SUBGRADE MODULUS OF UNDERGROUND PIPELINES SUBJECTED TO SOIL MOVEMENTS
YU Jian1，2，ZHANG Chenrong1，2，HUANG Maosong1，2
(1. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China；2. Key Laboratory of Geotechnical
and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China)
Abstract：The soil movement induced by the excavation may affect any nearby underground pipelines. In the Winkler displacement-controlled analysis，the free soil movement is applied to the pipeline as external load or passive displacement and the pipe-soil interaction is modeled as a series of Winkler spring，the coefficient of which is obtained by Vesic?s equation. The assumption of the Vesic?s equation is that the beam is on the surface of the elastic half space and loaded with vertical force or moment(active load) in the middle，which is different from the conditions discussed here. To consider that effect of the pipe?s embedment and the applied passive soil displacement to the soil modulus of the Winkler subgrade model，the theoretical equation for calculating the corresponding soil spring coefficient is proposed and used in the analysis of pipeline?s behavior due to tunnel excavation；the correctness and validity of the equation are proved by comparing with elastic continuum solutions，centrifuge model tests and practical engineering.
2012, Vol. 31 
