Analysis and Prediction of Ground Settlements Due to Slurry Shield Tunneling in a River-crossing Tunnel
LIN Cungang,WU Shiming,ZHANG Zhongmiao,LI Zongliang and LIU Guanshui
DOI:10.3969/j.issn.1674-4764.2012.05.005
Received ,Revised , Accepted , Available online July 01, 2015
Volume ,2012,Pages 25-32
- Abstract
Through analysis of monitored ground settlements of Hangzhou Qing-chun Road cross-river tunnel, characteristics and influencing factors of ground settlements due to large-diameter slurry shield tunneling were summarized, and a modified hyperbolic model was proposed to predict the settlements. The results indicate that: 1.Peck equation is well used to predict ground settlements induced by slurry shield tunneling in Hangzhou district. The trough width parameter ranges from 0.25～0.32 while soil volume loss from 0.04%～0.33%. 2. Settlements before the shield tail leaving the monitoring sections are small, while soil closure at the shield tail and long-term consolidation settlements make most of the total settlements, with percentages of 57.27% and 41.08% respectively. 3. Increasing the pressure of slurry and synchronized grouting appropriately can counterbalance some ground loss, which can reduce the ground settlements. 4.Transverse ground settlements induced by ground loss represent the shape of Gaussian curve while heave movements behave irregularly. Ground heave movements due to large pressure of slurry and synchronized grouting often lead to the transverse ground settlements' deviation from Gaussian curve. 5. The modified hyperbolic model can be used to predict ground settlements due to slurry shielding in Hangzhou district with great accuracy.