水下隧道流固耦合模型试验与数值分析

STUDY OF SOLID-FLUID COUPLING MODEL TEST AND NUMERICAL ANALYSIS OF UNDERWATER TUNNELS

我国水下隧道蓬勃发展,对其进行相似材料试验研究非常必要。通过改装由高强PVC板和型钢组成的试验架,开发光纤监测系统和渗流量计量器,并改进研发的新型固流耦合相似材料,在此基础上以青岛胶州湾海底隧道为工程背景开展流固耦合模型试验。试验过程中记录渗流量和关键点的位移、应力及渗透压力等多元信息。为了相互对比验证,采用软件FLAC3D进行与物理试验相似的数值模拟。代表性工况多元信息的空间分布情况符合一般规律,这说明试验采集的结果是可靠的。与数值模拟相比,物理试验能够考虑开挖扰动、水位波动以及海水浸泡、渗流造成的围岩弱化等因素的影响,其结果更接近于工程实际。

Recently,underwater tunnels have progressed vigorously in China.Therefore it is necessary to research this type of tunnel using the analogous material test.The test bench composed of high-strength PVC board and structural steel was manufactured.Optical fiber monitoring system and collection device of water seepage were exploited.The new type of solid-fluid coupling analogous material was improved.Then the fluid-solid coupling model test was performed for the Kiaochow Bay Subsea Tunnel.Water inflow and multiple information like the displacement,stress and seepage pressure of key points were recorded in the test process.In order to verify each other,numerical simulation which was similar to the physical test was made using fast Lagrangian analysis of continua in 3 dimensions（FLAC3D）.The test results are credible because that the spatial distributions of multiple information got from the representative working condition accord with the general rule.Compared with the numerical simulation,physical test can take influence factors such as the excavation disturbances,water level fluctuations and wall-rock weakness due to seawater immersion into account;so that the results obtained from physical test approach the actual engineering conditions more.