深圳孖洲岛友联船坞围堰抽水施工与位移沉降分析

Analysis of pumping construction,displacement and settlement of dock's cofferdam of Shenzhen Mazhou Island Youlian Project

深圳孖洲岛友联修船基地船坞堵口围堰采用沉箱式,基床厚度为0.5～9.0 m,在深基床内进行高压旋喷作防渗止水结构。在降水过程中,要确保围堰内水位平稳下降,避免基床产生突变;同时要观测渗水量,以检验防渗止水结构的效果;并对围堰的沉降位移进行观测,及时进行分析,以便指导施工。因此,在船坞围堰内降水时,保证围堰的稳定性是抽水中的首要问题。对这次抽水施工的若干问题如抽水方案、测定渗水量方法、沉降位移观测及分析等进行总结。

The dock＇s cofferdam in the ship repair base at Shenzhen Mazhou Island adopted caisson type structure.Since the seabed thickness is from 0.5 m to 9.0 m,high-pressure rotary spraying is implemented to prevent seepage.In the process of lowering of water level,a steady decrease of water level in the cofferdam shall be ensured to prevent the bed settlement and displacement of the cofferdam shall be inspected and analyzed timely to guide the construction.Therefore,it is the most important thing to guarantee the stability of the cofferdam during water level lowering construction inside the dock＇s cofferdam.The pumping scheme,seepage measurement method,as well as the observation of settlement displacement are summarized.