Influence of Benoto bored pile construction on nearby existing tunnel: A case study |
| |
| Authors: | Guoyao Gao Yan Zhuang Kangyu Wang Liang Chen |
| |
| Affiliation: | 1. Key Laboratory for RC and PRC Structures of Education Ministry, School of Civil Engineering, Southeast University, No. 2 Sipailou, Nanjing, Jiangsu 210096, China;2. School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China;3. National Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, Hunan, China;4. School of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310014, China;5. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Geotechnical Research Institute, Hohai University, 1 Xikang Road, Nanjing 210098, China |
| |
| Abstract: | The monitoring and analysis of lateral displacement for metro tunnels are very important because the metro systems are the lifeline of metropolises. This paper presents a case study of a site in Nanjing, China, where the Benoto bored piles were constructed nearby the existing tunnel. The construction technology, a combination of the Benoto bored piles construction and the conventional construction technology of circulating slurry, is illustrated in detail. The lateral displacement at six test sections were measured and discussed to assess the impact of piles installation on the stability and integrity of the existing tunnel. The measured results showed that during the construction period using the Benoto method, relatively large lateral displacement occurred at the depth with soft soil (Mucky silty clay), with characteristics including a large void ratio, high plasticity, poor permeability, high water content, low shear strength, and low modulus of deformation. During the construction period of the conventional Circulating-Slurry method, negative lateral displacement occurred below the tip of the casing due to the soil arching effect, indicating an inward movement towards the Benoto bored piles. The maximum lateral displacement decreased as the distance between piles and inclinometers increased, with a maximum difference of 45% at the end of the measurements. It was also observed that the measured maximum lateral displacement was less than the cumulative trigger value of 20 mm, indicating an effectiveness of Benoto bored piles constructed adjacent to existing tunnel. This case study may provide the means for a qualitative assessment for engineering constructions where the situation bears similarities. |
| |
| Keywords: | Corresponding author Lateral displacement Benoto bored piles Existing tunnel Construction technology Case study |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
