Excavation technique of shield launching crossing adjacent river and under-passing voltage tower(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年06期
- Page:
- 83-91
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Excavation technique of shield launching crossing adjacent river and under-passing voltage tower
- Author(s):
- HU Chang-ming; ZHANG Yan-jie; YUAN Yi-li; MEI Yuan; ZHANG Wen-cui
- School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, Shaanxi, China
- Keywords:
- tunnel engineering; shield construction; numerical simulation; sand gravel stratum; risk management
- PACS:
- U455.43
- DOI:
- -
- Abstract:
- In order to study the interaction between different kind of adjacent risk sources under multi-factors, and solve the risk problem of shield launching under the condition of adjacent risk sources, on the basis of the shield tunneling of Chengdu Metro Line 3, settlement data of the excavated section were summarized. Different types of construction risk were analyzed and the risk response measures were also determined. Moreover, a three-dimensional numerical simulation of the metro shield tunneling construction was conducted, in which the soil improvement and ground reinforcement were simulated by changing the property of soil in front of the TBM, and the variation of the strength of grouting material along with time was simulated by changing the material properties. Influence of soil improvement, grouting in tunnel, and ground grouting on shield tunneling crossing constructions was analyzed. Calculation result verified the feasibility of the numerical calculation hypothesis and the rationality of the selected parameters. A series of auxiliary measures for the construction of adjacent risk sources proved the feasibility of the shield tunneling technological achievements. The specific measures included surface precipitation, waterproof paving of river and embankment reinforcement before shield launching, hole sealing, soil improvement and soil replacement of warehouse before crossing the river and after shield launching, the underground grouting of electric tower, ground reinforcement and optimization of tunneling parameters after crossing the river. The results show that attention should be paid to ground settlement of the excavated rings in the construction of shield tunneling under buildings and the monitoring of the trend of ground settlement in the section where the segments are coming off the shield tail should be enhanced. Based on the soil improvement and effective excavation parameters, underground construction measures and ground reinforcement both can effectively control the ground settlement, while the underground grouting and other measures have better effect than the ground reinforcement. It can provide the theoretical basis and guidance for the construction of shield near the multi-hazard sources like crossing adjacent river and under-passing voltage tower by construction measures and comprehensive excavation technology of the research.
Last Update: 2017-12-18