大型三维地质力学模型试验系统研制及其应用研究

为研究泥灰岩隧道开挖诱发突涌水灾害机制及信息演化规律,以兰州至海口国家高速公路秦峪隧道为工程依托,研制泥灰岩隧道围岩相似材料,研发大型隧道突涌水三维地质力学模型试验系统。该系统可实现低频周期循环加卸载、数据自动化采集,可提供稳定水压加载,基于Python编程语言开发了隧道突涌水灾害预警系统,在此基础上开展泥灰岩隧道突涌水灾害演化过程模型试验。研究结果表明： 1）隧道开挖扰动会破坏围岩压力与渗透水压力之间的平衡,致使隔水围岩内产生微裂隙并扩展贯通,进而发生突涌水现象; 2）当发生突涌水现象时,隔水围岩压力、渗透水压力及位移均会发生明显的突变现象,围岩压力及渗透水压力最大释放率分别为18.6%、73.35%,最大位移量为0.18mm; 3）泥灰岩相似材料能够较好地满足试验需求,证明了隧道突涌水三维地质力学模型试验系统的稳定性及可靠性。

Development and Application of a Large-ScaleThreeDimensionalGeomechanicalModel Test System

To investigatethe water inrush disaster mechanism of tunnel excavation in marlite and theinformation evolution law, a case study is conducted on the Qinyu tunnel of theLanzhou Haikou National Expressway, and similar material of marlite tunnelsurrounding rock is developed. Then, a large scaletunnel water inrush three dimensional geomechanicalmodel test system is developed to achieve low frequencyperiodic loading and unloading, automatic data collection, and stable waterpressure loading. Furthermore, an earlywarning system for tunnel water inrush disaster is developed using the Pythonprogramming language, based on which the model test of the evolution process ofwater inrush disaster in marlite tunnel is performed. The research results showthe following: (1) The tunnel excavation disturbance will destroy the balancebetween the pressure of the surrounding rock and that of seepage water, causingmicro fissures in the surrounding rock to expand andpenetrate, and the water inrush phenomenon is caused further. (2) When waterinrush occurs, the pressure, seepage water pressure, and displacement of thewater resisting surrounding rock will show an obvioussudden change; the maximum release rates of surrounding rock pressure andseepage water pressure are 18.6% and 73.35%, respectively, and the maximumdisplacement is 0.18 mm. (3) The similar materials of marlite can better meetthe test requirements, as well as the stability and reliability of the three dimensional geomechanical model test system for tunnel water inrush.