高祥宇, 高正荣, 卢中一. 海域岛隧结合区水流结构和沉管沉放过程水流力试验研究[J]. 水科学进展, 2019, 30(6): 854-862. DOI: 10.14042/j.cnki.32.1309.2019.06.009
引用本文: 高祥宇, 高正荣, 卢中一. 海域岛隧结合区水流结构和沉管沉放过程水流力试验研究[J]. 水科学进展, 2019, 30(6): 854-862. DOI: 10.14042/j.cnki.32.1309.2019.06.009
GAO Xiangyu, GAO Zhengrong, LU Zhongyi. Experimental study on flow structure of island-tunnel bonding zone and flow force during sinking the immersed tube[J]. Advances in Water Science, 2019, 30(6): 854-862. DOI: 10.14042/j.cnki.32.1309.2019.06.009
Citation: GAO Xiangyu, GAO Zhengrong, LU Zhongyi. Experimental study on flow structure of island-tunnel bonding zone and flow force during sinking the immersed tube[J]. Advances in Water Science, 2019, 30(6): 854-862. DOI: 10.14042/j.cnki.32.1309.2019.06.009

海域岛隧结合区水流结构和沉管沉放过程水流力试验研究

Experimental study on flow structure of island-tunnel bonding zone and flow force during sinking the immersed tube

  • 摘要: 港珠澳跨海通道由东、西人工岛实现桥隧过渡,海中隧道采用沉管法,沉管段总长5 664 m,从西人工岛开始布置E1—E33管节,标准管节长180 m,宽37.95m,高11.4 m,重约8万t。岛隧结合区受到人工岛挑流和基槽开挖水深突变的影响,水流结构复杂,沉管沉放时也会引起水流变化。沉管安全沉放和精准对接安装需掌握受到的水流力大小。利用宽水槽几何比尺为100的正态模型,开展岛隧结合区水流分布和沉管沉放过程水流力试验研究。结果表明:岛头无掩护措施时,岛壁挑流影响到E1管节中部附近,表、底层流速大于中层;E1管节沉放过程中纵向水流力最大可达4 601 kN,E2管节纵向水流力平均5 149 kN;掩护E1管节后,E1管节处流速大幅减小,E2管节中部受掩护体挑流影响最大,流速最大增加40%,中层流速大于表、底层;E2管节纵向水流力平均5 240 kN。当沉管完全入水后,基槽内流速较小,沉放过程中受到的水流力逐渐减小。岛隧结合区水流垂线分布并不是指数分布,受到岛头壁挑流的影响沿管节长度方向流速分布也不均匀,管段浮运水流力公式并不适用计算沉管沉放过程受到水流力的大小。

     

    Abstract: East and west artificial islands are used to realize the transition from bridge to tunnel for Hong Kong-Zhuhai-Macao Cross-sea Tunnel. Immersed tunneling method is applied in sea tunnel and the total length of the sinking section is 5 664 m. The tube sections of E1-E33 are arranged from west artificial island. The standard pipe section is 180 m long,37.95 m wide,11.4 m high and weighs about 80 000 tons. The connection area of the island and tunnel is affected by the deflecting flow and the sudden change of the water depth during the foundation trough excavation,and the flow pattern is complicated. Moreover,the flow pattern will be changed when the sinking joint is subsided. It is necessary to obtain the magnitude of water flow force to guarantee the safe sinking and accurate docking of the immersed tube. By using the undistorted model in a wide flume with the geometric scale of 1:100,the experimental study on the flow distribution and water flow force during the sinking process of the island tunnel is carried out. The results indicate that,when there is no protective measure at the head of the island,the deflecting flow would affect the middle part of tube E1 and the flow velocities on the surface and at the bottom layers are larger than that of the middle layer. When sinking tube E1,the maximum longitudinal flow force can reach 4 601 kN,and the averaged longitudinal flow force of tube E2 is 5 149 kN. After sheltering tube E1,the flow velocity at tube E1 decreases significantly. The middle part of tube E2 is mostly affected by the sheltering body,the maximum increment in the flow velocity reaches to 40%,and the flow velocity of the middle layer is larger than those on the surface and at the bottom layers. The average longitudinal flow force of tube E2 is 5 240 kN. When the sinking tube is completely immersed into the water,the flow velocity in the foundation trench is relatively small,and the water flow force during the sinking process decreases gradually. The vertical distribution of water flow in the connection area of island and tunnel is not exponential one,and the velocity distribution along the length of the pipe section is not uniform due to the influence of deflecting flow on the island head wall. The formula of floating water flow force at the pipe section is not suitable for calculating the magnitude of the water flow force during the sinking process of immersed pipe.

     

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