二线船闸基坑施工对既有一线船闸扰动实测影响分析

Measured influence of disturbance of second-line ship lock foundation pit construction on existing first-line ship lock

依托北江航道扩能升级工程清远水利枢纽二线船闸深基坑工程,通过开展既有船闸水平位移、沉降、振动与闸间土体深层水平位移实时监测,分析了二线船闸深大基坑开挖对临近一线船闸的扰动特征。结果表明:二线船闸基坑开挖过程,既有一线船闸闸室水平位移与沉降呈现两侧大中间小的分布规律;基坑开挖深度大于5 m后,既有一线船闸沉降速率显著增大,且一线船闸两侧易产生不均匀沉降;闸间土体水平位移与临时支撑轴力的设置密切相关,最大累积变形为11.6 mm;一线船闸振动监测点最大振速为0.079 6 cm/s。由结果可知,二线船闸深大基坑开挖过程中,临近一线船闸的变形扰动控制在安全范围,确保了船闸结构及通航运营安全,研究成果可供船闸监测借鉴与参考。

Relying on a deep foundation pit project of the Qingyuan water control project second-line ship lock in the channel capacity expansion and upgrade project of North River,by carrying out real-time monitoring of the horizontal displacement,settlement,and vibration of existing ship lock and deep soil horizontal displacement between ship locks,this paper analyzes the disturbance characteristics of the second-line ship lock deep foundation pit excavation on adjacent first-line ship lock.The results show that in the process of second-line ship lock foundation pit excavation,the horizontal displacement and settlement of the lock chamber of the existing first-line ship lock follows the distribution law of large on both sides and small in the middle.When the excavation depth of the foundation pit is greater than 5 m,the settlement rate of the first-line ship lock increases significantly,and uneven settlement is likely to occur on both sides of the first-line ship lock.The soil horizontal displacement is closely related to the setting of the temporary axial force of the internal support,and the maximum cumulative deformation is 11.6 mm.The maximum vibration velocity of the first-line ship lock vibration monitoring point is 0.0796 cm s.During the second-line ship lock deep foundation pit excavation,the deformation disturbance on the adjacent first-line ship lock is controlled within a safe range,and the safety of the structure and operation of the ship lock is ensured.The research results can be used as a reference for the monitoring of ship locks.