Hazard Mitigation of the Impact of a Progressive Tunnel Collapse
In order t o ascert ain the risk of collapse of a new road embankment over a historical railway t unnel, a number of int rusive and non int rusive invest igat ions were undert aken. The nonintrusive invest igat ions comprised: a visual inspect ion, a delaminat ion survey, a ground probing radar survey from the ground surface and an electrical resist ance tomography survey from within t he t unnel it self. Int rusive invest igat ions comprised of rot ary coring of t he surrounding rock and of t he t unnel lining. Numerical modelling of t he proposed development including it ’s const ruct ion sequences were undert aken. A number of models were analysed including 2D boundary and finit e element analysis and a 3D st abilit y analysis of t he t unnel it self. The findings of the analysis were t hat the t unnel ‘bore’ it self was generally st able but the t unnel lining was in a st at e of degradat ion wit h approximately 11％ failed to dat e. This led t o the conclusion that a progressive failure mechanism may form, where the t unnel lining degrades further and collapses, leading to block failures t hroughout t he surrounding rock, along the lines of t he discont inuit ies, event ually progressing upwards t o affect the embankment and road. T he final remedial solut ion was t o incorporat e geot ext iles wit hin the embankment const ruct ion in order to mit igat e the risk of cat ast rophic failure.
P.Beetham R.Hutchison R.Lowe
Opus International Ltd
国际会议
香港
英文
1-5
2009-05-19（万方平台首次上网日期，不代表论文的发表时间）