Settlement and deformation law of a doubletrack shield tunnel underpass airport expressway(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年04期
- Page:
- 100-108
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Settlement and deformation law of a doubletrack shield tunnel underpass airport expressway
- Author(s):
- LUO Gang1; PAN Shaokang1; ZHANG Yulong1; CHEN Liang2; 3
- (1. School of Highway, Changan University, Xian 710064, Shaanxi, China; 2. School of Civil Engineering, Changsha University of Science & Technology, Changsha 410114, Hunan, China; 3. Guangxi Communications Investment Group Co., Ltd., Nanning 530022, Guangxi, China)
- Keywords:
- tunnel engineering; shield tunnel; underpass airport expressway; numerical simulation; Peck formula; low of deformation and settlement
- PACS:
- -
- DOI:
- -
- Abstract:
- To analyze the impact of expressway pavement and the stability of a cutting slope when constructing a shield tunnel under an expressway and determining the feasibility of the shield construction method, the construction of the shield tunnel under the airport expressway of the Xianbei Railway Station as part of the Xian Xianyang International Airport Intercity Railway Project was taken as the research object and explored deformation rules of the expressway cutting slope, pavement, and tunnel structure was studied. The superimposed Peck formula was used to calculate the subsidence law of the ground caused by the underpass of a double line shield tunnel. In the Code for Design of Metro (GB 50157—2013) (shorter for code), a concept was termed diameter deformational rate in the radial direction of the subway tunnel lining structure. This concept was used to calculate the horizontal and vertical diameter deformational rates of the tunnel. Furthermore, the finite difference software FLAC3D was used to simulate the excavation process of the doubletrack shield tunnel and the deformation rules of the expressway cutting slope pavement and tunnel structure were explored, respectively. The results show that the maximum settlement of the pavement appears at the foot of the south slope when the rightline tunnel excavation is directly below the airport expressway, the value is 6.2 mm. The maximum settlement of the slope is 7 mm and it appears immediately above the middle of the doubletrack shield tunnel. After the doubletrack shield tunnel penetrates through, the maximum vertical displacement and the maximum horizontal displacement of the structure are 14.86 and 12.25 mm, respectively. The horizontal and vertical diameter deformational rates of the tunnel lining structure are 0.20 and 0.24%, respectively, which are near each other and meet the code requirements. Depending on the displacement control limit of the airport expressway pavement, the shield construction method meets the deformational requirements of the pavement. The results of this study provide a reference for the construction of a shield section. Meanwhile, it can be a mirror of the same type of approaching construction. 2 tabs, 16 figs, 23 refs.
Last Update: 2019-07-29