汉江取水泵站深基坑开挖施工降水技术探讨

Discussion on precipitation technology of deep foundation pit excavation in Hanjiang intake pump station

由于汉川市位于软土地质地带,地下水位浅,水量丰富,需采取可靠降水措施方可保证工程的顺利施工。运用经验公式计算得出基坑总出水量,设计采用管井降水方案,并规划相应的布置形式。现场观测发现,由于施工过程中连续降雨,外江水位持续偏高等因素影响,降水效果不能满足施工要求,采用在基坑临江侧另外增加轻型井点的措施,保证了地下水位平稳下降、基坑顺利开挖和边坡安全。

Since Hanchuan is located in the soft land,which is characterized by shallow underground water level and rich water yield.Reliable precipitation measures should be adopted to ensure smooth construction of the project.Total outflow runoff of the foundation pit can be calculated according to empirical formula.Tube well dewatering plan is adopted in the design.Corresponding layout form is planned.In-situ observation shows that the precipitation effect can not meet the construction requirement due to influence of the following factors,such as continuous raining during construction,continuous high water level in external river,etc.Light well points are increased additionally in the riverside area of the foundation pit,thereby guaranteeing stable decrease of underground water level,smooth excavation of foundation pit and slope safety.