深中通道沉管隧道推出式最终接头设计原理分析及试验研究

Experimental Research and Design Principle Analysis on Push Type Final Joint of Immersed Tunnel in Shenzhen-Zhongshan Link

为解决推出式最终接头关键构造设计及施工工艺等问题,通过自主研发最终接头推出试验平台开展关键构造缩尺模型试验研究。在试验中对注水参数、滑道摩擦因数、推出稳定性等进行重点记录分析,对关键结构受力进行数值分析。试验结果表明:1)最终接头水力推出实现机制符合伯努利方程,推出段内侧流体雷诺数控制在2000以下可保持流速在层流范围;2)推出过程管节下挠角度小于0.1°,左右偏位3 mm,水力推出实现过程效果良好;3)水压作用下的管节关键结构受力安全,数值分析与试验实测值基本一致,验证了最终接头关键构造方案的合理性,推出方式具备可行性,滑道设计摩擦因数可取0.13。

The design principle and technology feasibility of the final joint are key difficulties for the whole project construction.In order to improve the structural design and construction technology of the push-out final joint,the scale model test research is carried out through the original hydraulic push-out test platform.In the test,parameters such as water injection,slide friction coefficient,and push-out stability were recorded and analyzed,and the stress of key structures is analyzed by finite element method.The results show that:(1)the push-out realizing mechanisms of final joint conforms to Bernoulli equation,and the Reynolds number of the fluid inside the ejection section is controlled below 2000 to maintain the flow rate in the laminar flow range;(2)the downward deflection angle of the pipe joint in the pushing process is less than 0.1°,and the left and right deviation is 3 mm,the effect of the hydraulic pushing process is good;(3)the stress of the key structure of the pipe under the action of water pressure is safe,the numerical analysis is basically consistent with the measured value of the test,the rationality of the key structural scheme of the final joint is verified,and the launching method is feasible,the friction coefficient of the slide design can be taken as 0.13.