京张高铁正盘台隧道强涌水段单次开挖瞬时涌水量预测

当前,隧道涌水量计算的研究方向多为总体涌水量或分段涌水量的预测,在顺坡排水段或涌水量不大的隧道中,不会遇到太大的问题。在强富水的反坡排水段,瞬时涌水量可能很大,有时远超隧道施工时的剩余抽排水能力,容易导致淹井,严重影响隧道施工安全,造成工期延误。因此,对于采用反坡排水的强涌水段,必须进行单次开挖瞬时涌水量的计算和淹井评估,以确保施工安全。结合崇礼铁路正盘台隧道工程实践,采用多种方法对隧道强涌水段的单次开挖瞬时涌水量进行预测,并根据预测结果确定采用带水作业的开挖长度,节省了工期,确保了奥运隧道工程按时顺利开通。

Prediction of Instantaneous Water Inflow for Single Excavation of Zhengpantai Tunnel in Beijing-Zhangjiakou High-speed Railway

Current research directions of tunnel water inflow calculation are mostly to predict the total or sectional water inflow of the tunnel,which will not have too many problems in the downslope drainage section or the tunnel with small water inflow.However,in the strong water-rich back slope drainage section,the instantaneous water inflow may be very large,sometimes far exceeding the residual pumping capacity of the tunnel,which may easily lead to flooding,seriously affecting the safety of tunnel construction and causing delay of construction time.Therefore,for the strong water gushing section with tunnel reverse slope drainage,it is necessary to calculate the instantaneous water gushing volume of single excavation and evaluate the submerged wells to ensure the safety of construction.Based on the practice of Zhengpantai Tunnel project in Chongli Railway,various methods are used to accurately predict the instantaneous water inflow of a single excavation in strong gushing section of tunnel.According to the prediction results,the excavation length of the tunnel with water is determined,which saves the construction period and ensures the smooth opening of the Olympic tunnel projects on time.