深圳富水地区限排型城市隧道的结构安全性研究

依托深圳市东部过境高速公路连接线工程，选取典型深埋与浅埋断面，针对二衬外水压力荷载减小导致隧道结构局部安全系数出现下降的情况，运用数值模拟进行结构安全性计算分析。结果表明:对于深埋两车道马蹄形隧道，由于埋深大、水位高，当水位降低引起荷载减小时，结构安全系数略有升高。对于浅埋隧道，由水压力作用产生的围压能够提高结构的抗弯能力，二衬外水压力减小使结构的安全系数降低。

Study Concerned Structural Safety of Discharge-limited City Tunnel in Shenzhen’s Water-rich Area

Relying on the transit highway project of the east of Shenzhen, this paper selects typical deep and shallow buried section to carry out researches the decrease of tunnel structural safety coefficient caused by the decline of water pressure behind the secondary lining, and calculate and analyze the structure safety through numerical simulation methods. The results of analysis concerned structural analysis shows that, due to the large buried depth and high water level, for the deep-buried horseshoe tunnel under two-lane road, the tunnel structural safety coefficient increases slightly, when the water level drop. However, the structural safety coefficient of shallow buried tunnel decreases when the water level drop because of the confining pressure produced by water pressure which improves the flexural capacity of the structure.