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Analysis on Vibration Influence of the Construction of Short-distance Pile Foundation on Existing Shield Tunnels
(1. School of Emergency Management, Xihua University, Chengdu 610039; 2. School of Architecture and Civil Engineering , Xihua University, Chengdu 610039; 3. China Railway Academy Co., Ltd., Chengdu 610032)
Abstract In order to analyze the dynamic response of the adjacent existing shield tunnel under the impact load during the construction of precast piles, relying on the tunnel project between the Nijiaqiao Station and the South Railway Station of Chengdu Rail Transit Line 18, the infinite element static-dynamic unified artificial boundary is introduced, and the "pile-soil-tunnel" 3D dynamic finite element-infinite element coupling model is constructed in combination with the actual engineering geological conditions for numerical tests. The results of geotechnical centrifuge tests are compared, and the validity of numerical model is verified. Based on this, the influence of different piling parameters on the vibration of adjacent existing tunnels is studied, and the limit value of tunnel peak vibration caused by piling construction of similar projects is proposed. The results show that: (1) The distribution of the maximum vibration velocity of the lining reflects the relative orientation of the vibration source and the tunnel. The most unfavorable vibration position of the tunnel affected by piling generally occurs on 1/4 arc or 1/2 arc near the pile side of the tunnel; (2) The vibration velocity increases with the increase of piling depth. When the pile driving depth exceeds the bottom of the tunnel, the influence of the increase of piling depth on the vibration of the tunnel is no longer significant; (3) When piling is carried out within the scope of the overlying soils pile above the tunnel, the influence of the horizontal spacing between piles and tunnels on the vibration of the tunnel is less than that of the piling depth.
Abstract：
In order to analyze the dynamic response of the adjacent existing shield tunnel under the impact load during the construction of precast piles, relying on the tunnel project between the Nijiaqiao Station and the South Railway Station of Chengdu Rail Transit Line 18, the infinite element static-dynamic unified artificial boundary is introduced, and the "pile-soil-tunnel" 3D dynamic finite element-infinite element coupling model is constructed in combination with the actual engineering geological conditions for numerical tests. The results of geotechnical centrifuge tests are compared, and the validity of numerical model is verified. Based on this, the influence of different piling parameters on the vibration of adjacent existing tunnels is studied, and the limit value of tunnel peak vibration caused by piling construction of similar projects is proposed. The results show that: (1) The distribution of the maximum vibration velocity of the lining reflects the relative orientation of the vibration source and the tunnel. The most unfavorable vibration position of the tunnel affected by piling generally occurs on 1/4 arc or 1/2 arc near the pile side of the tunnel; (2) The vibration velocity increases with the increase of piling depth. When the pile driving depth exceeds the bottom of the tunnel, the influence of the increase of piling depth on the vibration of the tunnel is no longer significant; (3) When piling is carried out within the scope of the overlying soils pile above the tunnel, the influence of the horizontal spacing between piles and tunnels on the vibration of the tunnel is less than that of the piling depth.
CHEN Fujiang1 DUAN Rongqian1 ZHANG Xin2 LIU Jingang3 SUN Cangqian1 LI Xiqian1
.Analysis on Vibration Influence of the Construction of Short-distance Pile Foundation on Existing Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(1): 140-148
2023, Vol. 60 