复杂工程地质条件下过江盾构隧道风险管理与对策

On Risk Management and Countermeasures of Cross-river Shield Tunnel under the Conditions of Complicated Engineering Geology

为了研究复杂地质条件下水下盾构隧道的施工风险管理技术,依托长沙地铁4号线跨江段盾构工程,进行工程地质、水位条件、施工范围周边环境的勘察,对此施工区间地质风险进行了详细分析,主要包括盾构机在富水圆砾层、高水压强渗透强风化砾岩层以及岩溶地层中掘进的风险,结合PC法对复杂地质条件下水下盾构隧道地质风险进行分析评估,并提出了对应的风险管理措施,最大程度的降低了风险发生的可能性.为类似地质条件下的盾构隧道施工提供施工风险管理参考.

In order to study the construction risk management techniques of underwater shield tunnels under the conditions of complicated engineering geology, this paper relies on the shield construction of the Changsha Metro Line 4 across the river to survey on the engineering geology, water level conditions, and the surrounding environment of the construction scope. The geological risk is analyzed in detail, mainly including the risk of excavation of shield machine in water-rich round gravel layer, high water pressure and strong weathered conglomerate, and karst formation. Combined with the PC method, the geological risk of underwater shield tunnels under complex geological conditions is analyzed and evaluated. It puts forward corresponding risk management measures to minimize the possibility of risk occurrence, which provides construction risk management references for shield tunnel construction with similar geological conditions.