Performance of primary tunnel support systems under seismic loads in weak rock masses
R.B. Jishnu, Ayothiraman Ramanathan, Shaz Ahmed, Patra Chayan, Salu Ghosh
Available Online November 2016.
- https://doi.org/10.2991/rare-16.2016.33How to use a DOI?
- Pseudo Static Analysis; Quasi Static Analysis; Seismic Analysis
- With the decrease in the over ground utilizable space and increase in growth of metro structures, cut and cover structures are becoming rather impossible to conceptualize and construct. Hence they are slowly replaced by underground openings made by NATM methods. These tunnels could be using rock bolts and shotcrete as support systems for poor-fair quality rock masses whereas ground improvement will be needed for extremely poor quality deposits. At this point it will be prudent enough to understand the seismic performance of these support systems if such a demand comes in short term. Since for extremely weak deposits grout curtain for ground improvement acts as a barrier, the focus will be on better quality rock masses where rock bolts and shotcrete are only used as primary supports. For the same a relatively low RMR value is adopted for the rock mass under consideration. A typical NATM tunnel geometry is adopted which has to be excavated using conventional methods. Suitable support systems for the same are designed. Then seismic performance of these support systems are deduced using two different approaches namely (1) Pseudo Static Method as per IS 1893 and (2) Quasi Static displacement approach as per EC-8. A sensitivity analyses for the support systems at different cover depths are explored. Comparative studies of the above approaches are made and their applicability for similar problems is discussed
- Open Access
- This is an open access article distributed under the CC BY-NC license.
Cite this article
TY - CONF AU - R.B. Jishnu AU - Ayothiraman Ramanathan AU - Shaz Ahmed AU - Patra Chayan AU - Salu Ghosh PY - 2016/11 DA - 2016/11 TI - Performance of primary tunnel support systems under seismic loads in weak rock masses BT - Recent Advances in Rock Engineering (RARE 2016) PB - Atlantis Press SN - 2352-5401 UR - https://doi.org/10.2991/rare-16.2016.33 DO - https://doi.org/10.2991/rare-16.2016.33 ID - Jishnu2016/11 ER -