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0.18 mm； 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-Scale ThreeDimensionalGeomechanical Model Test System

To investigate the water inrush disaster mechanism of tunnel excavation in marlite and the information evolution law, a case study is conducted on the Qinyu tunnel of the Lanzhou Haikou National Expressway, and similar material of marlite tunnel surrounding rock is developed. Then, a large scale tunnel water inrush three dimensional geomechanical model test system is developed to achieve low frequency periodic loading and unloading, automatic data collection, and stable water pressure loading. Furthermore, an early warning system for tunnel water inrush disaster is developed using the Python programming language, based on which the model test of the evolution process of water inrush disaster in marlite tunnel is performed. The research results show the following: (1) The tunnel excavation disturbance will destroy the balance between the pressure of the surrounding rock and that of seepage water, causing micro fissures in the surrounding rock to expand and penetrate, and the water inrush phenomenon is caused further. (2) When water inrush occurs, the pressure, seepage water pressure, and displacement of the water resisting surrounding rock will show an obvious sudden change; the maximum release rates of surrounding rock pressure and seepage water pressure are 18.6% and 73.35%, respectively, and the maximum displacement is 0.18 mm. (3) The similar materials of marlite can better meet the test requirements, as well as the stability and reliability of the three dimensional geomechanical model test system for tunnel water inrush.