Centrifuge modelling of injection near tunnel lining. Issue 1 (March 2001)

• Record Type: Journal Article
• Authors: Lee, S. W.; Bolton, M. D.; Mair, R. J.; Hagiwara, T.; Soga, K.; Dasari, G. R.
• Is Part Of: International journal of physical modelling in geotechnics. Volume 1:Issue 1(2001)
• Page Start: 9
• Page End: 24
• Publication Date: 2001-03
• Subjects: geotechnical engineering -- dense and loose sand -- grouting pressure -- grouting volume -- lining deformation -- surface heave; Rock mechanics -- Periodicals; Soil mechanics -- Periodicals; Geological modeling -- Periodicals; 624.151011
• DOI: 10.1680/ijpmg.2001.010103
• Languages: English
• ISSNs: 1346-213X

Abstract

Abstract : Centrifuge modelling was carried out to simulate the effect of compensation grouting on segmental tunnel lining and ground surface movement in dry sand. Two types of injection were investigated, namely strip injection and multi-point simultaneous injection. For strip injection, the investigated parameters are injection depth, injection distance to tunnel crown (separation), and injection width. The surface heave and lining deformation are found to follow the ratios of injection depth/injection width, and separation/injection width, respectively. To predict the ultimate uplift resistance of soil, two failure mechanisms are proposed for dense and loose sand conditions. In addition, a simple grout pressure transfer mechanism is also suggested to clarify the relationship between the maximum lining deformation and the parameters investigated. The multi-point simultaneous injection tests were conducted to investigate the effect of distributing the injection area. It was found that the sparseness of the injection points has brought beneficial effect to the surface heave and to the lining deformation. In all tests, dense sand shows dilation while loose sand undergoes compression as injected volume increases.