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| The influence of long-distance and small-spacing pipe gallery construction on existing section shield tunnels |
| GAO Yang1, DONG Wei1, CAO Jiajia2, LUO Jianjun2
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1.Sinohydro Bureau 7 Co., Ltd., Chengdu 610081, Sichuan, China;
2.Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China |
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Abstract In order to study the influence of long-distance and small-spacing pipe gallery excavation on the deformation of shield tunnels, relying on the common construction project of Shenzhen Metro Line 12 pipe gallery, numerical simulation software was used to simulate the comprehensive pipe gallery excavation to study the influence of different excavation length of pipe gallery on shield tunnel under the working condition of excavation width of 10.5 m and the excavation depth of 6.5 m. The influence of different excavation steps, embedded depth of bored piles and thickness of grouting layer on tunnel deformation were studied to provide technical guidance for the subsequent construction of the integrated pipe gallery. The results showed that: the deformation of the tunnel below the excavation of the comprehensive pipe gallery increased with the increase of the excavation length, when the excavation length was 3 times greater than the excavation width, the influence of the excavation length on the tunnel could be ignored; the smaller the step of the bunker excavation was, the smaller the tunnel deformation after the completion of the excavation of the pipe gallery; there was an optimal thickness of the grouting layer and grouting pile embedment depth, beyond the optimal value, the tunnel deformation was basically unaffected by it.
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Received: 31 March 2021
Published: 20 June 2021
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