大流量进水工况下主隧系统水气运动特性

为给深层隧道排水系统工程的主隧系统结构设计和工况控制提供依据,采用数值模拟与物理模型试验相结合的方法,建立与物理模型体型结构相同,包含两竖井和相连主隧段的主隧系统三维数值模型,利用该数值模型对两种大流量极端工况下的进水过程进行三维动态数值模拟。结果表明:主隧系统在大流量下的进水过程可归纳为水流从两端竖井进入主隧,水流碰撞形成液面波并在主隧内相互碰撞叠加,主隧下游、上游侧端口先后被封堵,以及进流停止这4个阶段;进水流量主要影响主隧系统端口封堵程度、滞气现象和进水各阶段进程时间,流量越大,主隧端口的水流封堵、滞气现象越严重,进水过程各阶段进程时间也大幅缩短。

Characteristics of air-water movement in a main tunnel system under large inflow condition

In order to provide scientific basis for the engineering structure design and working condition control for the main tunnel system of a deep tunnel drainage system, numerical simulation was carried out combined with physical model test. A three-dimensional numerical model of the main tunnel system including two shafts and a connected main tunnel section was established, which had the same body structure as the physical model. A three-dimensional dynamic simulation of the inflow process was performed under two extreme large inflow conditions. The results show that the water intake process of the main tunnel system under large flows can be summarized into 4 stages, flow entering into the main tunnel from two shafts, flow colliding to form surface waves which are transmitted and superimposed in the main tunnel, lower and upper side tunnel ports blocked successively, and inflow stopped. The inflow mainly affects the seal degree of the port in the main tunnel system, the phenomenon of hysteretic gas and the process time of each inflow stage. The seal degree of the port in the main tunnel system and the phenomenon of hysteretic gas is more serious under larger inflow condition, and the process time of each inflow stage is substantially reduced.