Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Quantifying the Influence of Construction Parameters on Hollow-Bar Micropiles Pullout Capacity in Sandy Soil
The influences of construction parameters on the overall axial capacity of hollow-bar micropiles in sandy soils were quantified based on results from full-scale field testing. Eight micropiles were constructed at a site in the Outer Banks of North Carolina in two phases. The field testing program included installation of micropiles to a depth of 25 feet while varying the drilling or drill-bit insertion rate (IR) and the grout flow rate (QR). In addition, the installation methods included micropiles that were continuously drilled and grouted with neat grout water-cement ratio (w/c) of 0.4, and others that were first drilled and grouted continuously with thinner grout (w/c-0.7) and then flushed from bottom to top with thicker grout (w/c-0.4). Eight micropile installations were designated as Fast/Fast (w/c-0.4), Fast/Slow (w/c-0.4), Slow/Fast (w/c-0.4), Slow/Slow (w/c-0.4), Fast/Fast (w/c-0.7/0.4), Fast/Slow (w/c-0.7/0.4), Slow/Fast (w/c-0.7/0.4), and Slow/Slow (w/c-0.7/0.4). The results of pullout field load testing are presented in terms of load-displacement curves and load transfer mechanism. The load-testing results showed an appreciable high ultimate pullout capacity by using slow drilling and slow grout pumping rate (w/c-0.4) as compared to the other three approaches. The result showed that an additional 50% pullout capacity could be achieved by using Slow/Slow construction approach with w/c-0.4 grout, as compared to commonly practiced (Fast/Fast) installation approach.
Quantifying the Influence of Construction Parameters on Hollow-Bar Micropiles Pullout Capacity in Sandy Soil
The influences of construction parameters on the overall axial capacity of hollow-bar micropiles in sandy soils were quantified based on results from full-scale field testing. Eight micropiles were constructed at a site in the Outer Banks of North Carolina in two phases. The field testing program included installation of micropiles to a depth of 25 feet while varying the drilling or drill-bit insertion rate (IR) and the grout flow rate (QR). In addition, the installation methods included micropiles that were continuously drilled and grouted with neat grout water-cement ratio (w/c) of 0.4, and others that were first drilled and grouted continuously with thinner grout (w/c-0.7) and then flushed from bottom to top with thicker grout (w/c-0.4). Eight micropile installations were designated as Fast/Fast (w/c-0.4), Fast/Slow (w/c-0.4), Slow/Fast (w/c-0.4), Slow/Slow (w/c-0.4), Fast/Fast (w/c-0.7/0.4), Fast/Slow (w/c-0.7/0.4), Slow/Fast (w/c-0.7/0.4), and Slow/Slow (w/c-0.7/0.4). The results of pullout field load testing are presented in terms of load-displacement curves and load transfer mechanism. The load-testing results showed an appreciable high ultimate pullout capacity by using slow drilling and slow grout pumping rate (w/c-0.4) as compared to the other three approaches. The result showed that an additional 50% pullout capacity could be achieved by using Slow/Slow construction approach with w/c-0.4 grout, as compared to commonly practiced (Fast/Fast) installation approach.
Quantifying the Influence of Construction Parameters on Hollow-Bar Micropiles Pullout Capacity in Sandy Soil
Ahsanuzzaman, Mohammad (Autor:in) / Smith, W. Alex (Autor:in) / Gabr, Mohammed A. (Autor:in) / Borden, Roy H. (Autor:in)
Eighth International Conference on Case Histories in Geotechnical Engineering ; 2019 ; Philadelphia, Pennsylvania
Geo-Congress 2019 ; 340-347
21.03.2019
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
| British Library Conference Proceedings | 2019
Imrovement of loose sandy soil deposits using micropiles
| Online Contents | 2012
Imrovement of loose sandy soil deposits using micropiles
| Springer Verlag | 2012