Chu H.C.,Raito Engineering Corporation Ltd. |
Wong K.N.,Sanshin Corporation Ltd. |
Yu C.F.,Central District Project Office |
Liao H.J.,National Taiwan University of Science and Technology |
Cheng S.H.,National Taiwan University of Science and Technology
Geotechnical Special Publication | Year: 2012
Jet grouting method has been widely used in Taipei MRT construction projects. Due to the limitation of construction space and complicated utilities layout at the shallow depth, there is a need to minimize the number of borehole drilling and maximize the diameter of grout column to facilitate the jet grouting work in urban area. Accordingly, this study discusses the Rapid Jet Grouting (RJG) method that can install a large diameter grout column at large depth. A test on RJG method is to be performed to demonstrate its applicability in urban area. The observation of the excavated RJG grout columns in deep silty sand and silty clay layers shows that the RJG method had excellent quality and could deliver the designed diameter (up to 3.5 m) of grout columns at a depth of 20 m through adequate operating parameters. Besides, the strength of bored specimens from jet grout columns can also meet the designed strength by proper control of water-cement ratio. © 2012 American Society of Civil Engineers.
Liao H.-J.,National Taiwan University of Science and Technology |
Cheng S.-H.,National Taiwan University of Science and Technology |
Wong R.K.N.,SanShin Corporation |
You C.-F.,Central District Project Office |
And 2 more authors.
Proceedings of the Institution of Civil Engineers: Geotechnical Engineering | Year: 2015
This paper provides a summary report on measures taken to remove embedded steel ‘H’ pile obstacles from the cutter head of an advancing tunnel-boring machine. The piles were part of the soil-mixing retaining wall built for the cut-and-cover tunnel construction of a Taiwan high-speed rail tunnel and a Taiwan railways administration tunnel, which were directly above the mass rapid transit tunnel that was to be constructed. The collision zone between the boring machine and piles was below groundwater level and was approximately 23 m below the ground surface in a silty sand layer. To remove the piles safely from the cutter head, horizontal grouting from two adjacent work pits was conducted for waterproofing and solidification purposes. By controlling the amount of soil being flushed out during the grout hole drilling first, and also the pressure used for grouting later, the measured tunnel settlement resulting from grouting was negligible. Because of the favourable watertightness of the grouted zone and the dewatering influence of a nearby construction site, pile removal was conducted under particularly dry working conditions. In total, 12 piles were identified in the collision zone and were successfully removed from the cutter head by hand tools. © ICE Publishing: All rights reserved.