time data. All parameters to be recorded and submitted for approval should be established in the project specifications. According to Bruce (2001), parameters that should be monitored and recorded during column installation include depth, rpm of mixing shaft(s), the amount of binder added as a function of depth, penetration rate, withdrawal rate, and verticality of drill shaft(s). Usui (2005) notes that the degree of mixing is one of the most important factors affecting the strength of the treated element and can be expressed in terms of the Blade Rotation Number (BRN). The BRN is a function of the total number of mixing blades on the shaft, rotation speed during penetration, penetration rate, rotational speed during withdrawal, and withdrawal rate. Some deep mixing technologies also incorporate slurry delivery under pressure to provide jet assistance to the mechanical mixing. Similarly, some deep mixing technologies include air pressure to create a slurry emulsion that facilitates mixing. Slurry pressure and/or use of air should be controlled and monitored. Werle et al. (2000) adds that freshness of stabilizers, batch plant records, orientation of mixing blades, and installation air pressure at the tip and top of the column should also be recorded. Elias et al. (2006a) notes that the specific gravity of the binder slurry used in wet DMM applications should be checked at regular intervals. Broms (2003) recommends that settlements, pore pressures, and lateral displacements be monitored both during and after column installation.</p><p>Other general information that should be documented during installation includes date, sequence of installation, type of machine and mixing tools, column location, column length and diameter, weather conditions, and any difficulties encountered during installation such as boulders or roots.</p><p>Recorded parameters and observations made during installation should be included in daily reports submitted according to project specifications. These reports should be reviewed by the owner’s engineer.</p><p><strong> </strong><strong>Accuracy and Precision</strong></p><p>The observed and recorded conditions help to verify the final geometry and degree of mixing, but some form of post-construction testing is still required to validate uniformity and mixture strength.</p><p><strong>Adequacy of Coverage</strong></p><p>Data are collected on each column that is installed.</p><p><strong>Implementation Requirements </strong></p><p>Standard deep mixing equipment has some form of electronic monitoring system. The equipment operator(s) should have sufficient previous relevant experience with the specific monitoring equipment that is being used.</p><p><strong>General Comments</strong></p><p>Installation monitoring is vital to a deep mixing project regardless of the application. It helps to confirm the geometry, mixing energy, quantity of binder added, and other important aspects of column construction.</p></p>