Innovative seismic and resistivity tools for determining the diameter of jet grouting columns
- Jet grouting is used for soil improvement, foundation support and groundwater low control all over the world. It is well accepted and subject of standardization in many countries. However, some issues with the method remain. As the grout columns are produced in the subsurface without visual control in an often inhomogeneous soil, the prediction of the column’s diameter is still a challenge. All methods applied so far have their limitations. The approach presented in this study is twofold. At Colorado School of Mines a resistivity probe has been developed, which is pushed into the fresh grout directly after production. ERT sections are measured and inverted. Given some background information is available, the diameter of the columns can be evaluated. At BAM the focus has been on post-production investigations using seismic borehole methods. After hardening of the concrete seismic waves are sent through the column downhole (sensors placed in a casing in the column’s axis, source onJet grouting is used for soil improvement, foundation support and groundwater low control all over the world. It is well accepted and subject of standardization in many countries. However, some issues with the method remain. As the grout columns are produced in the subsurface without visual control in an often inhomogeneous soil, the prediction of the column’s diameter is still a challenge. All methods applied so far have their limitations. The approach presented in this study is twofold. At Colorado School of Mines a resistivity probe has been developed, which is pushed into the fresh grout directly after production. ERT sections are measured and inverted. Given some background information is available, the diameter of the columns can be evaluated. At BAM the focus has been on post-production investigations using seismic borehole methods. After hardening of the concrete seismic waves are sent through the column downhole (sensors placed in a casing in the column’s axis, source on top) and crosshole (source and sensor in boreholes on opposite sides of the column). We have developed a scheme to evaluate the diameter of the column based on travel time measurements without calibration. As this method is eventually more time and cost intensive we assume its application mainly for test columns. These are casted and dug out for visual inspection to determine appropriate grouting parameters. Our method would replace the often very cost intensive visual inspection. Both approaches have been tested at three test columns produced at BAM’s test site at Horstwalde, Germany and on an actual constructions site. Both methods have been in good agreement with the diameters predicted by the jet grouting contractors, which were confirmed in one case by mechanical measurements.…
Autor*innen: | Ernst NiederleithingerORCiD |
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Koautor*innen: | R. Bearce, M. Mooney, Julio Cesar Galindo Guerreros, S. Mackens, T. Fechner |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2016 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurbau | |
Freie Schlagwörter: | Diameter; Jet grouting; Quality assurance; Seismic |
Veranstaltung: | SAGEEP 2016 |
Veranstaltungsort: | Denver, CO, USA |
Beginndatum der Veranstaltung: | 20.03.2016 |
Enddatum der Veranstaltung: | 24.03.2016 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 15.04.2016 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |